The Bee Pasture

After the fires in New Mexico

noreply@blogger.com (Unknown) — Thu, 23 Apr 2015 02:10:00 +0000

Valles Caldera Grande, Jemez Mountains, NM

I've been traveling a lot for work lately, and last week I was in Santa Fe NM. I was there to attend a conference on native seeds. The day before the presentations started I was able to attend a field trip touring recovering wildfire sites in the Jemez Mountains, near Bandelier National Monument. Most of the sites we visited had burned twice, once in 2008 (I think), and again in 2011.

wild candytuft (?) in the caldera

We visited the Valles Grande in the Valles Caldera, an active volcano complex 13.7 miles across altogether. This caldera last erupted approximately 1 million years ago. We were given half an hour to explore it, and most of us made a bee-line to the meandering creek dividing the center of the caldera. The problem is it appears deceptively close. I'd guess the Valles Grande is ~3 miles across where we parked. Not one of us made it to the creek by the halfway point, and we were called back short of our goal. Oh well. At least we got to tromp around this montane clearing.

What I didn't understand is this: why no trees? Ponderosa pine and aspen grew at elevations both above and below the caldera, so why not in the caldera itself? Is the ground too saturated with water? The caldera supported a luxurious grass thatch, even with the recent wildfires and historic grazing. Candytuft and marsh marigold (questionable IDs) were the only non-grass plants active at this point in the season.

We could see an abundance of human activity despite the remoteness of the location. The Valles Grande has a (now defunct) ranch within it, and shards of flaked obsidian near the overlooks marked the points where native peoples had sat and worked the stone long ago. The presence of the obsidian shards on the soil surface is a testament to the relative remoteness of the locations we toured. Surely more travelled trails would have had these remains pocketed years ago. It is also possible that the tremendous fires of the past ten years have exposed these remains at the surface.

Unmolested flint knappings at the soil surface

I know that in the tropical rain forests, the first fire marks the beginning of disturbance, but it is the second fire that destroys the ecosystem. This area suffered the same fate. Trees that survived the earlier fire were killed 5 years later when the second fire came through and burned the underbrush and deadwood. Apparently, the smokejumper team from Prescott Arizona that perished in 2013's Yarnell Hill Fire cut their teeth on the 2011 fires in the Jemez.

Compare the brown areas to the green

With this is mind, it was easy to lose myself re-enacting fire behavior in the mountains from the fire scars and standing trees. At its peak it advanced an acre a second. You could see where some (very few) pines had been spared, but you could also see white scars on the earth where the fire had burned so hot the soil had been mineralized, still visible 4 years later. Would my instincts have led me into a trap? I'll never know.

Mineralized soil and dead trees, 4 yrs later

The monarchs have returned to Texas

noreply@blogger.com (Unknown) — Sat, 11 Apr 2015 21:33:00 +0000

Monarch butterfly, probably male

Actually, they returned over a week ago. I believe I saw my first monarch of the year April 1st. It was a female, hopping from milkweed to milkweed. She deposited one egg on each plant. One of her cousins was doing the same nearby. I was impressed with how she homed in on each plant, wasting no time in the search.

side-cluster milkweed w/egg

Monarch butterflies are incredibly widely distributed, and are found in all lower 48 states. They even introduced themselves to Hawaii. The Hawaii population is especially unusual because they have developed a unique white morph in contrast to the bright orange we see on the mainland. However, the two major populations are found in the lower 48 states. They can be further split into the western population (approximately 5% of total), and the eastern population (most of the remainder). The eastern population is the subject of the listing petition, and it is the group we see in Texas. This group has seen a 90% decline in overwintering numbers in the past 20 years. While monarchs as a species are secure, this eastern migration is an endangered biological phenomena.

Monarchs have a peculiar life history. The first 3-4 generations of the year live approximately 4 weeks and grow and reproduce like a standard butterfly. They follow the fresh milkweed and flowers north as the season progresses. However, the last butterflies of the year to hatch live 6-9 months and migrate thousands of miles south from the Upper Midwest to Mexico. These butterflies are in reproductive diapause- that is, they don’t breed- and they focus their energy on gliding south in September, October, and November. Once they hit Texas (generally in October), their migration slows. Instead they feed, intent on gathering enough fuel to support themselves during the 6 months they spend overwintering in the oyamel fir forests in the mountain highlands west of Mexico City.

Monarch ovipositing on milkweed

The monarchs arrive at their overwintering grounds in Mexico around the first of November most years. Their arrival coincides with the Day of the Dead celebrations, and monarchs are taken to represent the visiting souls of departed loved ones. Once the monarchs arrive, they become dormant and roost in high density “shingles” entirely coating the trees in their chosen forests. They don’t feed or breed, and spend most of their time resting on the branches and trunks of these oyamel firs. It is at this time that the monarchs are counted. Because the monarchs roost socially in high numbers, you can get a population estimate based on the area occupied. The lowest ever numbers were recorded in the winter of 2013, when the entire eastern population, ~95% of the world’s population, only occupied 1.7 acres.

Fresh monarch egg

By mid-March, spring returns to the Mexican highlands and monarchs break dormancy. They mate and begin their migration north. Monarchs return to south Texas in late March, making the thousand mile trek from Mexico in about a week. Once they reach Texas, they search out fresh milkweed sprouts on which to lay their eggs. It was these tired, 9 mo old females I observed ovipositing earlier this month. After breeding, this generation dies. It is their offspring which continue the journey north to recolonize their North American range. Each subsequent generation moves a little farther north, until September when the “methuselah” generation hatches and the cycle begins again.

2nd instar monarch caterpillar

Texas is crucial to the monarch habitat for two periods of the year- those first monarchs returning to the states, and the last generation to leave. In March and April, the returning females nectar on wildflowers and lay their eggs on milkweed, the only food plant which can support their caterpillars. Texas becomes important again in September and October, when migrating monarchs stop to re-fuel on wildflower nectar before their long slumber in Mexico. Without nectar in the fall, these monarchs will not survive the winter. Without milkweeds in the spring, their offspring will starve. We can support monarchs as they funnel through our state by planting milkweed and fall blooming nectar plants. We cannot control what happens to these butterflies across the entirety of their range, but by working in our own backyards we can support the start and end of their migration.

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Photo credits: Figures 2 & 4: Philip Barbour, CNTSC; Figure 1 & 3: Anne Stine; Figure 5: Rosanna Brown, CNTSC.

Fighting slime with slime

noreply@blogger.com (Unknown) — Wed, 08 Apr 2015 01:41:00 +0000

Or: the tale of two gastropods, slime and punishment, etc etc...

A curious brown garden snail

I've often noticed large round snails clinging to plant stems in the shade or on wet mornings. They seem to be everywhere. Known as the the brown garden snail, these beefy vegetarians are native to the mediterranean. They were originally imported to North America to serve as escargot. Edible, though perhaps not palatable to American tastes, these snails now range across most of the southeast and California.

These introduced snails are a minor garden nuisance, but high populations in California have vexed the citrus industry. The best snail management plan has a multi-pronged approach. Removal of daytime hide-outs, snail baits and traps, using copper barriers, and releasing another non-native mollusk: the decollate snail [1, 2] are used in tandem to knock back populations. Unlike the brown garden snail, the decollate snail is a predator. It hunts other snails.

Releasing one non-native to control another is called "classic" biological control, and has a storied history. In Australia the cane toad was introduced to control a pest beetle, but has since become a much larger threat to ecological stability than the beetle ever was. Closer to home, in North America a parasitic fly introduced to control gypsy moths has directly contributed to the scarcity of our own beautiful silk moths. The luna, the cecropia, the polyphemus, and the promethea are all much rarer than they once were. A little bit of magic left our eastern forests. On the other hand, biological control is our last best hope in the case of the hemlock woolly adelgid and purple loosestrife , so it cannot be discounted completely.

While the UCANR Integrated Pest Management (IPM) guide noted that releases of the carnivorous decollate snail are prohibited outside certain areas (because the decollate snail is a generalist, and will eat native snail eggs as readily as those of a pest), I have not heard of the decollate snail causing problems. Of course, how would we know. I can count the number of individuals I know who can even identify snails on one hand, let alone track and monitor native population dynamics.

But, what's done is done. When I turn the soil in my garden bed, the shells of both non-native snails surface in abundance. Eradicating either species is likely an exercise in futility at this point. However, their history piques my interest in our native snails! I'll have to keep a look out for these tough survivors.

Foreground: decollate snail shell. Background: brown garden snail shells

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1. http://entnemdept.ufl.edu/creatures/misc/gastro/brown_garden_snail.htm
2. http://www.ipm.ucanr.edu/PMG/PESTNOTES/pn7427.html

Early spring wildflowers part 1: Marion Sansom

noreply@blogger.com (Unknown) — Wed, 01 Apr 2015 00:54:00 +0000

Yucca and mexican buckeye on a limestone slope

Fredericksburg Division limestone
exposed, north end below dam

Most of Texas is afflicted with spring fever lately, its sweetness tempered by urgency because we know it cannot last. Any moment inside feels like a prison sentence. It is with this sentiment that I set about exploring Marion Sansom Park last weekend.

Marion Sansom Park is owned by the city of Fort Worth but has been adopted by the Fort Worth Mountain Bikers Association (FWMBA). These cyclists build and maintain the trails and signage. They are an enthusiastic presence on the trail, but I tend to move at a much slower pace. Especially when there's so much new stuff to see. The park itself borders the Lake Worth Dam, interesting because it looms near a limestone exposure in the Fredericksburg Division [1].

Lake Worth Dam, north side.

honey bee, mexican buckeye

The park is situated near the juncture of the western cross timbers and the grand prairie. This site, underlain by shallow limestone on a south-facing hillside, has a somewhat peculiar flora.

honey bee, redbud

I was most surprised to see mexican buckeye in abundance, which I had thought to be a more southern species. Mexican buckeye has pretty pink flowers and unique, pendulous tri-lobed fruits. The seeds, once released from their capsules, resemble rich brown marbles. I also saw blooming new jersey tea, redbud, plum, ten-petal anemone, prairie verbena, prairie parsley, fringed puccoon, and coral honeysuckle. The coral honeysuckle has emerged just in time for our returning hummingbirds, and it is one of their preferred nectar flowers.

A few coral honeysuckle flowers are already open

Mexican buckeye fruits

More butterflies are out too. Checkerspots, southern dogfaces, and swallowtails are now fanning about in addition to the familiar sulphurs and commas. I am almost certain I caught a glimpse of an early monarch gliding over my back garden.

The vertebrates were also out enjoying the weather. A coy green snake stuck his head out of a hollow tree to watch me walk down the trail, but retreated when I turned to take his picture. I had to wonder: how did he raise and lower himself so easily within his tree trunk? Is he braced against the walls, or does he have an interior shelf on which to rest?

It already felt warm on this southern exposure in the sunshine, and I was glad to wander the slopes of Marion Sansom in early spring. Last year we came close to 100 F by late April, and we are already projected to break into the 90s this week. Spring in Texas, like much of the rest of the world, is fleeting. I intend to get out in it as much as I can.

Cute green snake, peeping out of his front door.

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1. http://northtexasfossils.com/geologytarrant24-39.htm

The emerald city stinks

noreply@blogger.com (Unknown) — Sun, 22 Mar 2015 16:29:00 +0000

Oil and gas refinery? Or something else?

I've been thinking a lot about the future, in particular about how the world in which I retire will be different from the one I now inhabit. I'm at the point in my life where I'm seriously thinking about where I'll 'make my stand', buy a house, plant fruit trees... It's hard to plan for such things when you are very much aware that the world is changing, and you can't count on the place you settle staying the same over the coming decades. How do you put down roots when the Earth itself is shifting beneath your feet?

You may remember that I went to southeastern New Mexico over my winter vacation. High Country News recently published an article on oil and gas extraction titled "Lessons from boom and bust in New Mexico," which brought that trip back to mind. There, oil and gas exploitation dominates the landscape. There is no urban clutter to distract from the pump jacks and gas flares. The night sky is orange from the natural gas burned off, relieving pressure on extraction equipment. The air stinks like cancer, and you drive past warning signs saying: "Danger: Toxic Fumes when lights flashing".

It's all your fault, car (not really).

Obviously, I was not so taken with the local industry as I was with the scenery. Oil and gas exploitation is one of those trades that is inherently extractive. Its nasty byproducts, and its contributions to our changing climate, make it an easy scapegoat. However, when communities have nothing else, how can you tell them not to mine the money stored in their shale piggy bank? Don't their kids deserve college as much as ours?

Additionally, one could argue that fossil fuels built Texas. Without oil, we'd be just another south central Ag state. Our economy might be more similar to that of Oklahoma. The Texas GDP, at $1.6 trillion, is second only to California in the United States. Our state's GDP is higher than that of Australia. This quick money does come at a public cost. Policy wonks call these "externalities." These costs are borne by those other than the organization which incurred them; and they include the poor air quality and increases in atmospheric carbon dioxide.

Climate Central's summer and winter projections for Fort Worth, year 2100

In a series of projections put out by http://www.climatecentral.org/, Fort Worth doesn't look quite uninhabitable by year 2100, but it's certainly less pleasant. Believe it or not, as hot as our summers get, the average temperature is only ~94F. We'll be adding ten degrees to that by the end of the century. This addition brings our temperatures to those of the Phoenix metro area, averaging 103F (including nightly lows!). Indeed, our winters will warm too. Instead of 31 nights below freezing on average, we are likely to have only 8. I am tempted to console myself with "Well, at least I'll be able to grow avocados outdoors", but it isn't that simple. Changing global temperature averages shift the prevailing winds too. This changes precipitation regimes.

Projected precipitation changes (%) by year 2100

The map of projected precipitation shifts posted on the EPA's climate science hub suggests Texas will be drier, especially in the summers. Less rain + increased evapotranspiration (water lost to the atmosphere from plant exhalations and soil surface evaporation) is likely to shift our ecotype from Cross Timbers/Blackland Prairie into something much more arid. From our temperature projections, we could very well resemble the Sonoran desert. So: should we all plant saguaros and be done with it? While I'm tempted to move into an adobe with a cleverly crafted cistern system, there's still some hope. We could shift to renewable energy. Or perhaps we could hold industry accountable for its "externalities".

In a more basic, blind luck sense, precipitation changes are much harder to predict than temperature. While the scientific consensus is that the Earth will warm, the atmospheric eddies that determine rainfall are harder to model. You may notice that coastal areas are projected to increase in temperature more slowly than regions in the middle of the continent. This effect is due to buffering from the oceans. Water absorbs heat when it evaporates. Perhaps, if the air-stream shifts just so, we'll get enough moisture to prevent the "Arizonification" of Texas. Perhaps.

Don't be sad. Look at the pretty gypsum dunes!

Early spring at Copper Breaks

noreply@blogger.com (Unknown) — Tue, 17 Mar 2015 23:50:00 +0000

View from the edge of Bull Canyon, Copper Breaks State Park

Last weekend I took advantage of the warm weather and drove the 3 hours northwest to Copper Breaks State Park, 12 miles south of Quanah, Texas. Red dirt from the Permian has been cut and dissected into closed canyons and mesas. Thick cedars and brush on the interior of the canyon limit your line of sight. You feel so vulnerable to ambush. Of course, that could be me projecting my knowledge of the past onto the present. This canyon is within the Comanche heartland. Cynthia Ann Parker, one of the subjects of the popular book on Comanche history "Empire of the Summer Moon" was recaptured close to the park. Today the park is popular with families and youth groups. I wasn't the only one camping out last weekend.

Inside the canyon

The landscape is treed with juniper and mesquite. Mid-grasses grow well on the uplands, and they are dotted with cacti. Mormon tea (Ephedra antisyphilitica), pencil cactus (Cylindropuntia leptocaulis), and agarita (Mahonia trifolialata) are all more common here than further east. As you might guess from the latin name, mormon tea was once used as a treatment for syphilis. So many native plants have the species epithet "antisyphilitica" or "siphilitica", it makes me wonder about the prevalence of syphilis in North America pre-penicillin. I can think of three native plants off-hand that were used to treat syphilis specifically.

"Horse crippler" cactus

Anyway. I also saw the odd horse crippler cactus (Echinocactus texensis), so named because it hides semi-submerged in the dirt and is hard to spot. Supposedly, horses step on it. Looks like a deer knew to step around it. I'm a little skeptical as to how many horses have been crippled by this cactus. It makes me think about how in the upper Plains everyone's convinced horses are killing themselves by tripping on prairie dog burrows. Are they really so fragile? Does that really happen?

Blooming stretchberry sheltered by cedar

What I did not see was a ton of flowers. Spring is behind the metroplex in Copper Breaks. While our stretchberry (elbow bush, Forestiera pubescens) was blooming on Valentine's Day, theirs just started. I did see the standing dead stalks of gayfeather (Liatris spp.) and a number of composites, but very little new growth had been put on for the season.

Signs of life were mostly mammalian. Coyotes had heavily marked the trails with their scat, delineating the borders of their territory. When one of my neighbors at the campground fired up their grill (or other appliance…), it made a high-pitched keen and the coyotes were close enough to hear it and respond immediately. I also saw a rabbit out at dusk.

While it was early in the season, I did enjoy getting out somewhere nearby that looked so different from home. These little weekend trips help keep me grounded when I get to feeling desk-bound.

Galls are a good thing*

noreply@blogger.com (Unknown) — Mon, 09 Mar 2015 02:00:00 +0000

*Or at least, mostly harmless.

Galls on an oak tree. Probably mealy oak gall (Disholcapsis cinerosa).

Lately, I feel like my blog's tagline could be "It's just aesthetics: leave well enough alone." First I defended mistletoe, then tent caterpillars, now gall wasps. I have noticed more oak galls in Texas than anywhere else I've lived. When I visited Dinosaur Valley State Park on Saturday, some trees were hung so thickly with them they looked like persimmon fruits. Others, which had supported leaf galls instead of twig galls, instead looked like they had odd round red acorns scattered about their trunks. You can get an idea for which critter created the gall by its appearance.

Gall wasps (Cnipidae) are the creatures that create the little brown orbs hanging in your oak trees. These cryptic creatures spend most of their lives as grubs. Adults are the size of a fruit fly and live about a week. They emerge, mate (every other generation), and then oviposit their eggs in stems, leaves, and twigs of oak trees all within that brief window. Note I didn't say "eat". Adult gall wasps don't eat- they live entirely of the plant matter they consumed as grubs inside their gall. They alternate generations between asexual females (who live in one type of gall), and sexually reproducing males and females (who live in another).

Another type of gall. Possibly Belonocnema kinseyi.

The galls themselves are an abnormal plant growth. They are not directly created by the wasps, but instead are similar to an immune effect in the host tree. There is consensus that this gall-making does not seem to hurt the host. The impact is so minuscule when weighed against the mass of the tree, it does not do measurable damage. I suppose it's like when you knick yourself shaving. You might bleed a little, but beyond the initial cut you don't suffer for it. I could not find a single source suggesting that galls harmed trees or required intervention. Most sources suggested doing nothing at all in response to an "infestation". The galls are not a danger, and they are only a problem if their untidy looks bother the homeowner.

A closer look at possible B. kinseyi galls.

Bizarrely, gall wasps are prevented from becoming super abundant because there are more trophic levels above them: they themselves are parasitized by a different kind of wasp. Then, the wasp which parasitized the gall wasp is parasitized by ANOTHER kind of wasp. Nature just doesn't quit. It seems that being born a wasp is an awful tough way to make a living. An interesting effect this hyperparasitism has on the casual naturalist is that you have no idea if the bug which emerges from the gall is the one that built it. You could say that the gall structures the first wasps create serve as protective homes for many other insects. At a minimum, they provide an example of intense competition within the animal kingdom.

Iced in again

noreply@blogger.com (Unknown) — Sun, 01 Mar 2015 21:09:00 +0000

Yep, those are all wrecks

On friday I drove home through some of the gnarliest traffic the metroplex has seen this winter. It was bad enough to make the national news. By the time I was on the roads, most of the wrecks had already happened but had not been cleared. Abandoned cars facing the wrong direction lined the interstates. It looked apocalyptic. The few of us out trying to get somewhere were hitting top speeds of 20 mph. I wouldn't have tried it, but I was heading home from a meeting in Austin so I could pick up my dog from daycare and return a rental car. I knew all these tasks would be much harder the next day.

I tried to get out again on Saturday, and I made it a block before I slipped into a skid on a downhill and came to a gentle stop wedged against the curb. I was totally unharmed and rather lucky to be within an easy walk of my house, but I felt foolish for letting my cabin fever get the better of me. It was so slippery I couldn't even walk-- one of my neighbors came out to offer me a hand leaving the ice patch. I was slowly sliding downhill in my snow boots. He seemed skeptical when I said I was fine and could make it home on my own. I guess I was so fired up to get out because I haven't really gone walking in a couple weeks and it's been wet and cold. I appreciate the snow and ice for recharging the aquifer, but I miss going outside.

View of my backyard

I did get to see a little nature in Austin, however. I went to an amazing nursery called "East Austin Succulents" to peruse their collection of weird plants. I ended up taking two home, a split rock plant and a ~~rattlesnake tail~~ Crassula columella, both native to the South African Karoo. So cool. I'd love to tour the Karoo someday. I adore botanical oddities.

Two new friends.

I also saw some diminutive native wildlife. A moth sheltered from the cold under a blade of agave in the outdoor portion of the nursery. Thanks to the "Mothing and Moth Watching" Facebook group, this fluffy little guy was ID'd as a Hyphantria cunea, or Fall Webworm Moth. He looks quite stylish to my eyes-- I admire his fuzzy stole and leopard-spotted wings.

A male fall webworm moth

Fashionable as he may be, the fall webworm moth is a pest to many horticulturalists. They are called "webworms" because their caterpillars graze socially within a silk tent on branches. The netting lessens predation. Their caterpillars tend to prefer broadleaf trees, and in Texas they favor pecans. Like many other pests, their damage is mostly cosmetic. Even complete defoliation by webworms is unlikely to seriously harm a tree. It's just unsightly. Though it was certainly too cold for this moth to fly (many insects are unable to fly at temperatures below 55F), late february is not excessively early for these fellas to emerge.

Fall webworm moths are native to most of North America, and they have invaded eastern europe and asia. Apparently they were accidentally introduced in Yugoslavia in the 40s, and they expanded from there. I feel a little vindicated, because there are few other non-native insect pests you hear about colonizing in that direction. While they are not a major problem in the States, I'd be interested to hear whether they are harder on the ecosystem outside their native range. Considering that we live in a world with truly catastrophic invasive pests, I have trouble taking a little aesthetic damage seriously. I hope that's something horticulturalists consider when creating a management plan for this little moth.

An everyday epiphyte

noreply@blogger.com (Unknown) — Sat, 21 Feb 2015 21:06:00 +0000

Mistletoe, Phoradendron spp.

Great Purple Hairstreak

Remember this guy (at left)? Remember how his caterpillars only eat mistletoe? For this and other reasons, our Texas mistletoe (Phoradendron spp.) is worth another look. Mistletoe is an arboreal hemiparasite, related to sandalwood (another hemiparasite), with fleshy green leaves and stalks. It grows best as a rounded clump in the upper branches of hardwood trees where it has access to abundant sunlight and can practice its nutritional thievery unmolested.

Besides the caterpillars of the lovely great purple hairstreak and some other Lepidoptera, few creatures eat the toxic leaves of this plant. Birds, however, adore its fruit. The berries are a valuable winter food source. Providing winter nourishment is not an act of philanthropy on the part of the mistletoe. Mistletoe berries are extremely sticky. Birds eat and poop them out, wiping off their little tails, feet, and beaks on the branches of a preferred roost, effectively dispersing the mistletoe progeny. It's ingenious. Humans appreciate and disperse mistletoe berries for their own purposes. Specifically-- stolen kisses in the holiday season.

A few white berries

Despite its bad reputation, mistletoe is unlikely to bring down a tree single-handedly. It may sap the vigor and weigh down individual branches, but it is unlikely to seriously harm an otherwise healthy tree. This is good news, because once established mistletoe is nigh impossible to remove. Cutting off a branch to excise the plant causes more harm to the host tree than leaving it in place. This practice is unlikely to completely remove the mistletoe anyway.

By flowering and fruiting in the winter, mistletoe provides resources when little else is available. It is well past time for blooming, but I saw some mistletoe flowering today anyway. The inconspicuous yellow flowers are a pollen source during this season of scarcity. Male and female flowers occur on different plants, and reproductive development is slow. Mistletoe doesn't typically flower before its third year. The large clusters you see in treetops are decades old.

I like epiphytes and parasitic plants. I don't really have a good reason-- I guess they have a "tropical" feel. I can understand a homeowner not being thrilled at the arrival of this clever little plant on a favored shade tree, but seeing as there's no stopping it, you may as well take a philosophical perspective. You can decide to appreciate its genius, and be comforted that it is unlikely to do serious harm for a few more decades.

Male flowers?

Spring heralded on valentine's day at Tandy Hills

noreply@blogger.com (Unknown) — Mon, 16 Feb 2015 21:49:00 +0000

A honey bee enjoys her non-traditional flowers on Valentine's day

We had perfect weather for a walk on Valentine's day this year, so I decided to tool around Tandy Hills and see how spring is progressing in this part of the metroplex. More butterflies were out. I saw little yellows and possibly dainty sulphurs, in addition to the occasional question mark canvassing about in the sunshine. I know question marks over winter as adults, but I didn't expect the appearance of the little yellows. Apparently they also overwinter as adults in the southern part of their range.

Blooming vetch?

These butterflies weren't nectaring, but they were actively flying on the ridge top. I didn't notice many green legumes for their caterpillars to eat, so I wonder if what I saw were males patrolling for females. In many butterflies and moths, the males emerge first in the season. They use their head start to stake out females.

I also saw a few honey bees out scouting for food. Other than dandelions, hen bit, and the occasional vetch, there wasn't much available. The honey bees seemed to ignore these flowers in favor of the small yellow elbow bush blossoms (Forestiera pubescens). Elbow bush is one of the first shrubs to bloom in Texas. It's flowers tend to appear in February or March, so it's right on time this year. Other common names for this plant include "spring herald" and "stretch berry".

It is fortunate that these honey bees have a few flowers from which to chose. Flowers like dandelions are deficient in multiple amino acids which honey bees are unable to manufacture. The bees would effectively starve and be unable to rear brood if that was the only pollen available. By collecting pollen from multiple sources, they ensure that their diet satisfies the colony's nutritional requirements.

Busy loading up her saddle bags with food for the hive

Emergence and old skins

noreply@blogger.com (Unknown) — Sun, 08 Feb 2015 17:54:00 +0000

Shed snake skin

I was out looking for the first signs of spring at Fort Worth Nature Center yesterday. Trout lilies and other spring ephemerals emerge about this time of year in Texas, and spring itself will be truly upon us in another month. The birds were chattering and excited. I only realized I had missed them upon hearing them call again.

Question mark butterfly

I jumped the gun a little on wildflowers, however. It's still a bit early for them, despite the taste of perfect weather we've had this week. I did see other signs of the new season. A neatly coiled snakeskin sat on top of crispy brown leaves. Its perfect placement made me think it hadn't been there all winter. I don't know when snakes normally emerge from hibernation in Texas, but February seems premature.

Question mark butterflies were also awake and flying in the sun. These butterflies overwinter as adults. They roost in crevasses in tree bark, but they break dormancy on warm days. I didn't see much for them to feed on, but they seemed compelled to flit about. I don't imagine that butterflies 'play', that's what it looked like they were doing.

I also found an empty silk moth cocoon dangling from a small shrub. I'm on the fence as to whether the cocoon is from this year or last. It is remarkably well preserved, and it is certainly well attached to its little twiglet, but in our region silk moths don't normally begin to emerge until March.

Native silk moths are enormous, fuzzy, and brightly marked. The sea green luna moth is one of the more familiar representatives. Silk moths have an outer silk cocoon protecting their pupa. The silk moth used for commercial silk production is the only fully domesticated lepidopteran. They don't exist in the wild.

Adult silk moths do not have mouths. They do not feed as adults- they live for a week or two and are entirely consumed by the need to breed. In fact, some moth watchers rear female moths in order to use their pheromones as bait to lure in males of the species.

A luna moth- a type of silk moth

Until yesterday I'd never wondered how these mouthless moths fight their way out of their cocoons without mandibles. Apparently they either split their cocoons with a built-in escape hatch that only works from the inside, or they exude silk dissolving chemicals ("cocoon-ase") to ease their emergence.

Snakes and silk moths are both taken as symbols of rebirth and renewal, so it is fitting that I found them while out looking for signs of the changing season. As for spring beauties and trout lilies, I'll just have to keep checking. I don't mind the task.

A closer view of the cocoon

Spicebush, sulcatone, and mosquitoes

noreply@blogger.com (Unknown) — Fri, 30 Jan 2015 19:24:00 +0000

Aedes aegypti, wiki [8]

I fell down the google rabbit hole in a big way earlier today. I was digging around, looking for info on the chemical composition of some of my favorite scents from childhood. I wasn't doing this idly- essential oil companies sell these compounds. My though was this: wouldn't it be nice to blend a fragrance that captures where I grew up?

Sweetgum Range, from wiki [6]

The aromas of a southern childhood that I settled on were forest soil, cedar, tomato leaves, gardenia, maple syrup, wet dog, and the fragrant terpenes from sweet gum (Liquidambar styraciflua) and spicebush (Lindera benzoin). Most of these were pretty easy to find. Oakmoss and vetiver conjure a forest floor, two varieties of cedarwood oil are manufactured in Texas alone, a tomato leaf accord is a popular perfume top note, blended jasmine and honey smells similar to gardenia, immortelle flower smells of maple syrup, costus of wet dog, etc etc. In fact, the resin of sweet gum’s Chinese cousin, also in the family Liquidambar, is a perfume staple. It is sometimes referred to as a variety of ‘styrax’.

Spicebush was the only fragrance without an obvious analog. Its crushed leaves smell of fresh citrus and camphoraceous cloves (like a hot toddy!). This lovely odor is referenced in its species epithet- ‘benzoin’. Derived from the the resin of trees in the genus Styrax, benzoin is another staple in perfumery. It smells of vanilla, warm powder, and musk. Spicebush was used by early American colonists as a substitute for allspice, and native peoples used it as a panacea, marinade, and fragrant tea. The spicebush swallowtail relies on spicebush as its only larval food source. It is also a preferred food of the gorgeous promethea silkmoths, and its bright red berries are a treat for the birds.

Spicebush, image from wiki [7]

So what is it that makes spicebush smell so delicious? A 1994 journal article written on the chemistry of its distilled essential oils recorded notably high concentrations of 6-methyl-5-hepten-2-one (sulcatone), α-phellandrene, 1,8-cineole, and β-caxyophyllene [1]. This molecular information is how my descent into the deep internet began.

Sulcatone, a ketone which smells of fresh, fruity citrus and is found in lemongrass and tomatoes, is a controversial odorant in the world of tropical disease research. A recent study which garnered the notice of popular science publications identified sulcatone as a possible mosquito attractant. However, most other studies note it as a natural repellant. Seeing as sulcatone is present to some degree in existing natural insect repellants like lemongrass and citronella, and that it has the same characteristic citrus odor, I’m inclined to defer to the bulk of the literature.

Sulcatone, along with geranylacetone (fresh, rose-watery magnolia), are manufactured on the skin in greater amounts by some lucky individuals [5]. Sulcatone and geranylacetone mask your delicious blood smells from mosquitoes, which search out prey by sniffing the air for carbon dioxide and skin exudates. They do this by blocking key odorant receptor areas on a mosquito’s antennae [4].

Things that smell like this probably smell good to mosquitoes.

Octenol (1-octen-3-ol) is also manufactured on your skin. It smells of mushrooms (and is in fact a chemical mushrooms produce—think of this the next time you see a toad stool covered in flies), earth, and musk. This molecule is like catnip to insect parasites. Distressingly, octenol is sometimes used in perfumes to impart an earthy, animal base. This fact has rendered me skeptical of any perfume with base notes of vegetal decay. I’ll think twice before I apply a mossy fragrance in the summertime without a hefty dose of citrus and terpenes in accompaniment.

I almost wonder if humanity loves the smell of resins and terpenes because blood feeders detest them. It seems like an adaptive trait, to rub yourself with fragrant oils and disguise your scent from the small pests which would make a meal of you. Otherwise why would we cover up our natural odor, especially if it (supposedly) helps us identify potential mates? It is just a stray question, some food (or fragrance) for thought.

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1. Tucker, A. O., Maciarello, M. J., Burbage, P. W., & Sturtz, G. (1994). Spicebush [Lindera benzoin (L.) Blume var. benzoin, Lauraceae]: a tea, spice, and medicine. Economic botany, 48(3), 333-336.

2. Logan, J. G., Birkett, M. A., Clark, S. J., Powers, S., Seal, N. J., Wadhams, L. J., ... & Pickett, J. A. (2008). Identification of human-derived volatile chemicals that interfere with attraction of Aedes aegypti mosquitoes. Journal of chemical ecology, 34(3), 308-322.

3. Singh, N., Wang, C., Cooper, R., & Liu, C. (2012). Interactions among carbon dioxide, heat, and chemical lures in attracting the bed bug, Cimex lectularius L.(Hemiptera: Cimicidae). Psyche: A Journal of Entomology, 2012.

4. Murphy, E. J., Booth, J. C., Davrazou, F., Port, A. M., & Jones, D. N. (2013). Interactions of Anopheles gambiae Odorant-binding Proteins with a Human-derived Repellent IMPLICATIONS FOR THE MODE OF ACTION OF N, N-DIETHYL-3-METHYLBENZAMIDE (DEET). Journal of Biological Chemistry,288(6), 4475-4485.

5. Logan, J. G., Stanczyk, N. M., Hassanali, A., Kemei, J., Santana, A. E., Ribeiro, K. A., ... & Mordue, A. J. (2010). Arm-in-cage testing of natural human-derived mosquito repellents. Malaria journal, 9(1), 239.

6. http://en.wikipedia.org/wiki/Liquidambar_styraciflua

7. http://en.wikipedia.org/wiki/File:Lindera_benzoin.jpg

8. http://en.wikipedia.org/wiki/Mosquito

A day-flying hypocala moth

noreply@blogger.com (Unknown) — Mon, 26 Jan 2015 00:01:00 +0000

The beautiful Hypocala andremona

As far as lepidoptera go, moths came first. Butterflies are essentially a type of moth, a moth with brilliant colors that flies in the daytime. Moths show up in the fossil record 190 million years ago. Butterflies appear as a sub group later, perhaps as late as 130 million years ago. It could be for this reason that there are ten times as many species of moths as there are butterflies. Some of the most primitive micromoths (Micropopterigidae- mandibulate archaic moths) hardly resemble their larger cousins at all. Their caterpillars are slug-like detritivores, and the adults retain their chewing mandibles. They are closely related to caddis flies.

Sphinx moth

I find moths fascinating because they surround us, but their nocturnal habits assure that we rarely notice them unless they are knocking against our porch lights. There are exceptions, however. Some moths, like the sphinx moths, fly in the daytime. Others, like the Hypocala andremona pictured above, stay up past their bedtime.

I was delighted to find a hypocala moth in south Texas (November 2014). S/he had obligingly posed on an orange bank of flowers, accentuating the bright underwing coloration. They can be a defoliating pest on persimmon leaves as caterpillars, but I can't begrudge them that. It is rare for a tree to die from periodic defoliation. Hypocala moths themselves are heavily parasitized by beneficial insects, especially the trichogramma wasps. To me, they don't seem like a pest that requires active intervention. Supposedly they are most frequently seen in Texas, and they can be found from Central America up through the southern states.

Distinguishing the very similar underwing moths (catocala) from the hypocala moths is not easy. Both are medium-large moths with drab upper wings and colorful, patterned underwings. I read that catocala means "beautiful below" in latin on bugguide.net, so hypocala must mean "beautiful underneath". Basically the same thing. They are both in the Erebidae family, but the precise taxonomic split varies by source. I doubt I could have teased apart this taxonomic distinction without help from the "Mothing and Moth Watching" Facebook group. Following this group is addictive. People post pictures from all over the world-- who knew there were so many gorgeous moths in China and Brazil?

If I've piqued your interest, you can read more about moths on this blog here and here, or you can become a member of "Mothing and Moth Watching" on Facebook.

Possibly a day-flying large lace border moth (Scopula limboundata)

A visit to the coastal prairie

noreply@blogger.com (Unknown) — Mon, 19 Jan 2015 18:33:00 +0000

Gayfeather on the dunes

I spent the end of last week down in San Marcos giving a "Monarchs 101" talk to agency personnel. My monarch talk was something of an opportunistic afterthought, appended to an existing gathering of the Gulf Coast Prairie Landscape Conservation Cooperative (GCP LCC). This organization was formed as a collaborative effort, driven by the Department of the Interior, to protect the Gulf Coast Prairie from threats including climate change and urbanization. Because Texas' geographic extent encompasses the funnel through which the majority of migratory monarchs pass every spring and fall, and because the Feds have been under a lot of pressure to develop a strategy to save the monarch butterfly migration, the GCP LCC and their partners are tackling this issue. I was brought in to provide an overview of monarch biology. I've discussed monarchs and other milkweed butterflies before in this blog.

It's easy to forget about the coastal prairies up here in the Great Plains. After living in Nebraska, it's a stretch to imagine a tall grass prairie within earshot of the surf, but I've seen it. Last November I stopped off in Corpus Christi to visit Padre Island on my way to the Texas Butterfly Festival. There I found tall grass species commingling with yucca and hardy halophytes.

As the southern-most extension of the tall grass prairie, you recognize seemingly misplaced familiar plants. I noticed little bluestem and gayfeather, among others. You also get coastal species, like sea oats and fleshy succulent forbs. It sure felt tropical-- my leeward arm was entirely coated in mosquitoes. Luckily, I was wearing a thick wool sweater over a flannel shirt. All I could think was "malaria, yellow fever". Prior to eradication efforts, visiting coastal Texas must have been a real gamble. I spent a summer as a research assistant in the salt marshes of coastal Virginia, but I've never seen mosquitoes like that.

A tallgrass dune system

The gulf coast prairies are also unusual because they exist in a land that receives more than enough rain to support forests and other vegetation. You can find these prairies from Lafayette, Louisiana to south Texas. Supposedly, edaphic (soil) characteristics and fire maintained these grasslands' open canopy. I would guess that salinity in the water table also prevents trees from getting established.

crested caracara

Corpus Christi is far enough south that you get some semi-tropical birds. In fact, Padre Island is renowned for birding. The National Park Service website claims that Corpus Christi won the "birdiest city" award for 10 consecutive years. You get both winter residents and migrants. It is one of the richest areas for birding in North America. Obsessive birders travel from all over to get 'lifers'.

I didn't do much birding, but I saw a pair of crested caracaras gliding and diving in the dunes. These funky raptors are most closely related to falcons, but they live like vultures. They are inefficient hunters, and prefer carrion and thievery to catching their own dinner. They also look like they are wearing poorly fitted toupees. This 'bad wig' effect, combined with their pink faces, make them look rather non-threatening for a bird of prey. Their range barely extends into the US. The crested caracara heartland is Central America and northern South America.

This bird doesn't mind the seaweed

Another distinctive facet of the Gulf Coast Prairies is their exposure to the by-products of petroleum exploitation. When I asked native Texans about the beaches, their responses tended towards "Eh." A friend of mine reminisced about digging tar balls on the beach as a child. Additionally, something about the rotation of the Gulf Coast gyre leads to heavy trash and seaweed accumulation. The Padre Island entry booth had signs posting the tides, the flag warning, and the levels of trash and debris on the beach. It's a shame, but the birds still come. If you want to add to your life list, or see a unique prairie system, it's still worth a trip.

Pelican and cormorants hanging out in the surf

Action plants!

noreply@blogger.com (Unknown) — Fri, 09 Jan 2015 02:00:00 +0000

Longleaf pine savannah, Louisiana

It is an interesting time to love rare and unusual plants. Just a few months ago, a man in Boone, NC became the first to be charged with a felony for poaching the rare (and highly lucrative) ginseng. Dried ginseng is worth four times its weight in silver. Most growers keep their operations secret because poaching, not the vagaries of weather, pests, or animals, is the biggest threat to their livelihoods.

A venus flytrap in situ at the Green Swamp

Again in North Carolina, a few days ago four men were the first to be charged with felonies for poaching venus flytraps. Unbelievably, before the law was changed December 1st of last year, the maximum penalty was a misdemeanor and a $50 fine. $50 seems down right paltry when you consider that venus flytraps are only found on poor soils in the longleaf pine savannah on the coastal plain of North and South Carolina. The Nature Conservancy estimates that there are fewer than 35,000 venus flytraps remaining in the wild.

I have lived most of my life in the southeastern United States, and I have had the privilege of seeing many different types of carnivorous plant in the wild in North Carolina, Alabama, and Louisiana. Plants develop carnivory as a means to get more nutrients on poor soils. Simply put, this strategy doesn't pay on better ground. Snap traps, sticky trap, or pitcher, these plants all must expend energy to build these contraptions. While flytraps are rather limited in distribution, sundews and pitcher plants can be found along much of the Atlantic coast and in the Great Lake states.

A sundew (no, that isn't my hand and no, I didn't pick it)

classic pitcher plant

I have seen venus flytraps, sundews, and pitcher plants. These three families, along with bladderworts, make up some of the major clusters in carnivorous plant taxonomy. Sundews and flytraps are actually somewhat related. Flytraps seem to have evolved from a sundew-like ancestor.

Sundews capture their prey with a sticky trap mechanism- what looks like dew is actually an adhesive. Once an insect is caught it will not be released. The venus flytrap, cousin to the sundew, is instead reminiscent of a steel trap. Once an insect brushes its trigger hairs, the jaws snap shut and imprison it.

Pitcher plants are less closely related, and their traps are much more passive. An insect falls in and is slowly dissolved in an enzyme bath at the bottom of the pitcher. Should it try to climb out, downward facing hairs trip it up and hinder its escape.

Another type of pitcher plant. Notice the hair.

Texas has one species of pitcher plant (Sarracenia alata) and up to four species of sundew (Drosera brevifolia, D. capillaris, D. intermedia, and D. tracyi). I haven't yet found these plants, but the BONAP maps show them pretty far inland. Sundews are unobtrusive and hard to spot, but pitcher plants might be worth an expedition. Especially during their summer bloom.

A blooming pitcher plant

Longleaf pine savannah, North Carolina

Back from holiday in Carlsbad, NM!

noreply@blogger.com (Unknown) — Wed, 31 Dec 2014 02:53:00 +0000

On the way to Carlsbad Caverns

I've recently returned from holiday in Carlsbad, NM. Averaging a little under 13 inches of rain annually, this region is where the the Chihuahuan Desert takes over after the last gasp of the short grass prairie fades in far eastern New Mexico. My main impression was of a thinly grassed chaparral dotted with spiky yucca-like plants I couldn't tell apart. Remarkably, it rained or snowed two of the three days I was there. This was some feat considering the area averages only 41 days of precipitation per year. I have a knack for getting rained on in deserts.

Closer view of the vegetation

I'm not totally clear on differentiating the various spiked rosettes that dominated my visual impression of the landscape. I do not think I could tell them apart without their dried floral stalks. Thanks to guidebooks, I know I saw sotol (Dasylirion leiophyllum), torrey's yucca (Yucca torreyi), mescal agave (Agave parryi), and lechuguilla (Agave lechuguilla).

I've gleaned the following: sotol and lechuguilla's leaves have hooks curved back toward the base, but sotol leaves are finer with dried, light brown fibers extending far beyond the tips of their leaves. Mescal agave looks like what we call a 'century plant' in horticulture, and torrey's yucca is raised up on a brown pedestal of its previous growth, leading me to initially call it a 'joshua tree'. Yuccas (vs. agaves and sotol) don't seem to have hooks on their leaf edges. Of course, most people go to Carlsbad to see what's underground, not to do a comparative study of spiny rosettiform succulents.

Possibly a torrey's yucca?

A giant fungus-like speleothem

One of the stories my dad tells about me is that as a small child I essentially had a 'freak out' in Luray Caverns, VA. I remember reading some Tom Sawyer-y/Little House on the Prairie-type book about children getting lost in the caverns at about that time. I imagine I was pretty concerned about the lights staying on and getting back to the surface. Supposedly we completed the tour but I begged and whined the entire time.

This family story of some early childhood cave-associated terror came to mind as I prepared to go down into the cavern. I hadn't toured a cave system since that experience, so I was curious if I would discover some forgotten fear. I am pleased to report that I enjoyed visiting the fantastic Carlsbad Caverns without incident. Some things do change.

The big room

Carlsbad Caverns is famous for its remarkable speleothems (cave formations including: stalactites, stalagmites, columns, etc). While most caves are formed by carbonic acid, the limestone of Carlsbad Caverns was dissolved by sulfuric acid. The caverns started forming approximately 4 million years ago, and progress ceased with climate change at the end of the Ice Age. These caves might start building again, if climate changes bring the area more rain.

Despite the lull in geologic activity, you could hear dripping water echo through the caverns. It smelled like dust and wet stone. Human odors seemed sharper for some reason. Whenever I passed someone wearing cologne, it was stronger than at the the surface. I'm not sure if the human scents were being thrown into relief by the spareness of the cave, or they were more efficiently picked up by my nose because of the 90% humidity underground.

It is astonishing to me that early explorers dropped ladders in the abyss and descended into the darkness in total ignorance of what they would find. It seems likely that this need to have a finger in every pie is a characteristic human trait.

I saw more of New Mexico than the caverns, and I will write on that shortly. Until then: have a happy New Year's Eve!

Higher elevation desert slopes near visitor center

Tracks

noreply@blogger.com (Unknown) — Fri, 12 Dec 2014 02:07:00 +0000

Skunk tracks in tuff? Badlands National Park

Winter is a good time to work on your tracking. I am not especially skilled. I can generally tell canid from feline, and anything with unexpectedly burly claws on a smallish paw could be a skunk or badger. Those rascals love to dig. I learned most of the little I know from a day long class with a biologist that I took when I was in grad school in North Carolina and the rest from books.

What struck me most was the diversity of wildlife you share a space with but never see. Many creatures are either active at night or are crepuscular, so you are unlikely to stumble upon them on your hike or jog. In the semi-rural piedmont of North Carolina where I took my class, we saw sign of river otters, mink, beavers, foxes, mice, rabbits, house cats, and coyotes. You can get a feel for the lushness of North Carolina's forests from that list.

Shortly afterwards I moved to Nebraska. My regular jogging route was up and down gravel roads. I'd pat the nose of the neighbor horse, and I flushed deer and turkey most mornings. I saw plenty of their tracks, but I also saw coyote, badger, skunk, and, in the western part of the state, antelope. My impression of Nebraska was that it was a sportsman's paradise. They are drowning in game. Between the resident turkey flock (one technical term is 'rafter'; as in 'a rafter of turkeys') and the jumping deer, Nebraska seemed veritably made of meat.

What happened here? Near Paria canyon, UT

Something long dead
(fossil dino tracks)

Tracks and sign can tell you more about a place than you might otherwise sense. In Utah I saw the marks of desert beetles, lizards, and crows. I also saw the signs of long dead creatures. I was in Utah volunteering as a range technician's assistant, and one of our monitoring locations happened to be near a fossil bed. Dinosaur tracks preserved in ancient mud had been exposed at the surface by erosion.

I was shocked that these fossils didn't have so much as a fence around them. You could walk right up and touch them, or put your feet in the tracks and mimic the dinosaur's gait if so inclined. The location was self-guided, so there wasn't even anyone to stop you from taking a pickaxe to the rock and hauling away a chunk of dino-print. It seems that the people who have trekked out so far have managed to restrain themselves. Let's hope that continues to be the case.

People! Chipped toeholds near Paria Canyon, Utah

Also in Utah, I enjoyed seeing the signs of ancient peoples. These chipped 'toe paths' were pretty common. I took the above picture next to my campsite. These lines seem too perfect to have been caused by erosion, but I'm open to someone else's interpretation.

Raccoon tracks look like children's hand prints (Old Alton Bridge)

I must admit I haven't devoted much time to tracking since I got to Texas. I've been travelling so much for work I've neglected to take all the dreamed of road trips to the western part of the state, where the bare ground shows more evidence of passing creatures. I have seen a few mud prints in the parks around town. Raccoon and fox, nothing too exceptional, but pleasing to see all the same. Raccoon prints look for all the world like a baby pressed their hands into the dirt. Fox prints are smaller and less rectangular in composition than the average canine, but they have the permanently extended claws of their family. Canids leave claw marks in their tracks and cats don't because cats have retractable claws.

I hope to tour a little of the western part of the state over the holidays. I'll certainly takes pictures to document any interesting traces of the resident wildlife that I should come across!

Canid, probably red fox (Old Alton Bridge)

Winter Ducks at the Drying Beds

noreply@blogger.com (Unknown) — Sat, 06 Dec 2014 19:08:00 +0000

How many can you spot?

I took my bird-dog bird watching at the Village Creek Drying Beds in Arlington, Texas this morning. This was not as fool hardy as it may sound. As I have mentioned in previous posts, Colby is something of an embarrassment to her line-- she prefers butterflies to coveys. She also knows that when I have my camera out tugging and general knuckle-headed-ness is futile. I will remain un-moved until I'm done. She seems to enjoy our excursions though, and I get a kick out of watching her try to figure out what's got my attention. This morning it was ducks.

The Village Creek Drying Beds are locally renowned as an excellent place to view ducks in the winter. Or they were renowned, I should say. The site is in the process of decommissioning. Originally used as a solid waste treatment facility, it is now the domain of birders, dog walkers, and nature photographers. Water levels are kept much lower than they used to be, and thus the numbers of visiting waterfowl have declined. I only saw one bed with enough water to draw ducks when I visited.

A northern pintail

I was actually visiting the drying beds to work on my duck ID. I know basically nothing about ducks, and a warm winter day where most of the other wildlife has gone cryptic seems like as good an opportunity to learn as any. In addition to the ubiquitous mallards, I saw northern pintails, green winged teals, and northern shovelers. There were many other ducks drifting and dabbling with less obvious field markers. I had to look up the term "dabbling"-- this is the word for the duck feeding behavior where they go 'bottoms up'. Ducks are described as being dabblers or divers, where divers dunk themselves entirely and the dabblers do underwater headstands leaving their rear-ends visible above water.

Green winged teal

I think my favorites were the pintails, probably because they were the easiest to spot to my untrained eye. Pintails have… an elongated pin-tail. They also have a white breast and grey head. Green winged teals were easiest to identify based on the white slash ahead of their wing. Their copper heads seemed to make their green ear patch hard to spot at a distance. Northern shovelers were distinctive because of the strong white/chestnut patterning on their bodies and their dark heads.

Northern shovelers

The origins of the names 'pintail' and 'green-winged teal' are pretty obvious, but what about 'shoveler'? Do they use their bills to shovel and pick through mud? Well, not really. I suppose their bills vaguely resemble shovels, but the term most commonly used to describe them in the literature is "spatulate". Their bills are broader at the end than at the base, and the edges are toothed like a comb. They use these crenellations to filter food from the water. This species is remarkable in that it is common to North America, Europe, Africa, and parts of the Indian subcontinent.

Another picture of a shoveler

Supposedly the Village Creek Drying Beds are even better during the spring and fall migrations. I imagine that its usefulness as a duck pond will ebb and flow with rainfall and chance as the drying beds are totally phased out. Until that happens, I can still recommend this spot as an excellent place to see ducks.

Dry drying beds

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Useful Links

visual guide to Texas ducks:
https://tpwd.texas.gov/publications/pwdpubs/media/pwd_bk_k0700_0517.pdf

list of ducks and relative commonness:
http://www.nctexasbirds.com/home/checklist/test-table

Bird World's map of birding hotspots:
https://www.google.com/maps/d/viewer?msa=0&mid=z9S4BN39WyME.kdjnnF6IFvJg

The description of Village Creek Drying Beds:
http://www.birdwatchingdaily.com/hotspots/45-village-creek-drying-beds-fort-worth-texas/

FW Audubon's list of hot spots:
http://www.fwas.org/index.php?pageid=birdingdfw

Five hairstreaks of south Texas

noreply@blogger.com (Unknown) — Fri, 28 Nov 2014 19:33:00 +0000

Sweet face on a dusky blue groundstreak

Hairstreaks, of the subfamily Theclinae within the family Lycaenidae ("gossamer wings"), are small butterflies that are most diverse in the New World tropics [1]. I think they are highly underrated, as far as butterflies go. While they are certainly 'cute', telling them apart can be a challenge. Many of them are dainty gray butterflies with wing bands, eye-spots on their hindwings, and wispy tails.

I thought it might be instructive to go through key field markings. For this purpose, I searched through my back catalog and pulled images of five different species of hairstreak I've observed here in Texas. The subjects I've selected include three relatively similar-looking hairstreaks (the dusky blue groudstreak, the gray hairstreak, and the mallow scrub hairstreak) and two more distinctive hairstreaks (the great purple hairstreak and the silver banded hairstreak).

A gray hairstreak (Strymon melinus)

First, let's start with one of the most common and widespread hairstreaks in North America: the gray hairstreak. Larva tend to eat mallows and legumes, while adults are nectar generalists [2]. I would consider the gray hairstreak to be the "generic hairstreak", the hairstreak from which all others are differentiated. Note the relative cleanness and lack of clutter between the wing bands and wing edges. Also, remember the thickness, numbers, and placement of the orange markings on the hindwings. These are all traits that will vary from species to species.

Dusky blue groundstreak (Calycopis isobeon)

Now let's compare the gray hairstreak with the dusky blue groundstreak. This butterfly's larval food source matches its name ('groundstreak'): it's caterpillars feed on decaying leaf matter and other detritus [3]. At first glance these two hairstreaks look pretty similar. However, remember to check the eye-spots. The dusky has two well defined eye-spots outlined in red, versus the gray's one and a half. The dusky blue groundstreak has a third iridescent blue spot on the bottom edge of its hindwing, below the red and black eye-spots. This marking is totally missing in the gray hairstreak. The wing bands also differ- the dusky has obvious red outlining the post-medial band on its hindwings, and the thickness of this red outline is one of the field marks distinguishing it from its cousins. There's also provenance. The dusky blue groundstreak is only found in south Texas within the United States. If you anywhere but south Texas, then odds are it isn't a dusky blue groundstreak.

Mallow scrub hairstreak (Strymon istapa)

The mallow scrub hairstreak, which is actually in the same genus as the gray hairstreak, looks a bit different from the preceding two butterflies that I covered. When I saw this butterfly up in the canopy nectaring on Mexican olive (not pictured), I initially couldn't decide if it was a hairstreak or a tailed blue. I was better able to pick up on some of the identifying markers upon closer inspection.

Remember when I wrote about the uncluttered wings of the gray? The mallow scrub hairstreak is most definitely messy. There's a whole host of scribbles and bands in white and dark gray after the post-medial line. There's also minimal red on the eye-spots. Lastly, look at the front part of the hindwing and note the two dark gray spots. These two spots before the hindwing's band distinguish this hairstreak from all others. Like its con-generic the gray hairstreak, the mallow scrub hairstreak's caterpillars feed on mallows. This species is confined to the southern-most portions of the United States.

Another important thing to remember when identifying hairstreaks is that sometimes they don't have tails. The entire purpose of the eye-spotting and enticing tails on their hindwings is to encourage birds to take a nip there instead of other, more critical, areas. Many species of hairstreak even twitch and fidget their tails such that they resemble antennae.

Silver banded hairstreak (Chlorostrymon simaethis)

This silver banded hairstreak has seen better days. Either he's scrunched up, ~~or something took a medium-sized chomp out of his right hindwing~~ (he's scrunched up- ed.). The other side still seems to have its tail. Silver banded hairstreaks are another southern species. Their larvae are rather sly. Instead of feeding on leaves and exposing themselves to visual hunters, they hide inside the pods of balloon vines and eat the seeds [5]. This green hairstreak is pretty distinctive for a number of reasons. Its green coloration and straight silver bands are some of the easiest cues to pick up on in the field.

Great Purple Hairstreak (Altides halesus)

I'm going to end this post on the unmistakable great purple hairstreak. This butterfly has a wide distribution across southern North America. When I first saw this butterfly I was floored by its iridescent markings. The blue green markings on the edge of hindwings flashed in the sunlight whenever the butterfly re-arranged itself on the flower head. Its body is bright orange, and its wings are touched with bright blue. Their larvae eat mistletoe [6].

Obviously, this butterfly is quite distinct from most hairstreaks. However, the tells are still there. Like other hairstreaks, Great purples are petite with thin little tails, in contrast to the thick, chunkier tails on swallowtail butterflies. They also tend to sit with their wings folded, instead of spread to catch the sunlight.

In summary, many small butterflies with eye-spots and thread-like tails on their hindwings are in the Theclinae sub-family. After you have narrowed your search to this particular group, sorting through your options to get to species will probably require a combination of eye-spot characteristics, wing band size and coloration, and location. Good luck!

A silver-banded behind

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1. http://www.butterfliesandmoths.org/taxonomy/Lycaenidae
2. http://www.butterfliesandmoths.org/species/Strymon-melinus
3. http://www.butterfliesandmoths.org/species/Calycopis-isobeon
4. http://www.butterfliesandmoths.org/species/Strymon-istapa
5. http://www.butterfliesandmoths.org/species/Chlorostrymon-simaethis
6. http://www.butterfliesandmoths.org/species/Atlides-halesus

Palo Pinto and the Butterfly Hound

noreply@blogger.com (Unknown) — Sat, 22 Nov 2014 17:31:00 +0000

Clouds echoing the topography, Palo Pinto County

God help me, I've turned a red-blooded bird dog (my german shorthaired pointer) into a butterfly chasing hound. It wasn't planned. It just happened naturally. Ever since I adopted her, I've taken her with me on my invertebrate photo hunts. I strap her to my waist with a leash, leaving my hands free to snap away with my camera. My impressionable pup seems to have picked up on me stalking bees and butterflies with my lens. She's realized these flittery creatures are of some importance, and worthy of attention. Now it's a race to see who can reach the bug first- me with my camera or her with her snapping teeth. Funny enough, she's somewhat indifferent to her ancestral prey. We've actually spooked coveys without her paying much mind, but butterflies- she just loses her little head. I suppose we end up with the dogs we deserve.

View from the mesa

My dog's enthusiasm for lepidoptery got us in trouble a few weeks ago when we were poking around Palo Pinto County, the home of a (relatively) soon-to-be-opened 5,000 acre state park. My dog Colby does not have what I would call "cactus-sense". Time and again, running headlong after a butterfly (this time of year it's sulphurs, admirals, buckeyes, and southern dog-faces) she would face-plant into a prickly pear or pencil cactus. I'd pin her down, grab her little maw, and pull the spines out with the pliers on my leatherman. You'd think she'd learn to take more care, but it seems her joie de vivre simply cannot be dampened by something so insignificant as a spine between the eyes or a nopal hanging from her wet little nose.

Keeping a willful dog out of the opuntia was... tricky.

Topo and satellite images of our trek.

Bringing my naive dog to cactus-country was just one of many poor decisions that accompanied my trip to explore this rugged landscape prior to its development as a state park. I was in search of a sheer canyon with unusual plants located in the southern section of the parcel, off a recently bull-dozed road, not yet added to maps of the area.

I should mention that I have a somewhat poor sense of direction. I am great at following trails and using maps and compasses, but if I rely on 'instinct', it generally ends poorly. I had thought to bring a borrowed GPS unit and printed out satellite photos, but somehow I forgot about the unmarked road leading more or less directly to my target. As a result, we ended up bushwhacking straight up and over a low mesa, through thick juniper and opuntia scrub, when we could've just gone around. I just about had a conniption fit up on top when it was cactus thickets in every direction. I was convinced I was going to blind my poor dog (or, rather, she would blind herself being an idiot), and I'd have to carry her back to the car and race off in search of an emergency vet. Despite these complications, we did find what we were looking for. We ended up turning back at the cusp of the canyon because it was fringed in a wall of cactus, and I just couldn't justify blinding my dog for the sake of exploration.

View from near the road to the canyon

Despite our misadventures, I was very impressed with the landscape. It looked like a translation of my mental image for "Texas" from before I actually moved here. Low, flat topped mesas were edged in rocky drop-offs, and they were lightly covered in juniper and mesquite. It is hard to believe that something so rugged and western exists less than an hour and a half from green, treed Fort Worth. It was a world away from the hackberry and pecan groves. I could see going into full-hermit mode out there. I'm a real sucker for rocks and spare landscapes.

Migrating sand hill cranes passed overhead

Once we reached the peak of our ill-advised mesa scaling adventure, we had a moment of peace. I could see for miles down the valley, a valley that raptors funnel through in their fall migration. I stopped and ate an orange and Colby huffed quietly. Then I heard a familiar gurgling trill from overhead: sand hill cranes! They were using the same flyway on their migration south to their coastal wintering grounds. I'm not sure Colby appreciated it, but I got a lot of joy from hearing the cranes. Seeing them pass through provides something of a thread linking my year in Nebraska with my time here in Texas. I'd like to return to this undeveloped landscape to see it change with the seasons, though if I bring Colby we'll stick to the roads.

Dog tired. (Hah!)

Three polyphenic butterflies

noreply@blogger.com (Unknown) — Fri, 14 Nov 2014 03:26:00 +0000

This question mark hasn't given up on summer. (11/2/2014, Mission TX)

In an organism that is seasonally polyphenic, also termed seasonally polymorphic, the same genetic code produces different physical traits in response to environmental conditions. In butterflies this is quite common, and it is often expressed as "summer" and "winter"/"dry season" morphs. Day length and temperature seem to trigger these changes. Butterflies are most sensitive to these seasonal cues while they pupate, and they only get to choose their morph once (see comments).

Some researchers believe that polyphenism evolved as a solution to differing needs for camouflage and thermoregulation in summer vs. winter. Perhaps summer butterflies survive better on fresh green leaves in bright coats, while fall butterflies are more comfortable with darker coloration that allows them to soak up the weak winter sun. Fall butterflies also tend to live much longer-- some late-emergent butterflies hibernate for 9 months before reproducing, instead of the brief flight window and immediate reproduction of their summer kin.

Dainty sulphur. (11/8/14, Palo Pinto Co. TX)

I've encountered at least three polyphenic butterflies in the past couple weeks. Interestingly, these three butterflies couldn't agree on the season. Two were plainly marked for winter, while one insisted on hanging onto summer.

The question mark's dark morph is its summer form. In the winter, the hind wings lighten. Question marks don't typically nectar on flowers-- like the hackberry emperor, they prefer to feed on dung and rotten fruit. That's the reason you see the question mark perched on a log in the picture above- someone had smeared the log with bait. You'll notice s/he shares the perch with flies.

Another pic of the dainty sulphur

For the dainty sulphur, the summer morph is paler with more yellow markings, while the winter morph has a mostly sooty coloration, especially on its hind wings. Dainty sulphurs are the smallest member of their family found in North America.

In white peacocks, the winter morph is larger and whiter than those which emerge in summertime. White peacock males are notable for a behavior that is somewhat unusual in the butterfly family. They defend patches of their larval host plant in hopes of monopolizing any passing females. These harmless insects perch in their small territories and engage rivals in aerial duels. I'm not sure how a 'winner' is determined. Each participant is essentially incapable of harming the other, unless it is by exhaustion.

The seasonally confused question mark looked pretty fresh, not at all like some holdover from longer days and warmer weather. I wonder if he will suffer for his poor judgement? Perhaps he pupated during a warm snap, confusing his cues. The verdict of the dainty sulphur and white peacock, and the arrival of an arctic front, tend to suggest that cooler weather is here to stay, at least for a little while.

White peacock (11/2/2014, Mission TX)

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References
Wiklund, C., & Tullberg, B. S. (2004). Seasonal polyphenism and leaf mimicry in the comma butterfly. Animal Behaviour, 68(3), 621-627.

Lederhouse, R. C., Codella, S. G., Grossmueller, D. W., & Maccarone, A. D. (1992). Host plant-based territoriality in the white peacock butterfly, Anartia jatrophae (Lepidoptera: Nymphalidae). Journal of insect behavior, 5(6), 721-728.

Nylin, S. (2013). Induction of diapause and seasonal morphs in butterflies and other insects: knowns, unknowns and the challenge of integration. Physiological entomology, 38(2), 96-104.

Karlsson, B., Stjernholm, F., & Wiklund, C. (2008). Test of a developmental trade‐off in a polyphenic butterfly: direct development favours reproductive output. Functional ecology, 22(1), 121-126.

Tropicalia at the Texas Butterfly Festival 2014

noreply@blogger.com (Unknown) — Sun, 09 Nov 2014 19:43:00 +0000

The red-bordered pixie, a tropical butterfly in the metalmark family. Unique to So. TX within the US.

I saw so many 'lifers' at this year's Texas Butterfly Festival in Mission, I've honestly been putting off writing about it. It's such a huge bite to take. Some butterflies were rare, some were deceptively common on site, and others were overwhelmingly abundant. I've decided to break my sightings down into more easily digested chunks. Because many of the butterflies I saw are limited to the subtropical regions of the United States and farther south, I'm going to focus on those species today.

Zebra heliconian, of the tropical longwing family

I was fortunate enough to spot a number of the more distinctive members of the local butterfly community. I think I most enjoyed finding the pixies and heliconians. These are two of the 'flag-ship' butterflies of the Lower Rio Grande Valley (LRGV). There they were- and in profusion. I also saw a Julia heliconian flit past, but sadly I couldn't get a picture.

Zebra and Julia heliconians are in the "longwing" family. These butterflies all feed on passionflower as larvae. The gulf fritillary is one of the more widespread representatives of this group. Gulf fritillaries were actually quite common on site-- the daft creatures were still reproducing. I even found a caterpillar climbing up a plumbago plant looking for a place to pupate. Gulf fritillaries perform a migration of sorts. They cannot survive freezing at any lifestage, so every year they must recolonize their entire northern range. The University of Florida's entomology page claims that the adults move south over the winter. For all I know the butterflies we see north of the freeze line are representatives of a giant population sink.

I'm pleased to have finally captured the full life cycle. First comes a passionflower, then a funky caterpillar, and then 'voila', a gulf fritillary.

How to make gulf fritillaries

My other tropical finds included the soldier, white peacock, the surprisingly lovely brown longtail, the sickle-winged skipper, (possibly) a silver-banded hairstreak, among others. Pictures and the full list after the jump.

Next week: the finer points of hairstreak ID.

White peacock

Brown longtail

Silver-banded hairstreak?

sickle-winged skipper

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My list for 11/2/2014:

ID’d butterflies

subtropical(ish) species

brown longtail

sickle-winged skipper

red-bordered pixie

soldier

white peacock

dusky-blue groundstreak

silver-banded hairstreak (damaged)

zebra heliconian

Julia heliconian

mallow scrub hairstreak

large orange sulphur

celia’s roadside skipper

southeastern species

hypocala andremona (underwing moth)

red banded hairstreak

phaon crescent

clouded skipper

southwestern

queen

bordered patch

funereal duskywing

widely distributed

fiery skipper

common checkered skipper

tawny emperor

gulf fritillary

monarch

little yellow

American snout

painted lady

cloudless sulphur

southern dogface

question mark

gray hairstreak

eufala skipper

A new savanna outside College Station, TX

noreply@blogger.com (Unknown) — Fri, 07 Nov 2014 22:26:00 +0000

This savanna made possible by heavy equipment.

College Station has a new oak savanna, thanks to a creative restoration effort by a local landowner and a TPWD biologist. Originally, the landowner had approached TPWD with the thought of putting his land back to native grasses. He was getting older, and he wanted his holdings to look like native prairie again. Most land in the area is dominated by the commonly over-seeded nonnatives: bahia grass, bermuda grass, johnson grass, and various old-world bluestems.

Great purple hairstreak nectaring on old frostweed

On this particular site, however, the problem was thick brush, especially yaupon holly, choking out the native post-oak's understory like a green wall. Inspired by the compensation offered from the frackers who owned the mineral rights and were coming in to build a new pad on-site, the landowner instead negotiated for hours with a bulldozer. After clearing the brush he over-seeded with the native grasses recommended by TPWD.

The site looked great, exceptionally so for a year '0' restoration. Many of the seeded native grasses have established, as have some pioneering flowering plants. Beautyberry and pokeweed were most abundant. I also spotted a few tendrils of maypop, frostweed, smartweed, and some other species.

closer: great purple hairstreak

Frostweed (Verbesina virginica) is a wonderful plant, an important late-season butterfly resource with a unique attribute: during the first freeze, its sap is extruded through the stem where it solidifies into curling 'ice sculptures', similar in appearance to the icy frost flowers that burst up through the ground in colder climates.

A gorgeous great purple hairstreak was investigating the few remaining blossoms on a tall frostweed in the center of the savanna. He (?) was shimmying the tails on his hindwings enticingly- evidently a behavioral adaptation to encourage birds to take a nip there instead of places where they could cause real damage. Interestingly, great purple hairstreak larvae eat only broad-leaved mistletoe. I didn't think to examine the treetops for these arboreal parasitic plants, but I can imagine that a savanna with an understory of rich nectar sources and an overstory hosting their larval food plant would be a good place to make a living as a butterfly.

I think most people find savannas quite aesthetically pleasing, and I hope this site stays lovely, propelled forward by a solid start.

Beautyberry lit by a patch of sun in the understory

Lady's tresses, Spiranthes spp.

The landowner's other sites were not so easy to restore. Simply making room for other plants in a matrix of the aggressive non-natives is no small undertaking. Repeat applications of glyphosate or imazapyr are often needed to even make a dent in the exotic grasses. This sort of broadcast chemical application makes my little heart sad, but sometimes it is a necessary evil. Notably, in the case of this landowner's other holdings, applications of herbicides had successfully suppressed the nonnative grasses and released the native grasses that had been holding out all along. I do still worry about the broadleaf plant community under these circumstances. However, a lone lady's tresses orchid had managed to put up a bloom in the middle of a sprayed patch. If an orchid, a representative of a characteristically delicate family, can push through, then maybe there is still hope for the others.

The three milkweed butterflies of the United States

noreply@blogger.com (Unknown) — Mon, 03 Nov 2014 03:41:00 +0000

Queens (Danaus gilippus) were... not uncommon.

I have had a wonderful time exploring central and south Texas over the past few weeks. After attending the Texas Butterfly Festival, I feel it is appropriate to write a brief butterfly-centric post. I see more of the ilk in my future-- I saw so many new butterflies, including tropical species! At any rate, it's been a blast.

The controversial non-native tropical milkweed
(Asclepias curassavica). The leaves are evergreen.

One of the highlights of my travels has been to finally see a soldier butterfly (Danaus eresimus). Soldier butterflies, like monarchs and queens, use milkweed exclusively as their larval host plant. Unlike monarchs and queens, their range barely extends into the United States. The subtropical tips of of south Texas and Florida are the only places you can really hope to find them. I was fortunate enough to see all three milkweed butterflies in the same garden on the same day (!) in Mission, Texas at the National Butterfly Center. They were really loving the betony-leaf mistflower (Conoclinium betonicifolium)

This is the best time to see butterflies down in south Texas' Rio Grande Valley. This area hits its peak butterfly density in October and November. The Rio Grande Valley is special. It marks the northern-most extent of number of largely tropical butterflies- a few of which I saw and will cover in a future post.

The monarch butterfly

Because the queens, soldiers, and monarchs (Danaus plexippus) are all very similar in appearance, I thought it would be useful to include pictures of all three to compare the various field markings. First: the classic monarch butterfly. Flashy and readily seen, though threatened by habitat loss in much of North America, this species can be found from Texas to Canada. They are the only milkweed butterfly with a confirmed long-distance migration, and they are much larger than both the queens and soldiers. Their size and bright orange coloration make them pretty easy to distinguish. Also, their veins are a high-contrast black instead of brown or undifferentiated in color from the wing.

Mating queens

Queen butterflies (Danaus gilippus) are smaller, more brown than orange, and they don't have the same contrasting black venation visible on their dorsal (topside) as monarchs. They also have two lines of white dots on the dorsal side of their forewing (leading wing), versus the single line observed in soldiers. Their overall color is darker and duller. Queens are quite common in the parts of south Texas I visited- they are much more frequently found than monarchs along the coast here. They are something of a southwestern species.

Soldier butterflies are definitely the most uncommon of the three milkweed-feeders. Sometimes they stray into southern Arizona, but they primarily stick to the subtropical areas of the United States. They are the veritable four-leaf clover in the field. In addition to being distinguished from queens by their single (instead of double) line of white dots on the forewing, they also have a dusky dark patch in the middle of their hindwing. Overall, they are a rich shade of brown.

The uncommon, hard to spot soldier butterfly

So that's it! The three North American milkweed butterflies. Stay tuned for a more lengthy update on the other unusual species I found down on the border...

The Ethics of Seed Collection

noreply@blogger.com (Unknown) — Fri, 24 Oct 2014 00:08:00 +0000

Nice, unharvested seeds.

I am passionate about native plants. I’m quite serious- it has been years since I intentionally introduced a non-native plant to my yard (other than vegetables, of course). Naturally, I jumped at the chance to get involved when my work gave me the ‘go-ahead’ to help with native seed sourcing. However, seed collection is not so simple as “find, harvest, propagate”. Many native plants have suffered population declines from over-collection, so it is important to take steps to ensure an ethical harvest.

Ginseng, orchids, carnivorous plants, echinacea, black cohosh, golden seal, and galax have all suffered from over collection. What do these plants have in common? They are the medicinal, the rare, and the weird. This damage is nothing to be sniffed at. Galax is harvested for its value in floral arrangements. The majority of galax stands along the Blue Ridge Parkway in the Southern Appalachians were targeted by poachers in 2012 [2]. Even worse, plants like ginseng, echinacea, and black cohosh are entirely destroyed by harvest, as the root is the part of the plant consumed. Others, like orchids and carnivorous plants, are delicate and often do not survive transplanting in their new environs anyway.

Someone may have beat me to it.
Or was it the wind?

Declines in medicinal plants have been well studied. Ginseng is a famous example. Recently, a ranking criterion was created to estimate the vulnerability of a plant to over collection. Traits on this list included: life history (i.e., how long does it take to reach maturity, what is its reproductive rate), effect of harvest (is the plant killed when harvested), population size, habitat, and demand [1]. To avoid over collecting, one should limit the amount of seed collected from a population, and not collect from the same site year after year. There isn’t a consensus on exactly how much seed you can collect from a population without causing harm. Some sources say no more than a third, others say 10%, and others yet say 5% per year over 10 years. I am sure that the exact details of a ‘safe collection rate’ vary by species, population size, and location. Generally agreed upon exceptions to these guidelines are in the case of plant salvage—where plants are removed from a site prior to its destruction or development. In this case, 100% harvest is acceptable.

In addition to calibrating your harvest level against the possibility of causing real damage to the landscape, one must consider legality. Obviously it is illegal to collect protected species. It is also illegal to collect in most State and National Parks. Often one can collect on Forest Service or BLM land, but this typically comes with restrictions and requires the purchase of a permit for a small fee. Collecting on private land is OK with permission as long as the target plant is not protected. Roadsides are something of a toss-up—most seed collectors (including myself) believe road sides to be fair game. However, if someone requested that I stop collecting from along their property, I certainly would.

Restored crop-field prairie

Somehow, while juggling all these factors, I have managed to harvest from two sites. One was a roadway in Denton County. The other was a private prairie north of Temple. My harvest protocol in Denton was pretty clear-cut. Unless someone stopped me, I would be able to collect seed. Additionally, the roadsides had been mowed and most of the seed heads shattered, so I wasn’t too worried about over collecting. I probably couldn’t have collected more than 5% of the seed produced even if that had been my intent.

The second site, the private prairie, was a little fuzzier. While I made sure to get permission prior to collection, once I arrived on site it became clear to me that someone had already harvested some seeds from the target species earlier in the year. A few stalks had legible cut marks on them, while others did not. So the question became: how much could I take sustainably? How much seed had there been before the previous collector came?

After doing some looking around I decided that the original collectors had not taken much, and had collected from a central location along a mown path. Most of the bare stalks outside that area had a few seeds still hanging off them, suggesting that they had been shattered and scattered by non-human means. The plants that still held their seed were lower and had not been so exposed to the wind. I fretted some, and I never did settle on an exact amount that it would be OK to collect, but I did the best I could. I am comforted that, someday, the descendants of this foundation seed will be used for prairie restoration and will support many pollinators and other wildlife.

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1. Castle, L. M., Leopold, S., Craft, R., & Kindscher, K. (2014). Ranking Tool Created for Medicinal Plants at Risk of Being Overharvested in the Wild. Ethnobiology Letters, 5, 77-88.

http://ojs.ethnobiology.org/index.php/ebl/article/view/169

2. http://www.smokymountainnews.com/outdoors/item/8894-galax-takes-a-beating-from-blackmarket-trade