Weekly Reports

On June 10, the Lesser Slave Lake Bird Observatory wrapped up Spring Migration Monitoring after 56 consecutive days of counting birds. Spring began promising on April 16 with counts of over 5,000 Slate-coloured Juncos despite the warm temperatures and little snowfall over the winter. Juncos normally move through before we can start monitoring when early April is warm.

It was one of the only years we had open water already peaking through cracks in the ice that rotted away by May 5. Often waterfowl will crowd near the shore in open pockets through early May. The rapid disappearance of our lake ice may have lowered duck counts, but did not stop geese from flying by so May 4 counted nearly 22,000 geese overhead – a significant contribution to the over 78,000 birds recorded this spring.

Among the wonderfully diverse 161 species encountered was our station’s first ever Willet and Western Kingbird, becoming the 243 and 244 bird species to be recorded during standard monitoring efforts. Both these species are found almost exclusively in the grassland and parkland regions of southern Alberta.

Other observational highlights included American Coots (common around town, but only found on-site every two to eight years), the first two Caspian Terns since 2020, and the first Western Meadowlark since 2015.

Relative to recent years, Tennessee Warblers and Trumpeter Swans have begun nesting locally in decent numbers, but Western Tanagers and Lincoln’s Sparrows seem rather sparse.

Since much of May experienced high winds and rain, the nets could only be opened for 61% of possible net-hours. Therefore, at a preliminary 835 birds banded, this spring was below the average of 947 birds banded per spring and was the 14 lowest total of our 30 year of standardized monitoring efforts. With 53 species banded, however, capture diversity was above the average of 46 species banded per spring.

The top five most frequently banded species accounted for 46% of all captures: Slate-coloured Junco (88 banded), American Redstart (83 banded), White-throated Sparrow (76 banded), Swainson’s Thrush (74 banded), and Chipping Sparrow (63 banded).

Capture highlights included our first spring Chestnut-sided Warbler since 2014, first spring Nashville Warbler since 2015, fourth ever Vesper Sparrow, and second ever Northern Shrike and MacGillivray’s Warbler. No species broke their record high band total, but Common Yellowthroats tied with 2010 for a record low (6 banded) and Orange-crowned Warblers tied with 1994 (2 banded).

The last bird captured of spring was an American Redstart that was banded back on June 12, 2023 in one of our stations focused on breeding birds. He was not recaptured again in 2023, but we have found him in our nets on June 6, 7, and 10, 2024. Next up we will focus our attentions on monitoring breeding birds and catching up on data entry and net repairs.

Preliminary band totals of Spring Migration Monitoring, 2024:

By Robyn Perkins, LSLBO Director of Field Operations