This article has been changed to correct the species of a bird and to identify the US Fish and Wildlife Service as the agency Mariah Stephens is interning with.
A birdsong recording station that happened to lie in the path of the Card Street Fire shows birds returning to the area soon after the fire passed.
Mariah Stephens, a wildlife biology undergraduate at Oregon State University, came to the Kenai Peninsula for the summer to study bird behavior as an intern with the US Fish and Wildlife Service. Her project involved collecting birdsongs from microphones placed in the Kenai National Wildlife Refuge.
With microphones and recorders in place by April 29, Stephens set out to determine whether Kenai Peninsula song bird migration and mating schedules were being affected by climate change. However, her study itself was affected by a more immediate event.
“We just happened to have it where there was a fire,” Stephens said.
One of Stephens’ microphone installations, mounted on an aspen trunk in the west side of the Refuge’s Skilak Recreation Area, was in the path of the Card Street Fire when it burnt through the area on June 19. The microphone and its recording survived the fire and were picked up about three weeks ago, Stephens said.
The microphone captured the loud stutter of flames and the hiss of fire-driven wind, but after the noises of burning had passed, it also recorded the return of birdsong. On the day following the fire, Stephens heard the songs of thrushes, warblers, sparrows, the Alder flycatcher, and the dark-eyed junco.
Although birdsong was present very soon after the fire, Stephens said it was definitely diminished.
“There was at least a three to four day period where there was very little bird activity,” she said.
Stephens is uncertain whether this was an effect predominantly of the fire or of the natural rhythm of bird activity she originally set out to observe.
“Because of the timing of it, it wasn’t really what we believe the peak birding time was…” Stephens said. “So we don’t know how much of it is that the birds have moved on … versus there was a fire and they’re no longer in the area. We do know it had an impact. We just don’t know how much.”
Stephens said she eventually heard all the birds she’d recorded before the fire singing again afterward, with the exception of the golden-crowned kinglet — a rarer bird which she said doesn’t breed in the area.
The specific birdsongs Stephens is studying are nuptial songs sung to find a mate and establish a nesting territory.
Because the burnt microphone site was near a previously-existing clear-cut, undamaged nesting habitat still existed on the cut’s far side, where the fire only burnt in small patches.
For the purposes of Stephens’ study, the fire was only a minor incident. Since then she’s continued to focus on her original question: whether migrating song birds are nesting on the Peninsula sooner because of an increasingly warm regional climate.
“Because there’s been hotter temperatures here in Alaska, and because there wasn’t a really cold winter… we believed (the birds) were going to be arriving sooner,” Stephens said.
A competing hypothesis is that lengthening daylight hours — a change not affected by climate — are a more important factor than temperature in the timing of bird nesting. In this case, climate change will have less of an effect. Stephens said that anecdotally, bird behavior does seem to be changing.
“Historically, the peak birding period is the last three weeks in June,” Stephens said. “I’ve been noticing a peak before June, and a lot of the species got here before I was even ready for them.”
The results of Stephens’ research may be used to change the time when Refuge biologists conduct bird surveys. Before conclusions are drawn, however, the science needs to be finished.
“We’ve noticed things, but we don’t have any specific proof,” Stephens said. “So we’re trying to get out there and see if it’s an actual thing before we start saying it is.”
Reach Ben Boettger at ben.boettger@peninsulaclarion.com
