BIRDS OF MAY 2017

Each spring, millions--more likely billions--of birds depart the New World tropics to begin a perilous northbound migration to their breeding grounds in North America. Most fly by night, probably plotting their paths via an inherited map synchronized with the stars. Some may have an internal compass that follows Earth's gravitational fields, while other species use clues such as infrasonic sound or visible landmarks. That they make it at all is one of the great wonders of nature, and we are enthralled come May at Hilton Pond Center to capture and place bands on these migrants as they continue northward.

As a Carolina Piedmont locale, the Center lies halfway between two flyways--Atlantic Coastal and Appalachian--one likely reason we don't see really big numbers that occur along those routes. Even so, the diversity of bird species we handle is always interesting, and this year in May we had 122 individuals of 28 species. Most were migrants--some of which will stay the summer--but several were year-round Hilton Pond residents that put on new plumage for the breeding season ahead. To celebrate the "Birds of May 2017," our installment below is mostly avian images with brief comments about local abundance and breeding status reflecting our 36 years of on-site banding research.

All text, maps, charts & photos © Hilton Pond Center

RUBY-THROATED HUMMINGBIRD (RTHU)
(adult male above; female and young males lack red throat)

STATUS AT HILTON POND: Migrant & summer resident; likely breeds on-site, with one nest found on adjoining property.
LOCAL ABUNDANCE: Common spring through summer and abundant in August-September; 5,696 captured since 1984, our fourth-most-commonly banded species.
NOTES: About 11% of our banded RTHU have returned in at least one later year; one female showed up eight years in a row.

All text, maps, charts & photos © Hilton Pond Center

ROSE-BREASTED GROSBEAK (RBGR)
(Adult male, above, has jet black head, bib, and back with prominent white wing spots, plus rosy breast and under-wing coverts)

STATUS AT HILTON POND: Migrant; no confirmed breeding records from South Carolina.
LOCAL ABUNDANCE: Uncommon but regular in spring & fall. migration, especially at our black sunflower seed feeders in spring; 54 banded for both sexes since 1982.
NOTES: This species' sharp, metallic chink call is usually our first clue RBGR have arrived in spring from their Neotropical wintering grounds.

All text, maps, charts & photos © Hilton Pond Center

All text, maps, charts & photos © Hilton Pond Center

ROSE-BREASTED GROSBEAK (RBGR)
(mostly brown female, just above, and immature male are
similar in appearance)

NOTES: Female and immature male RBGR both resemble a giant brown sparrow but with prominent white superciliary line (see photo above); under-wing coverts (photo below) are yellow in female, rosy in immature males; young males may have pale, rosy breasts.

All text, maps, charts & photos © Hilton Pond Center

All text, maps, charts & photos © Hilton Pond Center

GRAY CATBIRD (GRCA)
(sexes similar)

STATUS AT HILTON POND: Migrant, with some staying to breed and others undoubtedly going further north; a few may spend the winter in the area; breeds on-site with nests found.
LOCAL ABUNDANCE: Very common & regular, especially in spring (62% of bandings); 940 banded since 1982.
NOTES: During our mid-winter Operation RubyThroat hummingbird expeditions to Crooked Tree in Belize, GRCA were among the most commonly banded Neotropical migrants.

All text, maps, charts & photos © Hilton Pond Center

GREAT CRESTED FLYCATCHER (GCFL)
(sexes similar)

STATUS AT HILTON POND: Migrant & summer resident; breeds on-site with one nest found.
LOCAL ABUNDANCE: Uncommon but regular; 53 banded since 1982.
NOTES: Alerted by a snake skin hanging from the entrance hole, we found a GCFL pair nesting in one of our Wood Duck boxes; both male and female acquire a prominent brood patch and share incubation duties; (Susan Hilton's favorite species and first bird she ever identified.)

All text, maps, charts & photos © Hilton Pond Center

BLUE-GRAY GNATCATCHER (BGGN)
(female above; sexes similar but male has black superciliary line)

STATUS AT HILTON POND: Migrant & summer resident; breeds on-site with several nests found.
LOCAL ABUNDANCE: Relatively common & regular; 136 banded since 1982.
NOTES: One of our first spring migrants to arrive; pairs collaborate on nest building, incubation, and nestling care; nest adorned with lichens resembles a tall Ruby-throated Hummingbird nest.

All text, maps, charts & photos © Hilton Pond Center

WHITE-EYED VIREO (WEVI)
(sexes similar)

STATUS AT HILTON POND: Migrant & summer resident; likely breeds on-site; females with fresh brood patches have been captured but no nests found.
LOCAL ABUNDANCE: Common & regular; 324 banded since 1982.
NOTES: Although vireos are yellow and warbler-sized, they are in an entirely different family (Vireonidae). Note the hooked bill in the photo above, characteristic of vireos; compare that to the straight bill of the several warblers just below.

All text, maps, charts & photos © Hilton Pond Center

COMMON YELLOWTHROAT (COYE)
(male has black mask edged in gray; paler female lacks
these marks but is otherwise similar)

STATUS AT HILTON POND: Migrant & questionable summer resident, although the species breeds across South Carolina; most captures--the vast majority being males--have been in May as probable migrants; no nests found and no females captured with fresh brood patches; this is an enigmatic species at Hilton Pond.
LOCAL ABUNDANCE: Uncommon and regular, although far more common when the Center was in the shrub stage of vegetational succession; 366 banded since 1982 (70% in spring).
NOTES: The Warbler Family (Parulidae) includes COYE and 37 other "eastern" species, 35 of which have been seen at Hilton Pond Center since 1982. All but a few are migrants that pass through, heading for breeding grounds in Canada, New England, the Great Lakes States, or the higher elevations of the Blue Ridge and Appalachian Mountains; our "missing" warblers are Cerulean, Mourning, and the endangered Kirtland's--all of which take migration routes to our west.

All text, maps, charts & photos © Hilton Pond Center

BLACKPOLL WARBLER (BLWA)
(adult male has prominent black cap; adult female similar but paler
and with gray cap; immatures are olive and yellow green without distinctive marks; note bright orange legs of adults)

STATUS AT HILTON POND: Migrant, mostly in spring (see below).
LOCAL ABUNDANCE: Uncommon but regular; 127 banded since 1982.
NOTES: We're not surprised only 7% of our blackpolls have been banded in fall because this species follows a circular migration pattern; in spring it flies overland across eastern North America going north; in autumn a very different southbound route takes it out over the Atlantic Ocean en route to South America.

All text, maps, charts & photos © Hilton Pond Center

AMERICAN REDSTART (AMRE)
(adult males & females have similar patterns, but female is
olive green where male, above, is jet black; male has orange
markings, females have yellow)

STATUS AT HILTON POND: Migrant; no local breeding evidence, although there are a few state records less than 50 miles to our east.
LOCAL ABUNDANCE: Very common & regular; 459 of both sexes captured since 1982--our second-most-commonly banded parulid (after Yellow-rumped Warbler with 2,239).
NOTES: In spring we've watched AMRE flash their bright wing and tail patches; this may have a courtship function but also apparently startles insects into flight where redstarts can capture them.

All text, maps, charts & photos © Hilton Pond Center

AMERICAN REDSTART (AMRE)
(second-year males resemble females--see preceding note--
but have varying amounts of black, as shown in
the photo just above)

NOTES: First-year male AMRE are sometimes difficult to differentiate from females; usually, however, the males have flanks with more of a salmon tint, while females are yellow.

All text, maps, charts & photos © Hilton Pond Center

NORTHERN PARULA (NOPA)
(sexes similar, but female--as above--
lacks an irregular rusty necklace)

STATUS AT HILTON POND: Migrant & summer resident; likely breeds on-site; no nests found, but females with fresh brood patches and recent fledglings have been captured in June.
LOCAL ABUNDANCE: Very uncommon but regular; 68 banded since 1982.
NOTES: One of our smallest warblers; moves rapidly through tree leaves in pursuit of insects and other invertebrates; winters primarily in Mexico and Caribbean.

All text, maps, charts & photos © Hilton Pond Center

BLACK-THROATED BLUE WARBLER (BTBW)
(sexes very different; adult male, above, has blue back,
black throat and face, and prominent white wing patch;
female is grayish green with more or less obscure wing patch)

STATUS AT HILTON POND: Migrant; only a few breeding records from mountains in extreme northwestern South Carolina.
LOCAL ABUNDANCE: Relatively common & regular; 189 banded since 1982.
NOTES: Male and female BTBW are so different in appearance early ornithologists thought they were two separate species; overwinters in relatively small area of eastern Costa Rica, Panama, and the Caribbean.

All text, maps, charts & photos © Hilton Pond Center

BLACK-AND-WHITE WARBLER (BAWW)
(sexes similar; male has a blacker cheek patch)

STATUS AT HILTON POND: Migrant & summer resident; likely breeds on-site; no nest found but females with fresh brood patches have been captured.
LOCAL ABUNDANCE: Uncommon but regular; 178 banded since 1982.
NOTES: This species' long claws allow it to cling to tree trunks and undersides of limbs as it probes bark crevices for insects, spiders, and other invertebrates.

All text, maps, charts & photos © Hilton Pond Center

SUMMER TANAGER (SUTA)
(adult males all red, adult females & immature males all yellow; second-year males, above, are a calico mix of red and yellow)

STATUS AT HILTON POND: Migrant & summer resident; likely breeds on-site; no nests found but females with fresh brood patches have been captured.
LOCAL ABUNDANCE: Uncommon but regular; 190 banded since 1982.
NOTES: Adult male is sometimes mistaken for male Northern Cardinal but lacks black mask and crest; SUTA catches bees and wasps on the wing, crushing them with its heavy yellow-brown bill.

All text, maps, charts & photos © Hilton Pond Center

BROWN-HEADED COWBIRD (BHCO)
(male, above left, with brown head and shiny black body;
female, above right, is mousy brown)

STATUS AT HILTON POND: Migrant, with 99% captured during spring; some may remain during winter in mixed blackbird flocks; likely breeds on-site, with gravid females and recent fledglings captured.
LOCAL ABUNDANCE: Common and regular; 442 of both sexes banded since 1982.
NOTES: As brood parasites, BHCO undoubtedly take a toll on many breeding bird species at the Center.

All text, maps, charts & photos © Hilton Pond Center

SWAINSON'S THRUSH (SWTH)
(sexes similar)

STATUS AT HILTON POND: Migrant, especially in fall.
LOCAL ABUNDANCE: Very common & regular; 530 banded since 1982--90% in fall migration.
NOTES: The most common of our "spot-breasted thrushes"; usually captured in the lowest shelves of our mist nets as they fly low through the woods; this low-flying behavior also makes them one of the most commonly killed migratory birds due to first-floor window strikes on private homes.

All text, maps, charts & photos © Hilton Pond Center

WOOD THRUSH (WOTH)
(sexes similar)

STATUS AT HILTON POND: Migrant & summer resident; likely breeds on site; no nests found but females with fresh brood patches and recent fledglings have been captured.
LOCAL ABUNDANCE: Uncommon but formerly regular; in decline over past 10-15 years for unknown specific reasons; 193 banded since 1982.
NOTES: Of the "spot-breasted thrushes," this is the only species that truly has round "spots" in the adult; the others have streaks; precipitous decline in numbers has been attributed to cowbird nest parasitization and loss of invertebrate prey due to acid rain.

All text, maps, charts & photos © Hilton Pond Center

INDIGO BUNTING (INBU)
(adult males bright blue, females and young males brown; older
females, as above, may have flecks of blue; second-year males
may be a mix of blue and brown)

STATUS AT HILTON POND: Migrant & summer resident; likely breeds on-site; no nests found but females with fresh brood patches have been captured.
LOCAL ABUNDANCE: Relatively common & regular in spring migration, especially at our black sunflower seed feeders; 359 banded since 1982--76% in spring.
NOTES: The bi-colored bill of both male and female INBU in breeding condition is an excellent field mark.

All text, maps, charts & photos © Hilton Pond Center

EASTERN BLUEBIRD (EABL)
(sexes similar, but with blue and orange in males--as above--usually much brighter; immatures resemble females but have spotted breasts)

STATUS AT HILTON POND: Year-round resident; breeds on-site, with nest boxes (and old woodpecker holes) used on many occasions.
LOCAL ABUNDANCE: Common & regular; 302 banded since 1982, including many chicks in our local nest boxes.
NOTES: Recently fledged EABL often hang out with their parents through the first winter, joining with neighbors in flocks of 10-20; to our knowledge, none of our local bluebirds migrate, and we doubt we host any migrants from further north; established pairs maintain year-round pair bonds and can be seen inspecting nest boxes all winter.

All text, maps, charts & photos © Hilton Pond Center

NORTHERN CARDINAL (NOCA)
(sexes similar)

STATUS AT HILTON POND: Year-round resident; breeds on-site with many nests found.
LOCAL ABUNDANCE: Abundant & regular; 2,644 banded since 1982--our sixth-most-commonly banded species.
NOTES: NOCA have declined in local abundance since the 1990s, primarily because of successional loss of shrubs (where they foraged and found shelter) and densely vegetated Eastern Red Cedar trees (where they frequently nested); some decline may also be due to West Nile Virus.

All text, maps, charts & photos © Hilton Pond Center

EASTERN TOWHEE (EATO)
(adult females, photo above, mostly brown dorsally; adult males,
as in photo below, mostly black dorsally)

STATUS AT HILTON POND: Year-round resident; apparently breeds on-site; no nest found but females with fresh brood patches and recent fledglings have been captured.
LOCAL ABUNDANCE: Formerly common & regular at the Center, now very uncommon, possibly because of West Nile Virus and loss of local shrub habitat through vegetational succession; 722 of both sexes banded since 1982.
NOTES: As ground nesters, EATO chicks often fall prey to feral cats.

All text, maps, charts & photos © Hilton Pond Center

EASTERN TOWHEE (EATO)
(adult males, as in photo just above, mostly back dorsally)

NOTES: Eastern Towhees, formerly Rufous-sided Towhees, were renamed when ornithologists learned they did not breed with western populations now known as Spotted Towhees; young EATO have brownish-gray eyes that usually turn red in adults (as in photo just above).

All text, maps, charts & photos © Hilton Pond Center

HOUSE FINCH (HOFI)
(adult males mostly red, as above; females & immature males brown; young males acquire red plumage by first winter)

STATUS AT HILTON POND: In early 1980s HOFI were migrants only, now most are year-round resident breeders with no known long-distant migrants in nearly 20 years; most bandings in past decade have been recent fledglings; breeds on-site with nests found.
LOCAL ABUNDANCE: Very abundant & regular; 10,153 banded since 1982--our second-most-commonly banded species (edged out by American Goldfinches with 10,865).
NOTES: This species from the western U.S. was introduced to Long Island NY in the early 1940s; eastern HOFI extended their range about 25 miles per year both south and west and now meet the species' western population in western Nebraska.

All text, maps, charts & photos © Hilton Pond Center

DOWNY WOODPECKER (DOWO)
(sexes similar, but male has red on nape; immature males,
as above, have red crowns)

STATUS AT HILTON POND: Year-round resident; breeds on-site with nests found.
LOCAL ABUNDANCE: Common & regular; 221 banded since 1982.
NOTES: We had at least four pairs of banded Downy Woodpeckers captured in Spring 2017 at Hilton Pond Center--a surprisingly large number for an 11-acre island of mostly undeveloped habitat with a limited number of mature hardwood trees suitable for woodpecker cavities.

All text, maps, charts & photos © Hilton Pond Center

PINE WARBLER (PIWA)
(sexes similar, with males usually having much more yellow on breast; immatures, as above, resemble very drab females)

STATUS AT HILTON POND: Year-round resident; apparently breeds ons-site; recent fledglings and females with fresh brood patches have been captured.
LOCAL ABUNDANCE: Relatively common & regular; 174 banded since 1982.
NOTES: Any small yellowish bird coming to our sunflower seed feeders is typically either an American Goldfinch or a Pine Warbler; although PIWA are also insect- and berry-eaters, the recent fledgling in the photo above was captured in a seed-baited trap.

All text, maps, charts & photos © Hilton Pond Center

RUBY-THROATED HUMMINGBIRD (RTHU)
(female, above, see male photo at top of page; females & immature males do not have full red throats, but both may have light to dark greenish throat streaking; young males may have one or more
red gorget feathers)

NOTES: Adult male RTHU have returned to Hilton Pond as early as 27 March (four different years), with first adult females arriving a week or two later (early record is 8 April); not until mid- to late May do our nectar-rich Trumpet Creeper vines begin to bloom and deposit yellow-green pollen on the heads of hummers that visit (see photo above); in 2017 through 31 May we banded 23 new RTHU at the Center, already supplemented by a whopping 31 returns banded in previous years; ten of those were recaptured on 29 May, with nine more the day following.

May is always a good month for banding birds at Hilton Pond Center, especially if one appreciates the diversity that comes with having a mix of resident birds AND Neotropical migrants. Those individuals depicted above represent a mere smidgen of countless birds arriving, staying, or passing through the Carolina Piedmont this spring. Our mist netting efforts were limited somewhat because of out-of-state travel and heavy rains on several days, else we likely would have caught even more to decorate this page. If the weather is good in September it will be interesting to compare our fall banding results with what we've just accomplished in May 2017.

All text, maps, charts & photos © Hilton Pond Center

Don't forget to scroll down for Nature Notes & Photos,
plus lists of all birds banded or recaptured during the period.

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1432 DeVinney Road
York SC 29745

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