“Our conclusion is that because islands A and B have standing trees, the islands are viewed as better habitat to such an extent that they continue to nest there even without success.”
MANY NOT LOCAL
The reduction in offspring has obviously translated into reduced numbers overall, but there was still another section of the cormorant population that had to be accounted for.
“In the past, we’ve operated on the assumption that the Lake Champlain cormorant population was a closed population, that we don’t have a lot of (new) birds coming in or leaving,” Capan explained. “But there is evidence that more birds are coming in during the summer months to feed on Lake Champlain.”
Vermont Fish and Wildlife, in conjunction with the Lake Champlain Fish and Wildlife Management Cooperative, has also been working to reduce the cormorant population through a controlled shooting program.
Birds killed during that program included banded cormorants from Four Brothers Islands as well as unbanded cormorants, and Capan was able to determine that many of those that had been shot did not appear to be “local” but were “passing through” to enjoy the rich populations of alewives and other fish species.
“The Lake Champlain Management Cooperative (which helped establish an acceptable population level for cormorants on the lake) was not as concerned about whether the cormorants were breeding here or just moving through,” he said, noting the bottom line was how many cormorants were on the lake during the summer months.
The shooting program continued through this summer, and though results have not yet been released, Capan believes those numbers will be down because the cormorant population has decreased.
Over the past several years, more than 10,000 cormorants have been removed from the lake, some through the shooting program and others when the birds and their nests were taken from other areas.
A specific management plan for continued management is still being considered, but Capan believes he will continue his work on Four Brothers Island at least into next summer.
Email Jeff Meyers:
firstname.lastname@example.orgSEE THE REPORT To find the Four Brothers Islands cormorant-management report online, go to www.lcbp.org and click on the report beneath the "What's New" column.