Falco sparverius

The American Kestrel, Falco sparverius,  can be seen in Albemarle County year round.  They prefer open habitats covered by short ground vegetation, such as along Plank Road and the fields of Bundoran.  It is the smallest and most widespread North American falcon.  The specific name sparverius was given to it by Linnaeus because of its mistaken connection with the European sparrowhawk which is in a different genus, Accipiter.   The facial pattern is distinctive, with one vertical black stripe across the malar region and another across the auricular area.   The male has blue gray wings and a rufous tail with a single broad black band.  The female is slightly larger and has rufous wings barred with black and has multiple bands on the tail.  In flight it has a characteristic falcon silhouestte with long pointed wings and deep wing-beats.

The kestrel migrates from its northern most breeding grounds in Canada and the northern US to spend the winter in many of the “lower 48” and Central America. In the southern US some individuals are resident year round and some move about in the winter.

Even though kestrels prefer open habitats they need perches and nest trees.  They may be seen on braches of large trees or power lines when looking for prey.   Occasionally they “hover-hunt”.   Insects and small rodents, especially grasshoppers, beetles, mice and voles, are predominant in their diets but small birds and reptiles are eaten.  Both sexes will cache uneaten remains and surplus kills in tree limbs fence posts, grass clumps etc for later use.

Kestrels breed and nest in April and May in our area.  The male locates potential nest cavities, then escorts the female to them.  The female apparently selects the site.   They are “obligatory” secondary cavity nesters, using woodpecker excavated holes and natural cavities.   Nest boxes are sometimes used, usually when well concealed by vegetation.  They prefer cavities surrounded by large open areas with perching areas nearby or along the edges of forests.  The female lays 4 to 5 eggs and both parents (predominantly the female) incubate the eggs using incubation patches.  After about 28 days the eggs hatch; the altricial young are almost naked.  All of the brooding is done by the female; after 8-10 days the young are developed enough to maintain their body temperature during the day and the female stays on the nest only at night.

Density of kestrels in an area varies greatly, as does nesting density.  Nesting boxes can increase the density particularly if cavities for nesting are limited.  Nesting or roosting boxes can be important for overwintering birds as well.  Twentieth century farming practices of large areas of monoculture without hedgerows or edge habitat have reduced Kestrels’ habitat.  Nesting boxes have been associated with a reversal of kestrel decline in many areas.

Kestrels have been successfully raised in captivity more than any other native North American “hawk”.   Hand-reared kestrel commonly exhibit play behavior and single-sex colonies do not show overt physical aggression.Kestrel’s have 3 main types of vocalizations; the klee call, consisting of 3-6 notes,  is most often heard from stressed or excited birds.  The whine callis made by both sexes during courtship as well as in response to human disturbance.  The chitter call is used by both sexes when interacting with the opposite sex or with other kestrels.

Kestrel vocalizations can be heard:

http://www.allaboutbirds.org/guide/American_Kestrel/sounds

An excellent site to read more about kestrels and nesting boxes is:

http://www.wildlifehc.org/new/wp-content/uploads/2010/10/American-Kestrel.pdf

Molothrus ater

Brown-headed cowbirds are common in Bundoran and widespread throughout “the  lower forty eight” except for southern Florida.  Originally they were limited to short-grass plains where they followed herd of buffalo feeding on the insects stirred up by the buffalo.  Since they moved about with the buffalo and did not stay in one place long enough to nest and raise young they developed “brood parasitism”, laying their eggs in other birds’ nests.  As Europeans settled the country and opened up forests the cowbirds have greatly expanded their range and the birds whose nests they utilize.

In a heavy snow late this winter cowbirds began visiting one of my bird feeders for the first time.   They have continued to come back occasionally to eat the sunflower seeds.   Even though the cowbirds liked insects stirred up by the herds they used to follow, it turns out they eat more seeds than insects in recent populations studied.  Females also will eat eggs removed from parasitized nests.

Brown-headed cowbirds are found in our area year-round.  They do exhibit short distance migration between breeding and wintering habitats.  In winter they are usually in mixed species blackbird flocks.   They prefer scattered trees among grassland vegetation and are often found in pastures.

Because cowbirds are “generalists” when selecting nests to lay their eggs in they are quite successful in their parasitism: they can always find some nests to lay their eggs in.  Cowbird populations seem to have stabilized after expanding out of the Great Plains.  Host birds have developed some strategies that help keep the cowbird population from continuing to expand.   American Robins, Blue Jays, Brown Thrashers,  Gray Catbirds and Northern Orioles eject the cowbird eggs from their nests.  The yellow warbler will build a new nest on top of the parasitized nest, burying her own eggs as well as the cowbird eggs.   Some birds will abandon a parasitized nest.  Blue Jays will eat fledgling cowbirds.

Female cowbirds lay many more eggs in a season than do birds who raise their young.  Since the female does not need to expend energy raising young she will lay about one day a day during the breeding season.  One research study concluded that females lay about 40 eggs per season.  Overall survival of cowbird eggs from laying until leaving the nest is only 13% because of the strategies mentioned above.   But if the host bird treats the cowbird egg as one of her own the survival is 36%.

Cowbirds are a threat to the survival of a few species: Kirtland’s warbler, Blac-capped Vireo and Least Bell’s Vireo.   They are no significant threat to birds that nest in “deep” woods since they are found in grasslands and fragmented forested areas.

The cowbird is quite vocal, with a liquid song and many squeaks.  The link below has numerous recordings under the “Sound” tab.

http://www.allaboutbirds.org/guide/Brown-headed_Cowbird/id

Submitted by Dorothy Tompkins

Turdus migratorius

April 2013

We have been seeing many American Robins flocking in Bundoran this winter and early spring.  The American Robin, Turdus migratorius, is the largest and most abundant North American thrush.  Migratorius means wandering as well as truly migratory and in the mid-Atlantic states robins are more wandering than actually migratory.  Large wintering roosts are often established in Virginia but these flocks shift their concentrations with weather changes and to find food.  Birds who nest in Canada or more northern states do migrate to the southern states and Mexico for the winter.

The robin is easy to recognize by its coloration, stance and song..  The male has a blackish head and both male and female have rich rufous underparts with white throat streaks.  The juvenile is distinguished by black spotting on its underparts.  The robin usually runs along the ground then stands “proudly” to look about.  It feeds on terrestrial invertebrates and fruit.   Hence our late heavy snow made it difficult for a few days for the robins to find some of their usual food.  When seeking earthworms robins demonstrate the “Head-Cock” and “Bill-Pounce” behavior that is so characteristic of them.  Robins also feed on native berries including juniper (red cedar), and chokecherry.   They can become intoxicated from the berries of non-native honeysuckle.  Robins lack the enzyme sucrose in their digestive systems and avoid fruits with that sugar.  They will regurgitate fruit seeds, especially if the seeds are relatively large: birds have many adaptations to reduce the amount of weight they carry when flying!

The song of the male robin at dawn or dusk is a complex array of familiar syllables that have a liquid quality.  There is a less familiar “whisper song” often heard at the end of the characteristic song.  Whisper syllables have a greater range of frequencies and higher frequencies.  Both males and females produce a variety of calls and notes.  A loud alarm call in response to predators is distinctive.  Males sing more frequently before mating but continue during nesting season.

The female constructs the nest; working from the inside, she constructs the outer wall with dead grass and twigs, occasionally adding other material, then adding mud from worm castings, and finally lining the nest with fine pieces of dead grass.  Completion of the nest can be delayed by dry weather and the lack of mud.

Beginning in April eggs are laid one day at a time for 3 to 4 days, then the female incubates the eggs for 12-14 days.  Eggs vary in color from “Nile” blue to a deep grayish blue.  Hatchlings are altricial, completely dependent on the parents for food and temperature regulation.  They are so immature that the skin is translucent and the greenish gall bladder as well and the purplish-red liver can be seen through the skin.  The egg tooth may be retained until fledging.  Eyes open on day 5, and fledging occurs at 9-16 days after hatching.  Both parents feed the young.

Robins are important prey items for Coopers’s and Sharp-shinned  hawks and domestic cats.  Snakes, ravens, blue jays and house cats eat the eggs and young of robins.  Robins recognize and reject the eggs of cowbirds by puncturing and removing the eggs.

Like all birds robins engage in frequent preening: keeping their feathers in good condition is a must for efficient flight as well as warmth.

Ring-necked ducks nest predominantly in Canada with an extension of nesting area into Montana, North Dakota and Wisconsin.   They winter in the southern and western states, with an extension along the eastern seaboard.   We are near the western edge of their winter habitat in Virginia.  They feed on plants in very moist soil, and aquatic plants and their seeds as well as aquatic invertebrates.  They feed mostly by diving, but sometimes “tip” or dabble at or just below the water surface.  They may ingest food during a dive, or bring it up to clean or separate out edible parts.

Since ring-necked ducks are diving ducks their legs are more posterior than birds that walk on land and they are quite awkward on land.  Their feet and strong legs propel them underwater.

The ring-necked duck has a distinctive white wedge extending upward in the area in front of the folded wing, a white area at the base of the bill and a white band near the tip of the bill.  The male has a black head, neck breast and upper parts with whitish to grayish belly and flanks.  It is distinguished by a peaked angular head profile.   The female is grayish brown and darkest on top of the head and has a white eye ring.

Ring-necked ducks’ populations have appeared to be fairly stable in the past few decades.  Life span has been documented from tagging to be about 20 years.

Ring-necked ducks sounds can be heard at the following link:

http://www.allaboutbirds.org/guide/Ring-necked_Duck/sounds

This fall, Bundoran Farm and Local Food Hub were proud to launch the first ever Innovation in Agriculture Award.  The award’s concept originated from Bundoran Farm’s commitment and belief in the conservation and sustainability of the rich agricultural heritage of Central Virginia.  

This $1,500 award recognized a small-scale family farmer who has demonstrated creativity and innovation in order to grow or expand their farm business.  Selected by a 5-person committee, we were delighted to present Bundoran Farm’s first Innovation in Agriculture Award to Mike Clark founder of Planet Earth Diversified.

Parkesia motacilla

The lovely, resonant song  of the Louisiana Waterthrush with its descending notes is one of the delightful indications that spring is really here.  The Waterthrush returns from wintering in Central America and the West Indies to look for nesting sites along relatively unpolluted headwater streams.   The male returns before the female and until he finds a mate he sings vigorously all day.  Once a mate is acquired his singing is predominantly in the morning.   The female also sings, though a shorter version of the song, as well as gives the same calls as the male.

The Louisiana Waterthrush is noted for constantly wagging its tail in a teetering motion as it forages.  Both the generic and specific name mean “tail-wagger”.

Louisiana Waterthrush populations and successful reproduction are decreased by the lack of benthic macroinvertebrates found in healthy streams and by the impact of acid rain on streams.  Thus this species is an indicator of a healthy ecosystem.

Preferred nesting sites are along fast flowing small steams, frequently at the headwaters of the streams.  Hence western Albemarle County is a good area to find them.  In upland forests the nest is usually placed in a cavity along a stream bank.  The male and female both walk along looking for the site.  The male will enter a potential site, turn around several times and drag nearby leaves into the cavity.   If the female does not enter, he follows her further up the stream to explore other sites.   Once she enters a site that is acceptable they both gather leaves from the immediate area to build the nest.   Once the nest is finished there is often a delay until the female begins laying one egg a day until 5 eggs are laid.  The eggs are approximately one third the mass of the female.  Incubation by the female begins the day before the last egg is laid and all of the eggs hatch the same day, after 10-14 days of incubation.  They leave the nest at 10 days of age.

The young are given the same food as the adults eat.  The predominate food consists of adult and immature stages of aquatic invertebrates.  They may forage along the forest floor, trails, and even in gardens and in trees if there is a shortage of food near their nest.

The brown-headed cowbird will frequently lay eggs in the Louisiana Waterthrush nest.  The adults will chase the cowbirds but if the cowbird is successful in laying in the nest the waterthrush may bury the alien egg under the floor of the nest, or peck, puncture and discard the cowbird eggs.   Since the eggs are similar in size and the cowbird will remove a host egg for each parasitic egg laid, sometimes the waterthrush will raise both species.  In some areas  studied cowbird parasitism led to a 50% reduction in fledglings of waterthrushes.

To  see a picture of and hear the song of the Louisiana Waterthrush go to:

http://www.allaboutbirds.org/guide/Louisiana_Waterthrush/id

and click on “Sound”

Submitted by Dorothy Tompkins

The female does most of the incubation of the eggs with the male sitting on the nest for 3-4 hours per day until the last week when his presence on the nest declines.  The incubation period is estimated to be 4-5 weeks.

The hatchlings are altricial (immature and helpless) and unable to raise their heads initially.  They weigh about 58 grams.  By the second day they begin to utter peeping calls and by day 10 make high whistling notes in response to the adults being overhead..  By 30 days of age they begin stretching their wings and exercising, and leave the nest by day 46.  The female broods the young; the male brings the food.

The Red-tailed Hawk is found from central Alaska south to Venezuela and east to the Virgin Islands, thus is found in all states but Hawaii.  The species varies considerably, with up to 16 subspecies, but all adults have a uniformly reddish tail with a narrow dark band across the end of the tail.  We usually have two or more pairs at Bundoran and get to observe their magnificent flight year round as well as the spectacular aerial maneuvers during courtship.  Because of the density in our area, the territories are defended year round.  Because the Red-tail inhabits open areas interspersed with patches of trees, it enjoys the habitat established in our country and their population expanded during the 20^th century.

The Red-tail often hunts from a perch enabling us to easily see it.  Its diet includes small mammals, birds, reptiles, amphibians, arthropods and fresh carrion.  Because of the latter it may perch by roadsides looking for road-kill.  It is probably important in keeping the population of small rodents in check.   I have seen a Red-tail catch a full grown squirrel, however it could not fly away with it.  One did fly away with my pet bantam chicken many years ago.

Red-tails are magnificent soaring birds: they spend about 75% of their flight soaring and 25% flapping.  Their flapping is generally slow, ponderous compared to crows.  Typical of hawks females are larger than males; the male is 45-56 cm and female 50-65 cm long.

If the nest is still visible after the trees leaf out we can hope to see the young as they become active in mid to late May.

A link to the red-tailed hawk on allaboutbirds (Cornell) follows.  Click on “Sound” to hear the hawk.

http://www.allaboutbirds.org/guide/Red-tailed_Hawk/id/ac

Submitted by Dorothy Tompkins, 3-16-12

Food Network named Crozet’s Pizza as one of the top 50 best pizzas in the county.  According to the NBC 29 segment, “The pizza that won editors’ hearts is a combination of shiitake and portobello mushrooms over a base of garlic, herbs and olive oil.”

Congratulations to Crozet Pizza on this well deserved honor.

What are your favorite places to get pizza in the Charlottesville/Albemarle County area?