14 April 2009

First-ever Rusty Blackbird Blitz a "Smashing Success"

The first-ever "blitz" to count wintering Rusty Blackbirds was a "smashing success," according to results indicated by information presented by the Smithsonian Institution.

The survey was carried out from February 7-15, 2009, and sponsored by the International Rusty Blackbird Technical Working Group associated with the Migratory Bird Center at the Smithsonian Institution, and Ebird, supported by the Cornell University Laboratory of Ornithology and National Audubon Society.

"One of the intangible, but important, outcomes was a heightened awareness of the plight of this species and the desperate need for more information on its distribution and abundance," according to details on the website with results of the blitz. And "173 birders submitted 453 rusty blackbird surveys under the E-bird Blitz protocol. Of these individual reports, 249 sightings totaling 19,243 individuals were recorded. 204 surveys did not record any rusty blackbirds (but negative data are very valuable as well). Some of these reports were repeats from the same site." Counts were provided from 27 states.

"The highest mean counts were found in the states of the Lower Mississippi alluvial valley including Tennessee, Mississippi, Arkansas, and Alabama averaging over 100 birds per site. The next tier (50 or more per site) includes two states along the South Atlantic Coastal Plain and adjacent Piedmont (North and South Carolina) and two more states in the greater Mississippi Valley (Missouri and Louisiana).

"The Rusty Blackbird has shown severe documented declines," according to Russell Greenberg, a member of the technical working group, and biologist at the Smithsonian. "We don't understand it, but it seems likely changes in the amount and quality of winter habitat is playing a big role. In order to proceed with research and conservation action to protect Rusties, we need a rapid assessment of the winter strongholds for the species as well as its overall distribution."

"Rusty blackbird populations have fallen steeply, with estimates of an 85-99% population drop over the past 40 years." – Rusty Blackbird blitz page provided at the Smithsonian Institution

The International Rusty Blackbird Technical Working Group saw a "tremendous opportunity to harness the knowledge and bird finding prowess of the birding community to locate wintering Rusties," Greenberg said in an email. "E-bird is the perfect vehicle to gather and collate the data from the birding community.

This blitz was viewed "as a way of enhancing birder awareness of the plight of the Rusties and to efficiently gather important winter distributional info. This information can be followed up with more focused regional research and population monitoring," he said

Further details are available on the webpage with summary information for this count, including an interactive map showing the locations where Rusty Blackbirds were counted.

According to the details on the webpage, the results "have much more to tell us and we are plowing through the comments fields to learn about specific flock size, sex ratios at different sites, and habitat conditions associated with hot spots. We also need to distinguish between foraging and roost or staging sites. As we complete these analyses, we will update you on what we have discovered."

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