Weekly Reports

On October 3, Fall Migration Monitoring at the Lesser Slave Lake Bird Observatory ended after 84 days. We normally end on September 30, and this is the first time since 2008 that we pushed into October due to the unseasonably warm weather, which may have delayed movements of some short-distance migrants. It remains unclear if the slow end to fall is due to warm weather, extreme forest fire and smoke activity, or something else entirely.

Preliminarily, we encountered nearly 48,000 birds of 147 species – 7,000 birds short of last fall (in large part due to 4,000 fewer Myrtle Warblers being counted overhead), but with eighteen more species identified. Notable highlights included an influx of Semipalmated Plovers following a lull since 2017 and Sanderlings for the first time in twelve years. Our station’s rocky shoreline is poor habitat for most shorebirds which are common on Devonshire’s sandy beaches. We see Bald Eagles near daily, but both juvenile and adult Golden Eagles joined 2023’s tally. Bohemian Waxwings arrived early with multiple sightings – we have detected this species during fall only once, in 2021.

While we recorded good observational data, between wildlife and poor weather, we were only able to have our nets open for 68% of our standard monitoring hours. The loss of our nets was acute in August, which only achieved 43% of possible netting effort because Black Bears often forced us to keep our ground level nets closed. Perhaps for this reason, after five consecutive years of over 3,000 banded birds each, this year we see a return to average with 2,604 birds banded of 62 species. The last songbird banded was an American Tree Sparrow – a short-distance migrant targeted by our modest season extension.

Despite half the number of Myrtle Warblers being banded this year compared to last, they retain the first-place position, as always, with 516 banded, followed by Tennessee Warbler (337 bands), Swainson’s Thrush (328), American Redstart (159), and White-Throated Sparrows (86). One of our usual Top 5 species, the Yellow Warbler, saw the sharpest drop in numbers, from their record high of 391 last fall to a meager 57 banded this fall.

Even though the season’s preliminary band totals were average overall, there were two record-breakers. Gambell’s White-Crowned Sparrows broke their previous 2017 record of 37 with 47 banded this fall and Purple Finches set a dramatic new high with quadruple their previous record of 11 in 2015 with 43 banded. Honourable mentions go out to our rare fall captures of LeConte’s Sparrow, Common Grackles, Belted Kingfisher, Lapland Longspur and, just last week, our sixth ever Townsend’s Solitaire.

All that remains is the Owl Migration Monitoring program that runs until the end of October. No Boreal Owls have been captured yet, but we have banded a modest 57 Northern Saw-whets thus far. Our Family Owl Nights are October 13 and 14. Space is limited and filling fast. For more information, contact the Boreal Centre for Bird Conservation at info@borealbirdcentre.ca or (780) 849-8240.

By Bronwyn Robinson, Assistant Bander and Robyn Perkins, Bander-in-Charge

Preliminary totals for all species banded during Fall Migration Monitoring 2023 from most banded to least: