The environment determines Caribbean hummingbirds' vulnerability

Date:  March 21, 2018

Source:  Faculty of Science - University of Copenhagen

Hummingbirds' specialization and vulnerability are often predicted based on their physical traits. Scientists now found that this is not the case for hummingbirds on the Caribbean islands. Instead, the bird's environment is the determining factor. The new study was led by scientists from Center for Macroecology, Evolution and Climate, University of Copenhagen, and published today in the scientific journal Proceedings of the Royal Society B.

Hummingbird's body size and bill length are often used to predict how specialized and vulnerable the birds are to extinction of the flowers they feed on. However, a new study shows that vulnerability and specialisation of Caribbean hummingbirds are determined by their environment. The study is published in Proceedings of the Royal Society B. Associate Professor Bo Dalsgaard from Center for Macroecology, Evolution and Climate explains,

"Our study shows that Caribbean hummingbirds living in rainy mountainous landscapes with cooler temperatures are more specialized and vulnerable to extinction of the flowers they drink nectar from, compared to hummingbirds in the lowlands."

Bo Dalsgaard elaborates on the findings, ." .. we believe our results display a general trend that applies to many other animals and plants throughout the world. Thus, protecting nature in mountain regions is very important, if we want to conserve specialized and vulnerable species, which exist in just one or a few places on earth."

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Breeding Birds Vulnerable to Climate Change in Arctic Alaska: A Story of Winners and Losers

Apr. 2, 2013 — A new report from the Wildlife Conservation Society (WCS) looked at the vulnerability of 54 breeding bird species to climate change impacts occurring by the year 2050 in Arctic Alaska. The assessment found that two species, the gyrfalcon and common eider are likely to be "highly" vulnerable, while seven other species would be "moderately" vulnerable to anticipated impacts. Five species are likely to increase in number and benefit from a warming climate.

Arctic Alaska harbors some of the most important breeding and staging grounds for millions of birds -- many from around the world -- representing more than 90 species. A rise in mean annual temperatures of at least 3.1 degrees Celsius in northern Alaska is expected by 2050, and will likely impact species in myriad ways.

The report, Assessing Climate Change Vulnerability of Breeding Birds in Arctic Alaska, co-authored by WCS Scientists Joe Liebezeit, Erika Rowland, Molly Cross and Steve Zack, details in-depth vulnerability assessments conducted on 54 species to help guide climate-informed wildlife management in the region. The project was aided by the participation of more than 80 scientists who are experts on the assessed species.

Results showed that along with the highly vulnerable gyrfalcon and common eider, seven other species were moderately vulnerable, including: brandt, Steller's eider, pomerine jaeger, yellow-billed loon, buff-breasted sandpiper, red phalarope and ruddy turnstone. Five species, including the savannah sparrow, Lapland longspur, white-crowned sparrow, American tree-sparrow and common redpoll are likely to increase in number, according to the assessments.

The authors note that the assessments calculated vulnerabilities looking exclusively at the impacts of climate change experienced by breeding birds in Arctic Alaska, and not in other parts of their range.

"The primary value of this assessment is to tease out the underlying factors that make species more or less vulnerable to climate change," said WCS Conservation Scientist and report co-author Joe Liebezeit. "Through this effort we can begin to prioritize subsequent management actions and identify data gaps. The results represent a starting point to help prioritize management actions and conservation planning efforts."

Continued:  http://www.sciencedaily.com/releases/2013/04/130403092537.htm