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Nature is an amazing thing. Instincts long hardened into the
brain become active when day length changes, when temperatures dip, or when
moisture dries up. Survival skills and inbred behaviors ensure that wildlife
endures the changes of the seasons. That is why, when summer is waning and days
begin to grow shorter, the birds seem to disappear.
They have not actually disappeared, thankfully. They are
simply not 'hanging out' where humans may have become used to seeing them.
Audubon Society of Rhode Island naturalist Kim Calcagno notes that she receives
numerous calls and emails this time of year from concerned people who have
noticed a remarkable dearth of birds in their yards and local parks. "Just as
we can set the seasonal clock by the springtime robin and woodpecker phone
calls, the start of autumn is distinctly marked by the profusion of calls asking
what has happened to the birds," she says.
Well, what does happen to the birds? Calcagno explains that it is part
behavioral and part nutritional. "During the spring and summer, birds are
focused on breeding. They come out to find a mate. They search to find nesting
material. They forage endlessly for all those mouths to feed," she explains.
"The birds you see are constantly taking risks by coming out in the open and
exposing themselves to predators to get these things done. Once breeding is
over for the season, they have some time before the winter comes to 'lay low' a
bit, staying out of the view of predators and keeping out of the open areas.
This behavior is normal and comes with the season."
There is another reason why the birds seem to clear out, however.
That has wholly to do with food. Many people are disappointed to hear the
birdseed they lovingly put out for their feathered friends is not the birds'
first choice. The seed you put out, even in the cold of winter, is only a
percentage of the birds' complete diet. The birds take advantage of it, but do
not require it (and will not starve if you go away on vacation, so don't
worry.) "In late summer and early fall, the forests and fields are simply
burgeoning with trees and shrubs that are full of ripe fruit, berries, seed
pods and other fresh, highly nutritious and easily obtainable food," adds
Calcagno. "The birds are
foraging in these trees, thickets and meadows in search of these treats.
Whether a bird will migrate or will stay in the area and face the cold of
winter, this fall harvest helps them build up the necessary fat and muscle for
the work ahead. They take advantage of the food sources while they can. It will
be winter soon enough and they will once again have to work harder to find
food."
Now, of course, there are sometimes sources not related to
nature that cause the disappearance of birds. Noise from local construction,
clearing of land, and the use of pesticides can affect local bird populations.
It has been long a concern in the scientific community that across North
America there has been a steep decline of songbirds over the last fifty years.
Some species are down by 50% or more. This is due to many different reasons
including human encroachment, dynamic changes in habitats, chemical use,
invasive species and climate change. Sometimes decline is temporary and
unfortunately sometimes it is not. Calcagno notes that most of her callers are
observing the normal fall behavior of birds, and many of the species will
return after a few weeks of scarcity.
If
you would like to learn more about wildlife, bird feeding, or have
questions about nature the Audubon Society of Rhode Island presents
many programs year-round about wildlife and local environmental issues.
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