A biologist recently returned from a survey of seabirds on Kodiak Island, and she says some colony numbers have decreased this summer.
Kodiak National Wildlife Refuge bird biologist Robin Corcoran says terns are having a difficult year. She says there are three colonies on the road system: at the Pasagashak River, the head of Kalsin Bay, and the head of Middle Bay.
“Two of those colonies, Pasagshak River and Kalsin, have already failed. Both Arctic and Aleutian terns that were nesting at those locations abandoned and we believe it was due to a combination of predation by a variety of predators. We caught a lot of different predators at the nest cameras. But it was also bad weather.”
She says some of the terns have been noncommittal and aren’t nesting yet.
When they do breed, she says crows, red foxes, magpies, and brown bears are some of the predators that snack on their eggs.
And when it comes for them to hatch, timing is key for survival. She says birds that are at least couple of weeks old have a better chance of surviving bad weather.
“A cold, stormy spring can be difficult because of the storms, but ocean conditions are typically better for forage fish, so if you are lucky enough to hatch in a stretch of weather that’s good, there’s plenty of food around, those conditions are very good for seabirds.”
She says that’s opposed to the last two summers, when warmer temperatures hurt the number of forage fish available to the seabirds.
Corcoran says, like the terns, there are also fewer puffins and cormorants. She says it’s hard to tell in different cases if predators or weather had more of an effect.
She says refuge staff will take another look later in the summer to see if the trend has changed.
“The birds might be delaying nesting, so we’re gonna go back in August to see if we have more activity then, and we can get productivity information in August too.”
She says, meanwhile, land birds could be looking forward to a good year, and August surveys may give staff a better idea.