HONOLULU — For the first time in decades, researchers have found a new bird species in the United States, although where it breeds remains a mystery. Based on a specimen collected in 1963 on Midway Atoll, Northwestern Hawaiian Islands, biologists have described a new species of seabird, Bryan’s shearwater (Puffinus bryani), according to differences in measurements and physical appearance compared to other species of shearwaters and DNA analysis.
Bryan’s shearwater is named after Edwin Horace Bryan, Jr., Curator of Collections at Bishop Museum from 1919 until 1968. Bryan participated in several biological expeditions in the 1920s, including the Tanager Expedition to the Northwestern Hawaiian Islands from 1923 until 1924. He was the author of many publications on Hawaiian insects and birds between 1926 and 1958 and wrote several popular books on astronomy and stargazing from Hawaii.
Biologists found the species in a burrow among a colony of petrels during the Pacific Ocean Biological Survey Program (POSBP) in 1963, and originally identified it as a little shearwater (P. assimilis), a species known to breed only in sub-Antarctic waters of the southern Pacific Ocean. However, Peter Pyle, an ornithologist at the Institute for Bird Populations recently examined the specimen and found that it is too small to be a little shearwater and that it has a distinct appearance.
“It did not seem to fit any other shearwater species in size and appearance,” Pyle said. “The closest being Boyd’s shearwater, a species that breeds in the Azore Islands of the Atlantic and would be extremely unlikely in the middle of the Pacific.”
Subsequent analysis of its DNA by Andreanna Welch and Rob Fleischer of the Smithsonian Conservation Biology Institute’s Center for Conservation and Evolutionary Genetics confirmed that it is an entirely new species and the smallest shearwater known to exist. It differs genetically to a greater degree than most other species of its genus, and is relatively distantly related to Boyd’s shearwater. Based on this DNA evidence, researchers estimate that the Bryan’s shearwater separated from other species of shearwaters more than 2 million years ago.
The Bryan’s shearwater is the first new species reported from the United States and Hawaiian Islands since the Po‘ouli was described from the forests of Maui in 1974. The Po‘ouli was last seen in 2004 and is now probably extinct. Entirely new species of birds have rarely been discovered since most of the world’s 9,000 plus species (including about 21 other species of shearwaters) were described prior to 1900. Most new species described since the mid 1900s were discovered in remote tropical rain and cloud forests, primarily in South America and southeastern Asia.
Given that Bryan’s shearwaters have remained undiscovered until now, they could be very rare, and possibly extinct. “The best conservation strategy for Bryan’s shearwaters at this time is to discover and protect primary breeding locations and to protect other breeding sites where they may potentially breed, such as Midway," Pyle said. “Introduced mammals such as rats and cats are among the greatest threats to seabird colonies and it will be important to keep potential breeding islands as free as possible from such predators.”
Researchers do not know where Bryan’s shearwaters breed, however. According to Pyle, shearwaters and other seabirds often visit nesting burrows on remote islands only at night, and the breeding locations of many populations remain undiscovered. Individual seabirds from colonies also often ‘prospect’ for new breeding locations, usually far from existing colonies.
“We don’t believe that Bryan’s shearwaters breed regularly on Midway or other Northwestern Hawaiian Islands, based on the extensive seabird work in these islands performed during the Pacific Seabird Project,” Pyle said of the single observation of the species during the 1963-1968 project. “They would have encountered more Bryan’s shearwaters if they bred regularly in the Northwestern Hawaiian Islands.”
See the original article at: KHON2 Developing Stories
