It could be happening again this year, experts say.
Read on for insight posted on Inland Northwest Birders by raptor biologist Bud Anderson in Western Washington:
In the 1960's, it used to be “common knowledge” that all Snowy Owls that came to Washington in winter died here. As a result, there were seldom prosecutions for birds being shot back then. Of course, this belief was incorrect but I have found few raptor species that have more misinformation surrounding them than Snowy Owls.
When I lived in the Kent Valley of western Washington in the 1960's (it was primarily farmland at that time), we noticed that whenever we had a large Snowy year we usually had Snowys returning to the same locations in subsequent years, albeit in smaller numbers. Since we did not mark them, we couldn't be certain if they were the same birds but I think it was very likely they were. In one instance, we had birds return for four years in a row in ever decreasing numbers to the exact same field. So we assumed that Snowy Owls in all likelihood did not all die down here as was incorrectly assumed back then.
For some reason, this seems to happen a lot with Snowy Owls in the fields by Thomle Road south of Stanwood too.
In another Snowy Owl year, several FRG volunteers helped us capture and wing-tag 12 individual Snowy Owls on the Samish Flats in Skagit County. We placed a single, numbered yellow patagial marker on each of these birds to see both where they went and whether they returned to the same area. During the first year, most of these owls remained on the Samish Flats. It seems to be pretty ideal habitat for them. One bird even learned to roost inside a barn like Barn Owls. During the next winter, only one Snowy returned there. In the next winter, we observed yet another one not too far from the original banding site. So we had definite observations of known owls, confirming that at least some of them do return to the same area in subsequent years. While we had all assumed this to be true, it was nice to have definite proof.
When a non-resident raptor returns to the same wintering area, it is called winter philopatry. Merlins, peregrines and Gyrfalcons often exhibit this type of behavior. For example, Island Girl, our satellite tagged peregrine just completed her fourth complete migration from Baffin Island to Chile yesterday. She returns to the exact same perches in Chile every year.
Some Snowy Owls exhibit the same behavior, returning to the same US wintering areas in subsequent years. But others are what is called nomadic, i.e. they wander widely during winter and do not necessarily return to the same area each winter. One Snowy tagged at Logan Airport in Boston many years ago went all over the east coast, eventually returning to Logan. So you can seldom predict what they will do as it depends on the behavior of the individual bird. Just like us. BTW wintering Great Gray Owls are also nomadic.
If this is a typical “echo” year, there should be fewer Snowy Owls appearing here this year. Some birds die, others may not migrate, others go elsewhere.
However, we have also experienced years where a low number Snowy Year is immediately followed but an even larger irruption with considerably more birds showing up. It may be too early to tell just yet but it seems like this may be happening this year with so many observations in unusual places.