The last few days have featured light westerly winds and the migrant birds have been slowly increasing in numbers, with a 41-bird high on Sept 4. Today we woke up to humid conditions and birds in the air. We caught nothing for the first couple of net runs, and then some birds finally settled into the woods. Bobolinks continued to flow overhead for a large part of the morning. On the ground we had diversity today, with 10 species represented among our 17 captures. Several of these birds were very fat, including a Louisiana Waterthrush weighing in at 27.5 grams! These guys usually weigh around 20 grams so he was carrying quite the fat load.
Birds are on the move to the north of us in Georgia due to a cold front that will fizzle as it works its way down the state. Hopefully it will encourage migrants to get a move on and continue down the peninsula this weekend! We are just starting to really get into the heart of migration season.
As August rolls into September our species diversity is slowly climbing. We have added Chuck-will’s Widow and Traill’s flycatcher to the roster, while the pace of the Caribbean-wintering warblers is picking up. Today we banded 19 new birds of 8 species and captured one returning Ovenbird, banded in Fall 2020. The weather was bright and hot but there were birds around anyways, and they stayed active all morning. Blue-gray gnatcatchers were up in the canopy evading capture, and a couple of them (plus a Prairie warbler) were singing a little bit. Not with the same enthusiasm as spring, of course, but any song is nice to hear!
We banded our first Black-throated Blue Warbler of the season on August 23, and there will be many more to come. There always are a few early individuals moving through already, but we don’t expect the bulk of the Blues until late September and October.
The star of the day (OK the week) is this young Canada Warbler. We only have banded 11 others out of 40,000 birds so they are not very common here at all. These birds have a slender shape with large eyes, very similar in structure to Hooded Warblers but with a very different color pattern. The big eyes suit their lifestyle in the understory of thick boreal forests in the Northeast and, yes, Canada. They go all the way to northern South America to spend the winter.
The weather cleared up this week and the winds continued out of the east, making for a slow trickle of birds coming south. Most days we caught only between 2 to 5 birds, including young Northern Cardinals that are exploring the woods and stumbling into the nets that their savvy uncaptured parents know are there. A second Louisiana Waterthrush and two Prothonotary Warblers were nice captures, as these species are early migrants that will already be on their wintering grounds by September. In the old days the Prothonotary was known as the Golden Swamp Warbler, and they can be found breeding as close by as Big Cypress.
Today we had a nice burst of activity and ended the day with 13 new captures. Despite the brilliant sunshine, August heat and quiet woods, multiple migrants found the nets throughout the morning. A minor invasion of Black-and-white Warblers took place late in the morning, and we banded 5 of them between 11 and 12.
We were able to band most of the morning today under cloudy and drizzly conditions, and started the season with 9 birds of 6 species! Our first capture was an adult male American Redstart and # 2 was a Louisiana Waterthrush, a very early migrant that first arrives in our region in July. Migration seems to be well underway at this time, and interesting birds are being reported around South Florida. The pace of migration will accelerate, slowly at first and with more momentum in September, reaching a peak in numbers and diversity between late September and mid-October.
It is always so exciting at the start of a new banding season, wondering what we will catch this year. The weather, proportions of regular species caught, any rare birds and the energy of the volunteer teams combine to make each banding season have its own ‘atmosphere’.
Fall banding will start on August 15, 2021 and continue daily through Nov 7. We have a few slots open for new volunteers. If interested, please contact Michelle Davis at firstname.lastname@example.org or text 305-582-4165.
The last week of banding for the Spring 2021 season followed a similar pattern to the previous week. Banding was slow at the beginning of the week and picked up a little towards the end due to a brief wind shift to the west and then north. As has been the case all spring, the north and west winds didn’t last long so our biggest day was 42 birds. We had only one 100+ bird day the whole season, back on April 22. The biggest fruit crop we have seen in years from the native trees and shrubs largely fell to the ground uneaten.
Where were the migrating birds this spring? Passing by our region to the west most likely, based on overnight weather radar images. Large numbers of spring migrants generally don’t put down in our area unless the winds are out of the west or north, causing them to pause their journey. Winds were east or southerly for the majority of the spring season, providing a tailwind for the birds. The bulk of spring migration generally is over the Gulf or around the western edge through Mexico and Texas. Fall migration is shifted east enabling us to catch more birds of a greater number of species and this is the main reason we have put our effort into maintaining a continuous fall banding presence since 2002.
In spite of the lower numbers, we caught all of the species we expect to see more in spring than in fall. This last week added Bicknell’s thrush and Connecticut warbler to the roster, bringing the total to 963 birds banded of 33 species. 26 of these birds were banded in other seasons and were recaptured in 2021 either because they are residents (Northern cardinals) or wintering individuals that are using the restored habitat at Bill Baggs Cape Florida State Park year after year. The oldest of these was an Ovenbird that has been returning to spend the winter since 2012.
Thanks to all of our fantastic volunteers new and returning! This project would not be possible without you.
One of the most important food trees for migrating songbirds is the Florida Strangler fig (Ficus aurea) and they are heavily in fruit right now on our site, although there aren’t too many birds around to take advantage of it and fruit is falling uneaten to the ground. These distinctive trees are known for sending tendrils around other trees that become roots in ornate patterns. They fruit year-round but seem to be especially prolific this spring. Watch for Black-throated blue warblers with the large fruit impaled on their bills while they eat it from the inside out, eventually dropping the husk on your head as you look up at them.
We had a burst of activity on Friday May 7 and Saturday May 8 associated with another brief westerly wind shift, and caught 40 then 35 birds each day. American redstarts in particular were abundant in this wave of birds, and we started to see more young males and females.
Southeasterly winds had returned by Monday and we were back down to an 8 bird day, despite passing showers overnight and during the morning. One was this beautiful female Blackpoll with an intricate black, yellow and white plumage.
The total number of migrants captured during the last week went back down but we had some highlights that added some interesting diversity. The most notable bird is this male Mourning warbler banded today; a very rare species in South Florida. We see them occasionally in the Fall but there are very few spring records. Mourning warblers almost entirely migrate around the Western Gulf up through Texas on their way to and from breeding grounds in Canada, so this guy is pretty far off course. They are somewhat similar to Common yellowthroats and also hang out in dense understory, but Mourning warblers are brighter yellow underneath and the adult male has a distinctive dark gray head with a black bib.
Here are some of the other new species to come through in recent days:
Winds are forecast to be out of the south for the rest of this week with little rain, so we don’t expect any big numbers of migrants to settle in as the tailwind will likely carry them over us each night.
This last week did prove to be much more active, and our overall total for the season jumped from 241 to 605 birds captured. We added Yellow-billed cuckoo, Gray-cheeked thrush, Blackpoll warbler and Summer tanager to the species list, and caught a lot more of species such as Black-and-white warbler, Black-throated blue warbler, American redstart and Common yellowthroat. Several fronts worked their way down Florida in the last week, causing brief windshifts to the west and bringing us birds. The overall volume of migration has been steadily increasing, with large pulses of birds coming up overnight from western Cuba or from the southeast through the Bahamas. There have been a lot of strong southerly winds this spring which have made for a quick passage through Florida; great for birds but less exciting for birders in deep South Florida. Still, we managed to have better days this last week and broke out of the 5 to 20 birds a day rut we were stuck in for the previous 5 weeks with 46 birds on the 21st, 142 on Earth Day, 60 on the 23rd and 72 birds today. All the new volunteers were finally able to practice their extraction skills and get up to speed.
Sometimes excellent migration conditions take birds away from the Cape without replacing them. This happened over the weekend with the ripping southerly wind overnight on Saturday; all the singing Gray catbirds were gone as well as the lingering birds from the big movement on the previous Thursday. We caught 2 new birds on Sunday but were back up to 72 new birds today when the wind came around to the NW then W overnight. Flocks of warblers trickled in all morning, and they had collected in a couple patches of fruiting ficus and budding trees of other species by the afternoon. Black-and-white and Black-throated blue warblers as well as American redstarts were well-represented today. A Black-whiskered vireo sang his head off all day but never stumbled into a net. Blackpoll warblers have been noticeably absent so far this spring; I was expecting some to come in later today but nope! Usually they are moving through in good numbers by late April.
We still are waiting for a big day of banding, but the weather remains mild. The winds have been mostly southerly all week and there has been little rain, so the conditions for migrating are excellent and birds are making as much distance as possible each night. Still, more are landing at Cape Florida and our daily captures are ranging from 10 to 24 birds instead of 2 to 7. Some new species are starting to show up:
The Black-whiskered vireo is the tropical counterpart to the widespread Red-eyed vireo, and South Florida is close to the northernmost extent of its breeding range. This guy, unlike the other three warblers pictured, is probably going to stop in the area and set up a territory somewhere. They do breed on Cape Florida, but are mostly gone when we come back to band in the fall. One year we did have a male still singing on his territory around the banding station in August, so eventually we caught and banded him!
The forecast for next week calls for continued south to southwest winds and chances of rain most days. We will see if this weather interacts with the migrants to make more of them land at the Cape. The volume of birds passing over is increasing every night. Many of the ficus trees (strangler figs) have ripe fruit right now, so the buffet is set!