Migrants are finally starting to trickle through the area! We had a front pass last Friday; a squall line passed late in the day and the winds shifted hard to the NW and N immediately afterwards. The timing wasn’t the greatest for getting lots of birds to fall out at Cape Florida, but there was a noticeable influx of Prairie warblers on Friday and Saturday and we banded nearly 20 of them.
The wind then continued around to the NE and is now out of the E for the rest of this week, with a new front possibly coming this Sunday or Monday. As a consequence of the wind shift the bird activity dropped again to mostly the wintering species. Gray catbirds seem to be in no hurry to leave, and they are serenading us at sunrise with their beautiful songs. A few Swainson’s warblers and Worm-eating warblers are also on the move right now, coming up from points south. We also recaptured two Northern cardinals originally banded in Fall 2019 and Fall 2020. These are one of the few species that stay year-round at Cape Florida and breed here.
We continue to catch mostly birds that have spent the winter at Cape Florida, including this Ovenbird which has come back for 9 years at least; he was banded as an adult in 2012!
Male Chuck-will’s widows are on the move, and we have banded 3 so far. We hear them singing every morning in the dark while we open the nets. This is truly a bizarre bird, and don’t let the tiny beak fool you. Their mouth opens up to be half the size of their head like a feathery Pacman.
Among the species getting ready to leave for the summer is this handsome Blue-headed vireo. They will head to forests across the Northeast US and Canada to breed. Some are singing already before they go.
We finally caught a migrating individual! This Worm-eating warbler was extremely fat, compared to the lean birds we had otherwise been catching. Fat is the fuel for migration, and the physiology of migrating birds changes to accommodate the extreme demands of the trip. The most important are the metabolic changes that make birds hungrier and cause their bodies to deposit these fat loads. Non-migratory birds usually do not carry large fat loads, so this is one way we can tell wintering individuals from those in-transit among species that winter here. The Ovenbird from 2012 was also fat, so he is getting ready to begin his migration. He is probably gone by now with all the southerly winds we have had over the last week.
The partnership between Tropical Audubon Society and the Cape Florida Banding Station is allowing us to begin regular spring migration banding for the first time in our 20-year history. We have had spring banding sessions previously in 2007, 2009-2011 and 2014 in cooperation with researchers that were using our site to collect data. Our very first bird banded this year was this Hermit thrush, an uncommon wintering species in the Miami area.
We technically have not banded an active migrant yet as it seems to be a little early. Instead we are getting an interesting sample of who has been spending the winter in the restored hardwood hammock habitat at Bill Baggs Cape Florida State Park. This is important data, even though right now we only catch a couple of birds a day. Several of these birds were banded during previous seasons, including an Ovenbird which has been returning to spend the winter here since 2014. The waves of northbound migrants will increase all through April and peak in late April or early May. In the meantime our new volunteers have time to learn where the nets are, and we are all enjoying the beautiful spring temperatures!
(Nov 7) Since 2020 insists on continuing to be weird we are ending the season under a tropical storm warning. We were expecting to be taking the nets down in the pouring rain but it held off all morning, allowing us to band until we were ready to stop. The wind was up and the skies were overcast, layered and complex like they get when something tropical is coming. I heard a thrush call while I opened nets in the dark, and when I came back by the first net I had opened, she was captured already. A very small Catharus; she measured out as a pure Bicknell’s and was our second of the season, breaking records for yet another species that is usually migrating out over the open Atlantic.
And this is why we close when we do, since migration becomes a trickle again in November. The species lineup is still mostly long-distance migrants, although a lot of individuals of these species do spend the winter in the local area. Some nice portraits of our regulars to end the day on:
L: HY M Black-throated blue warbler; R top: Gray catbird, R bottom: Northern parula (photos by Marc Kramer)
We’re hoping the torrential rain that is forecast to start this weekend holds off long enough so we can enjoy our final day. Right now the air feels slightly drier and pleasant, but the moist tropical air is never too far away at our latitude and remnants of Eta are percolating to our south, possibly heading our way. We have had a lot of rain this fall, making it hard to run Net 20 which right now looks like it could be in the middle of the Everglades.
Today turned out to be a majority recapture day, with 9 recaps of 9 species comparing to only 6 new birds of 4 species. The birds are once again waiting for a weather window for a good passage to the Antilles and Central America. Perhaps they even sense the low pressure in the Caribbean, and know not to leave right now.
The theme of slow and windy yet diverse days continues as we pick up a few extra species right at the end. This young female Yellow-bellied sapsucker is the first one we have banded since 2013. Before then we used to catch them about every other year. This is a highly migratory woodpecker, unlike most other species that are residents year round. They are responsible for the neat rows of holes you can sometimes see in the trunks of trees and palms.
The strong east winds continue and they will be with us for the last 4 days we are open, with rain chances picking up by the weekend. This will likely keep us from having any more busy days, but we can always go for quality. And today delivered as the 19 new birds banded were of 11 species, including a Wilson’s warbler! This species is an extremely abundant migrant across the West but is rare in Florida. We have only banded 6 in the past 18 years. And it is too bad that the genus Wilsonia is no longer a thing, because otherwise we would’ve gotten a hat trick with Hooded, Canada and Wilson’s warblers this year. Here is a photo gallery of some of today’s beauties.
Left: Wilson’s warbler (Brian Cammarano); Middle top: Black & white warbler, Bottom: Painted bunting; Right: White-eyed vireo (all Steffanie Munguia)
It is getting really windy due to a strong gradient between high pressure in the Atlantic and low pressure in the Caribbean that also includes Hurricane Eta who is about to cause major problems for Nicaragua and Honduras. Our nets are protected by the trees so we were able to band today, although if it gets much windier we will have to close. Land areas are currently under a high wind warning while the ocean is under a gale warning. Today featured a little more than half of the numbers as yesterday but the species lineup was quite nice, including two first-of-the-seasons: Tennessee warbler and Myrtle warbler. The 2260 birds captured so far puts 2020 in third place for overall numbers: second place 2015 with 2324 captures is in reach but there is almost no way we will beat 2006’s 2561 captures.
Left: Tennessee warbler Right: Myrtle warbler (photos by Brian Cammarano)
Most banding stations along the Atlantic coast are swarmed with Myrtle warblers, AKA ‘butterbutts’, in fall migration. They are also abundant in South Florida, but they take so long to trickle down here that we often don’t catch any before closing.
This morning we at least heard and saw warblers dropping in right after sunrise, especially Northern parulas, Cape Mays, and a couple of first-of-season Myrtle warblers. The nets, however, seemed to only attract Gray catbirds and Black-throated blue warblers until the 1000 run, which contained all of the diversity for the day. Nearly all of the captures today were very fat, so they seem to be enjoying a good migration.
These two females are perfect examples of confusing fall warblers: whitish-yellowish streaky underneath, greenish on top, wing bars, tail spots, stripe through the eye. They actually are more different structurally than plumage-wise this time of year. The Cape May warbler on the left is a smaller bird with an overall stockier build and a slightly downcurved bill. The yellow rump patch can be diagnostic, but a third species (Myrtle warbler) pretty much looks the same as these two, has a much more obvious yellow rump, and is extremely abundant by December. The Blackpoll warbler on the right is a long-distance migrant, with some individuals traveling between Alaska and South America. They are large (by warbler standards) and have very long wing tips. Blackpoll legs and feet are at least slightly orange, while the other similar plumaged warblers all have black or grey legs.