Friday, November 30, 2012

White-faced vs. Glossy Ibis

White-faced and Glossy ibis are difficult to tell apart. If you are close enough in the breeding season, note the white feathers lining the White-faced Ibis’s bare, red facial skin. The legs are pinkish-red. The first photograph shows a White-faced Ibis from Sand Lake National Wildlife Refuge near Aberdeen, South Dakota.
Glossy Ibis, on the other hand, do have white on the face, but the white lines do not meet behind the eye. Furthermore, this white color is not feathered, but a skin color. The facial skin is otherwise dark or bluish. If you are really close, eye color differs (red in Glossy, brown in White-faced). Finally the legs are dark on a Glossy Ibis. The lower photo was taken in Florida. In non-breeding plumage, the two species can be almost impossible to separate.
Some ornithologists consider the two ibis to be only racially distinct. The ibis interbreed in captivity. In the wild, in Louisiana and Alabama, where their ranges overlap, the two ibis nest in the same colonies but do not interbreed (Ryder and Manry 1964). Glossy Ibis are found along Eastern and northern Gulf coasts and in Florida; White-faced Ibis are western birds. Both species tend to wander, with Glossy and White-faced ibis occasionally seen well away from their expected ranges.

Wednesday, November 28, 2012

Merlin

While birding on Tuesday, John Holden and I came upon this Merlin in Rice County, Minnesota. The name Merlin comes from the Old French, "esmerillion." In North America, Merlins used to be called Pigeon Hawks. Although they take small birds, Merlin’s are falcons.

As did other raptors, Merlins suffered serious declines when DDT was in wide use. But the species is recovering, even colonizing urban areas. Three races of Merlins inhabit North America (and the species is found across all of the Northern Hemisphere). These races are the Black Merlin from the Pacific Northwest, the Taiga Merlin from the northern forests, and the Prairie Merlin from northern prairies and aspen parklands. Black Merlins are not found in Minnesota. The other two races are to be expected here and are often easily identified; intermediate-plumaged individuals can be encountered. This individual gave me pause and may well be intermediate. I finally decided that its overall dark coloration, creamy eye-stripe, and buffy breast add up to a taiga bird. Prairie Merlins are much paler birds and are rare in eastern Minnesota.

Tuesday, November 27, 2012

Golden-Plovers

Ornithologists have determined that the three populations of golden-plovers are actually three distinct species—where they overlap, they do not interbreed.

The first photo is of an American Golden-Plover. Older field guides refer to this bird as the Lesser Golden-Plover. In the photograph, note that the under-tail feathers and the flanks are black in this breeding-plumaged bird. In the other two species, these areas are either white or splotchy. The fact that this picture was taken in South Dakota also supports an identification of American Golden-Plover, as the other two species are rarely found inland.

The second photo is of a Pacific Golden-Plover. This shorebird used to be considered a race of the American Golden-plover. The Pacific occurs in greater numbers than the American and breeds in western Alaska and eastern Siberia. Both species winter in South America. In the United States, Pacific Golden-Plovers migrate along our Pacific Coast. A few winter in California, like this bird that I found on the beach at La Jolla. The prominent dark ear spot helps to distinguish winter-plumaged Pacific Golden-Plovers. Their backs are also brighter than American Golden-Plovers, which have duller backs (which can lead to confusion with Black-bellied Plovers). The fact that American Golden-Plovers are unknown from our country in the winter also helps with identification.

The third species is called the European (or Greater) Golden-Plover. I have listed it in France, but I lack a photograph. The species is occasionally reported from Newfoundland and Greenland but not elsewhere in North America.

Sunday, November 25, 2012

Black-bellied Plover

Black-bellied Plovers breed in the Arctic of the New and Old Worlds. In this hemisphere, they winter along most coasts of the United States and south along the South American coasts. During migration they fly across the Great Plains. These photos were taken in Florida in the winter. Usually this species is not difficult to identify. Their backs are grayer than those of golden-plovers—indeed these birds are called Grey Plovers in Europe. Identification is clinched when you see their black “arm pits.”

In mixed shorebird flocks, Black-bellied Plovers act as sentinels. They are “wary and quick to give alarm calls” (Johnson and Conners 2010). Due to this wariness, Black-bellied Plovers better survived the market hunters of the early 1900s than did other large shorebirds.

Friday, November 23, 2012

Bald Eagle

Very late in the afternoon during John Holden's and my swan expedition down the Mississippi River, the fog finally lifted. The Mississippi in southeastern Minnesota is a great place to watch Bald Eagles. Eagles are so inspiring that the species was adopted by the American congress for the Great Seal of the United States in 1782. Most birders are aware that Benjamin Franklin was not pleased by this decision. Although he did not express his opinions elsewhere, he wrote the following paragraphs to his daughter in 1784:

"For my own part I wish the Bald Eagle had not been chosen the Representative of our Country. He is a Bird of bad moral Character. He does not get his Living honestly. You may have seen him perched on some dead Tree near the River, where, too lazy to fish for himself, he watches the Labour of the Fishing Hawk; and when that diligent Bird has at length taken a Fish, and is bearing it to his Nest for the Support of his Mate and young Ones, the Bald Eagle pursues him and takes it from him.

"With all this Injustice, he is never in good Case but like those among Men who live by Sharping & Robbing he is generally poor and often very lousy. Besides he is a rank Coward: The little King Bird not bigger than a Sparrow attacks him boldly and drives him out of the District… 

"For the Truth the Turkey is in Comparison a much more respectable Bird, and withal a true original Native of America... He is besides, though a little vain & silly, a Bird of Courage, and would not hesitate to attack a Grenadier of the British Guards who should presume to invade his Farm Yard with a red Coat on.” This quote is reported in http://www.greatseal.com/symbols/turkey.html and only slightly edited in this post.

Wednesday, November 21, 2012

Tundra Swans

Yesterday pea-soup fog greeted John Holden and me along the Mississippi River south of Brownsville, Minnesota. We birded the riverside in search of Tundra Swans, which use this region as a staging area during their migration to the Chesapeake Bay area. Despite the uncooperative weather, I was able to take a few interesting—or, at least, different—photos.
In the middle photo a swan is using its toes for landing gear. In the fog, I am not sure of the relative position of the flying and swimming swans. In the final photo, two young swans are following an adult. For more information on swans, see my posts of 7 November 2010 and 10 November 2010.

Sunday, November 18, 2012

Red-tailed Hawk

Red-tailed Hawks can be identified, of course, by their red tails; but also by the neckless of dark streaks across their lower breasts. Last week Gerry Hoekstra and I took a photo of this raptor just west of Faribault in Rice County, Minnesota. All three photos are of the same bird (but they are not sequential). I have previously blogged on Red-tailed Hawks on 9 January 2011.


Thursday, November 15, 2012

Rusty vs. Brewer’s Blackbirds

On Tuesday Gerry Hoekstra and I discovered a dozen Brewer’s Blackbirds among some 75 Red-winged Blackbirds, all feeding in a recently fertilized corn field. Brewer’s Blackbirds are common in northern Minnesota, but less so elsewhere. According to Eckert, Brewer’s Blackbirds are less often seen during migration than are other blackbirds. Rusty Blackbirds, on the other hand, are common fall migrants in Minnesota. 

These two species can be difficult to tell apart (especially males in breeding plumage). In these fall birds note the uniformly dark wings of the Brewer’s Blackbird in the first photo. The winges of the Rusty Blackbird have chestnut edgings, as you can see in the lower photo. The Rusty Blackbird’s supercilliary stripe is much bolder than the face of the Brewer’s. Finally note the habitat—Rusty Blackbirds favor swampy or wet areas whereas Brewer’s are often found in dry fields and feedlots. I took the Rusty Blackbird’s photograph on 26 October at the Bass Ponds near the Minneapolis Airport.

Tuesday, November 13, 2012

Pine Siskin and American Goldfinch

This year large numbers of Pine Siskins are invading Minnesota from Alaska and northern and central Canada. The species is an “unpredicrtable” winter visitor—sometimes absent, sometimes abundant. Dawson (1997) writes, “presumably this pattern is related in some way to annual variation in the distribution and abundance of the seeds that make up…its diet.” After these invasions, wintering siskins occasionally breed in their wintering grounds before heading north.  Dawson concludes that Pine Siskins are opportunistic and indifferent to the constraints of time and space.

Yesterday, 12 November 2012, we banded 36 Pine Siskins at the thistle feeder. We also tagged 12 American Goldfinches. Among the goldfinches we encountered five already ringed individuals. All had be previously banded at the banding station: 2640-60456 banded 6 January 2012; 2430-16891 banded 6 December 2010; 2640-60451 banded 30 December 2011; 2640-60388 banded 21 November 2011; and 2640-60801 banded 12 November 2012 (same day as being banded). I can not prove it, by it is my impression that these goldfinches were not among our summer goldfinches, but, rather, are migrants from the north returning to spend the winter (see also my blog of 31 January 2012).

Sunday, November 11, 2012

Gray Partridge

Gray (or Hungarian) Partridge were introduced into North America from the Old World in the early 1900s. Where hedgerows are left standing, partridge flourish—these game-birds enjoy high reproductive rates (but with short lifespans and hight mortality rates). They suffer in areas with industrial agriculture and high pesticide use. Hunting does not seem to adversely affect population growth. The main threats to this species include predators and weather (Carroll 1993). I am surprised to read that partridges are increasing out of the northern Great Plains into Nebraska and Missouri. Most ecology textbooks tell you that Gray Partridges prefer cold, dry northern climates and do poorly in warm, humid areas. Perhaps the species is adapting to these southern climates. (This photo was taken in western South Dakota.)

Friday, November 9, 2012

White-necked Stilt

After avian geneticists investigate, another bird I may add to my life list is the White-necked Stilt. I took the first photo many years ago near Buenos Aires, Argentina. Currently this bird is considered to be a race of the Black-necked Stilt, the common stilt of North America. The second photo is of a Black-necked Stilt taken several years ago in South Dakota.

White-necked Stilts are found in southern South America. White-necked Stilts have the white collar on their necks and more white on the top of their heads than do Black-necked Stilts. In the northern parts of the range, White-necked Stilts may interbreed with Black-necked birds. The two races have also interbred in captivity. Captive Black-necked Stilts have also interbred with American Avocets, which are clearly different species (Robinson et al. 1999).

Tuesday, November 6, 2012

Hammerkop

The Hammerkop, another odd bird, is often classified near the storks, but might be closer to pelicans and cormorants. The species is found in Africa and is attracted to wetlands, even those that are created by people. I took this photo in Kenya in the early 1960s.

When courting, up to 10 birds run circles around each other. Often they practice “false mounting,” but they might not be mates and they may not actually copulate. Hammerkops build nests among the heaviest of all birds—the nests can weight up to 110 pounds! The nests are often over 1.5 meters in diameter and contain some 10,000 sticks cemented with mud. The nests are decorated with bright objects and built in trees or on the ground. They build up to five of these monster nests, even when the birds themselves are not breeding (Wikipedia).

Sunday, November 4, 2012

Red-billed Tropicbird

Tropicbirds, found in tropical seas around the world, are gull-like birds with greatly elongated central tail feathers. Erika discovered this Red-billed Tropicbird because the long tail feathers tickled her ankles as she walked by the bird’s nest under the rocks in the Galapagos Islands.

Tropicbirds are yet another member of the order Pelicaniformes (along with pelicans and cormorants) because of all their toes being webbed. The order, however, is under revision by geneticists, who are finding that the various families in the order are not closely related. Expect to see changes in the taxonomy of these birds. Recently researchers suggested that tropicbirds are actually most closely related to sunbitterns (heron-like birds of the American tropics).

Friday, November 2, 2012

Yellow-rumped Cacique

Yellow-rumped Caciques are South American blackbirds found north into Mexico. This photo was taken in eastern Peru. The species is common and noisy in cultivated areas with large trees. It eats insects and fruit. These caciques breed in compact colonies, containing up to 100 hanging nests, usually built around an active wasp nest. The wasps may protect the birds from nest predators; the birds may alert the wasps to the presence of wasp-eating predators.

According to Wikipedia, Peruvian folklore reports that a boy, who always wore black pants and a yellow jacket, started a false rumor about an old woman. But the woman was a witch who turned him into a noisy, wandering bird. I do not know if Yellow-rumped Caciques were ever little boys, but, if you look closely, you may notice that these caciques have bright blue eyes, a trait uncommon among birds.