Snowy Owl, Newburyport, MA, 28 November 2011. Photograph by Ryan Schain.
As late fall becomes early winter this year, listserves are buzzing with exciting news of birders finding Snowy Owls south of their normal winter range! Slowly at first, but now quickly picking up steam, Snowy Owl reports continue to mount, signaling a significant movement of this species into the Lower 48 from coast to coast — or in other words, an irruption year! But what is really causing these birds to move into our area? We need your observations of this species to learn more. Some locations are now hosting multiple Snowy Owls, and new birds are being found nearly every day. With eBird, we now have a great way to track the extent and scale of this year’s invasion. Get out there and find your own Snowy Owl, and don’t forget to submit your observations to eBird!
Snowy Owls rely mainly upon rodents to survive the cold winter months in the far North. The boom-and-bust cycles of their primary food choice, lemmings, can determine if they are able to spend the winter in the North, or whether they are forced to move farther south in search of food. Since Snowy Owls are appearing in numbers in our area this year, one would guess that the population of lemmings has crashed, forcing more birds south than usual. Arctic researchers suggest an interesting twist, however, that the lemmings this year were at historical population highs allowing for a very successful breeding season for Arctic raptors, including Snowy Owls. The resulting population boom causes overcrowding and competition at typical wintering grounds pushing inexperienced birds farther south into the Lower 48. In years when Snowy Owls irrupt, watch for Rough-legged Hawks too–their similar prey choices could create similar patterns of occurrence. It’s important to document these records in eBird.
Take a look at the current distribution in North America based on checklist submissions in eBird:
eBird map of Snowy Owls — 31 October – 31 Dec 2011
Toggle the “Show Points Sooner” box on the right to click on specific checklists and see more accurate points of occurrence.
Below is a static view of this fall’s observations up to 30 November.
It’s interesting to note that a vast majority of birds in the eastern portion of the US have been occurring along shorelines such as the Great Lakes, the Saint Lawrence River, and the Atlantic Ocean, whereas birds in the upper Midwest are more evenly spread out across the landscape.
An important word of caution about this striking and photogenic species–the birds we see in the states are already stressed, since they moved from locations in the north due to a lack of food. One of the southeast Wisconsin Snowy Owls in Ozaukee County was seen for a few days and then found dead by a farmer. Apparently the bird was extremely emaciated, so it likely starved to death. While very beautiful and often approachable, life for them can at times be very difficult, and keeping a good distance so as not to disturb them is the best approach. Please don’t use live mice to lure them in to roadsides for photography. Flushing a large raptor, especially a white one can catch the attention of nearby crows causing unnecessary mobbing. We want these birds to successfully over-winter and then return back to the tundra to breed next spring.
eBird encourages all birders to submit Snowy Owl observations so we can adequately track their movements this year. eBird has become in popular in many birding circles, but still has a lot of room to grow! It’s never too late to submit observations and contribute your piece of the puzzle to citizen-science. Your observations can go a long way toward painting a beautiful mosaic of observations from all corners of the United States and beyond.
Contributed by Sam Galick, eBird Data Reviewer, New Jersey