In 1985, the subspecies of Sharp-shinned Hawk found only in Puerto Rico, Accipiter striatus venator, was estimated to have a population of 240 birds. In 1994, it was listed as endangered throughout its range by the U.S. Fish and Wildlife Service. When the Peregrine Fund’s team of biologists surveyed the population in 2017, they found 75 birds comprising 16 breeding pairs in four locations on the island.

Last week, Peregrine Fund biologists returned from the island and reported that after Hurricanes Irma and Maria, the population is down to just 19 individual birds.

Nearly 75 percent of the subspecies has been lost in one year’s time. Of the 19 hawks, only two pairs show signs of breeding this year. And without foliage cover due to the massive loss of trees, their chances of success are extremely low.

Puerto Rican Sharp-shinned Hawk depends on intact, montane forest habitat for survival. “The amount of destruction was astonishing,” said Russell Thorstrom, a Peregrine Fund biologist and project director. He described “homes with roofs ripped off, trees downed, power poles snapped, and lines downed. The forest stronghold of the hawk was leveled with a majority of the mature trees knocked down, uprooted, or snapped in half, leaving only palm trees and tree ferns standing.”

Habitat loss was already putting pressure on the subspecies, but now little habitat is left, and it will be difficult, if not impossible, for the population to recover on its own.

The Peregrine Fund is seeking public help to save these hawks through an emergency donation page at www.peregrinefund.org/crisis-fund.

The Peregrine Fund has specialized in recovery of critically endangered birds of prey for almost 50 years. The organization spearheaded the massive collaborative effort to return the Peregrine Falcon to former abundance after only 30 pairs were left in the United States. The organization’s captive propagation was pivotal in recovery of the Mauritius Kestrel when only four individuals were left in the world. With their partners, they are saving the California Condor, which was once down to just 22 individuals. The Aplomado Falcon was extirpated from the United States, but with captive breeding and release, the species has established a small but self-sustaining population of nearly 40 breeding pairs along the Texas Gulf Coast.

To address the catastrophically low numbers of Puerto Rican Sharp-shinned Hawks, the Peregrine Fund says it will:

• Provide supplementary feeding of hawks in the wild to increase survival and improve body condition to thereby encourage breeding in the wild.
• Construct facilities and hire specialists needed to begin a captive propagation effort in Puerto Rico.
• Collect eggs from wild nests and hatch them in captivity to begin a captive breeding flock of hawks that will supplement wild populations upon release.
• Receive consultation on reforestation activities by partners to ensure that suitable habitat is regrown as quickly as possible.
• Continue field surveys to monitor wild population for size, distribution, and changes.

“Saving a subspecies when there are only 19 individuals remaining seems like an audacious goal, but because of people who care enough to support this critical work, the Peregrine Fund has been successful before,” the organization said in a statement. “Today, we are ready to do it again.”

 

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Originally Published March 7, 2018