Blog Birding #424

A survey of museum specimens from Chicago’s Field Museum suggests that migratory birds are getting smaller, likely due to climate change. Read more at BirdWatching Daily. 

“We had good reason to expect that increasing temperatures would lead to reductions in body size, based on previous studies,” says study lead author Brian Weeks, an assistant professor at the University of Michigan School for Environment and Sustainability. “The thing that was shocking was how consistent it was. I was incredibly surprised that all of these species are responding in such similar ways.”

At Birdwatching NC, Sally Siko shares what she loves most about birdwatching.

‪I love the idea of going outside somewhere new to take pictures with an end goal of finding a specific as-yet-unseen bird in mind.
Heck, the planning stages of the trips is half the fun! Nerding out on the latest species sighting reports and habitat data for planned outings makes me happy and eager for an adventure into an unknown area.
The research done beforehand that gives me the confidence to take that knowledge out into the field to test my skillset.
It’s a really nice feeling to go into a new place/habitat yet feel comfortable in understanding my surroundings well enough to find what I’m looking for. Even if it’s my first time stepping on to that trail.

At Avian Hybrids, Jente Ottenburghs summarizes research that uses the incredibly similar Golden and Blue-winged Warblers to determine the genetic underpinnings of migration.

Both species breed in North America and winter in two particular regions: South America (mainly Venezuela) and Central America (Panama to Guatemala). By linking these migration strategies to genomic sequences, the researchers attempted to find the genetic basis of migration. And they did: the analyses converged on a small region (120,000 base pairs) on the Z-chromosome. This region showed reduced genetic diversity in warblers migrating to South America and Tajima’s D (a statistic to identify selective processes) was also much lower in these birds.

Many of us have the countries with the largest bird lists ingrained in our memory, but what countries have the highest diversity per square mile? The answers discovered by Dragan Simic at 10,000 Birds might surprise you.

Here we are talking about far less known destinations. Seven of them are island states, or a part of a larger island (Brunei). Not surprisingly, most are underdeveloped. What comes as a surprise, two of them have already positioned themselves as known birding destinations attracting a substantial number of birders: Trinidad and Tobago with the world-famous Asa Wright Nature Centre (cover photo), and The Gambia with experienced local guides, plus cheap packages for African beginners from Western Europe.

At the Freiday Bird Blog, Don Freiday documents the occurrence of a pair of great birds at Cape May, New Jersey.

But, I figured why not walk through St. Mary’s cemetery (a bit south of the Cape May canal and west of Seashore Road) to see if the cranes were hanging out in one of the adjacent fields, and then, since I was going right by, why not stop for the ‘Western” flycatcher.  So I did, running into Glenn Davis who had some flycatcher excrement in a bag for later DNA analysis. He asked if I knew if empids could produce excrement that large . . . you can’t make this stuff up. Then a Cooper’s Hawk flew in giving its ‘sapsucker call,” and I heard the flycatcher. High, up-slurred whistle. Pacific-slope, thinks I, and ready the phone to record it. And wait. And wait. No more vocalizations, until I was ready to leave and ran into Claudia Burns and Warren Cairo, got some good photos. . .and it called again, same sound. Claudia heard it too.

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