Birds : Sliding toward spring
The only constant thing in life is change. The constant movement of the earth around the sun while spinning on its own axis makes change in the natural world a constant. While subtle, many changes are taking hold as February progresses.
Days are getting noticeably longer and, while it's still cold outside, the sun's rays provide far greater power than just a few short weeks ago. Any readers who utilize solar panels or a passive solar design to heat water or the air space in your house already know this.
Most welcome is the addition of tunes. Birds have begun to sing on sunny mornings. Still needing to conserve energy and any fat reserves, the singing is constrained but hard to miss. Bird song in early February is hardly overwhelming but after the cold, dark, and bitter weather, it seems a miracle providing further proof that spring and improved weather are not far off. White-breasted nuthatches, song sparrows, northern cardinals and Carolina wrens were among the species frequently singing this past week.
Photo by E. Vernon Laux
Martha's Vineyard's black-capped chickadees have become vocal in the past week. This widespread species that ranges across the northern states and southern Canada from coast to coast has a different love song on the Vineyard than anywhere else. They are evolving. Already distinct from mainland chickadees they are distinguished most noticeably by the quite different two-note song. All over North America where this species occurs, the song is a clear whistled two-syllable, peee-weee, with the first note much higher in pitch than the second. The Martha's Vineyard race or subspecies gives these two notes on exactly the same pitch.
While bird feeders have been providing much-needed sustenance to wintering birds, they have also been luring in small birds of prey that have a harder time surviving the winter than small land birds. Imagine having to capture fast flying little birds to survive! Most raptors, particularly the young birds attempting to survive their first winter, do not make it.
Sharp-shinned and Cooper's hawks have been widely reported. They are best identified by a number of characters that are rather subtle and require having some comparative experience. Things to look for include the bird's relative size - is it the size of a crow, pigeon, or blue-jay; its shape - is it sitting straight up and down or does it appear hunch-backed. The length of its tail, thickness of its legs, color of its eyes, etc. - there are all important identifiers. The best rule of thumb is to remain uncertain of the bird's identity unless you can get an excellent digital photo and send it to someone who will know what it is.
Members of the genus accipiter, the small hawks are not well liked by small birds for obvious reasons - they want to eat them. The immatures of both these species have reddish/brown streaked breasts and yellow eyes compared to adults which have red-barred breasts and dark orange or red eyes.
The temperatures moderated considerably in the past week from the January extremes that had frozen small portions of Nantucket Sound and Buzzards Bay. During this past week virtually all sea ice in these areas broke up and moved off. Large blocks of ice moved east along the south shore of Cape Cod after coming through Woods Hole out of Buzzard's Bay. Some chunks were large enough for seals to haul out on and many were seen doing just that in the last week.
Most ponds remain mostly frozen but more water is open now than a week ago. Conditions are excellent for observing birds in the limited areas that are open for the birds. Because they have little choice - either flee and use up energy or remain and offer fantastic visuals for birders - most waterfowl have been extraordinarily accommodating. The break-up of this ice cannot happen soon enough for these birds.
Winter stresses all plants and animals. The colder it gets, the longer it stays frozen and the depth and percentage of snow cover, all play roles in determining survival rates. Some years semi-hardy species that are pushing the outside of the envelope attempting to over winter this far north pay dearly for not flying farther south to escape winter's icy grip. Every winter is different and this one has been hard in New England.
The good news is that spring is just six weeks away on the calendar. For resident birds, it starts now as they start to defend territories by singing when the weather is nice. Birds are already beginning to behave like the nesting season is here. Interesting behaviors and interactions will be revealed with some limited observations.
Until next time - keep your eyes to the sky.