Maine Birds – Page 16 – A resource for Maine birds and birding

A Birding Trip to the Dominican Republic

April 21, 2018 By Herb Wilson in Taxonomy, Trip Report, Uncategorized

Oceanic islands are fascinating to anyone with an interest in biology. Thrust up from the deep ocean floor, oceanic islands are blank canvases. Colonization of plants and animals from continental areas occurs by rafting or by being carried on the wind. Some of these colonists establish a stronghold on the new island, enriching the diversity. Over time, these colonists often diverge from their mainland relatives, producing new species. Thus, endemic species are born, found nowhere else.

Oceanic islands often occur in groups so adjacent islands serve as sources of colonists as well. A group of oceanic islands may have shared endemic species as well as species endemic to a single island.

The Caribbean islands offer the opportunity to see a diversity endemic species. For birds, Cuba has 30 endemic species, Jamaica has 30, Puerto Rico has 18 and the winner in the endemic species contest is Hispaniola (the island shared by Haiti and the Dominican Republic) with 32 endemic species. Other smaller islands have their own endemic species. In addition, some species are restricted to the Caribbean but are found on multiple islands. Altogether, the Caribbean offers over 170 bird species that can be seen nowhere else.

In January, my wife Bets and I along with our friends Pat and Dave Lincoln participated in a guided tour of the Dominican Republic with the goal of finding all 31 endemic bird species (one Hispaniolan endemic is found only in Haiti).

As a hedge against a winter storm in Maine, Bets and I booked a flight a day early to make sure we would arrive in the Dominican Republic when the tour started. We used that extra day to explore the colonial area of Santo Domingo. We had no trouble finding our first endemic, the Palm Chat. This streaked bird, about the size of a Blue Jay, is common everywhere. It is the Dominican national bird. This species is so different from other birds that it is placed in its own family, the Dulidae. DNA comparisons tell us that waxwings are its closest relatives.

We found Hispaniolan Parakeets as well. Oddly, this species seems to be most common in urban areas. Other species seen included Antillean Palm Swifts, Gray Kingbirds, Magnificent Frigatebirds and Bananaquits.

Our tour began the following day with a trip to the National Botanical Garden in Santo Domingo.

Antillean Grackles greeted us at the gate. The cement trails through the extensive garden made for easy walking.

We saw lots of familiar birds, particularly warblers. Black-and-white Warblers, Cape May Warblers, American Redstarts, Northern Parulas and Prairie Warblers were common.

Stolid Flycatchers flitted around as well. A Red-legged Thrush was spectacular in the sunlight.

With considerable effort, we got good looks at Black-whiskered Vireos. We got great views of a Hispaniolan Lizard-Cuckoo and Hispaniolan Woodpeckers, our third and fourth island endemics of the trip.

A few West Indian Whistling-ducks, included eight polka-dotted ducklings, showed nicely. We saw a few tiny Vervain Hummingbirds, the second smallest bird in the world, barely larger than the Cuban Bumblebee Hummingbird.

On the way out, we found a Black-capped Palm-Tanager, another endemic I was keen to see. This species, along with three other Hispaniolan species, is placed in its own family, the Phaenicophilidae.

With five endemics under our belt, we headed to the southwestern part of the country. Our home for the next two nights was Villa Barancoli, a field station in Puerto Escondido. Arriving late in the day, we got a nice look at White-necked Crows for another endemic species under our belts. A brief walk at dusk yielded Common Gallinules, Green Herons and a Baltimore Oriole

After a nice dinner, we all hit the sack. We departed at 4 AM in three four-wheel drive vehicles the next day for one of the most memorable birding days of my life.

We departed at 4:00 AM from Villa Barancolí in Puerto Escondido to visit the mountainous region of Sierra de Bahoruco National Park at Zapoten, just east of the Haitian border.

We departed in three four-wheel drive, high-clearance vehicles for the eight-mile ride to the field site. The last six miles of the trip were over a boulder-strewn road with frequent wash-outs. It took us nearly two hours to drive those six miles.

It was still pitch-dark when we arrived and our first quarry of the day, Hispaniolan Nightjar, would not begin to vocalize until closer to dawn. Attracted by a recording, one male perched briefly over a branch spanning the road and we got short but satisfying looks at this island endemic.

Our next target was La Selle’s Thrush, a dead ringer for an American Robin in silhouette but strikingly colored and furtive. The birds come out on the road to forage at dawn but are difficult to see at other times of the day. This species became our nemesis. Several whizzed across the track, affording no views. Our leader walked further up the track and found one foraging on the road. By the time our party had gotten to the scope, a Zenaida Dove had landed on the road and scared the thrush away. But a White-fronted Quail-Dove, an endemic even more secretive than La Selle’s Thrush, walked onto the road.

As the sun rose, we gave up on the La Selle’s Thrush for the morning and concentrated on other birds. Where to start? Hispaniolan Emeralds, an endemic hummingbird, flitted about as we had our picnic breakfasts.

Different species kept popping up, each as wonderful as the one before. We had Hispaniolan Trogons, Antillean Piculet (a woodpecker relative), Hispaniolan Pewees, Golden Swallows and wonderful flutists, Rufous-sided Solitaires.

We saw several delightful Narrow-billed Todies. These are small but feisty green birds with long, thin bills. The four species of todies are all endemic to the Greater Antilles and two of them are only found in Hispaniola.

I was most eager to see several species whose taxonomic position has only recently been clarified. We saw some Western Chat-tanagers, one of two members of the endemic family, Calyptophilidae. These are skulking birds, difficult to see well.

We found White-winged Warblers and Green-tailed Warblers, both now classified in the Phaenicophilidae family along with the Black-crowned Palm-Tanager. Common names can be confusing!

We also found the stripe-headed endemic Hispaniolan Spindalis, one of four species in the family Spindalidae, found only in the Greater Antilles and Bahamas.

We drove around mid-day to a stand of pines in hopes of finding Hispaniolan Crossbill (a dead ringer for our White-winged Crossbill). We heard lots of Pine Warblers and finally spotted a couple of crossbills at the top of a large pine.

All of these endemic birds were joined by familiar friends: Northern Parulas, Black-and-white Warblers, Cape May Warblers and Black-throated Blue Warblers.

Later in the afternoon, a few of us were walking along the track and we heard a call note that seemed identical to a call note I have heard at tree line on Mt. Katahdin. Patience rewarded us with views of a Bicknell’s Thrush. Nearly all of these birds winter in Hispaniola and nest mainly in northern New England.

Determined to see La Selle’s Thrush, we decided to pile into a single pick-up and drive the track, hoping a thrush would be found foraging on the road at dusk. We got to hear several singing and had brief views. A Hispaniolan Parrot was a nice addition.

Departing in darkness, we arrived at Villa Barancolí for a late supper after an exhausting but exhilarating day.

After a spectacular day in Zapoten in the southwestern part of the country, we had found 24 of the 31 endemic species. The following morning, we left for La Placa with to search for three target species.

Our first target, Flat-billed Vireo, was easily found along with a couple of Broad-billed Todies. A Merlin whizzed by.

The second target, the Bay-breasted Cuckoo, is a species that most visiting birders fail to find. Our hopes were up when a large cuckoo appeared. Alas, it was the endemic Hispaniolan Lizard-Cuckoo, an endemic we had already found.

Our local guide suggested a different site. Sure enough, we heard the call of the Bay-breasted. It responded to a tape of its call and perched in view for several minutes. We were sky high!

A road alongside pastures and occasional trees held our last endemic of the morning, Hispaniolan Oriole. We also had nice views of Yellow-faced Grassquits.

After a nice lunch in Puerto Escondido, we departed for our motel in Pedernales. We made our usual pre-dawn departure the next day for the Alcoa Road in search of Ashy-faced Owl. No luck that morning so we headed to Cabo Rojo (Red Cape) after dawn to look for seabirds. Several White-tailed Tropicbirds delighted us there.

We continued from Cabo Rojo to a lagoon teeming with birds.

We saw dozens of Snowy Egrets, Great Egrets, Great Blue Herons, Little Blue Herons, American Wigeons, Northern Shovelers and Stilt Sandpipers. The assemblage could have been seen in Scarborough Marsh except for the Reddish Egrets, Roseate Spoonbills and White Ibises.

Back to the Alcoa Road, this time in search of Hispaniolan Palm Crows. We knew that a local ranger fed them and they usually arrived mid-morning. So we began a vigil, enjoying the Pine Warblers and Hispaniolan Parrots in the area while we waited.

Ranger’s home on the Alcoa Road where Hispaniolan Palm Crows were found

A couple of crows called to announce their arrival and then landed on the ground, affording great views. Our 28^th endemic species! A Hispaniolan Crossbill was an added bonus.

After a delightful lunch, we headed east for Cachote. We began the drive up the very rough road at dusk in search of Ashy-faced Owl. Our leader walked a bit ahead and located a perched owl. He about to call us when two mopeds drove past from one direction and a pick-up truck form the other, blaring loud music with a bunch of adolescent girls singing along from the back of the truck. The owl was gone!

Fortunately, our leader was able to relocate the owl and we all got great looks at this Barn Owl relative.

We descended to our motel, departing pre-dawn the next day.

Watching Eastern Chat-tanager at Cachote

We returned to Cachote, proceeding much further up the mountain. Our goal was the Eastern Chat-Tanager, an endemic that is mostly found in the eastern part of the country. Arriving at the site just after dawn, we got many brief but ultimately satisfying views of these skulkers.

We then began the long drive to Caño Hondo in the northeastern part of the country in search of our last endemic, the rare Ridgway’s Hawk.

We arrived after dark in heavy rain that continued all night. The next morning, we slogged along the muddy trail with a local guide to an observation site.

A bridge across a small stream was underwater from all the rain. We had to take off our boots, roll up our pants legs and wade across. It was worth it: a female Ridgway’s Hawk perched out in the open for over 15 minutes.

The hawk was our final target. Thanks to our knowledgeable leaders, we managed to find all 31 of the endemic birds of the Dominican Republic.

The next day, everyone got to see Caribbean Martins at the Santo Domingo Airport for a nice parting gift from this wonderful country.

Recent Big Years and Big Days

March 6, 2018 By Herb Wilson in Birding and Birders, Identification

Let’s take a look back at the year 2017 in terms of bird listing accomplishments. In 2016, two birders shattered the old year list record for North America. John Weigel’s Big Year resulted in a list of 780 species, narrowly beating Olaf Danielson’s count of 778 species.

Those records were not broken in 2017 despite three impressive Big Years. Comparisons of North American Big Years is problematic now because the American Birding Association, the keeper of listing records for North America, redefined North America to include Hawaii. The decision is defensible on geopolitical grounds but makes little sense to me on biological grounds. Nonetheless, birders attempting to break the North American Big Year record will need to plan a trip to Hawaii, like the three top Big Year birders in 2017.

Yves Morell found 813 species with an additional four rarities that will require confirmation by a state or provincial rare bird committee before they can be counted. Brothers Ruben and Victor Stoll also found 813 species but only have three provisional species.

For the truly obsessed, the World Big Year beckons. In 2015, Noah Strycker identified 6,042 species, birding in over 40 countries. Noah’s record obliterated the previous World Big Year record of 4,341 species. Noah’s record did not last long. The Dutch birder Arjan Dwarshuis listed 6,852 species in 2016, nearly two-thirds of all the birds in the world. I am not aware of any 2017 Big Years that threaten that record.

Closer to home, Josh Fecteau of Kennebunkport set a new Big Year record for Maine. His total of 317 species edged out the previous record of 314 species set by Doug Hitchcox.

Josh did not begin 2017 with the intention of doing a Big Year. Seeing Pink-footed Goose and Great Gray Owl in January provided the impetus to bird intensively for the rest of the winter and spring.

Every year brings a few rarities to Maine and those species can make or break a Big Year. Vermilion Flycatcher, Fieldfare, Fork-tailed Flycatcher, and Little Egret were among the rarest of the rare in 2017. Other unusual birds seen included Ross’ Goose, Red-billed Tropicbird, Black Vulture, King Rail, Connecticut Warbler, Yellow-throated Warbler, and Painted Bunting.

Josh reached the 250-species mark on May 18 and the 300-species mark on August 29. A Summer Tanager seen on November 1 is the species that broke the record. A Dovekie seen on New Year’s Eve was the 317^th of Josh’s odyssey.

For most kinds of organisms, species diversity increases as one moves from the polar regions to the tropics. That pattern is evident by comparing Josh’s impressive Big Year total of 317 species to the current Big Day record, set in 2015 in Ecuador, of 431 species!

That Big Day record was set by a team of four international birders: Dušan Brinkhuizen, Tuomas Seimola, Rudy Gelis and Mitch Lysinger. The previous Big Day record was 354 species, conducted in Perú.

The Ecuadorian team felt that a Big Day in excess of 400 species was possible since Ecuador has over 1700 species of birds. The challenge is how to sample the many habitats with the mere 12 hours of daylight.

The strategy was to thoroughly bird the Amazonian forests along the eastern slope of the Andes beginning at midnight. At dusk, the plan was to hop on a plane to the shore and bird the coastal regions after dark.

October 8, 2015 was the day. By 4:49 the list stood at 16 species with the fabled dawn chorus yet to come. By 8:45, the list had 195 species and grew to 329 species by 2:00 PM. By the time the team reached the airport, they had 392 species, shattering the old record.

Surveying heron and seabird roosts on the coast and observing night-feeding shorebirds, the team added another 39 species. An amazing day.

Highlights of Maine Christmas Bird Counts – III

March 3, 2018 By Herb Wilson in Christmas Count Summaries

This post is the last of three reviewing the highlights of Maine Christmas Bird Counts. These counts took place between mid-December and early January. Today we will visit some of the northern and central Maine inland counts.

The Misery Township Count (about 30 miles south of Jackman) was held on January 1. This count has the most severe winter weather of any count in the state and usually the lowest species total. This year, 20 species were tallied on a bitterly cold day.

No lingering fall birds were found here. The expected birds of the boreal forest were present: five Gray Jays, two Boreal Chickadees, 13 Red-breasted Nuthatches and three Golden-crowned Kinglets.

The most surprising bird to me was a Northern Cardinal, a testament to the continued northern range expansion of this species.

Northern finches were present in modest numbers with 48 Purple Finches, 11 White-winged Crossbills and 239 Pine Siskins.

The Caribou count, held on December 16, produced a total of 31 species. Four species of waterfowl were present, with 32 Mallards being the most abundant. Eleven Bald Eagles made for a nice total and a Red-tailed Hawk was unusual for this count.

Nine Horned Larks were found in the open countryside along with 108 Snow Buntings. Two Northern Cardinals were nice finds for this far north in the state. Five species of finches were present including 40 Purple Finches, 51 Pine Siskins, five Pine Grosbeaks and a couple of Common Redpolls.

Just a bit south, the Presque Isle count on December 30 yielded a count of 34 species. The 220 Mallards made for an impressive total. The only other waterfowl were 26 American Black Ducks. Bald Eagles were even more common here than in Caribou with 51 present along with one Red-tailed Hawk and one Sharp-shinned Hawk.

The 44 Red-breasted Nuthatches set a new high record for this count. Twenty-one American Robins were found, a fine count for this latitude. Two Northern Cardinals were spotted.

Finch diversity was good with six species found including a singleton Pine Grosbeak, 48 Purple Finches, three Common Redpolls, 22 Pine Siskins and an excellent total of 41 Evening Grosbeaks.

Let’s relocate to central Maine. The Unity counters on December 16 found 45 species. Waterfowl were scarce with only three species found, topped by 45 Mallards. A Common Loon was a nice find; some open water must have been available. Bald Eagles turned up in fine numbers with 47 seen, along with a Northern Goshawk.

Herring Gulls and a single Ring-billed Gull were joined by a remarkable Lesser Black-backed Gull.

Lingering landbirds included a Winter Wren, a Ruby-crowned Kinglet, two Rusty Blackbirds and 22 Brown-headed Cowbirds. As elsewhere in the state, Dark-eyed Juncos were more common than usual; 445 were found in Unity.

Just 20 miles southwest in Waterville, CBC counters found 52 species on December 17. Eight species of waterfowl were found despite little open water. The highlight was a pair of Barrow’s Goldeneye. Red-tailed Hawks were common with 18 spotted. A Peregrine Falcon was found along the Kennebec River.

The agricultural fields in the north part of the circle yielded 100 Horned Larks, one American Pipit, two Savannah Sparrows and two Lapland Longspurs but not a single Snow Bunting.

A new high count record of Northern Cardinals was set with 94 of these beauties tallied. A White-crowned Sparrow was unusual for this time of year.

Lingering birds included a Great Blue Heron, a Northern Flicker, two Hermit Thrushes, six Rusty Blackbirds and 20 Brown-headed Cowbirds.

In overview, the early winter bird populations across the state show perhaps a few more lingering birds than usual. It is shaping up as a poor winter for visitors from the north (Bohemian Waxwings, Northern Shrikes, northern owls and northern finches). Our resident birds seem to be holding their own.

Highlights of Maine Christmas Bird Counts – II

March 2, 2018 By Herb Wilson in Christmas Count Summaries

This post is the second of three reviewing the highlights of Maine Christmas Bird Counts. These counts took place between mid-December, 2017 and early January, 2018. Today we will take a tour along the coast from York County to the Machias region.

The York County Count on December 18 produced an excellent count of 85 species. A whopping 18 species of waterfowl were highlighted by a Green-winged Teal, a Ring-necked Duck, a Greater Scaup, a Lesser Scaup and 77 Harlequin Ducks.

Two Northern Gannets and 41 Great Cormorants were good finds. Along the shore, participants found 33 Sanderlings, 56 Dunlin and 132 Purple Sandpipers. Just offshore, a single Black Guillemot (low) and 26 Razorbills appeared.

Raptors put on a good show. The list included a Northern Harrier, two Red-shouldered Hawks, three Snowy Owls, a Northern Saw-whet Owl and a Merlin.

Birds lingering from the fall included three Great Blue Herons, two Belted Kingfishers, two Yellow-bellied Sapsuckers, three Northern Flickers, 94 Eastern Bluebirds, two Hermit Thrushes, five Yellow-rumped Warblers and two Chipping Sparrows.

One rarity was found, an Orange-crowned Warbler.

The Freeport-Brunswick Count produced 60 species on December 29. Thirteen species of waterfowl were found, capped by five Barrow’s Goldeneye. A Rough-legged Hawk was a thrill.

A dozen Red-bellied Woodpeckers made for a nice total of this species that is increasing in fits and starts in Maine.

Species that normally have migrated by now included a Northern Flicker, 41 Eastern Bluebirds, a Hermit Thrush and two Northern Mockingbirds. A Dickcissel was a great find. Just a few are seen in Maine each year.

The Bath-Phippsburg-Georgetown Count, held on December 16 produced a total of 80 species. Two Wood Ducks and eight Barrow’s Goldeneyes were the most notable of the 15 species of waterfowl. Twenty-two Red-throated Loons and 101 Red-necked Grebes were impressive totals for these diving birds.

Shorebirds put on a good show with 15 Dunlin joining the more expected 80 Sanderlings and 117 Purple Sandpipers. Five species of gulls were highlighted by two Black-headed Gulls. A gull relative, a Parasitic Jaeger, was a fantastic sighting.

Black Guillemots, our most common alcid seen from shore, were joined by eight Razorbills and two Atlantic Puffins.

Owls came in pairs this year with doubleton Great Horned Owls, Barred Owls and Snowy Owls. Diurnal raptors included a Peregrine Falcon and a Rough-legged Hawk.

The most notable land birds were lingering species, no doubt now departed either for eternity or for points south. These included a Yellow-bellied Sapsucker, three Eastern Bluebirds, two Hermit Thrushes and five Yellow-rumped Warblers.

Offshore we go to Matinicus Island, 20 miles off the mainland in eastern Penobscot Bay. The January 3 count yielded 41 species. A Green-winged Teal was certainly unexpected, among seven other species of waterfowl.

A couple of Northern Gannets and 18 Great Cormorants were nice winter totals. A Ruddy Turnstone was an excellent find. White-winged gulls seem to be uncommon this winter so the one Iceland Gull made for a good discovery.

The perching birds were a real grab-bag of interesting birds: a Red-bellied Woodpecker, seven Northern Flickers, a Gray Catbird, a Northern Mockingbird, 24 Yellow-rumped Warblers, a Common Grackle and 11 White-winged Crossbills.

The Moose Island-Jonesport count in eastern Washington County was conducted on December 16 and resulted in a total of 52 species. The most unusual of the 13 waterfowl species was a Green-winged Teal. Common Eiders were the most abundant duck with 394 counted.

Seventeen Northern Gannets made for an excellent count. Over 2,000 Herring Gulls greatly outnumbered the other gull species (Bonaparte’s, Ring-billed, and Great Black-backed).

The forests yielded one Ruffed Grouse and one Spruce Grouse. The count produced very few lingering summer birds: a Northern Harrier, a Gray Catbird and a Yellow-rumped Warbler.

Two species of finches were found: 31 American Goldfinches and an excellent duo of Evening Grosbeaks.

Highlights of Maine Christmas Bird Counts – I

February 25, 2018 By Herb Wilson in Christmas Count Summaries

The 118^th Christmas Bird Count (CBC) season has finished. In the next three posts, I will discuss the highlights of some of the Maine Christmas Bird Counts. These standardized censuses are a valuable tool to monitor the abundance of winter birds throughout North America and beyond. The data provide a lens to see how our Maine birds are doing.

I’m expecting some strong weather effects this year. The first part of the count period (December 16-24) was seasonably cold with a few inches of snow on the ground. Christmas brought a big snowfall to much of the area and brutally cold temperatures that show no signs of abating until the second week of January.

I’ll concentrate on any changes in regularly wintering birds, the arrival of erratic winter wanderers and records of any lingering birds whose wintering areas are well to our south. A rarity or two may pop up as well.

We’ll start with Lewiston-Auburn count, held on December 16. The counters enjoyed a fine day, accumulating a list of 53 species. The 342 Common Goldeneyes and 96 Lesser Scaup were all-time highs for this count. These waterfowl were joined by 10 other species including a Ruddy Duck, two Red-breasted Mergansers, 14 Greater Scaup and a Northern Pintail.

A Yellow-bellied Sapsucker was a great find along with five Red-bellied Woodpeckers. Two falcons were spotted, a Merlin and a Peregrine Falcon.

The most surprising songbirds were a Gray Catbird and a Yellow-rumped Warbler. Dark-eyed Juncos seem to be very common this winter; the 383 support that observation. Sixty Northern Cardinals set a new count record.

Black-capped Chickadees and American Crows were present in lower numbers than expected. A local aberration we hope.

The Mount Desert CBC was also held on December 16. Participants found 58 species. This count always produces lots of Common Eiders; 829 this year did not disappoint.

Only one Red-throated Loon was seen along with 64 Common Loons, 54 Horned Grebes and 71 Red-necked Grebes. Only four species of gulls were found, the most notable being eight Black-legged Kittiwakes.

A Yellow-bellied Sapsucker and a Northern Flicker would have normally migrated south by mid-December. A Black-and-white Warbler and an American Pipit were excellent finds.

Three species of northern finches were found: Purple Finch, Red Crossbill and Pine Siskin. All were in low numbers. So far, this winter does not look good for northern finch irruptions.

The Thomaston-Rockland count, also on December 16, yielded a fine count of 83 species. Nineteen species of waterfowl appeared, an excellent tally. Highlights were a Wood Duck, an American Wigeon, two King Eiders and a Ruddy Duck.

Two species of sandpipers were represented by two Dunlin and a dozen Purple Sandpipers.

Very late birds included a Pied-billed Grebe, a Turkey Vulture, a Belted Kingfisher, two Yellow-bellied Sapsucker, a Northern Flicker, five Eastern Bluebirds, a Vesper Sparrow two Savannah Sparrows and a Baltimore Oriole.

The best bird of the count was a Yellow-throated Warbler, a species whose nesting range is well to the south of Maine.

Two White-winged Crossbills were the only northern finches.

The Bunker Hill CBC was conducted on December 18. This count circle is in Lincoln County, including Nobleboro, Alna and Jefferson. A total of 55 species appeared this year.

Ten species of waterfowl were counted, the most notable being five lingering Ring-necked Ducks. Wild Turkeys put in a strong appearance with 181 birds sighted.

Four Red-shouldered Hawks make an excellent total for Maine in the winter. These hawks were joined by Cooper’s Hawks, a Sharp-shinned Hawk, a dozen Bald Eagles and eight Red-tailed Hawks for an excellent hawk total.

Lingering terrestrial species included 11 Eastern Bluebirds, a Red-winged Blackbirds and two Brown-headed Cowbirds. American Robins and Dark-eyed Juncos were particularly common this year with 377 and 462 individuals, respectively.

Introduced Birds

January 5, 2018 By Herb Wilson in Bird Conservation Tags: History

The 118^th Audubon Christmas Bird Count is now underway, concluding on January 5. The data provide a valuable tool to gauge changes in our winter bird populations.

As usual, I will devote three columns to results and general patterns from Christmas Bird Counts in Maine. Today I want to concentrate on four species that will be found, often abundantly, on most Maine counts: Rock Pigeon, European Starling, House Finch and House Sparrow. None of these species was present in eastern North America 500 years ago. All were introduced by human hands.

Rock Pigeons were introduced into North America in the early 1600’s, likely to provide a source of meat. Rock Pigeons can now be found in urban and agricultural areas throughout the United States.

Starlings were introduced for a quite different reason. A New Yorker named Eugene Schieffelin thought it would be wonderful if he could establish populations of all the bird species mentioned in Shakespeare’s plays in Central Park. He released 60 starlings in 1880 and 40 more in 1881. From those releases, starlings spread across the continent with a population now exceeding 200 million birds.

House Finches are native to Mexico and the southwestern United States. In the first half of the 20^th century, House Finches were illegally brought east and sold as cage birds called Hollywood Finches. The colorful males sing readily in captivity. Pet shop owners in New York City and environs caught wind of an impending raid by law enforcement officers and emptied their cages before the raids commenced. From those introductions, House Finches have spread across all of the states east and north of the original range. The range of introduced birds overlaps now with the original House Finch populations.

House Sparrows were introduced in North America first in Brooklyn in 1851 and 1852. Subsequent introductions occurred in San Francisco in 1871 and 1872 and in Salt Lake City in 1873 and 1874. Now House Sparrows are found throughout the Lower 48 states except for southwest Texas and much of Canada.

How to treat introduced birds? Some birders keep life lists in which they do not count introduced birds. Such a birder might report a life list of 311 NIB (no introduced birds) species in the state of Maine.

I think sorting birds into native birds and introduced birds is not a black-and-white issue. I wrote recently about Cattle Egrets, which reached the New World by dispersing from Africa on their own. Within a continent, birds may expand their ranges. Turkey Vultures and Red-bellied Woodpeckers are good examples for Maine. The avifauna of islands is built almost entirely by birds dispersing from mainland areas.

Should we bother counting pigeons, European Starlings, House Finches and House Sparrows on our Christmas Counts? Absolutely! All four species are well-established members of the Maine avifauna.

All four of these species interact with our native birds. These species are never far from human habitation so human-friendly native birds are more likely to be influenced by the introduced birds.

As seed-eaters, Rock Pigeons can be pests for farmers. The pigeons readily eat seeds planted by farmers and improperly stored grain. Pigeons may compete with other seed-eating birds like sparrows for natural seeds.

Starlings are cavity-nesting birds and compete with native cavity-nesters like woodpeckers, Great Crested Flycatchers, Eastern Bluebirds and even the introduced House Sparrows.

House Finches compete with Purple Finches and House Sparrows. We have pretty good evidence that Purple Finches are less abundant in proximity to human dwellings than they were before the arrival of House Finches. Purple Finches are doing fine in large forested areas where House Finches do not occur.

House Sparrows are cavity-nesters and have deleterious effects on wrens, chickadees and Eastern Bluebirds.

Like it or not, this quartet of introduced species are important members of our bird communities and deserve our attention.

[First published on December 24, 2017]

Feather Eating by Grebes

December 19, 2017 By Herb Wilson in Foraging, Species Accounts

Grebes are familiar diving birds belonging to the Order Podicipediformes. Although there are only 22 species in the order, grebes are found on all continents except Antarctica and on many islands.

All grebes nest in freshwater habitats although some spend the winter in marine waters. In Maine, the only breeding grebe we have is the diminutive Pied-billed Grebe. These birds migrate south for the winter. However, we have grebes throughout the year. Red-necked Grebes and Horned Grebes migrate to Maine coastal areas in the fall and spend the winter with us.

The Podiciped- prefix in the order name translates as “butt-foot”, an allusion to the rearward position of the feet. Loons have a similar morphology with the feet set far back on the body. This arrangement makes for efficient foot-propelled swimming but awkward walking on land.

Older field guides placed grebes next to the loons. However, DNA analysis shows that loons are only distantly related to grebes. In fact, the closest relatives to the grebes are, surprisingly, the flamingoes.

The paddles of loons and grebes are quite different. In loons, the three forward toes are fully webbed. In grebes, each of the three anterior toes has a flattened lobe to increase the surface area. The toes are connected only at the base by a narrow web. This same sort of toe is seen in the unrelated coots.

Grebes feed on small fish, crustaceans and freshwater insects. Note that all of these prey items have non-nutritious hard parts that pose a challenge for digestion.

All birds have feathers but grebes are the only birds that eat and then regurgitate their own feathers. The phenomenon of feather-eating has been known for over 500 years. In 1580, an Aztec author wrote that the diet of Eared Grebes was mostly feathers with occasional fish. This peculiarity was not appreciated in Europe until 1781 and even then, scarcely studied until the early 20^th century. It became clear that all grebes eat feathers.

But why eat feathers? Feathers have virtually no caloric value. Think of trying to live on a diet of fingernails. There has been no shortage of explanations of feather-eating, mostly unconvincing speculations.

In a recent article in the Wilson Journal of Ornithology, Joseph Jehl provides a definitive study of the functional significance of feather-eating in grebes.

To appreciate Jehl’s work, we need to first consider the digestive system of a bird. Food passes from the mouth, through the esophagus to the anterior stomach or proventriculus. This stomach produces lots of hydrochloric acids and enzymes, facilitating the chemical break-down of food. The food next passes to the gizzard or muscular stomach. With the aid of hard ridges and sometimes the presence of grit, the gizzard mechanically grinds the food. The gizzard plays the role of teeth. The gizzard is well developed in birds like ducks, grouse and seed-eating songbirds but poorly developed in predatory birds. The food then passes into the intestines for absorption.

Jehl found that grebes pluck flank feathers and swallow them. These feathers have a peculiar twisted, open-veined appearance. The feathers are ingested and pass into the gizzard. Most are accumulated there, forming a dense mass.

Jehl’s breakthrough in understanding feather-eating came from his discovery that Eared Grebes regurgitate the feathers nightly in up to six different pellets. The pellets consisted of eroded feathers and the hard parts of shrimp and insect skeletons.

Because insects and crustaceans are difficult to digest, Jehl suggests the main function of feather-eating is to delay the movement of food into the intestine until chemical digestion is complete. The gizzard plays no role in mechanical digestion. Each day the bird regurgitates the indigestible remains of its prey along with the feathers. In the morning, it is time to pluck some more feathers and start the process again.

[Originally published on December 8, 2017]

Caribbean Trip

December 11, 2017 By Herb Wilson in Trip Report

My wife and I recently returned from a relaxing ten-day cruise in the Caribbean (November 6-16, 2017). We visited seven islands, most of which had been spared from the wrath of Hurricanes Irma and Maria. Most of the land excursions were centered on general sight-seeing or visiting historical sites. We had to do our birding on a catch-as-catch-can basis while enjoying other aspects of the islands.

Caribbean birding is a mixed bag. On the one hand, the species diversity of the islands is generally much lower than the diversity of continents. On the other, many of the birds are endemic to the Caribbean. Some of these birds are island endemics, restricted to a single island.

During the winter, island bird diversity increases due to the arrival of wintering North American migratory birds.

We boarded our ship in San Juan, Puerto Rico. This island is still suffering mightily from Hurricane Maria. A planned trip to the El Yunque Rainforest was out of the question.

A walking tour through the historic part of San Juan did yield some birds. Greater Antillean Grackles, playing a similar role to our Common Grackles, were abundant. We saw several Gray Kingbirds, the first of many sightings of this common Caribbean species. Introduced Monk Parakeets were conspicuous, loudly announcing their presence. A couple of Pearl-eyed Thrashers posed obligingly. Several Spotted Sandpipers flew in their stiff-winged style along the shore.

We set sail for St. Kitts, arriving around noon. We were able to do some open ocean birding en route. Brown Boobies and Magnificent Frigatebirds were abundant.

Brown Booby. Between Puerto Rico and St. Kitts.

We picked out a Masked Booby and a couple of

Magnificent Frigatebird. Between Puerto Rico and St. Kitts.

Red-footed Boobies from the many birds following the ship.

A ride on an open-air train gave us a good feel for the island but few birds. Highlights were Zenaida Doves, Scaly-naped Pigeon, Carib Grackles and the ubiquitous Gray Kingbirds.

The following day, a visit to the gardens at Romney Manor turned up an old friend, an American Redstart. Bananaquits were common. Caribbean endemics were a Brown Trembler (a thrasher), Green-throated Carib (a hummer), Antillean Crested Hummingbird, Lesser Antillean Flycatcher and Lesser Antillean Bullfinch.

An excursion that afternoon to Fairview Great House yielded a White-winged Dove (unusual for St. Kitts) and a pair of American Kestrels.

On to St. Lucia. The highlight there was a two-mile tram ride through the rain forest canopy. Birds were few and far between other than Purple-throated Caribs, Antillean Crested Hummingbirds

Crested Antillean Hummingbird, Stony Hill, Saint Lucia

and a soaring Broad-winged Hawk. At the end of the tram, we went on a short hike and turned up a pair of delightful St. Lucia Warblers, an island endemic. A thrilling sighting! We also found Black-faced Grassquits and Lesser Antillean Bullfinches.

Our next stop was Barbados. Our target there was another island endemic, the Barbados Bullfinch. Several were feeding on the property of the historic St. James Parish Church, a stop on our driving tour.

Other birds seen on our route were Cattle Egrets, Snowy Egrets and tons of Carib

Grackles.

The following day took us to Guadeloupe. Most of our land

excursion involved visiting open-air markets in crowded villages so birding was limited. We did visit a peninsula with several offshore pinnacles. I was able to pick out three White-tailed Tropicbirds just offshore. Royal Terns, Brown Pelicans and Magnificent Frigatebirds were part of the show as well.

Antigua was next on the itinerary. From the dock, dozens of Great Egrets could be seen at a roost in the mangroves. Walking in the town of St. John’s yielded Common Ground-Doves and tons of Carib Grackles. Common Moorhens

and a Green Heron were at the Nevis Street Wetland.

We briefly visited Frederikstet, St. Croix for our last island stop. St. Croix was hard-hit by hurricanes so our land excursion was only a walk through the town. We did find two Ospreys, an immature Yellow-crowned Night-Heron and a “calico” Little Blue Heron.

Little Blue Heron, Frederikstet, St. Croix

Yellow-crowned Night-Heron, Frederikstet, St. Croix

Where Are the Birds?

November 26, 2017 By Herb Wilson in Behavior, Foraging, Migration

Where are the birds? I’m sure I have been asked this question at least 20 times in the last month. Lots of people are finding that many of our familiar, common birds have abandoned our feeding stations.

Fall migration is drawing to an end so many of our summer birds have moved on to warmer quarters for the winter. However, most of birds that frequent our feeders are resident birds. Many observers have noted the dearth of Black-capped Chickadees, Tufted Titmice, White-breasted Nuthatches, American Goldfinches, Downy Woodpeckers and Hairy Woodpeckers. Where did they go?

The abandonment of bird feeders does not indicate a precipitous decline in bird populations. The phenomenon of resident birds forsaking our handouts actually occurs every fall. This year’s pattern is, however, one of the most striking ones in my memory.

To understand what is going on, we need to realize that birds do not rely on our sunflower seeds and millet for their existence. Our feeders provide only a fraction of a bird’s daily energetic demands.

Birds wander throughout a foraging area to feed from many sources. The reason for this behavior is basically uncertainty. Any given food source can be depleted in short order. To spread the risk, birds do not depend on a single source of food.

Shrubs, trees and many herbs set seed in the late summer and fall. This banquet of acorns, birch seeds, winterberries and other bird delicacies is too much to resist for most of our common birds. Sunflower seeds seem to be pretty low on the preference list compared to natural food so our feeders go unvisited in the early fall.

I’m willing to bet you are seeing fewer squirrels and chipmunks at your feeding station now as well. These rodents are taking advantage of the autumn pulse of natural seeds, too.

Natural food is notoriously patchy. When resources are clumped, ecologists know that individuals can find more food by foraging as a group. One bird in a flock is likely to happen across a rich, localized source of food that is then shared with other members of the group. A lone forager would hit the jackpot if it discovered a rich food source, but like the lottery, the chance of a lone bird finding a mother lode of food is slim.

The common feeder birds listed in the first paragraph form mixed-species feeding flocks in the fall that persist well into spring. A flock offers the dual advantage of finding patchy food and avoiding predators because of the many eyes on the alert for Sharp-shinned Hawks and other predators.

Black-capped Chickadees are the nuclear species in a winter flock. A nesting pair of chickadees maintains a summer territory of one to four acres. In the fall, the pair expands its territory to include an area up to 25 acres in extent. Mom and dad kick the young ones out but are joined by eight to twelve juvenile chickadees from neighboring parents. For the juveniles, this winter flock provides a match-making opportunity. Most will have formed a pair-bond with another flock member by spring and will go off to nest for the first time in May.

The chickadees in a winter flock are usually joined by a couple of Tufted Titmice, a couple of Downy Woodpeckers, a few White-breasted Nuthatches or Red-breasted Nuthatches and even a Brown Creeper or Golden-crowned Kinglet. If your feeding station falls within a winter territory, it is possible that the flock has not even discovered it yet.

A possible contributing factor to the lack of feeder birds is a phenomenon called partial migration. Depending on food resources, some but not all members of a resident species may move southward. Blue Jays and American Goldfinches are perhaps the best known partial migrants but even chickadees will sometimes stage winter migrations.

[First published on November 12, 2017]

Birds Avoiding Feeders

November 14, 2017 By Herb Wilson in Behavior

Where are the birds? I’m sure I have been asked this question at least 20 times in the last few weeks. Lots of people are finding that many of our familiar, common birds have abandoned our feeding stations.

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