Today continued with a similar species composition to yesterday, minus 100 extra Black-throated blues and American redstarts. Another Yellow-billed cuckoo and Chestnut-sided warbler were banded, along with more Swainsons’ thrush, another Magnolia warbler, and the usual Caribbean migrants. A majority of yesterday’s birds were surprisingly lean; most still had good muscle but they had used up their entire fat reserves prior to arriving here. This is not what we usually see on a big day when fat birds are forced to land by a weather event. There was a percentage of very fat individuals mixed in, too. This was true across most of the species banded yesterday.
Two views of the adult male Connecticut Warbler. (Photos by Kristen Brush)
I follow the Kiawah Island Banding Station pretty closely since they are directly upstream of us, and yesterday they commented on the fact that there was a nearly continual band of storms just off the Atlantic coast stretching from Florida to the Outer banks of North Carolina. Any bird taking the offshore route south would have had to navigate these storms, so it is possible this cohort of migrants burned through their fat reserves fighting bad weather at sea. This is all speculation, however our first Connecticut warbler of the season was in fairly bad shape with no fat stores and reduced breast muscle mass. Once a bird’s body uses up its fat it will begin to break down its own muscle for energy, the same muscle that it needs to keep flying. This is a dire situation, so a landfall location such as Cape Florida means the difference between life and death. With a proper food supply the bird will rebuild fat quickly and muscle more slowly, allowing it to continue its migration. We banded an emaciated Magnolia warbler late last week and recaptured her Sunday, and she was on her way to regaining her lost fat and muscle mass.
Surprisingly, no one bothered to take a photo of the FOS Gray catbird. I suppose we’ll catch another one.
| SPECIES | NEW | RETURN | RECAP |
| Yellow-billed cuckoo | 1 | – | – |
| Red-eyed vireo | 6 | – | – |
| Swainson’s thrush | 2 | – | – |
| Gray catbird | 1 | – | – |
| Northern parula | 3 | – | – |
| Chestnut-sided warbler | 1 | – | – |
| Magnolia warbler | 1 | – | – |
| Cape May warbler | 6 | – | – |
| Blackpoll warbler | 1 | – | – |
| American redstart | 12 | – | 6 |
| Black-throated blue warbler | 8 | – | 6 |
| Black & white warbler | 4 | – | 3 |
| Northern waterthrush | 1 | – | 1 |
| Ovenbird | 10 | – | – |
| Swainson’s warbler | 1 | – | – |
| Worn-eating warbler | 5 | – | 1 |
| Common yellowthroat | 5 | – | – |
| Connecticut warbler | 1 | – | – |
| Painted bunting | 2 | – | – |
| # BIRDS CAPTURED | # SPECIES | # NETS | NET HOURS | CAPTURE RATE (BIRDS/100NH) | |
| DAILY TOTAL | 71 | 19 | 23 | 157 | 56.05 |
| SEASON TOTAL | 1437 | 44 | 23 | 6193.55 | 25.72 |