The endangered Bahama Warbler may be surviving on just one island following Hurricane Dorian’s devastation in 2019, according to researchers at the University of East Anglia.
A new study shows the bird’s distribution and ecology on Grand Bahama Island before the hurricane struck. The research team says that the warbler may now only survive on neighboring Abaco Island, after Hurricane Dorian destroyed the bird’s forest habitat on Grand Bahama.
The research comes from the same team that found what is thought to have been the last living Bahama Nuthatch, a species that may have gone extinct due to Dorian. David Pereira and Matthew Gardner, master’s students at UEA, conducted the fieldwork over three months as they surveyed Grand Bahama for the warbler and nuthatch.
“Although more than half the endemic birds of the Bahamas are judged in danger of global extinction,” says UEA professor and study supervisor Diana Bell, “there has been little international engagement to help remedy the situation.”
The nuthatch, which was declared a species distinct from the mainland’s Brown-headed Nuthatch in 2021, has not been reported on eBird since July 4, 2018. In the spring of 2018, research teams from UEA and the University of The Bahamas-North found the nuthatch at three distinct locations on Grand Bahama. No more than two individuals were spotted at any one time. Dorian hit the Bahamas 15 months later, and the species is now feared extinct.
Bahama Warbler now endangered
The Bahama Warbler is a small gray and yellow bird with a long bill that was previously considered a subspecies of the Yellow-throated Warbler. Before Dorian, it was only found on the islands of Grand Bahama and Abaco.
Since 2020, the only sightings posted to eBird have come from Abaco and a 1,000-acre nearby island called Castaway Cay (an exclusive port for Disney Cruise Line ships).
The warbler is now classified as an endangered species, largely because its pine forest habitat has been seriously affected by urban development, human-induced fires, illegal dumping of waste (aka, fly-tipping), logging, and increased strength and frequency of hurricanes.
The team wanted to assess the bird’s conservation status and determine its habitat requirements after a Category 4 hurricane (Matthew) hit the island in 2016. They also wanted to find out more about its habitat preferences for conservation purposes.
In the spring of 2018, Pereira and Gardner searched for the warbler across 464 pine forest locations on Grand Bahama. They played recorded warbler song to attract the birds and surveyed the habitat at each location, paying close attention to habitat damaged by hurricanes and fires.
They found a total of 327 warblers present in 209 of the 464 points surveyed. No less than 71 percent of sightings were in forests in the center of the island and 29 percent were in the East.
“We found that the warblers were more likely to be present in sites with fewer needleless mature trees and some burnt vegetation,” says Pereira. “They seem to prefer living among taller, more mature thatch palms. This is likely because these trees are capable of surviving forest fires and are also home to insects that warblers feed on.
Pereira and Gardner also found that “the species is quite adaptable, particularly when it comes to areas that have been affected by fire. This is probably because they can forage on tree trunks and use their bills to get under burnt peeling bark.”
Focus turns mostly to Abaco
Their co-supervisor, Professor Nigel Collar from BirdLife International, said: “We assume that Hurricane Matthew, which struck Grand Bahama only 18 months before our 2018 survey began, killed a significant proportion of the Bahama Warblers on the island. And it is possible that our findings on the bird’s preferences largely reflect the habitat that provided the best shelter.”
Fifteen months after the fieldwork ended, Hurricane Dorian devastated Grand Bahama with winds of 295 km per hour for over 24 hours, creating such human misery and economic damage that three years later the situation of the island’s wildlife remains unclear.
“It is possible that Grand Bahama’s entire population of Bahama Warblers was wiped out,” says Gardner. “But we know that the only other population of the species, on Abaco, has survived in the south of the island, where much of the forest remained standing.”
“We hope that our ecological insights will help conservation management on Abaco, but both islands now need to be surveyed,” added Bell.
Thanks to the University of East Anglia for providing this news.
The paper led by Pereira and Gardner is available from the journal Bird Conservation International.
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