After being delayed by high winds and rain late last week which brought a few small trees down over our nets and trails, the Lesser Slave Lake Bird Observatory finally completed our breeding-focused Monitoring Avian Productivity and Survivorship (MAPS) program on May 28, 2024. In general, MAPS went smoothly with a few delays caused by weather and one caused by a mother bear and her two cubs.
It was a year for firsts with captures of our first Varied Thrush of the MAPS program and our station’s first ever Broad-winged Hawk! The biggest first, however, was a change to our protocols. To detect if year-to-year differences are due to differences in bird populations and not due to how much effort is put into monitoring them, our programs are rigorously standardized. It is exceedingly rare to make any changes to our protocols.
However, songbird breeding and the peaks of both spring and fall migration appear to be advancing such that running MAPS from June 11 to August 8 no longer matched the breeding season well. To shift our monitoring efforts to line up better, this year we shifted the MAPS operation window to May 31 to July 29.
Despite shifting the monitoring period so that we would no longer catch the early peak of fall migration in late July and early August, we still ended with well above the average of 298 birds banded per MAPS season. Indeed, it was the fourth busiest year for MAPS out of our 31 years of running this program with 541 birds banded of 30 species.
Over 20% of our captures were American Redstart who became our top banded species for MAPS with 132 banded. They were followed by Tennessee Warbler (74 banded), Swainson’s Thrush (56 banded), White-throated Sparrow (54 banded), and Mourning Warbler (31 banded). These five species accounted for 64% of all birds banded. See the end of this article for a complete preliminary list of our MAPS bands.

The high capture rates were instigated mostly by young birds fledged in the last periods of MAPS who are now already undertaking their first journey south with only their instincts to guide them. Some parents may try for another brood, but attempting multiple broods can harm their own ability to survive their arduous migration. Instead, most adults are now replacing every feather on their body before they too begin the journey south.
Southward migration is being documented by our Fall Migration Monitoring program which began on July 12. Already we have banded 680 birds of 42 species – including rare captures of a Varied Thrush (10th ever) and a Brown-headed Cowbird (11th ever). Like MAPS, American Redstart are currently our top banded species with 124 banded. They are joined by Yellow Warbler (113 banded) and “Myrtle” Warbler (59 banded). These species, along with Tennessee Warbler and Black-and-white Warbler, account for the majority of what we are counting flying overhead as well.
Want to learn more in person? Join our Bird Observatory Tours taking place on Wednesdays and Saturdays through August.
By Robyn Perkins, LSLBO Bander-in-Charge
Preliminary totals by band frequency for MAPS 2024:
American Redstart | 132 | American Robin | 6 | |
Tennessee Warbler | 74 | Winter Wren | 4 | |
Swainson’s Thrush | 56 | Cedar Waxwing | 2 | |
White-throated Sparrow | 54 | Chipping Sparrow | 2 | |
Mourning Warbler | 31 | Purple Finch | 2 | |
Canada Warbler | 28 | Sharp-shinned Hawk | 2 | |
Ovenbird | 27 | Broad-winged Hawk | 1 | |
Black-and-white Warbler | 23 | Common Yellowthroat | 1 | |
“Myrtle” Warbler | 16 | Hairy Woodpecker | 1 | |
Black-capped Chickadee | 15 | Hermit Thrush | 1 | |
Magnolia Warbler | 15 | Northern Waterthrush | 1 | |
Yellow Warbler | 14 | Philadelphia Vireo | 1 | |
Least Flycatcher | 13 | Rose-breasted Grosbeak | 1 | |
Alder Flycatcher | 9 | Varied Thrush | 1 | |
Red-eyed Vireo | 7 | Western Wood-Pewee | 1 |