A final tally!

Three weeks have now passed since the nets were taken down and stored away at Cabot Head. Winter is in the process of slowly arriving. I have been busy with data analysis and report writing. As (more or less) promised, here are some numbers, reducing the beauty and magic of migration into cold, sharp mathematical summaries.

From August 16 to October 31, we detected a total of 133 species, which is around average for the fall season. Among them, 78 species have been seen every fall (58% of the seasonal total). Black-crowned Night Heron, with two birds seen in the morning of August 24, were a first for Cabot Head during monitoring period. I remember hearing them first, and then, seeing two of them one evening in spring 2010, flying towards and over Georgian Bay. Another first, this time for the fall, is the Eastern Meadowlark seen on October 25.

In total, this fall, 1,691 birds of 66 species were banded and 151 birds of 32 species were recaptured. The number of birds banded is around the average, although it is very variable at the species level, with ups and downs as expected. The week of October 3 – 9 was the time to be at Cabot Head: 531 birds were banded, that is, 31% of the season total! It was mostly the two species of kinglets (Rudy and Golden-crowned), Brown Creepers, and Dark-eyed Juncos.

Among the recaptures, there was a male American Redstart banded in spring 2010 in its Second-Year. It means that this bird hatched in the summer of 2009 and is now seven years old! It was also recaptured in fall 2013 and spring 2015, a strong indication of being a local breeder. The oldest American Redstart on record is ten-years and one-month old, banded and recaptured in Ontario. For fun, you can visit the “Longevity” page of the US Bird Banding Lab (at http://www.pwrc.usgs.gov/BBL/longevity/Longevity_main.cfm). Recapture data are always fun, even if the birds are banded during the same season. We can learn about the duration of their stay and the variability in their fat stores. For example, this year, we recaptured ten of the 58 Red-eyed Vireos we banded earlier this season. Only two lost some weight between the first and last captures, but the other put on weight (which is a good thing for a migrating bird!), some quite dramatically: from 15.1g to 18.5g in six days!

While these are interesting pieces of information, there is, of course, much more to say. The seasonal report should be up on BPBO website soon.

This should be now the last posting of 2016. I shall return to Cabot Head next spring. In the meantime, thank you for following and supporting BPBO. I wish you a good winter, filled with birds, of course!

Posted in STATION NOTES / BLOG

Leave a Reply

Your email address will not be published. Required fields are marked *

*