HOME: www.hiltonpond.org

GENERAL INFO

CONTENTS

RESEARCH

EDUCATION

PUBLICATIONS

MISCELLANY

HUMMINGBIRD MORNINGS
In 2004, informative and entertaining hummingbird banding presentations are scheduled for Aug-Sep in North Carolina, Ohio, Virginia & Kentucky/Tennessee.
Next Up: Canton, Ohio on 4 September
(Click on the logo at left for details.)
If your group would like to host Hummingbird Mornings anywhere in the U.S. or Canada in 2004 or later, contact
Bill Hilton Jr.

A WARBLER IN THE 'HOOD

There are about 30 places along our 2.5 meandering miles of trails at Hilton Pond Center where the path straightens for a short distance. Each of these stretches--approximately 45 feet long--serves as a "net lane" where we can string a mist net between two vertical poles. In spring and fall, we deploy a full complement of nets at dawn and spend literally all day monitoring them, removing and banding birds at regular intervals, and then closing the nets at dusk. From mid-July through August, however, we typically open only a half-dozen nets close to the Center's old farmhouse, mostly because on hot summer days over the past 22 years we've seldom netted more than a couple of birds and ofttimes none. Besides, August is our prime banding time for Ruby-throated Hummingbirds, so we prefer to spend time watching our pull-string traps and unfurling small-mesh mist nets near the feeders in the hope of catching hummers. Indeed, most of what we net in August ARE hummingbirds--not counting slow-learner Carolina Chickadees and Tufted Titmice fledglings that bumble into the nets over and over and over again--but we do occasionally capture other birds of particular interest. Such was the case this week at Hilton Pond when we netted a brilliantly colored Hooded Warbler just outside our office window.

All text & photos © Hilton Pond Center

The Hooded Warbler was an elusive bird for us. We had been birding actively for more than ten years without ever seeing the species until one hit our nets at the Center in the fall of 1985. We didn't add that particular individual to our birding "life list"--our personal rules require that we see the bird in the wild before counting it--and the same went for another Hooded Warbler we netted in 1987. Finally, just before we temporarily moved away from Hilton Pond in mid-summer 1988 to help design and start the South Carolina Governor's School for Science and Mathematics, we went to scout Kalmia Gardens in Hartsville SC as a possible field trip locale for incoming biology students.

Kalmia Gardens takes its name from Kalmia latifolia, the Mountain Laurel, which--to the surprise of many who associate it only with higher elevations--grows in abundance at this delightful preserve in the middle of the Coastal Plain. Shortly after entering the Gardens on that June day in 1988 we heard a distinctive but unfamiliar song resounding through the trees, something like ta-weet-ta-weet-eo slurred slightly at the end. The bird sang loudly and repeatedly, flitting around in the hardwood canopy above slow-moving, tannin-stained Black Creek. After about 15 minutes of fruitless searching for the source of the song, we finally spotted movement on an exposed branch 60 feet directly overhead, focused in with binoculars, and watched in wonderment as a bright yellow vocalist tilted back its head and sang again and again. At last we had a Hooded Warbler for our list, thanks to Coker College's foresight in protecting and maintaining Kalmia Gardens--a little piece of wilderness not far from the Hartsville campus they now share with the Governor's School for Science & Math.

Hooded Warblers are well-named. The adult male (top two photos) has a black bib connected to black sideburns that meet a black crown and nape--which together give the impression of a hood. The bird also has a blackish loral spot--the area between the large, dark eye and base of the rather heavy bill. The forehead and face are bright yellow, as are the breast and undertail coverts; even if seen from below there's no question about what species you're observing. The back, rump, wing coverts, and primary feather edges are olive, sometimes with more of a yellow cast. Females (left) vaguely resemble males except they often lack any black on their heads, usually sporting an olive cap but no bib or sideburns. (An occasional female has a hood nearly as well-developed as the male's, making it difficult to prove that males actually take on no incubation or brooding chores.) Juveniles look very much like females but with even lighter caps. Hooded Warblers never have wingbars, and all ages and sexes bear some of the largest white tail spots found in any wood warbler--spots they show off by spreading their tails laterally every second or two (below).

Hooded Warblers breed across the eastern U.S. and extreme southern Canada, generally east of a line between the southern tip of Lake Michigan and Corpus Christi, Texas. They occur primarily in deciduous woodlands laced with streams or standing water and with relatively dense shrub layer and understory. The neatly constructed nest sits just a few feet off the ground in a shrub or herbaceous plant. Despite their wooded locales, Hooded Warblers are one of those species whose nests are frequently parasitized by Brown-headed Cowbirds. Although we've never heard Hooded Warblers sing here at Hilton Pond Center, we suspect they breed nearby because we've caught recently fledged offspring in early summer. Nonetheless, they probably nest more commonly toward the Carolina coast and mountains than here in the central Piedmont. Most depart by late summer and fly only as far as Mexico and Central America, where they maintain winter feeding territories.

The Hooded Warbler's scientific name is Wilsonia citrina, for early naturalist Alexander Wilson and the lemony color of the bird's breast. Wilson accurately depicted the Hooded Warbler on Plate 26 of his trend-setting American Ornithology, first published in 1808-1814. The plate includes the now-extinct Carolina Parakeet (top right), the Hooded Warbler, and the Hooded's two congeners: Canada Warbler, Wilsonia canadensis (with black necklace) and Wilson's Warbler, W. pusilla (with black cap).

Returning to a more modern art form, we refer you to the photograph of the adult male Hooded Warbler at the top of this Web page. He appears to have a Fu Manchu moustache, but he's really just sporting a nice set of rictal bristles. These stiff, hairlike feathers protrude from the base of the upper (and sometimes lower) mandible (also see below) and allude to the Hooded Warbler's dietary preferences. Wild fruits and berries are sometimes eaten by warblers--epecially those like Pine and Yellow-rumped Warblers that overwinter north of the tropics--but the vast majority of warm-weather warbler food is insects or their larvae. After all, what could be more nutritious for an adult warbler--or its nestlings--than a big, fat, juicy caterpillar gleaned from a leaf? One problem with caterpillars, however, is that they tend to flop around when a warbler grabs them with its bill, and the caterpillars have six legs--plus all those extra pairs of prolegs--with which they grab at the warbler; that's when it's useful to have rictal bristles that prevent the caterpillar from scratching the bird's eyes. After getting a good grip with its bill, a bird usually slams caterpillars against a tree limb or the ground, beating the grubs into submission before trying to swallow them.

Including that first Hooded Warbler in 1985, we've now caught 41 at Hilton Pond Center--15 in spring and 26 after the end of June; our best totals were 1994 (seven individuals) and 1995 (nine). Most years, however, we see only one or two of these Neotropical migrants that get snared in a hummingbird net and brighten up the 'hood with their black and yellow plumage.

All text & photos © Hilton Pond Center

NOTE: After we posted the above account, we got an e-mail from Tegan George, one of Ms. Owens' sixth grade science students at Ligon GT Magnet Middle School in Raleigh NC. Tegan asks: "How big are Hooded Warblers?" In Tegan's honor, we provide the measurements below, based on birds we have banded. (Notice, Tegan, that they are all in metric, which is the system used by scientists and by most other countries of the world.)

Length (bill tip to tail tip in live bird): about 115mm in adult males, females somewhat smaller

Male Wing Chord: 63-72mm
Female Wing Chord: 58-67mm

Male Tail: 55-59mm
Female Tail: 52-56mm

Weight: 10-12g

Longevity for a banded bird (according to Bird Banding Laboratory records): 7 years, 11 months

Comments or questions about this week's installment?
Please send an E-mail message to INFO.