Friday, August 22

Nocturnal migrants August 2014

The following were recorded over my home in Elkins Park, PA during August. All identifications are presumptive.
Least Bittern (3.24am, early Aug)

Upland Sandpiper (3.26am, mid-Aug).

Black-billed Cuckoo (4.32am, early Aug).

Chestnut-sided Warbler, a relatively low fine buzz (12.13am, mid-Aug).

Compare with the higher, lazier buzz of Yellow/Blackburnian/Blackpoll/Connecticut Warbler. Most likely a Yellow based on the date (3.05am, early Aug).

The Common Yellowthroat call is usually easily separable as a low electric buzz, but calls are variable and not always double banded, as here (2.55am, mid-Aug).

Here's a nice comparison between American Redstart and Black-and-white Warbler, The calls have a similar shape but the sound is quite different (mid-Aug).

Canada Warbler can sound a bit like American Redstart, but is very different on the sonogram (3.24am, early Aug).

The Cape May Warbler call is sharp, high and usually descending (5.33am, mid-Aug).

Shortly before dawn, some warblers call frequently as they descend, similar to the vocal behavior of Catharus thrushes. Ovenbirds with a Mourning Warbler calling, a few Bobolinks in the background at the end (5.41am, mid-Aug).

Mourning Warbler is the lower call


Bill Evans said...

Nice selection of species and very good looking Mourning Warbler call -- I would think that one to be relatively uncommon flying over Philly area at night.

Paul Driver said...

Mourning Warbler was easier to pick out this year because of the exceptionally cool nights we had during August, reducing the insect noise at 5-6kHz that would normally hide the calls.