As the summer breeding season winds down for Maine’s seabirds, baby Atlantic Puffins are getting ready to hit the high seas. But on Machias Seal Island, near the border of New Brunswick and Maine, the burrows have been strangely quiet this month.
Home to the largest puffin colony in the region, the island hosts anywhere from 5,000 to 6,000 breeding pairs each summer. Typically, 60 percent of the colony’s newborns make it to the end of the season, but this year, only 12 percent were left after hundreds of chicks starved to death. It’s the lowest survival rate on record since scientists began monitoring the colony in 1995, the Portland Press Herald reports.
Experts are tying this mass starvation event to warmer ocean surface temperatures in the Gulf of Maine, which may have pushed the puffins’ preferred food items farther north in search of deeper, cooler waters this summer. In the absence of Atlantic herring, white hake, and other large fish, the birds on Machias were forced to turn to less nutritional sources, including northern puffers, a species that’s completely foreign to their diet.
But just 90 miles south on Seal Island National Wildlife Refuge, the story was quite the opposite. Puffin colonies on three islands near Bremen, Maine, posted healthy numbers, says Steve Kress, the director of Audubon’s Seabird Restoration Program. Though these birds also experienced a food shortage, they got a major boost from managed perch populations. By protecting stocks of endangered Acadian redfish, local fishermen also helped save a new generation of puffins, Kress says. “It’s an important message on fisheries management, and a great example of success.”
Nonetheless, the events on Machias still serve as a warning sign of larger climatic trends. Earlier this year, Kress and a team of researchers from Project Puffin discovered that post-fledging survival rates in Maine’s Atlantic Puffins have declined annually by 2.5 percent since 1993. A key part of their research involved weighing pufflings and finding how variations in diet were affecting mortality levels, the results of which showed how important the constancy of prey is. As Kress noted in a previous interview with Audubon, it’s a factor that needs to be considered when conserving any species: “You can protect the islands where puffins nest, but that’s not enough if the forage fish and marine habitat are not protected as well.”
And to that end, the disparate fates of North American puffin colonies this summer serve as a stark reminder of the importance of big-picture conservation.