April was a busy month for people at the Banding Station as we hosted Outdoor Afro, Tropical Audubon, and Boy Scout Troop 314, as well as independent visitors from as far away as Poland. We showed birds in the hand to dozens of local Key Biscayne residents and potential new birders at the inaugural Marius Robinson Bird Festival, held on April 23 in Bill Baggs Cape Florida State Park. Visitors braved the nasty mosquito outbreak to see a nice selection of catbirds, warblers and buntings.
Miriam and Rachel show a Worm-eating Warbler to bird walk participants at the Marius Robinson Bird Festival on April 23. (Photo by Eliana Ardila)
The east winds continued all through April, and bird migration was very sparse through Cape Florida during the last week of the month. We were entertained by several Indigo Buntings that were molting into their gorgeous spring colors, and thrushes started to appear, especially Veery. A male Scarlet Tanager remained frustratingly out of reach above one of the nets for an afternoon. Mosquitos were awful as a result of the flooding rains that occurred on April 11 and 12. And it was hot.
Indigo Bunting male (photo by Nasim Mahomar)
A dramatic squall line blew through South Florida on April 30, and we woke up to a new world on Monday, May 1. The wind was blowing strong out of the west, the humidity was lower, and mostly there were birds around!
Black-throated Blue Warbler female (photo by Miriam Avello)
The west winds held for the next 5 days, and the number of birds passing through Cape Florida kept increasing every day, peaking on May 3 and 4. All of the common species that winter in the Greater Antilles were well represented, and we banded our first Connecticut Warbler of the season on May 3! Hopefully we will see a few more in the next week before we close on May 15.
American Redstart second-season male (photo by Miriam Avello)
There were a lot of male American Redstarts around, including the splotchy second-year males that sometimes remind us of acne-riddled teenagers. The American Redstart is the only warbler that takes two years to reach the adult black-and-orange plumage, although the second-years can hold territories and breed. Black-throated Blue Warblers were also on the move, with a majority of them females. Some other less common species were sprinkled in, too, such as this Magnolia Warbler and two Swainson’s Thrushes; a rare spring migrant on the Atlantic coast in South Florida. Both Gray-Cheeked Thrush and the closely-related Bicknell’s Thrush were also banded.
Magnolia Warbler male (photo by Michelle Davis)
Blackpoll Warbler male (photo by Michelle Davis)
The species diversity in spring is much lower than in the fall at our location, as the majority of neotropical migrating birds are moving north across the Gulf or up through southern Texas to then spread out across eastern North America. Birds moving through the Florida peninsula are almost all coming from the Greater Antilles or northern South America, and the Central American wintering species that add exciting diversity to our days were mostly seen in Key West or points further west. However, sometimes we see more individuals during the big spring fallouts. It is rare that we have to close nets due to a high volume of birds in the fall, but we closed all the nets on May 3 and reopened only a section of them after we caught up banding. We only opened 11 nets on May 4 and still banded plenty of birds.
West winds were driving the northbound birds out over the Atlantic, and some friends on a boat offshore saw flocks of hundreds of warblers heading north. We had a mix of physical conditions and some birds were very skinny while others of the same species were very fat. One of the reasons we have larger waves of birds in spring is that their migration period is more compressed than in fall, with the bulk of migrants moving through our area in a two to three week period around the end of April and beginning of May. Fall migration is more drawn-out, with the adult birds moving quickly south and the young of the year finding their way down for the first time. Spring birds are on a mission: get that nice territory and get that nest built and eggs laid!
Julie, Michelle and Liz banding on May 3. (photo by David Die)
Total banded (May 3/May 4) 230/148
Veery- 1/0
Gray-cheeked Thrush- 1/0
Swainson’s Thrush- 1/0
Gray Catbird- 1/0
Northern Parula- 3/0
Magnolia Warbler- 1/0
Cape May Warbler- 2/1
Black-throated Blue Warbler- 37/56
Blackpoll Warbler- 4/2
Black & White Warbler- 40/7
American Redstart- 30/6
Worm-eating Warbler- 3 /4
Ovenbird- 19/20
Northern Waterthrush- 18/17
Connecticut Warbler- 1/0
Common Yellowthroat- 68/35
