A blast of summer before mid-May!
There was some incredibly hot weather last week, brought in with strong south wind blowing furnace air into southern Ontario. It was summer weather in early May bringing a sudden explosive leaf-out at Cabot Head, greening the trees in a matter of days. After a long Canadian winter, I – like anyone – enjoyed soaking in the newly arrived warmth. Beyond the hedonistic moments though, there were nagging fears of climate chaos bringing life-altering mismatch between birds and plants and insects and all the web of connections that sustains life on earth (read https://www.audubon.org/magazine/spring-2022/a-matter-timing-can-birds-keep-earlier-and for a fascinating view on the challenges birds face in a warming world).
The warm weather and strong south wind provided great conditions for a massive push of migrant birds during this week, and truly massive it was Hundreds of millions of birds moved North during these nights, as modeled by BirdCast (https://birdcast.info). At Cabot Head, we experienced the icicles from the tip of the classical iceberg, with many birds and new species detected during the week and a good banding harvest as well. As an indication of the rapid and intense movement, new species were detected every day, notably 11 new species on May 10, and good daily banding totals without any recaptures from newly banded birds.
A few examples of what a week it was: On May 8, there was an impressive morning flight of over 400 Yellow-rumped Warblers, with a spattering of other warblers notably 15 Cape May Warblers and 6 Northern Parulas and a brief glimpse of the FOY Blackburnian Warbler. On May 9, birds were seen mostly feeding instead of flying over, resulting in 45 birds banded as opposed to 8 the day before. Birds were also giving us very good views of their resplendent breeding plumage. In the still leafless trees, it was easy to spot the black and orange of the first of year (FOY) male adult American Redstart, right on time. The FOY American Redstart has been detected between May 8 and 10 in 13 years of the previous 19 (2020 being Covid-excluded). On May 10, as mentioned, 11 new species arrived among a total of 76 species detected that day, the highest spring total so far. After a winter in northern South America, Swainson’s Thrush and Veery have finally arrived at Cabot Head, with maybe only a “short” jaunt left into the boreal forest. Other newly arrived species were Lincoln’s Sparrow, Common Yellowthroat, Mourning and Chestnut-sided Warbler, Baltimore Oriole and Rose-breasted Grosbeak, (always a relatively late date at Cabot Head), Least and Traill’s Flycatchers (don’t search for Traill’s Flycatcher in your favourite bird guide – Willow and Alder Flycatchers are lumped together as they cannot be told apart in hand and are mostly distinguished through vocalizations in the bush: one bird in hand can actually be two birds in the bush!) and two Chimney Swifts were seen flying high and fast, because Swifts will be swifts.
As a bonus, we were treated with rare sightings of one Red-throated Loon on flight on May 11 and one Northern Mockingbird on May 12 around the station for a few minutes.
After this mad week of intense migration it now almost feels like summer with many birds singing and defending territory, not least the very abundant American Redstarts. There are still birds to arrive but it does seem that huge numbers of them took advantage of these unique conditions, resulting in a very condensed and rushed migration. As a consequence, we birders might feel deprived on more opportunities to watch migrant birds, but birds don’t care much in providing easy watching for us. Very often a “good” migration in the point of view of birders (lots of birds for many days in unsettled weather) is a “bad” migration for birds (birds forced to stop and struggle feeding in bad unsettled weather).
As I said earlier, there was no recapture of newly banded birds this past week because birds did not linger, however we have started recapturing birds banded here at Cabot Head in previous years. So far, all of them have been American Redstarts, the most common local breeding species. Of the 8 recaptured birds most came from last fall, a few from summer or fall 2020, and one from spring 2016. This adult female was banded as an after-second-year bird in spring 2016, so in banding lingo that means this bird was born before the year 2015, which makes it at least 8 years old! A very old bird indeed! The oldest known American Redstarts are 10 years old (https://www.pwrc.usgs.gov/bbl/longevity/longevity_main.cfm). Without banding we would have no idea how long birds could live.