Bird subspecies

Mew 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 means changing the name of the species on your list from Mew Gull to Short-billed Gull. The North American population, common …

Mew Gull is now two species! How to identify Common Gull and Short-billed Gull Read More »

Distinguishing 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 observers it’s more practical to assign birds to two subspecies groups: Lesser and Greater. The Greater subspecies group includes five of the named subspecies, …

Distinguishing subspecies of Sandhill Crane Read More »

Underwing 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 on Atlantic Islands, and many authorities have split the two into separate species recently. Both populations occur off the Atlantic coast of North America, although Cory’s in …

Underwing pattern in Cory’s Shearwater Read More »

Comparing 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 no overlap in breeding range and very little in winter range. There is a lot of good information in print about how to identify them …

Comparing the songs of Willet subspecies Read More »

Cackling-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 through the flocks and picking these birds out, and once a candidate is located the identification has usually been straightforward – …

Cackling-ish Geese Read More »