The Lesser Slave Lake Bird Observatory’s spring migration monitoring program continues to wind down. Only a handful of species including Cedar Waxwings, Mourning Warblers, and Alder Flycatchers are still passing through, although recent encounters with a Short-billed Gull (formerly Mew Gull) and an American Pipit were exceptionally late in the season for some excitement. With 561 birds banded from 40 species, we have gratefully lost the title of the slowest spring on record and are now instead the fifth slowest year since 1995.
Since most species have concluded their northward migration and many birds are already sitting on eggs, we have begun another banding program geared towards tracking songbird breeding efforts over the summer. This program is called Monitoring Avian Productivity and Survivorship (MAPS). Although we historically did not start MAPS until June 11, due to climate change shifting both the breeding and fall migratory windows earlier, we now start ten days earlier on May 31 as of 2024.
MAPS is off to a good start with 67 bands from 18 species, but we did have to close one of our four stations early due to the threat of rain. Since we visit each station only once every ten days to minimize our impact to our birds’ sensitive breeding efforts, a week will pass before we visit any MAPS station again.
Unlike our migration monitoring programs which tend to see a wave of new individuals daily which results in high band totals, MAPS tends to see a much higher proportion of captures that are already banded because birds will not stray far from their breeding territory in the summer. Our MAPS sites are in prime breeding habitat for many species and if a bird successfully fledged young in a site last year, it is likely to return to the same site this year. In other words, songbirds exhibit high site fidelity. Some birds can even return to nest within 8 m of where they nested last year! Imagine flying all the way from your wintering home 7,000 km away in Columbia and guiding yourself back to the same patch of Boreal Forest in the spring. We are still not entirely certain how they accomplish such accurate navigation.
So far we have already captured 41 birds in MAPS which were actually already banded. Most of these recaptures were banded in previous years, but some were banded recently in the nearby Migration Monitoring Station before moving deeper into the forest to nest. Among the oldest of birds recaptured was an Ovenbird that was banded July 26, 2021 and is now at least five years old.
By Robyn Perkins, LSLBO Bander-in-Charge
