Dan Tallman's Bird Blog

Great Blue Heron on Ice

2012-03-09T20:02:00.005-06:00

For the second time in the last few years, Great Blue Herons greeted me on the ice at Wells Lake in Rice County, Minnesota.This past Wednesday, 27 birds loafed on the ice. Why don't these birds get hypothermic? I have previously posted on counter current exchanges in birds. In the upper legs, many birds have networks of arteries and veins. The arteries bring warm blood from the bird's body. This warmth is captured by the cool veins flowing back from the bird's extremities. These heat exchanges can be very efficient, leaving relatively little heat to be lost to the ice.

The second heron photograph was not taken on the ice at Wells Lake. Rather, this Florida bird had more sense to take on an early Minnesota spring!

Osprey

2012-03-07T11:37:00.002-06:00

Ospreys are magnificent raptors. They dive feet first into the water, 99% of their prey consists of fish. As spectacular as their dives are, they only reach depths of about a meter. Thus they take only fish from the shallows or surface. Other prey items have been reported for Ospreys (birds, snakes, voles, squirrels, muskrats, salamanders, and even a small alligator (Pool et al. 2002)) and I once saw one carrying a small mouse over a forest clearing.

Ospreys breeding in Minnesota winter in Central and South American. Poole et al. (2002) calculate an osprey may "fly more than 200,000 kilometers in migration during its 15-to 20-year lifetime." From the 1950s to 1970s, Osprey populations crashed primarily due to pesticide poisoning. Their numbers have rebounded due to pesticide control and an aggressive program of providing Ospreys with artificial nest sites. In some areas, perhaps due to the cutting of old trees, almost all Ospreys use these sites.

I took these photographs a couple of winters ago in southwest Florida. These birds, as many across North America, are tolerant of humans and sometimes allow close approach.

White-fronted Goose

2012-03-05T09:54:00.000-06:00

In late February, eBird, in conjunction with the National Oceanic and Atmospheric Administration (NOAA) predicted an early beginning for waterfowl migration due to an unsually "early blast of warm air." Writes eBird, "Snow, Canada, Cackling, Greater White-fronted, and Ross’s Geese should all be on the move with this weather system. Watch for them to potentially move north to staging areas in Nebraska, and possibly to Quebec and points further east. There is also a possibility that some western geese (Cackling, Greater White-fronted, and Ross's) could be displaced eastward with the strong southwesterly flow."

Sure enough, on 25 February 2012, local birders found White-fronted Geese on Wells Lake near Fairibault in Rice County, Minnesota. It took Erika and me three trips to Wells Lake to finally locate the White-fronts. In the upper photo, taken on 3 March, one is clearly visible in the center left of the photo: note the orange-yellow bill and feet, white face patch, and speckled belly. If you look closely, however, you will note two more White-fronted Geese asleep behind the Canada Geese at the far right of the photo. Note the white line below their wings. Several years ago, as you can see below, John H. and I photographed a pair of White-fronted Geese at this same location.

Green Frog

2012-03-03T07:20:00.000-06:00

Last summer in the water feature, we thought we spawned a tiny and timid Loch Ness Monster. We slowly realized the monster is probably a Green Frog, Rana clamitans.

Green Frogs seemed super-abundant in Northfield last summer. Their abundance, no doubt, is related to their laying up to 4000 eggs per summer. The eggs hatch within a week, but the tadpoles overwinter and metamorphose into adults the next summer (MN Department of Natural Resources). I spied them in almost every roadside pond and even in other neighborhood water features. They often rested on the shore, leaping into the water to avoid predators.

Leopard Frog

2012-03-01T08:09:00.002-06:00

Northern Leopard Frogs are found across the northern United States and southern Canada (with the exception of the far west coast). They were abundant, but their populations since the 1970s have declined. The reasons for this decline are obscure, but might involve a combination of "pollution, deforestation, and increasing water acidity" (National Geographic Society). Nevertheless, Leopard Frogs were common last summer in the Carleton College Arboretum.

Why care about Leopard Frogs? Besides the stock answer that they occupy an essential niche of the ecological system, Leopard Frogs produce enzymes that are being studied as cancer drugs for humans. One enzyme, ranpirnase is in clinical trials for lung cancers and another, amphinase, may be effective in combating brain tumors (Wikipedia).

House Sparrow

2012-02-27T08:25:00.001-06:00

Looking through my bird photographs, I was surprised I lack the ubiquitous female House Sparrow. Last summer I set about to remedy this situation, but I failed to obtain a good photo. The closest I got was this male, molting into Basic Plumage.

The plumages of juvenal male and female House Sparrows are similar as they leave their nests. But soon thereafter they begin a post-juvenal molt. As time progresses, their bibs, due to feather wear, become more extensive. The bib on the bird in the photograph indicates this House Sparrow is a first-year male.

House Sparrow numbers have been declining in North America. The Breeding Bird Survey indicates declines of almost 3% a year in most regions. One reason for this trend may be that House Sparrows thrived when we humans depended on horses to get around. (They fed on grain, both before and after it passed through livestock.) But with the advent of automobiles, the sparrows shifted to more rural environments. Lowther and Cink (2006) explain that "changes in farming practices in the 1960s--towards larger farms and greater degree of monoculture crops--have probably contributed to a general decline in continental populations of House Sparrows...." (I have previously posted an account of the introduction and subsequent evolution of House Sparrows.)

Red-tailed Hawk

2012-02-25T08:50:00.000-06:00

On Saturday, 11 February 2012, Erika and I discovered two Red-tailed Hawks bouncing through our back woods. They chased each other this was and that, dropping to the ground and flying into the trees. What was this behavior--courtship? Aggression? We are not sure. Courtship usually involves aerial maneuvers. Territories are defended, even during the winter, but, as you can see, our birds perched in close proximity. Usually aggressive interactions, which are rare in winter, also include aerial fights and attacks with wings and talons open (Preston and Beane 2009).

Evening Grosbeak

2012-02-23T07:38:00.000-06:00

After seeing these handsome birds in Montana, I blogged about Evening Grosbeaks in my post of 29 June 2011. This species also breeds in northeastern Minnesota, but is not seen every year. Winter bird feeders are the best places to look for them. Elsewhere in its range, Evening Grosbeaks, tied to Box Elder seed and Spruce Budworm abundance, tend to show a two year cycle.

The top photo of a female was taken this February during our recent trip to Sax-Zim Bog. The lower one was taken several years ago, near the bog. The ice on the bottom male's crown indicates that the winter the photograph was taken was more typically cold (-38 degrees F) than the abnormally warm winter of 2012.

Varied Thrush

2012-02-21T07:33:00.003-06:00

The Varied Thrush is found along the west coast of North America from Alaska to southern California. Northern birds leap-frog over southern ones during migration, wintering further south than more southern breeders, which may be fairly sedentary. Every two to five years, populations irrupt, and Varied Thrushes occur in very low numbers across North America.

Erika and I drove over to a backyard in Hastings, Minnesota, on Sunday afternoon to see a Varied Thrush that has attracted a plethora of birders during the past few months. Remarkably tame, but difficult to photograph, the thrush roosted deep within the lower branches of a spruce. This location is somewhat consistent with the bird's breeding habitat--dark, wet northwest rainforests where it prefers old-growth and avoids fragmented tracts (Luke 2000).

Snowy Owl

2012-02-19T22:04:00.000-06:00

This winter witnessed one of the largest Snowy Owl invasions in recent memory. But seeing a Snowy took a whimsical road trip to Dodge County, Minnesota, on 17 February 2012 (thanks to a MOU listserv posting by Ken Vail), and eagle-eyed Erika to spot one. Snowy Owls prefer open country. Be wary of reports of Snowy Owls from forests--these owls may well be pale Canadian Great Horned Owls. I have seen Snowy Owls perch in small trees, but they prefer telephone poles or, like the one we found, on the ground in open fields.

The epicenter of this season's invasion seems to be the eastern Dakotas, but owls are also being reported from elsewhere in the Midwest (where they have reached Texas), the Pacific Northwest, and the northern Atlantic Coast (south to New Jersey and Pennsylvania). One Snowy Owl even made it to Hawaii! (Most of the data and the quote in this post are from an eBird article, interesting reading for anyone.)

When Erika and I lived in South Dakota, we could find a few Snowy Owls most winters. But larger invasions occurred more or less on seven-year cycles. Snowy Owl populations are dependent on Arctic lemmings. If a Snowy Owl does not see a lemming, the female does not even ovulate! Last summer was probably very productive for Snowy Owls in their Arctic breeding grounds. Lemming populations must have subsequently crashed, driving the owls south. The eBird folks speculate that, given the areas of winter concentration, "the source for these birds was presumably the central Arctic, or central-western Arctic. But without data from the breeding grounds, this connection is hard to make and even harder to prove." Few, if any, owls reaching the United States survive to return to their breeding grounds. Winter food sources are scarce here. Most owls are emaciated. The owls also suffer collisions with our abundant cars and power-lines. With fewer owls in the Arctic next season, lemming populations will rebound, and the cycle will renew.

Common Raven

2012-02-17T07:55:00.002-06:00

Ravens, the largest of all passerines, is a common bird of northern Minnesota. It is amazing, however, how big crows can appear when you are searching for your first raven! Ravens differ from crows in their larger size and wedge-shaped tails. As you can see in the first photo, ravens' central tail feathers are longer than the outer ones. The calls of ravens differ from those of crows--crows say "caw, caw," while ravens give a guttural "wonk, wonk."

The omnivorous Common Raven, found in North America, Europe, Asia, and North Africa, is one of the most widespread birds in the world. Now accidental in the prairies of the Great Plains, they were also abundant there in the days of American Bison and wolves. Now Ravens are found in wilderness areas, and are now reestablishing itself in eastern forests and urban areas of the eastern United States. The first photo was taken in the Sax-Zim Bog of northern Minnesota; the second from St. Jon in western Arizona.

According to Boarman and Heinrich (1999), ravens are part of Native American folklore. Many peoples "revere ravens as being the creator of earth, moon, sun, and stars, but also regard it a trickster and cheater. Poets and authors of Western cultures have often used the raven to symbolize death, danger, and wisdom."

Gray Jay

2012-02-15T08:42:00.003-06:00

Because Gray Jays are found across North America's northern forests, they were once known as Canada Jays. Their range, however, drops into northern New England, Wisconsin, Minnesota, the northern Rocky Mountains, and the Pacific Coast of the United States. Others name this jay Camp Robber, as the bird readily raids campsites for food scraps, even off picnic tables.

Gray Jays thrive in frigid northlands. They nest in late winter. Eggs are incubated at temperatures of -30 degrees C! They do not even attempt a second brood in the seemingly more benign weather in May. Instead they rely on hoarded cashes of food glued to the undersides of tree bark and lichens. The Gray Jay's salivary glands are enlarged, thus the bird has plenty of spit to use as glue!

In these years of climate warming, Gray Jay numbers are declining at the southern end of their range. Ornithologists speculate that this trend is caused by their food cashes thawing and rotting and, thus, not being available during their late winter breeding season (Strickland and Ouellet 2011).

Notice the white feather shafts on the Gray Jay's back in the bottom photograph. These streaks are present only in Gray Jays in British Columbia south to northern California. Until at least 1931, these birds were thought to be a separate species, the Oregon Jay. The photograph was taken at Crater Lake National Park in southern Oregon.

Pine Grosbeak

2012-02-13T09:10:00.001-06:00

This weekend two friends and I spent the weekend searching northern Minnesota's Sax-Zim Bog. This wild area, northwest of Duluth, is named for two small towns and is famous among birders as a good location Northern Hawk Owls and Great Gray Owls. A host of other infrequently seen birds inhabit the area.

We first found Pine Grosbeaks. A photograph of the male is above, a female below. These are large finches with small heads. They breed across the coniferous forests of northern Canada, south into the Rocky Mountains of the United States. They are annual winter visitors to northern Minnesota, but some years they are more common than others. Only during exceptional winters are they seen in southern Minnesota. Annual numbers fluctuate less dramatically than do many other winter finches. In fact, western populations apparently do not fluctuate or migrate (Adkisson 1999). Pine Grosbeaks feed on many tree buds and are often found at bird feeders.

Little Blue Heron

2012-02-10T08:09:00.000-06:00

The Little Blue Heron inhabits the southern United States and even wanders occasionally into southern Canada. This is a common, but often overlooked, heron. This species lacks the long plumes of other herons and egrets and, thus, populations were never decimated by the plume hunters of the 1800s.

Like the Reddish Egret, Little Blue Herons come in all-white and all-dark plumages. This dimorphism, however, is different. Little Blue Herons are unique among herons in that these plumages are correlated with the age of the bird. Young are white, older birds are dark. A white young bird molting into its dark adult plumage is sometimes called a Calico Heron.

The first photo was taken in the Corkscrew Swamp Sanctuary run by the Audubon Society. At any price, Corkscrew is a must-see location for birders visiting Florida--Audubon members are offered admission discounts. The young bird below was photographed in the Everglades National Park, another hotspot for birders.

BirdsEye Bird Log

2012-02-09T12:32:00.006-06:00

I discovered a wonderful Android App called BirdsEye Bird Log. The purpose of this app is to produce field checklists and submit them directly from your smart phone to eBird. The app appears to be both intuitive and easy to use.

The most awesome aspect of the app is the ability to enter your location. The Bird Log displays an eBird Google map showing public hotspots and previous personal locations. A tap of your finger, and your location is on your bird list. If you are at a new location, the map shows your exact location. One click enters the new location on to the list complete with location description. If the location description does not suit you, it is easily edited. You can even enter your location from a moving car, though I hope you are not driving at the same time!

Entering birds to the list is easy. As you start entering bird names, the app gives you a list of species choices. This process is even easier for folks who know bird banding alpha codes, as the app accepts these shortcuts. Numbers of individuals observed is also easy to enter. Click on the appropriate box and a numeric keypad appears.

Finally, entering appropriate eBird data is easy. Then click "submit" and your list is sent to eBird. If you need to edit the list, editing can later be done from your home computer.

The program can be found on the Android Market and costs $9.99. As far as apps go, this price is perhaps high. But proceeds support Cornell's eBird and further product development. I think it is worth every penny. Gone are the days of searching for pen and bird list. Also gone is wondering were the heck I am! Go to the market and just search for Birdseye. Be sure to read the product description. You can not use your android to search for birds on ebird. Not yet, but product development is heading in that direction.

Reddish Egret

2012-02-08T10:45:00.000-06:00

Reddish Egrets are found along our Gulf Coast states. Nearly brought to extinction by plume hunters in the 1800s, this egret is still relatively uncommon. Only about 2000 pairs inhabit the United States (Lowther and Paul 2002). Others are found in Mexico and the Caribbean.

As you can see in these photos, this egret is dimorphic--it comes in dark and white morphs. Most birds in our country are dark, like in the first photo, taken in Lovers Key State Park on the Florida Gulf coast. Only rarely are white morphs found in the United States, like the one below from Ding Darling National Wildlife Refuge on Sanibel Island, Florida. Curiously, in the Bahamas and Greater Antilles, white birds are more common than dark ones. A couple of other of our egrets and herons display dark and white morphs. The reasons for these difference are not understood. Presumably the colors confer advantages to each type of bird under different environmental conditions.

In any event, as they feed, Reddish Egrets flamboyantly dance with their wings held out. Probably this behavior startles the small fish upon which they feed. Other herons hold out their wings, casting shadows that are attractive to small fish--something similar may be happening here. Finally, casting shadows may help the egret find minnows by reducing the sun's glare off the water.

Hybrid American Black Ducks

2012-02-06T10:04:00.003-06:00

On Sunday, Gerry H. and I searched for Black Ducks along the Cannon River in Faribault, Minnesota. In the photo above, the bird in the background is a fairly typical female Mallard. The middle duck is likewise also a Mallard. The bird in front, however, has a dark bill with an olive tip,typical of the American Black Duck. On the other hand, its tail feathers are broadly edge white, as you would expect on a Mallard. I suspect this bird is a hybrid Mallard and Black Duck.

Ornithologists once predicted the demise of the American Black Duck due to hybridization, as Mallards expanded out of the Grteat Plains into the eastern range of the Black Duck. This expansion was the result of habitat change and game farm releases in the east. Recently, however, Black Duck populations have increased. The two species prefer breeding true. Nevertheless, about 13% of harvested ducks are hybrids. The situation is confounded in that the offspring of hybrids breeding with non-hybirds are often look identical to either Mallards or Black Ducks, depending on with which species the hybrid mates (Longcore et al. 2000).

As you can see in the bottom photograph, the facial pattern on these hybrids is also odd. I find nothing identical in any of my field guides. Note also the hen Wood Duck behind the hybrid. Wood Ducks do not usually winter in this part of Minnesota.

Orchids

2012-02-04T07:23:00.000-06:00

Residents and visitors to Saint Paul or Minneapolis, Minnesota, should not miss the Como Park Conservatory. This monster green house contains a myriad of tropical plants and occasional great exhibitions. Erika and I are fond of orchids. Although we can understand becoming passionately involved in orchid growing, we are not orchid growers. The photographs were taken during last weekend's St. Paul Winter Carnival's orchid show. I was not able to gather identifications of these flowers and welcome any input from my readers.

Eurasian Collared-Dove

2012-02-02T09:03:00.002-06:00

Eurasian Collared-Doves are an invasive species sweeping across North America. Individual birds tend to exhibit long-distance dispersal. In North America, however, the situation is confused by multiple local releases.

Originally this species was found only in India and Myanmar. In the 1600s, they expanded, either naturally or with human assistance, to Turkey. The range expanded again through Asia, in the 1800s, and Europe in the 1900s. In the mid-1970s, 50 Eurasian Collared-Doves escaped and were purposefully released from a Bahamian bird dealer. To save doves from a volcanic eruption in 1976, others were released from the island of Guadeloupe in the West Indies. Soon afterwards, collared-doves appeared in south Florida. By the late 1980s, they were established in the southeast United States. Both by natural dispersal and with the help of many releases (both on purpose and accidental) by private dove breeders, collared-doves have spread across the continent.

Whatever the actual origin of North American populations, little or nothing can stop them now. You should look for them near human habitation. In the midwest, they often inhabit areas near grain storage areas. In more urban areas, they are attracted to bird feeders. Collared-Doves can even survive Canadian winters. Disease may cull some dense populations, but "it seems highly likely that the Eurasian Collared-Dove will become a widespread, permanent member of the North American avifauna" (Romagosa 2002).

The first photograph is this post is from Key West, Florida, in 2011. The second, taken several years ago, is part of a flock of 80 birds near a grain elevator and cattle feedlot in Fort Pierre, South Dakota.

Banded American Goldfinch

2012-01-31T09:15:00.002-06:00

According to McGraw and Middleton (2009), goldfinches' "winter and breeding ranges overlap, with populations generally shifting southward in winter." They continue, "Early winter distribution apparently correlated with temperature..." During this warm winter, the recapture on 30 January 2012 of a goldfinch we banded on 21 November 2011 perhaps confirms the second statement.

I have had two long-range goldfinch recoveries. In Aberdeen, South Dakota, I retrapped a goldfinch that had been banded in Colorado. A Goldfinch we banded in Dundas was recovered in west-central Saskatchewan, an interesting record because it was recovered the summer after it's April banding.

I do not know if some of our wintering goldfinches are the same individuals that breed here. Definitely some are here during more than one winter. Looking at this American Goldfinch, caught on 27 January 2012, you know that the sex is male--the wing is jet black--and that the age is over two calendar years--note the bright yellow wing patch. We know more data than these--I banded this individual on 1 January 2009! We banded and retrapped this goldfinch at our Dundas banding site.

Willet Mystery

2012-01-29T09:24:00.001-06:00

Today I have a Willet mystery for you. Willets have two isolated populations. Western Willets breed from the Canadian prairies south through the Dakotas and west to northern California. Eastern Willets breed along the northeastern coast of North America. According to Sibley, you can identify these races in the field. Eastern Willets have broader, stouter bills. Western birds have broader wing stripes. Western birds are paler overall and have whitish central breasts; eastern birds are more uniformly gray.

Looking at my photographs, I conclude that the upper Willet is western, while the lower one is eastern. There is no problem with the upper bird--note the narrow bill and broad wing stripe--clearly a Western Willet. Western Willets winter on both coasts of North America, and this one was photographed on Sanibel Island, Florida. Eastern Willets winter south of the United States. My second photo, however, is from La Jolla, California. This bird, despite the broader bill and narrower wing stripe, should NOT be an Eastern Willet. Either this bird is well out of range or is an example of the dangers of field identification of avian subspecies. (The bird behind the mystery Willet is a Whimbrel.)

Brant

2012-01-27T09:50:00.000-06:00

Brants are fascinating. These small geese breed across the world's Arctic areas. Two races are found in North America, the Light-bellied Brant and the Black Brant. The first photograph (taken at Cape Hatteras, North Carolina) is of the Light-bellied form, which winters along the Atlantic Coast. The second photograph (taken at Morro Bay, California) is of a Black Brant, which winters along the Pacific Coast of California. Where the two races meet in the Arctic, they freely interbreed.

The situation is even more complicated. Brant wintering in Puget Sound look to be intermediate geese, but mainly breed on Melville and St Patrick's islands, and thus may actually be a third North American race (or species) of Brant. These "High-Arctic" Brants differ from known hybrids in genetics, range, and plumage. The story thickens. The first Black Brants were collected in New Jersey, well away from the Pacific winter range. These first specimens may represent a now extinct race of Brant, the Lawrence's Brant, which probably became extinct in the 1930s. Want more? Light-bellied Brant that now winter in New Jersey often have white neck collars that completely circle their necks. They are also genetically distinct from other Brants wintering in New York and Virginia. Are these birds yet another race of Brant? This information comes from Reed et al. (1998).

Common vs. Hoary Redpoll

2012-01-25T08:16:00.002-06:00

Seventeen Hoary Redpolls were among the 5167 Common Redpolls I banded in Aberdeen, South Dakota (1979-2004; see previous post). Redpoll taxonomy is complex and poorly understood (Knox and Lowther 2000a, 2000b). Not only are Common Redpolls extremely variable, many, if not most, show overlapping characteristics with Hoary Redpolls. One reason for this variability is that six species of redpolls could exist, since the various populations of redpolls may not interbreed.

The photographs above are of extreme birds from northern Minnesota. The first photograph is of a Common Redpoll. Note its somewhat elongated, siskin-like bill, streaky flanks, and dark back. The second bird is a Hoary Redpoll. Note its overall frosty upperparts, relatively short, triangular bill, very lightly streaked flanks, and almost unstreaked undertail feathers.

Many other individual redpolls are not so easily separated into Common or Hoary redpolls. Erika, who has seen me band many intermediate birds, raises her eye-brow whenever I identify a Hoary Redpoll. This similarity apparently is not due to interbreeding, which, contrary to published reports, may be quite rare between the two species. Common Redpolls begin breeding before Hoary Redpolls. They also leave their breeding grounds earlier. The two species sometimes nest in different habitats and differ in call, physiology, behavior, and perhaps in diet (Knox and Lowther 2000a).

Common Redpoll

2012-01-23T15:44:00.007-06:00

Common Redpolls appeared at our Dundas banding site on the first of January, but did show themselves to me until this cold, icy, snowy Monday. Redpolls are irruptive, winter finches. They breed in the high arctic, both above and below the treeline.

Although Knox and Lowther (2000) write that redpolls invade every other year, I found their presence not to be predictable in northeastern South Dakota. The most I ever banded in one year was 2179 in 1994. During my 26 years of Dakota banding (1979-2004) there were five years when I did not band a single redpoll. I did, however, band at least one redpoll in 21 of those years. I banded over 1000 individuals only in three years (1982, 1992, and 1994). The average number of redpolls banded per year was 198, but the standard deviation was 379!

In Northfield, I've banded Common Redpolls only in 2009. According to Knox and Lowther, the irruption cycles are caused by spruce and birch seed crop failures, which force the redpolls to winter further south during the lean-seed years. The redpoll in the photograph above is from Aberdeen, South Dakota. Bright red birds can be identified as second-year males. Females and first-year males can not be told apart by plumage.

Crossed-bill Chickadee Lives

2012-01-21T09:08:00.000-06:00

We banded this deformed Black-capped Chickadee on 14 November 2011, and the bird still lives. These photographs were taken yesterday, 20 January 2012. I apologize for the quality of the photos--they were taken through tinted windows on a dark, snowy morning. The bird visited feeders at the banding site near Dundas, Minnesota. I include the second photo to show both the bird's band and also what appears to be bill-cleaning behavior, as the chickadee wipes its bill along its perch. Being able to recognize individual birds and determining their survival is one of the many uses for banding birds.