After an extended summer hiatus, we opened our nets on Labor Day, September 2nd. This is a slightly later start than normal, but the move seems to have paid off, with a total of 150 birds banded in our first week! (Especially notable given this was across only four days of banding). We thankfully do not seem to have missed too many early migrants, with a couple of Swainson’s warblers among the 150 banded, but we managed to skip over those excruciatingly slow days that typically characterize our first week.
Unfortunately for us, that doesn’t mean we skipped over the high heat and humidity of late summer/early fall in South Florida.
This isn’t terribly surprising given that 2024 was one of the top 10 warmest summers on record in South Florida, and despite a relatively dry start, we’ve been experiencing atypical overnight and morning rains over the last month. But what does this mean for the birds, and the volunteers who monitor them?
First and foremost, it means we are taking extra precautions to minimize any risk to the birds and volunteers. Our leadership team is currently learning from best practices at other stations to set maximum operating conditions when the heat index is high. We are also paying especially close attention to our more exposed nets, making sure we close them when they are in direct sunlight. Volunteers and visitors should pack extra water and electrolytes (and I suspect CamelBaks will become the most popular accessory of the season). All of these changes, combined with our reduced opening schedule of only four days a week, means we can expect some lower numbers overall this season. That’s a trade off we’re happy to make to protect our birds and team.
These extreme conditions are likely to impact our migrants as well. While the most severe impacts of high heat conditions are typically experienced on the nesting grounds, when nestlings are unable to escape the heat in the nest, birds aren’t immune to high temperatures when migrating. When climate conditions change, species have three options: change their morphology, change their behavior, or change their range (including potentially becoming locally extinct in historic parts of their distribution). Data collected at bird banding stations like ours help scientists understand these shifts.
For example, a 2021 study found that the body mass of migratory birds had reduced significantly over the last 40 years of warming, while their wingspans became longer. The scientists hypothesized these changes may help the birds dispel heat, and may also facilitate longer, sustained flight to keep up with shifting ranges. Frequent birders might already be familiar with some of the behavioral changes associated with warm days, including birds becoming generally less active to reduce the risk of overheating (unless the insects are particularly active that day), and spending more time in the understory, as opposed to foraging in the upper canopy where they are more exposed to the sun. And of course, a warming climate means migratory birds are shifting their breeding and wintering ranges, and the timing of migration, often with disastrous effects.
There is still a lot left to unravel about bird migration, but scientists and bird lovers alike are increasingly left with the impression that time is running out to find these answers before climate disruption fundamentally changes the questions. You can help us keep up with the birds by recording your observations on eBird and supporting the banding station with a donation. In the meantime, we’ll continue to band our avian visitors and learning as much as we can from them as safely as possible so they may continue their herculean journeys. And of course, we’ll continue to share what we learn with you – stay tuned!
| SPECIES | NEW | RETURN | RECAPTURE | TOTAL |
| Chuck-will’s widow | 1 | 1 | ||
| Red-eyed vireo | 1 | 1 | ||
| Blue-gray gnatcatcher | 3 | 1 | 4 | |
| Northern parula | 5 | 5 | ||
| Cape May Warbler | 5 | 5 | ||
| Black-throated blue warbler | 7 | 7 | ||
| Yellow-throated warbler | 2 | 2 | ||
| Prairie warbler | 1 | 1 | ||
| Black & white warbler | 18 | 2 | 20 | |
| American redstart | 30 | 30 | ||
| Worm-eating warbler | 29 | 29 | ||
| Swainson’s warbler | 7 | 2 | 9 | |
| Ovenbird | 29 | 1 | 4 | 34 |
| Northern waterthrush | 12 | 12 | ||
| Louisiana waterthrush | 1 | 1 | ||
| Common grackle | 1 | 1 | ||
| TOTAL | 152 | 1 | 9 | 162 |
| # BIRDS CAPTURED | # SPECIES | # NETS | NET HOURS | CAPTURE RATE (BIRDS/100NH) | |
| Total from 9/2 – 9/7 | 162 | 16 | 21 | 417.84 | 38.77 |
Post by Steffanie Munguia, Data compiled by Nicole Rita