This is an older article (28 October 2020) from BirdsCaribbean, but this time of year marks the migration of many species. As Gail Karlsson writes, some warblers live in the Caribbean year-round, some spend the whole winter there, and others are brief visitors in Fall and Spring. Karlsson has also learned that some warblers, like the Adelaide’s warblers have begun to move from Puerto Rico to the Virgin Islands. Furthermore, she underlines the importance of preserving the native flora for the preservation of these and other birds. Here are excerpts; read more at BirdsCaribbean.
Migrating warblers generally arrive in the Virgin Islands without great fanfare. They are small and don’t travel in big groups. Then after they land, they hide in the treetops or underbrush. And although they are songbirds, they usually sing to attract mates during their breeding season up north and are pretty quiet when they are here.
I only recently began looking for migrating warblers. It takes a lot of patience, but if you look carefully, you can probably spot some of these tiny travelers.
Adelaide’s Warblers on The Move
The Yellow Warblers I do see near the mangroves are mostly permanent residents. At first, I thought those were the only ones living in the Virgin Islands year-round, but then I heard that some Adelaide’s Warblers had begun to move over to the Virgin Islands from Puerto Rico. I learned about them from Richard Veit, a professor from the College of Staten Island and the City University of New York Graduate Center, who for many years brought students to St. John for a Tropical Ecology course. [. . .]
The Elusive Warblers: Keeping Ears and Eyes Open
Although warblers don’t usually sing unless they are breeding, they do make small ‘chip’ sounds to communicate with each other. I learned that there are slight differences in the ‘chips’ produced by different birds, which experts can recognize. I couldn’t do that, so I was mostly looking around for movement in the trees, but I did get interested in spotting warblers.
I started paying more attention when I heard little ‘chip’ sounds in the trees and spent more time quietly waiting for the birds to show themselves. After a while I began to be able to identify some of them by how they moved around.
It also helps to learn more about which types of migrating warblers visit the Virgin Islands, and what they look like. Black and White Warblers generally crawl along a tree’s trunk or branches, looking for bugs.
On their way back to South America in the fall, the Blackpolls gather along the northern part of the east coast (a 3000-mile trip for the ones in Alaska). They wait for a night when there is a favorable tailwind blowing out of the northwest, and then take off. They head away from the coast far out into the Atlantic Ocean, flapping their tiny wings about 20 times per second. After a few tiring days, they get far enough south to be pushed back eastward towards South America by the trade winds.
A few Blackpolls sometimes stop in the Virgin Islands during their fall migration, though they don’t usually stay long. What a thrill to see them on their journey.
The Importance of Native Trees
For people living in the Caribbean, one of the best ways to be able to see wintering warblers is to preserve native trees that support a variety of insects. Non-native plants are often unattractive to local insects, and so are not useful for bug-eating birds. Also, cutting down trees, and using pesticides can eliminate important food supplies for birds. [. . .]
[Gail Karlsson is an environmental lawyer, writer and photographer – author of The Wild Life in an Island House, plus the guide book Learning About Trees and Plants – A Project of the Unitarian Universalist Fellowship of St. John. She writes frequently about connecting with nature, including for the St. John Source. See gvkarlsson.blogspot.com and uufstjohn.com/treeproject. Follow her on Instagram @gailkarlsson.]