There has been a lot of unusual bird activity in the Prescott area over the last week, which might be an indication of a very interesting winter.

Wild bird behavior is heavily influenced by food availability. This year, much of the country has experienced severe drought conditions, affecting the production of seeds and nuts at the northern latitudes. When food is scarce for wild birds in their traditional winter habitat, they instinctively move south in an effort to secure sufficient food to sustain them through the winter months.
In birding terminology this behavior is referred to as an "invasion" year by "irruptive" species-where species occur outside or beyond their traditional winter range.

Examples of species that show up in "invasion" years include evening grosbeaks, Cassin's finches and red crossbills. This past week there have been sightings of evening grosbeaks at Granite Basin and along Park Avenue. This is a very exciting development for backyard birders.

Another phenomenon we experience from time to time is when species that normally winter at higher elevations move down in elevation. This type of "migration" does not involve flying south. Rather, it is just a matter of birds moving down in elevation several thousand feet. This type of migration is referred to as "elevational migration."

When this behavior is observed, one is inclined to wonder if maybe the birds know something we don't. Perhaps we are going to have a hard winter. Examples of birds that move down in elevation include red-breasted nuthatches, Williamson's sapsuckers, western bluebirds, Townsend's solitaire and Steller's jays.

Some folks in the Prescott area are already seeing red-breasted nuthatches, Williamson's sapsuckers and Cassin's finches in their yards. Will this be an "invasion" year? I hope so. It would be very exciting to see these uncommon winter visitors occurring in unusually high numbers.

I still remember when we had an invasion of evening grosbeaks and Cassin's finches about 15 years ago here in Prescott. Hearing them singing in the trees in our yard was so incredibly beautiful.

Knowing that we are beginning to see winter birds arrive raises the question as to when the last of our hummingbirds will leave, and when hummingbird feeders should be taken down. It is a question we get asked here at the store over and over again each fall.

Granted, there are some Anna's hummingbirds that winter-over, but it is my opinion that if you are not seeing any hummingbird activity in your yard now, it is okay to take down your feeders. If you continue to have a straggler, then leave your feeder up longer. I generally remove my last hummingbird feeder by the end of October, which is still two weeks away.

As the days grow shorter, most hummingbirds will get the message that it is time to head south. Migration for Anna's hummingbirds is more elevational in nature, as they just go down to the Sonoran Desert elevation instead of going to Central America, as do rufous hummingbirds.

Even though the seed sale continues until the end of the month, the last day to vote in the wild bird photography contest is Monday, Oct. 22. We will announce the winners of the photo contest at noon on Saturday, Oct. 27, during our anniversary celebration. We will be providing a wonderful free lunch and we will have live birds of prey on display like we do each year during this festive event. I invite you to join us as we celebrate nine years of serving bird lovers in northern Arizona.