*** Wild Lens Scientific Director Neil Paprocki is currently in Nome, Alaska working on The Peregrine Fund’s Gyrfalcon Conservation Project with Boise State University graduate student Bryce Robinson. You can read more about this project on previous Wild Lens blog entries ***
When last I updated folks on the status of our Gyrfalcon nests in northwest Alaska, most of the nestlings were still balls of white downy fluff approaching banding age (~25 days old). My how the time flies during the brief but intense Alaskan summer! As we approach the end of our summer breeding season, nearly all of the successful Gyrfalcon nests on the Seward Peninsula have produced fledglings.
Gyrfalcon nestlings fledge, or fly for the first time, at 45 to 50 days of age. They usually stick around the nest site for a few weeks, and as we made our final nest visits to collect prey remains and retrieve nest cameras, we fully expected to see recently fledged Gyrfalcons around the eyrie. They did not disappoint…
Indeed at nearly all of our successful nests (ones that produced at least one fledgling) we observed young Gyrfalcons flying near the nest site. Several of our nests produced four fledglings, and at times all four birds were up in the air, testing their newfound ability to fly: flashing talons and playing with each other.
And what species of prey did we find at all of these nests? In a word: Ptarmigan. Lots and lots of Ptarmigan.
However, while the majority of Gyrfalcon nestling diet seems to consist of Ptarmigan, we found some variation at nest sites. Some nests had several Arctic Ground Squirrel pelts. Some contained a few larger shorebirds remains such as Whimbrel and Bar-tailed Godwit. Still others contained feathers of smaller shorebirds and songbirds including Northern Wheatear and Bluethroat.
Even with the broad diversity of prey found at nesting sites, one thing is clear: Ptarmigan are highly important to the diet of breeding Gyrfalcons. What would happen if Willow and Rock Ptarmigan populations suddenly plummeted? Could Gyrfalcons produce as many fledglings without this highly critical prey species? Would they switch to feeding nestlings other prey items such as ground squirrels and large shorebirds? Could they find enough of these to effectively replace Ptarmigan?
These are all questions to think about as Climate Change rapidly alters the arctic and subarctic ecosystems of North America.
Tags: alaska, climate change, Falco, Falco rusticolus, falcon, fledge, gyrfalcon, juvenile, prey, seward peninsula