Killdeer (Charadrius vociferous)
The very common Killdeer is uncommon in so many of its characteristics. Killdeer are plovers, a particularly smart-looking group of sandpipers. Killdeer, however, are an inland species that loves no place more than a large, flat-roofed building surrounded by fields. Most high schools have them breeding in spring, along with suburban corporate centers. Like our downtown bird the Common Nighthawk, Killdeer nest on rooftops, though they will just as readily lay their camouflaged eggs in the middle of a farm road or any gravely, open area.
The pictures above, taken by Hope Foote, Jason Hogle, and Jeff Lampe, show two of the defenses used by ground nesting Killdeer. The first is the famous broken-wing display, used to distract predators and lure them away from the nest. In one study, this ruse was observed to lure predators away in 1012 of 1017 cases! The amazing “Ungulate Display” is a threat display thought to have evolved to convince grazing animals to avoid stepping on killdeer eggs and young, though killdeer chicks can run fast within minutes of being born. The Killdeer’s name comes from its familiar and persistent call, which you can hear as the “flight call” at this link. Listen for Killdeer and then try to get a good look at our most striking sandpiper of upland habitats. You can also watch the broken-wing display here and see some cute Killdeer chicks running about here.
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American Kestrel (Falco sparverius)
The male of our smallest falcon is as colorful as many tropical birds, and just as exciting to watch. One was hanging around on Rt. 101 in Keene for a good while late this winter. Kestrels are not as common in New Hampshire as they are in other parts of the country, where they are abundant and thriving. NH is one of five states with significant decline of Kestrels, possibly due to the reforestation of the state over past decades. Kestrels love open fields, where they sometimes hover in place while hunting for mice and even grasshoppers. It has been shown, however, that putting up nest boxes can increase Kestrel populations. You can watch a Kestrel hovering on this video, then learn more about them at The Cornell Lab of Ornithology.
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Pileated Woodpecker (Dryocopus pileatus)
This magnificent species is active in our woods throughout the year, excavating insects in the trunks and branches of trees. While they seem a bit reminiscent of the extinct pterodactyl, Pileated Woodpeckers are the northern equivalent of tropical ant-eaters; some populations show a 98% ant diet. While ant-eaters use sharp claws and a sticky tongue to get colonies of social insects, Pileateds have different, yet perfect tools: a huge chisel-bill to excavate trees to the heartwood where the Carpenter Ants nest, and a long, barbed tongue to spear and extract the nutrient-rich larvae, pupae and adults.
To find a crow-sized Pileated Woodpecker, you can stake-out a tree they are excavating; a sure sign are the long, rectangular holes and the pile of fresh wood chips on the ground below as you can see in our slide show above. The laugh-like call of the Pileated is similar to a Northern Flicker, but it is louder, harsher, and has a lower note at the end. Listen to their calls and learn more at All About Birds.
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Turkey Vulture (Cathartes aura)
No, we didn’t catch a Turkey Vulture in the nets – we just decided to branch out to some non-banded birds for a while. It seemed timely to note that the year’s first Turkey Vulture (in our corner of the world) was seen on February 15. Compared to past years, that’s early! Maybe spring should be predicted by vultures, rather than a rodent who can’t really tell what is going on outside the burrow anyway…
Turkey Vultures do some cool things besides cleaning up carcasses. They find their “prey” using both sight and smell. Note how you can see right through the vulture’s nose in Byard’s photo. Ethyl mercaptan, produced by carcasses and the substance that utilities use to make natural gas stinky, has been shown to attract Turkey Vultures. They have even helped locate gas leaks by hanging out where gas is escaping, hoping in vain for a meal. To make themselves even more wonderfully disgusting, vultures cool themselves by covering their legs with their own excrement, and defend themselves by regurgitating rotten meat they have consumed.
Click on this video to see the characteristic “rocking V” that tells you a soaring bird is a Turkey Vulture, and that spring is almost here. You can watch one preen up close on this video, and hear their strange guttural croaks at All About Birds.
So while we certainly look forward to spring’s colorful tropical migrants, let’s hear it for the early bird, Turkey Vulture, who is quite beautiful from below, soaring gracefully and effortlessly on rising thermals.
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Winter Warbler Series
During the summer and fall bird banding seasons, we net many more species than we are able to present as a Bird of the Week. With cold, snowy weather calling a halt to banding activities at present, we’d like to take this opportunity to add a splash of color to these winter days by sharing some of the warblers encountered in our banding endeavors. While these birds overwinter in warmer climes, we in New Hampshire can appreciate the diversity of plumages, habitats and behaviors exhibited by this remarkable group of birds while we wait for their return. Enjoy!
Black-and-white Warbler (Mniotilta varia)
For a final bird in the Warbler of the Week series, I thought to leave you with one that is near and dear – the very bird that is found on the AVEO logo. Black-and-white Warblers are one of the first warblers to return in the spring, so look for them in late April. This early arrival stems, in part, from their habit of searching for insects in the bark of tree trunks and stout branches in a manner similar to that of nuthatches or creepers. This means that they don’t have to wait for leaves to emerge for reliable foraging, unlike many other warblers that are foliage gleaners (although Black-and-whites occasionally do this too).
Black-throated Green Warbler (Dendroica virens)
Come May, Black-throated Green Warblers are a familiar voice in New Hampshire’s forests. This species sings two distinct song types, including the “trees, trees, murmuring trees” and “zay zay zay zoo zee” mnemonics that birders often use to help remember the song of a particular species. The song type varies depending on time of season, time of day, and the message that the male is communicating. Birds sing for many reasons, such as defending a territory and attracting a mate. Visit the Cornell Lab of Ornithology website to read more about bird vocalizations.
Nashville Warbler (Vermivora ruficapilla)
During the breeding season, Nashville Warblers are generally associated with second-growth habitat created by either natural or man-made disturbance. The habitat available to this warbler is limited in New Hampshire, where the landscape has become increasingly forested since the era of farm abandonment. According to the Breeding Bird Survey (BBS), this species has declined by 2.2% annually since 1966 in NH. Population trends of this species are linked to human land use; timber management, in particular, provides the edges and regenerating shrub layer that they prefer for nesting.
Blackpoll Warbler (Dendroica striata)
Blackpolls are renowned for their impressive migration. According to the Birds of North America and the NH Breeding Bird Atlas, this species has the most extensive migration of any warbler, traveling from 2,500 to 5,000 miles annually between breeding grounds in northern forests and overwintering areas in South America. Even more remarkable, a significant portion of this flight is over open water of the Atlantic.
Each fall, blackpolls forage voraciously to maximize energy reserves necessary for this flight. At the banding station, we can see this in the amount of fat that accumulates in the furcular hollow, wingpits, and abdomen. The lone blackpoll that ended up in our nets in 2009 had a fat score of 5, indicating that a thick layer of fat had accumulated in these areas in preparation for migration.
Northern Parula (Parula americana)
With January just drawing to a close and so many fascinating warblers waiting for the spotlight, I drew inspiration from today’s fair spring-like weather. The Northern Parula’s plumage reminded me of sunshine, blue sky and puffy white clouds. Unlike several other featured warblers that are boreal breeders, parulas inhabit much of the eastern U.S. where they nest in hanging moss or lichen. In New Hampshire, they are more common in the northern reaches of the state, and prefer coniferous riparian forest during the breeding season.
This spring, take a moment to observe the resource partitioning that warblers demonstrate. As Robert MacArthur demonstrated in his classic study, each species occupies a unique foraging niche – a particular height or part of the tree where they look for food, or a specialized foraging technique. Generally, parulas glean insects from the outermost edges of branches in the mid- to upper canopy. This behavior is particularly conspicuous in the presence of other warblers; if other species are not around, parulas are less selective.
Magnolia Warbler (Dendroica magnolia)
Sharp black and yellow plumage, white wing bars, black streaking on underparts, a bright eyebrow stripe and partial to complete eye ring – could a birder hope for a better combination of field marks? Although these characteristics are toned down on the plumage we see during fall migration, Magnolia Warblers are still easily identified by their distinct flair for wearing bold colors and patterns.
Maggies are as strong as they are beautiful; most individuals of this species cross the Gulf of Mexico – a nonstop flight over open water – during both spring and fall migration. Their association with young coniferous forest in the breeding season and flexibility in habitat selection during the winter has apparently contributed to stable or increasing populations, contrasting with many other Neotropical migrants that are currently experiencing declines.
Wilson’s Warbler (Wilsonia pusilla)
Wilson’s Warblers are a striking species with their splashy yellow plumage and distinguished black cap. Nesting primarily in riparian thickets throughout Canada and the western U.S., they spend only a brief time in New Hampshire while heading to or from wintering grounds in Central America and the Gulf coast.
If you look closely at the photo of the male warbler, you’ll notice that the bill is askew. Although we don’t see many bill deformities at the banding station, they are slightly more common than one may think. An article in North American Bird Bander identifies possible causes including genetics, injury, disease, and/or environmental factors.
Black-throated Blue Warbler (Dendroica caerulescens)
With a name that aptly describes the male’s breeding plumage, Black-throated Blue Warblers are certainly a handsome species. Their blue hues are created by the scattering of light as it hits the structure of the feather. Although less brightly colored, females have the same characteristic white patch on the wing as males do. This marking can be helpful in determining age; generally larger patches are found on older birds. On male Black-throated Blues, the edges of the alula coverts, small feathers at bend of the wing, are green on a young bird and blue on an older bird.
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Click here for Bird of the Week 2009.
Click here for Bird of the Week 2008.
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