The end of a Fall season is always bittersweet

As I’m writing these lines on November 3rd, the nets have been taken down and packed away, the banding lab cleaned and closed, and no one is doing the daily census: The Fall season ended once again on October 31st. It is always with a mixture of sadness and gratefulness, as well as a sense of accomplishment, that one ends another season of bird migration monitoring at beautiful Cabot Head. 

The last week was actually quite fun and busy, making it even harder to end… although the big snow squalls on the very last day, October 31st, made it less enticing to keep going. Not too surprisingly for this time of year, the first four days of the week were marred by bad weather, either rain (sometimes heavy) or wind, or a combination of both, making monitoring difficult, even almost impossible at times (except for the daily census; it happens rain or shine). 

A Rough-legged Hawk was seen on the rainy day of October 25, freshly (?) arrived from its northern tundra. This Holarctic species is a true denizen of the tundra, inhabiting treeless expanses of unfathomable horizons. Many, if not all, migrate South when winter arrives, hunting open lands for small rodents upon which to feast. While Rough-legged Hawks are relatively frequent on the Bruce Peninsula during the winter, they have been detected at Cabot Head in the fall in only five previous seasons from October 12 to 31 with one or two birds at the most. 

A young Red-headed Woodpecker was seen three days in a row in the alvar, from October 26 to 28. It is the latest sightings ever recorded for this Species-at-Risk at Cabot Head, which had been previously detected in 14 previous Fall seasons (usually one or two birds at the most).

After very little banding done in the first four days of the week, conditions improved enough to open most of the nets for the six regular hours. And not for nothing: the numbers of birds caught were among the highest – if not the very highest – throughout the years for these last three days, with 35, 41, and 47 birds caught, respectively. Most of the birds banded during this time were American Tree Sparrows, with a total of 51 birds for the three days, bringing the season total to 103 birds. Catching about 50% of the season’s total in the last three days of banding is a clear illustration that the American Tree Sparrow is a late migrant. It is likely that in some years, most of its migration is missed at Cabot Head, with birds largely moving through in November. As a consequence, Fall banding totals have been very variable across the years, from a low of four birds in 2018 to a high of 94 in 2015. Yes, the Fall 2023 total of 103 American Tree Sparrow is a new banding record for Cabot Head!

Quite a few Dark-eyed Juncos got banded as well during the last three days, notably 17 birds on October 31. This species breeds in small numbers on the Bruce Peninsula, which is why one Junco was banded as early as August 15 this year. Its migration is also more extended that Tree Sparrows, with birds arriving in numbers from mid- to late- September. Juncos were actually banded almost daily this Fall from mid-September to the end of the season, for a season total of 174 birds, the second highest ever after 184 Juncos in Fall 2021.

During census on October 29, my ears perked up having heard a soft whistle: a female Pine Grosbeak was quietly feeding in a low shrub, giving me perfect views. It is a relatively rare visitor from the Boreal forest, having been detected only in ten previous Fall seasons. 

It was a visitor from the South that surprised me on October 31: a male red-bellied Woodpecker was caught in a net! This sedentary, but with an expanding range, beautiful woodpecker is seen quite regularly at Cabot Head (in 14 of the previous 21 fall seasons) but does not often end up caught in a net: only eight birds have been banded in six previous Fall seasons (remarkably, three in Fall 2016).  

The last day of monitoring also brought a delightful observation of a family of Tundra Swan (with two young) heading South, gently calling while flying in front of Middle Bluff. It is only the third time that Tundra Swans have been detected in the Fall, with a family of four both previous times (October 4, 2014 & October 27, 2022).

The final banding tally for Fall 2023 is 2121 birds of 70 species. It is the fourth highest banding total for a Fall season. Two species, Red-eyed Vireo (with 302 birds) and American Tree Sparrow (with 103 birds) were banded in record numbers. Alongside Golden-crowned Kinglet (314 birds) and Dark-eyed Junco (174 birds), they account for 42% of the season total. There will be more details and more numbers in the upcoming seasonal report, to be posted on BPBO website (before Christmas).

Beside numbers, it was another immensely satisfying season, full of beautiful birds, changing weather, the slow movement of the Earth spinning through space, and, last but not least, fantastic volunteers. Without them, we couldn’t do what we do. So, I would like to extend my gratitude and thanks to them once again. (Rest assured that I do tell them in person too!)

I already (?) look forward for the next Spring season. In the meantime, may you all enjoy a wonderful winter.


Station Scientist