Bird of the Week
Barred Owl (Strix varia)
August 29, 2008
This sad looking fellow was standing dazed by the side of I-91 in Dummerston, VT, one of thousands of Barred Owls seen by motorists along roads last winter. During the winter of 2007-2008, our region experienced an irregular irruption of Barred Owls, coming both from northern areas, where vole populations crashed, and from our own woods, where deep snow made it hard to find food. Many Barred Owls were killed as they desperately searched for food on exposed roadways. Vermont Institute of Natural Science received 35 Barred Owls over the season! Fortunately for “Luna” — named by Deb Gode of Winchester Wildlife Rehabilitation Center after the owl’s savior, Lindsay Moon — life continues at the Adirondack Wildlife Refuge. Although he is blind in one eye and cannot therefore return to the wild, he travels to schools and other venues all over the Northeast to teach people about our wonderful owls.
Below Luna appears in much better shape with his keeper, Wendy Hall. Wendy and Luna made an appearance at Keene State College last night (Thursday, August 28) before we showed the film “Winged Migration.” Thanks to all of you who came out to support AVEO!
Click here to listen to the familiar call of the Barred Owl at Cornell Labratory of Ornithology’s All About Birds site.
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Brown-headed Cowbird (Molothrus ater)
August 20, 2008
photo: Byard Miller
Ooooh, this bird has a very bad reputation! Female Cowbirds don’t build nests, but instead lay their eggs in the nests of other birds. This practice, called “brood parasitism,” is common in the tropics, but not in North America, where Brown-headed Cowbirds are the only ones who do it. Their original ecological niche explains this behavior: in pre-colonial times, they followed bison to eat insects that had been kicked up by many hooves and that swarmed around warm-blooded masses. The source of their food was nomadic, so leaving the young for somebody else to care for was not only expedient, but necessary. Pictures of harried warblers trying to keep up with the insatiable hunger of a toad-like baby cowbird while their own young whither and die make birders dislike this species.
Cowbirds are suspected of contributing to the decline of forest-nesting birds in areas where the forest is fragmented into small patches with a high edge-to-interior ratio; cowbirds stay in the open. Before European settlers converted Eastern forests into pastures, cowbirds were not present to harry Eastern birds. We catch and hear very few of them in the “edgy” forests where we open nets, however, so it is not clear that cowbirds are having a strong negative effect on Keene’s birds. This year’s bumper crop of babies cheers us.
Learn more about cowbirds and listen to their weird song here.
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White-breasted Nuthatch (Sitta carolinensis)
August 4, 2008
Every bird species has a different “personality” in the hand, which may or may not reflect how they behave in the field. We are very fond of all of them, but some, like the Nuthatch, are stand outs. Nuthatches cutely beep their way around forests and feeders; when held, their wings strike a pose reminiscent of the ballet, as seen here:
Our area has more White-breasted than Red-breasted Nuthatches, as the latter prefer more uniformly coniferous forest. You can listen to White-breasted Nuthatch here, and Red-breasted Nuthatch here. After a few “beeps,” the distinction between their calls becomes clear. We don’t catch very many Nuthatches at the banding station, so this was quite a treat. Birds are such unique little packets of intricate design, all movement and purpose!
Bonus Bird!
When we offered a choice between Robin and Catbird a few weeks back, Bird of the Week fan Russ Cobb replied, “Ovenbird is always Bird of the Week.” Photographer Byard Miller certainly makes a compelling argument with this stunning Ovenbird portrait from this morning’s banding:
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Canada Warbler (Wilsonia canadensis)
July 25, 2008
People who study birds are all too aware of how quickly summer passes. This Canada Warbler tells us that the fall migration has begun! Canada Warblers are the last to arrive and the first to leave; this is our first “special migrant,” or a bird that does not nest in the banding area. The Canada Warbler’s schedule underscores the idea that tropical migrants really are “their” birds (not “ours”), who leave their preferred southern habitat to avoid the nest predation that is so rampant in tropical forests.
Canada Warblers have been declining steadily over the past three decades. Little is known about their breeding, other than they seem to prefer undisturbed forest, far from the edge, especially near wet, shrubby spots. The idea that they are an indicator of “forest interior” is described in this interesting piece from Ontario Extension. Learn more about Canada Warbler and listen to his song here.
Now the moment you’ve been waiting for….the results of last week’s Bird Ballot!
Catbird Wins!
Uh, how did Catbird win?
Baby Catbirds do improve, as this adult shows.
Catbird (13 votes)
I’m going to vote for the plucky catbird even though the robin seems to have more good sense, because my catbirds always leave a few blackberries for me to eat.
– Dan Carr, Ashuelot
I’m going with the much maligned Catbird.
– Steve Lindsey, Keene
It’s gotta be the catbird. We have one nesting in our backyard. He sings beautifully on and off all day and is surprisingly tame.
– Wayne Miller, Swanzey
Gee, I don’t know if “wee catbirds are simply lovely” . . . they can be, but have you experienced disheveled fledglings with baby gape and total pinfeathers? Whatever the plumage, they have an attitude that would humble an opera diva. Robins just want to be fed. I vote for catbirds.
– Mary Wright, Gilsum
Robin (8 votes)
Gotta say I’m voting for the robin out of dismay at what happened to “my” [predated?] robin’s egg—even though I love Catbirds & relish hearing their song in our yard.
– Dori Allmann, Hinsdale
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Robin or Catbird? (Turdus Migratorius or Dumetella carolinensis)
July 18, 2008
This week there was dissension at the banding lab over which bird has the most wonderful babies: American Robin or Gray Catbird? We’ll let you decide! After careful consideration of the fair-and-balanced material below, send Brett your vote at brett@aveo.org. Voting ends Wednesday, 7/23 at midnight.
American Robin
Robins are in the Thrush Family, Turdidea, which includes our beautiful singers the Wood Thrush and the Veery. Robins subsist on worms and squishy bugs in summer, and desiccated berries in winter. While they certainly serve as a harbinger of spring when they congregate on our lawns after a March thaw, they actually spend the winter skulking in the swamps and wet forests of our area. Learn more here.
photo: Byard Miller
Gray Catbird
The Gray Catbird is in the Mimic family, Mimidae, which includes sleek, talented species such as Mockingbirds and Thrashers. Catbirds do imitate other birds, and are named for the mewing sound that tells us “Summer is here at last!” Catbirds rid the woods of an overabundance of caterpillars to feed their avid chicks, shifting south to find fruit and insects through the winter. Listen to the Catbird’s quirky song, and discover other fascinating details here.
photo: Cynthia Nichols
We know its pretty tough to choose between the Robin and the Catbird, but here is one last aid in solving your conundrum:
So, Bird of the Week is in your hands, folks. Send a message to brett@aveo.org and let your voice be heard!
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Common Grackle (Quiscalus quiscula)
July 4, 2008
Prince or scoundrel? Sleek fashonista or trash bird? It all depends on your angle. Common Grackles are estimated to number around 73 million in the US, which makes them “super-abundant.” Their population has declined, however, by 61% from 190 million 40 years ago. Is this decline caused by changes to their habitat? Pesticides? Grackle “control” programs?! They do like agricultural land, and were less common in the east before the forests were cleared. Cornell Laboratory’s page on the Common Grackle lists them as abundant and widespread, but National Audubon’s Common Species In-Decline List places them fourteenth among the top 20 species that are in trouble. The decline of Grackles mirrors a number of other common bird species in the northeast, as described in an Audubon report thoughtfully summarized in this New York Times article.
Regardless of whether you like ‘em or not, Common Grackles have several features that make them interesting. Their diet varies from scavenging grain and berries to predating mice, frogs, and even other birds at feeders. Their stare is unnerving. They bite really, really hard in the hand. And then, they fly like living smoke when they are flocking in winter, as so wonderfully captured in this video:
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Black-and-white Warbler (Mniotilta varia)
June 27, 2008
Dad
Junior
The babies are here! Listen in your yard for birds that sound like they are endlessly whining and complaining. Those are hungry babies asking for food, and their cries cause their parents to search fervently for caterpillars to feed the nestlings. The above Black-and-white Warblers are probably parent & young. We think we often find families together as hapless young get tangled in the nets and parents charge to the rescue. You can listen to Dad’s squeaky-gate song here.
Black-and-white Warblers are common in our forests. They feed on bugs gleaned from tree trunks and large branches, a bit like Nuthatches and Brown Creepers.
A chief goal of the national “MAPS” banding program we participate in is to record data on bird productivity across various habitats and over time, trying to answer the basic question: Are some songbirds declining due to problems in northern breeding areas or in their migration and wintering areas to the south? We can compare productivity (the rate at which adult birds produce young) to survivorship (the survival of birds from over time) because a great many birds return to the same breeding territory year after year.
This “widdle bay-bee” was fairly disconsolate after being “almost eaten” by strange two-leggeds who probed and prodded her.
She sat for a while to redefine her self-concept before rejoining her family.
All of these lovely Black-and-white Warbler photos were taken by bander Polly Pattison.
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Red-eyed Vireo (Vireo olivaceus)
June 20, 2008
The Red-eyed Vireo is possibly the most abundant bird in the deciduous forests of North America, even though they fly here from tropical forests every spring. This extraordinary portrait shows how vireos are different from warblers: the hooked end of vireos’ stout upper mandibles allows them to handle bigger, juicier bugs (such as fat caterpillars) than warblers, who also glean arthropods from tree branches. This evolutionary adapatation on the part of vireos and warblers is known as niche-partitioning; the different species divide the “niche” of insect-gleaning into a wider array of prey sizes to avoid competition with one another for food.
How do we know we have so many Red-eyed Vireos? Just listen to the song at this link, the ubiquitous sound of summer in northeastern forests. These guys sing well beyond the typical “morning chorus” in order to maintain their territories without fisticuffs. Red-eyed Vireos are birds of the forest canopy, so they are underrepresented at the banding stations, but they do venture low enough to get caught in our nets every once in a while, when we are treated to their striking good looks (though this one will spend a while getting his feathers back in order).
Other Vireos have interesting iris color, such as the White-eyed Vireo. Cool!
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Ovenbird (Seiurus aurocapillus)
June 13, 2008
photo: Byard Miller
Docile and easy to handle, Ovenbirds are neotropical migrant breeders, so-named because of the nests they build. We band them regularly at Ashuelot River Park. Last Sunday, my friend Jon Udell and I walked up to Beech Hill in East Keene to see an Ovenbird nest he found with naturalist Al Stoops. Here is my short video of a nest I have wanted to see for many years:
You can see how one could easily miss it!
Our Ovenbird shares a common name with a South American species (Funarius rufus) who, as you can see in this video, deserves the name just as much. Seiurus aurocapillus (our Ovenbird) is in the warbler family, Parulidae, whereas the South American bird is in the treerunner family, Funariidae. To make things even more interesting, our Ovenbird looks more like a thrush than a colorful warbler. This may be a case of convergent evolution, as Ovenbirds are secretive forest floor skulkers like thrushes, rather than flashy canopy-dwellers like some other warblers.
Ovenbirds are one of the most prominent and common daytime singers in our forests. Check out their familiar “Teacher!, Teacher!, Teacher!” song here.
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Rose-breasted Grosbeak (Pheucticus ludovicianus)
June 6, 2008
We caught two pairs of Rose-breasted Grosbeaks (RBGR) at the KSC Wildlife Management area this week. Wow! This a great example of a bird that looks like it belongs in a tropical rainforest, but in fact nests right here in Keene. Although these birds do spend most of the year in the tropics, they nest further north, where their young have a better chance of survival.
Grosbeak is a common name used on 14 genera and 31 species of hefty, finchy birds with very large beaks that are placed in the cardinal and finch families, with one outlier in the weaver family. They are found in the Americas and Asia, from the Arctic to the tropics.
Holding birds in the hand can allow us to gain precise data about them. We know that this female grosbeak is in her second summer of life because many birds replace their “primary covert feathers” (just above the flight feathers) in a predictable pattern, and she has a mix of new coverts (with beige spots intact) and old ones (with the softer beige spots worn away). This pattern only appears on birds that were born last year. This bird will replace her whole set of primary feathers this fall; birds with consistent coverts are therefore aged as “after second-year.”
She also shows that banding birds like Grosbeaks and Cardinals is not for the faint of heart or tender of finger. This hurts. We don’t take it personally and feel it is only fair, as being caught in a mist net is rather inconvenient for them.
Click the video above to see skilled bander Polly Pattison gracefully handle a biting male RBGR.
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Gray-cheeked Thrush (Catharus minimus)
May 30, 2008
During the first week of banding, we sometimes find a few special migrants. This Gray-cheeked Thrush, a special critter that I haven’t seen since high school (!), was headed for the boreal spruce-fir forests of Canada when it wandered into one of our mist nets at Ashuelot River Park in Keene.
In 1995, the Bicknell’s Thrush (then a sub-species) was recognized as a separate species, though it is very hard to tell them apart in the field. To accurately distinguish this Gray-cheeked Thrush from a Bicknell’s Thrush, we had to take measurements of three sets of feathers and look at subtle coloration on the bird’s “soft parts” (bill, legs, toes). For example, one measurement that can distinguish between the two species is the distance between the ends of the 8th and 6th primary, or flight, feathers. Yikes! People with far too much time on their hands (mainly bird genius Peter Pile) have made so many measurements of bird feathers that we can use the tiniest bits of feathers to separate species, tell males from females, or discern their age.
Gray-cheeked Thrushes are seldom-seen, secretive birds with the characteristically beautiful song of all of the species in the genus Catharus, including Veery, Hermit Thrush and Swainson’s Thrush.
Learn more and listen to the song of the Gray-cheeked Thrush here.
