American Kestrel Monitoring Year 8: The Excitement of Returning Birds
It hardly feels like our American Kestrel Nest Box Project has been going on for nearly a decade, but here we are, 8 years deep into this amazing cooperative project. This year mirrored last year: high numbers of occupancies, high numbers of chicks produced, and unknown bonuses through the year. Here are some of the important highlights from the 2023 nesting season.
As I alluded to in the title, returning birds are always a highlight, especially when those birds have bands! It isn’t often that we see banded birds return to an area (a lot of that has to do with the high mortality rates of raptors in migration), so when we began seeing the return of kestrels to the Bog in March expectations run high that we might just find a banded bird or two. If you recall, we have been color banding nestling and transmitter bearing adult kestrels for the last two years. Last year (2022) we had a color banded female American Kestrel return to the area and incubate eggs! This year, in an entirely different location, we had a color banded, transmitter bearing male American Kestrel return to a nest box location! We never we able to recapture that bird to see who he was, but it was definitely another bird banded from our boxes who returned!!
Speaking of occupied boxes, this was the 2nd best year ever in the bog for boxes occupied (29), successful boxes (24), and chicks fledged (88). Unfortunately, we did also had the 2nd highest total of unhatched eggs due to predation, abandoned nests, or failed eggs (43). This may be due to a couple of factors, but higher than average nest predation events likely have something to do with this total. Over the last two years, there have been a greater numbers of nest predations (5) than the first six years combined (4)! This may have something to do with an increasing number of raccoons in the region (great climbers and a relatively “new” nest predator in the region), but this is just speculation for the time being.
Excluding those negative notes, the season was a great success! Supporting American Kestrels through this nest box project has added more birds to the landscape, as noted by visitors and staff alike! Hopefully, you too, have noticed good numbers of American Kestrels when you have visited the Bog during the summer months! It is heartening to know that some of these birds are likely hatched from our boxes, supported by the varied landscape and prey choices in the region.
Thank you so much to our growing group of American Kestrel Volunteers, now totaling over a dozen folks who are giving time through monitoring boxes, banding, or supporting the project through other ways! Without our volunteers monitoring boxes, research on this species couldn’t be nearly as successful as it has been over the last few years. THANK YOU!!
— Head Naturalist Clinton
