The Eurasian subspecies group of Common Merganser, known by the English name Goosander, has occurred numerous times in the Aleutian Islands of western Alaska, but has never been identified farther east in North America. The American subspecies has some potential to wander to Eurasia, but has never been recorded there. I’ve never seen any in-depth […]
Distinguishing Eurasian and American Common Merganser Read More »
The photo above was recently sent to me by reader Wil Domke. It shows an adult Trumpeter Swan (based on bill size and shape, and on Wil’s identification in the field) with a small yellowish patch on the loral skin. This yellow marking is similar to the yellow spot shown by most Tundra Swans. According
Trumpeter Swans with yellow loral spots Read More »
Dark morph (Cory’s) Least Bittern Note: I have never personally seen a living Cory’s Least Bittern. In fact, only six or so have been seen during my lifetime. Most of what follows is based on a very thorough 1996 research paper by Ron Pittaway and Peter Burke (see References below). The illustration shown below is
The mysterious dark Least Bittern Read More »
Last winter’s Common Moorhen in Newfoundland, given the likely split of New World and Old World moorhens into separate species, led me to try to determine the origin of the Newfoundland bird. That study of photos turned up a few small differences in bill color and shape, but nothing fully reliable. Now I have finally
The Newfoundland Moorhen was an American based on back color Read More »
In these two very similar species, the head plumes of adults provide the single most obvious and reliable distinction. The brief descriptions in field guides fail to convey the fundamental differences in these feathers, so a detailed description is given here to clarify those differences.
Differences in plumes of Little and Snowy Egret Read More »
This is a follow-up to my recent post about Optical illusions and bird identification. While working on some heron studies the other day, I found a good example of an illusory bill size comparison. Compare the bill in the two images of Reddish Egret shown below. To my eye, at least, the bird on the
More on illusions of size Read More »
I’ve been aware of some variation in songs of Blackpoll Warbler for many years, and now an interesting post by Andrew Spencer at Earbirding prompted me to check into it a little more closely. Many years ago Will Russell pointed out to me that the birds nesting in Alaska all sang a more rapid series
Does Blackpoll Warbler have song dialects? Read More »
In a footnote here I mentioned that blackish feathers can appear gray because of powder down, and now I will offer a little more explanation.
Powder down and the Black-crowned Night-Heron Read More »
On 18 May 1987, while birding at Cape May, NJ, I came across a small group of Cattle Egrets foraging in a field. Accompanying them was the bird in the photos below. In shape and behavior it was identical to all of the other Cattle Egrets, but its head and neck were mostly dark grayish.
Does Cattle Egret have a dark morph? Read More »
23 Jun 2011 – Concord, MA Sitting at my desk today I was roused by a bird call that I did not immediately recognize. This is a very rare occurrence for me, especially at my house where I spend many hours every day, and I know the birds that are here very well. As the