Puffins are one of Alaska’s most recognizable seabirds. But according to a study published June 8 in Ornithological Applications, the birds’ numbers are plummeting on the Kodiak archipelago. The study’s authors hope their research can inform conservation decisions both locally and nationally.
Katie Stoner, the lead author of the study and a marine ornithologist at Oregon State University has worked with dozens of different bird species, from Oregon to Hawaii. But puffins have a special place in her heart.
“Puffins are really amazing to see and to observe," she said. "These species are really part of the identity of the Kodiak archipelago.”
The iconic birds are struggling across their range. On the west coast of the United States, there are two species of puffin: horned and tufted. In the Lower 48, tufted puffin numbers have dropped by as much as 90% since the early 1900s. Not much is known about their horned puffin cousins, but scientists think their population is also in decline.
The U.S. Fish and Wildlife Service chose not to list tufted puffins as threatened or endangered in 2020. Stoner said that the number of puffins in the Gulf of Alaska was a factor in Fish and Wildlife’s determination. The Gulf population accounts for nearly 40% of all breeding tufted puffins in North America.
“The population within the Gulf of Alaska was considered to be stable in that assessment," Stoner said. "However, the assessment was only informed by data from a few colonies in the region.”
Studies in Prince William Sound and Cook Inlet have shown that puffins in the Gulf might be struggling more than the datasets used for the 2020 assessment might have let on. To see if the same was true in Kodiak, Stoner reviewed data on the area’s puffins going back to the 1970s.
One of the study’s co-authors, U.S. Fish and Wildlife Service wildlife biologist Robin Corcoran, collected over eleven years of that survey data for both tufted and horned puffins when she worked at the Kodiak National Wildlife Refuge. Corcoran was in Kodiak for more than 15 years, until leaving her refuge job in the fall of 2024.
Driving a boat along straight lines called transects, Corcoran and her team would count the number of puffins they could see within a certain distance around the island. Stoner compiled this data, which she labeled as “at sea” data, and also compiled data from surveys of the archipelago’s breeding colonies, which she called colony data. She used the data to generate a model estimating the populations of horned and tufted puffins over time, both at breeding colonies and at sea.
According to Stoner's model, tufted puffins on the Kodiak Archipelago declined by 88% at breeding colonies and 50% at sea between 1975 and 2021. For horned puffins, Stoner found a 67% drop at colonies and a 22% drop at sea. She said she’s not sure yet why there were such big differences between the colony and at sea numbers. Regardless, she finds the results concerning.
“This new information contradicts the fact that the population was classified as stable within the species status assessment," Stoner said.
Stoner is still studying why the Gulf is seeing such a steep decline, when other places in Alaska, like the Aleutians, are seeing their puffin numbers increase. She said the main causes are likely climate change and marine heatwaves, which have been stronger in the Gulf than elsewhere in Alaska. Events like the infamous Blob of the mid 2010s decimated Gulf of Alaska seabird populations.
But Corcoran said another factor is bycatch.
“Some of those set nets, they set them right on the colonies," she said. "It needs to be monitored just to see if it’s having an impact, which we strongly suspect it is, and then to have more regulation."
As part of the study, Stoner mapped out places that have high puffin concentrations across the archipelago. She said this data could inform management of activities around puffin colonies, like commercial and subsistence fishing, or aquaculture.
"Especially where it may occur near colonies, maybe that’s not the best location for an aquaculture facility," Stoner said.
Corcoran said she's waiting to see if puffins will be reconsidered for listing under the Endangered Species Act.
"It's above my pay grade," she said. "But I would not be surprised."
