A slow change of characters

As thoughts of summer slowly recede into the memories of most people, now in a “back to school” mood, migratory birds are also changing: we are saying good bye, one by one, to the earliest of the long-distance migrants, the warblers, the flycatchers, the hummingbirds, while the first short-distance migrants are making initial appearances. As such, we captured the first Ruby-crowned Kinglet on September 10, the vanguard of many, many more to come, and an early young White-crowned Sparrow was seen on September 11 and 12. The first birds of this species are usually detected in mid-September with the majority of arrivals at the end of the month. A few Lincoln’s and Swamp Sparrows have also been observed and banded, as well as White-throated Sparrows. The gaudiness of warblers is being exchanged with the subtleties of sparrows!

American Pipits were heard and seen a few times, notably a small flock of eight on September 10, tumbling down from the sky to explore the rocky shore of Georgian Bay. The American Pipit is a bird of open land and unbroken horizons, at home in the tundra of the Far North or in the alpine meadows of high mountains. In Ontario, it breeds along the shores of Hudson’s Bay. Features of its habitat preferences also apply during migration and winter, with it enjoying beaches and pastures and plowed fields. With nets in shrubby and treed habitats, only four Pipits have ever been caught in 22 years of banding at Cabot Head, one in spring 2016 and three in as many fall seasons (2002, 2004, and 2015). 

Already two paragraphs on and I haven’t mentioned REVI even once! Not to worry, they still enchant our days with their presence in trees and shrubs and lively spirit when caught in the nets (read: feisty and snappy!). As predicted, we broke the 18-year-old record of fall 2005 this past week (239 banded REVI) and easily galloped past it: the current total stands at 273 REVI banded. Numbers captured this past week were not as significant as in the weeks prior, with the one-day highest of ten birds on September 11. Nonetheless, with captures daily and still about two weeks of passage, it seems now quite possible to reach 300 banded REVI in one season…

In September, it is also peak passage for the long-distance Catharus thrushes, the Veery, Swainson’s and Gray-cheeked Thrushes, all on their way to South America. These secretive species are mostly detected through banding rather than observation/vocalization. Among this trio, the Swainson’s Thrush is always the most numerous, although with considerable variations across the years (fall banding totals range from 10 in 2006 to 79 in 2015). There are already 44 Swainson’s Thrushes banded this fall. In fall 2005, only 36 Swainson’s Thrushes were banded.

As mentioned in a previous blog, the fall of 2005 was remarkable with the numbers of berry-eating birds captured, notably REVI, but also Yellow-rumped Warbler, Cedar Waxwing, and White-throated Sparrow. Like Red-eyed Vireo, these three species were banded in record numbers that year. But, unlike REVI, these records appear secure and safe this fall once again as we are not banding these species in any ‘threatening’ numbers. Local resources (in the form of chokecherry or, like this year, arrowwood berries) clearly influence the stopover behaviour of migrant birds, in both attracting and retaining them. But it is also clear that there are subtle differences between species and within individuals, impacting who stays where and for how long. 

We have still so much to learn in this immense world.