3rd Week of August 2019 – Beaver River, Yarmouth County, Nova Scotia

Spectrogram of Night Flight Call of Magnolia Warbler

The density of nocturnal migration nearly doubled over the previous week. Flight calls increased 81% to 3,724 and total estimated birds by 90% to 2,344. The most common migrant was Magnolia Warbler with an estimated 326 birds. Chestnut-sided Warblers were not far behind with 298 estimated birds. The next five most common migrants were American Redstart (estimated 279 birds), Yellow Warbler (226), Black-and-white Warbler (201), Canada Warbler (174), and Ovenbird (148). A total of 22 species of warblers were recorded with Prairie Warbler being the rarest.

Shorebird migration was dominated by Spotted Sandpipers (estimated 27), with a few Least Sandpipers (4) and Semipalmated Plovers (5). There was the beginning of thrush migration with an estimated 4 birds each of Swainson’s Thrush and Veery. The only sparrows were an estimated 13 Savannah Sparrows.

The large numbers of Magnolia Warblers seemed early to me. However, when checking eBird I found that the highest average count for this species in Yarmouth County is in the 3rd week of August at 6.79 birds per checklist (counting only checklists that reported Magnolia Warbler).

The density of migrants was up 11% in total night flight calls and 6% in total estimated birds from 2018. The Canada Warbler was up 50% from last week and 31% from this week in 2018. A part of this increase from last year is likely due to adjustments I’ve made to the acoustic software for extracting warbler flight calls. The year, 2018, was an eruption year for Red-breasted Nuthatches, and during this week last year, an estimated 62 nuthatches were recorded. This year there were none.

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