Patterns of translucence in wing feathers provide useful identification clues for many species of birds – terns, gulls, hawks, and others. Generally the translucent parts of the wing are those where there are fewer layers of feathers to block the light, and less pigment in the feathers. I’ve written about this before in my book […]
The finer points of wing translucence Read More »
Now updated by a new post Progress on the Orange-throated hummingbird mystery. This adds to my previous post about orange-throated hummingbirds. After hearing from a couple of hummingbird banders affirming that they do not see a change in throat color in the fall as male Ruby-throated Hummingbirds go though their summer molt (and the fact
Orange-throated Hummingbirds: more questions Read More »
Albino and partial albino birds The presence of white feathers on a normally dark bird is the most frequently seen color abnormality. Every birder can expect to encounter white or partly-white birds with some regularity, and the more striking examples will stand out even to novices. All black and brown coloration in birds comes from
Abnormal coloration in birds: Melanin reduction Read More »
Update 16 August: a new post Progress on the orange-throated hummingbird mystery. Update 14 Aug 2011: A follow-up to this post is now available, tempering some of these points and adding more questions – Orange-throated Hummingbirds: more questions. Every year in August and September, a few perplexed observers in eastern North America send out questions about
The mystery of the orange-throated hummingbirds Read More »
A few records of “Snowy” Egrets with long head plumes have turned up in places where Little Egret has also occurred. Are they hybrids, or just rare variants of Snowy? Update 6 Aug 2011 – I had overlooked Martin Reid’s photos from Texas in May 1998 of a very similar long-plumed Snowy-like Egret. So obviously there is
Possible hybrid Little x Snowy Egrets Read More »
Usually. Experienced observers can almost always identify these species correctly based on careful judgment of head shape and bill size, but these are subtle and subjective impressions, and require a foundation of experience and/or direct comparisons with Sooty. Other features can offer supportive clues or draw attention to a potential Short-tailed, but are not very
Can Short-tailed Shearwater be identified in the field? Read More »
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 »