Passerines - itsaboutnature.net

March 8, 2014: And it is early Spring in southern Maine !

I cut the branch that you see in this image from a larger Norway Maple. For about 1 hour following the cut, the sap ran out of one of the wounds, froze, and hung like a tiny icicle. Here in southern Maine, the sap has been running in all the maples for maybe close to two weeks now.

The American Goldfinch in this image has obviously made it through the 2013-14 Winter in fine shape. Out of my group of about 30 birds……..several of them did not make it. But none of them would have survived, if not for a constant supply of hulled sunflower seed. Then again, they probably would not have stayed this far north, if not for the constant source of seed the entire Winter. That's what it has crushed all over its bill….sunflower seed. It just finished feeding in the station I have set up to the right of the image.

AGF's are crazy for seed. In fact, they eat seed exclusively. They even wait till mid-Summer to nest, because that is when seed becomes more available. The amount of available seed increases as the Summer progresses into the early Fall, assuring that plenty of seed is available for the development of the young. In nature, successful procreation is dependent on seasonal timing.

Why don't you plant some sunflowers in your yard and hope that the AGF's find them?

It is quite a sight in the Fall to watch AGF's (especially the bright yellow males) atop sunflower heads, ravaging them for every last seed.

PLUMAGE AND MOLTING:
The above bird is probably a female. How do I know? American Goldfinches molt twice a year, in early Spring (now), and in September (I believe :) ) What is molting? This is when the feathers are gradually (NOT all at once) replaced by new feathers. Why? So far as we now know, it is all solely related to sexual dimorphism. Sexual what? Sexual dimorphism is when the two sexes of a particular species have a different physical appearance, and this is usually manifested in the color of the feathers. Male birds are much more colorful than females.

Just last week I noticed that the plumage on some of my American Goldfinches is dramatically changing: On some of the birds, there are vibrantly yellow patches appearing. This is the new Spring-through-Summer plumage that the males will wear until next September. And so, if the bird in the above image is not showing at least some vibrant yellow plumage, and it is early Spring, it must be a female. Now later in the Summer, when the young have fledged (developed enough to have left the nest), it will be impossible to tell young AGF's from female AGF's.

That is all I know. :)