Dead Bird Quiz answers

4 09 2012

Bird A, not surprisingly, fooled no one. This intact carcass was a Greater Shearwater. Though it’s just about impossible to tell without dissecting the bird, if I had to guess, I’d bet it’s a juvenile. This summer, we had 14 dead shearwaters turn up on SEANET beaches in North Carolina and Georgia. Interestingly, we had only reported up north. We did get informal reports through the grapevine of some dead shearwaters floating off the oceanside of Cape Cod, but none of those chanced to wash up where Seanetters might find them. The shearwater die-off is a seasonal phenomenon, generally involving the young of the year birds unable to make the grueling northward migration from their hatching grounds way way down in the south Atlantic. I also posted this particular bird in honor of Katie Haman, veterinarian and now PhD student, who just had an article on Greater Shearwater mortalities accepted to the Journal of Wildlife Disease. SEANET data was included in that paper, and I will provide you with a link once it’s published.

Clapper Rail. A dark back, and just a bit of a reddish tinge to the breast

King Rail showing the rufous wing patches that distinguish it from the Clapper Rail. The breast and cheek (when head is present) are also quite reddish in this species.

 

 

 

As for Bird B, I am grateful for the unusual number of responses we got on this one, because I really did need the help. All of our contestants identified Bird B as a Rail, but then discussion ensued as to whether the bird was a Clapper or a King Rail. Lacking a head, this bird can only be identified based on leg color and plumage characteristics. The upper wings and back of Bird B appear rather drab overall (they may appear darker than normal since dead birds are rather often wet, sand-caked and disheveled.) This overall drab color, with no reddish patches on the upper wing argues for Clapper Rail. And on the underside of the bird, we see a pale brownish breast with barring on the belly and flanks. Adult King Rails usually have a rich orange breast sharply contrasting with strikingly barred flanks. Our Bird B is much more subtle than that, and while its orange-ish breast is rather more vibrant than Atlantic region Clapper Rails usually are, Bird B still appears to fit that species better. There is always the tantalizing possibility that is an Atlantic coast Clapper Rail/King Rail hybrid, which Sibley reports is rather common. The result would look rather similar the more orange-ish breasted Gulf Coast population of Clapper Rails, but Sibley cautions that these hybrids would be nearly impossible to detect visually, given the overlap between male Clappers and female Kings.

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