The mysterious dark Least Bittern
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...
View ArticleDistinguishing Eurasian and American Common Merganser
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...
View ArticleSubspecies of Scaled Quail
There are four named subspecies of Scaled Quail, three in the US and one in Mexico. The subspecies found in southern Texas is distinctly different from the other three, at least in adult male plumage,...
View ArticleA Wurdemann’s-like heron from South Florida
Thanks to reader Anne DuPont for sending in these photos of a pair of Great Blue Herons at Wakodahatchee Wetlands, Delray Beach, Florida. It’s clearly a mated pair, but the female (sexed by behavior)...
View ArticleVariation in immature American Herring Gulls
A recent discussion about geographic variation in Herring Gulls (on the ID-Frontiers listserve) prompted me to go back and scan some photos I took in 1998 at Cape May. At the time I was sorting out...
View ArticleAn unusual Cattle Egret in Florida
In late April 2012, Roy Halpin found and photographed an entirely buff-colored Cattle Egret in Saint Augustine, Florida. This is a particularly interesting bird because it provides an opportunity to...
View ArticlePeter Pyle on Sage Sparrows
The most significant change for North American birders in the 2013 AOU Checklist supplement is the split of Sage Sparrow into two species: Sagebrush Sparrow and Bell’s Sparrow. In this arrangement...
View ArticleThe extremely variable American Pipit
I have been noticing variation in American Pipit for many years, and last month I had the opportunity to photograph a small flock. The photos here are of three randomly selected individuals in that...
View ArticleCackling-ish Geese
Cackling Goose is a rare fall migrant through Massachusetts and I usually see a couple of them each fall among the hundreds of Canada Geese around Concord. I look forward to the challenge of sorting...
View ArticleComparing the songs of Willet subspecies
The Eastern and Western subspecies of Willet are often mentioned as likely candidates for splitting into two species. They differ in size, proportions, details of plumage, migration pattern, and have...
View ArticleUnderwing pattern in Cory’s Shearwater
If you keep up on the news of subspecies, you will have heard of Scopoli’s Shearwater. It’s the Mediterranean breeding population of Cory’s Shearwater, overlapping very little with populations nesting...
View ArticleA white Great Blue Heron in Massachusetts
I wrote about white Great Blue Herons in 2007, and thanks to a recent comment there by David Ammerman alerting me to a whitish Great Blue Heron chick in a nest, I made the short trip to Bolton, MA...
View ArticleDistinguishing subspecies of Sandhill Crane
Here’s a new illustration I’ve done as part of some work on distinguishing the two subspecies groups of Sandhill Crane. Six subspecies of Sandhill Crane are generally recognized, but for field...
View ArticleDistinguishing the subspecies of Redwing
Here is another recent project: I’ve been working on new and improved illustrations of Redwing for the bird guide and app, showing the differences between the two subspecies. The Redwing (Turdus...
View ArticleVariation in eastern Fox Sparrows
Mid-March is when the first northbound Fox Sparrows show up in Massachusetts, and it’s always a pleasure to see this burly, richly-colored sparrow. I’ve been working on some new illustrations showing...
View ArticleNew illustrations of Cave Swallow subspecies
Prompted by a couple of recent records of Cave Swallows in the northeastern US, I’ve taken a fresh look at subspecies and done some new illustrations. In April 2021 Cave Swallows have been found in New...
View ArticleMew Gull is now two species! How to identify Common Gull and Short-billed Gull
For North American birders the most consequential change in the 2021 AOS Checklist supplement is the split of Mew Gull into two species – Short-billed Gull and Common Gull. For most birders this simply...
View ArticleSubspecies of Common Grackle: Bronzed, Florida, and “Purple”
Common Grackle is a familiar backyard bird almost everywhere east of the Rocky Mountains, and shows some fairly striking regional variation in color. This variation involves mainly the colors of...
View ArticleIdentification of the newest meadowlark – Chihuahuan
In their 2022 checklist supplement the AOS voted to elevate the southwestern populations of Eastern Meadowlark to a full species, with the name Chihuahuan Meadowlark. it’s been recognized as a...
View ArticleTwo species of Cattle Egrets?
The 2023 Clements/eBird taxonomy update has just been announced, and the biggest surprise is that Cattle Egret will now be considered two species! Few people are familiar with variation in Cattle...
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