Q: I saw a bluebird today (1/16), is that normal? Aren’t they migratory?
-- Lisa, Pittsfield
A: I have answered this question numerous times before in this column to some extent. Yes, bluebirds are migratory, as are robins and blue jays, but that fact doesn’t keep us from seeing them (actually all three species) every month of the year. I cannot say that the bluebird you may have seen in June is the same individual you recently saw. It is my feeling that some individuals stay and others, from some distance north of us, settle on wintering here.
For years, numbers of bluebirds would either stay the winter or return in late February to stake out a nesting territory. Late February can be pretty rough on them, as is late January. And it has been thought to be one cause for their being here in lower numbers. In fact, at one time not all that long ago, there were very few bluebirds in Western Massachusetts or elsewhere in the Northeast, due to a number of reasons including competition from starlings, English sparrows and tree swallows, in addition to widespread use of DDT and other pesticides, and lack of winter roosting places.
As we caught on and eliminated DDT, and began erecting nest boxes that would eliminate at least one competing species, the larger European starling, bluebirds gradually began increasing. A dramatic reduction in number of English sparrows (topic for another time), may also have contributed to reduced competition.
I also think the wider planting of flowering trees, like crabapple and dogwood, and spread of invasive plants, like bittersweet, may have contributed to availability of winter foods. The widespread increase of nesting boxes may also contribute to warmer roosts on especially cold and stormy winter nights. Bluebirds pack themselves into some nesting boxes. And, on the increase, albeit slow, are the number of specially designed bluebird roost boxes, that may contribute to saving additional bluebirds from freezing. Q: I don’t remember ever hearing of "Polar Vortex" until recently. Is it a gimmick to keep us watching The Weather Channel, and a more exciting or frightening way of saying jet streams?
-- Andy, Pittsfield
A: I, too, wonder why all of a sudden, the term is being used on many weather reports, but it is not new, and another term for the powerful polar jet streams. Polar vortex was first described in the mid-1800s. These air currents are weaker in summer and stronger in winter. Also called polar cyclones, they are large-scale air movements that occur at either pole and can last for months, or so I have read.
The remedy is to get outside, exercise and explore. There is much going on in the Berkshires at this season. So many of us visit Bartholomew’s Cobble in spring and summer, and think nothing of it during the winter months. Surprise! It is still there and open.
Consider snowshoeing on Feb. 8 at the Cobble in Sheffield (Ashley Falls), providing there is ample snow. Join a Trustees naturalist to make your own tracks while exploring the beauty of forests, fields, hills (but not too many), and the Housatonic River. You will have the opportunity to search for wildlife tracks and signs, most likely see bald eagles and an assortment of winter birds, and end the jaunt with a cup of hot chocolate at the Cobble Visitor Center. Non-members $10 for adults, $3 for children. Snowshoe rentals available at nominal cost. For more information and to confirm, (413) 229-8600 or e-mail firstname.lastname@example.org.
Questions and comments for Thom Smith: Email Naturewatch@live.com