Tuesday, September 20

Nocturnal migrants September 16-18th 2011

The following are recordings of migrants flying over my house near Philadelphia, PA, during three consecutive nights of northwesterly/northeasterly winds in mid-September. The majority of calls were by thrushes, Rose-breasted Grosbeaks or warblers, and there was an occasional sparrow or heron. The most common thrush was Swainson's, with Veeries coming in second, this species being past its peak. Early Gray-cheeked Thrushes were heard in small numbers, and a few Wood Thrushes passed over. Most frequently heard warblers were Common Yellowthroat, Blackpoll/Blackburnian, Ovenbird and American Redstart.

All identifications are presumed, as no birds were observed.

Rose-breasted Grosbeaks call mostly earlier in the night, whereas thrushes call throughout with an increase towards sunrise. Grosbeaks have three main categories of calls, off-key whistles (which can sound like Swainson's or Hermit Thrush), hoarse calls and buzzy calls. The calls are quite variable.

Typical whistle, which could be confused with Swainson's Thrush, 2.47am

Commonly heard hoarse call, 1.05am


This call is Hermit Thrush-like, 1.30am

Short call, 1.01am (or perhaps Bobolink?)

The following are presumed Rose-breasted Grosbeak calls:




Presumed Wood Thrush (Rose-breasted Grosbeak can be similar) 5.45am

Swainson's Thrush, modulated and typical purer-toned calls, 6.03am

Veery, typical call, 4.57am

Gray-cheeked Thrush calls are higher than those of Veery and Swainson's Thrush, 6.08am

The Bay-breasted Warbler has a bisyllabic call that is more sibilant than other buzzy warbler calls (Blackburnian can be similar), 5.02am

Buzz, most likely Blackpoll or Blackburnian (less likely Yellow, based on date, or Connecticut, based on abundance) 12.02am

Northern Waterthrush, a rising buzz, 1201am (Louisiana Waterthrush is similar)

This is a good candidate for Cape May Warbler, a high, slightly descending buzz, 3.56am.

A possible Magnolia Warbler, a fine buzz, 2.02am

Chestnut-sided Warbler, a low, fine buzz, 1.52am

Common Yellowthroat, a distinctive low coarse buzz, 3.35am

Double rising call, Black-throated Green, Nashville or Tennessee Warbler, 12.02am

Black-throated Blue Warbler 1.39am

Northern Parula, a clear descending call, 2.00am

Palm Warbler, a distinctive emphatic "seemp", 2.00am.

Canada Warbler 3.50am

American Redstart, 12.02am

Black-and-white Warbler, a sharply modulated bisyllabic call, 3.35am

Ovenbird, a piercing rising call, 12.30am

Savannah Sparrow 11.58pm

Swamp/Lincoln's Sparrow 4.20am


Chase Schiefer said...

Great, great, great post! Thanks for putting this together!

Paul Driver said...

Thanks for the comment, Chase.