Shallow Thoughts has been nominated as a competitor in
round two of the
Force Best Personal Linux or FOSS Blog Competition.
There are plenty of excellent blogs on the list and I'm flattered to
If you have a moment, take a look and vote for your favorite
(whether or not it's Shallow Thoughts). You can vote for up to two.
If nothing else, it's a good excuse to check out some excellent articles
on free software from a variety of writers.
Voting ends on Monday.
[ 12:05 Aug 18, 2013
More blogging |
permalink to this entry |
I was awakened at 6:30 this morning by what sounded like a young house
finch learning to sing, just outside my window.
It got me thinking.
Every fall, songbirds which have stopped singing during high summer start
up again, briefly, to sing for a few weeks before weather gets cold.
A discussion several years ago on a local birding list concluded that
nobody knows for sure why birds sing in autumn -- are they
confused about the weather and think it's spring again, hoping
for a last fling before the cold weather sets in, or what?
a wonderful ditty about it, "The Autumnal Recrudescence of the Amatory Urge",
apparently written in the 1970s by Susan Stiles.
It's too early in the year right now for autumnal anything --
it's still quite warm.
But lying there in bed listening to the exploratory notes of a bird clearly
not yet confident in his song, I got to thinking about how birds
learn their songs.
In most birds it's not innate:
young male birds learn singing while still nestlings from listening to
their father sing, much like human babies learn the rhythms of their
native language from hearing their parents talk;
and if you raise a songbird in a nest of another species, they will
often learn the wrong song, or end up with some hybrid song that
doesn't attract females of either species. (A good overview:
Development of Birdsong on Nature.)
More recently, there have been all sorts of interesting studies on how
young birds learn their local dialect, since a species' song varies
quite a bit from one location to another.
But ... not all birds sing much once the eggs are laid, do they?
They sing their hearts out while acquiring a territory and trying to
attract a female; but once nesting starts, I don't remember hearing much
activity from the house finches. Mockingbirds are an exception:
I've seen mockers singing day and night even after they're feeding
nestlings, though not all male mockers are quite so industrious.
But I thought most species stopped singing much once the nest was
built and eggs laid.
But if that's true, when do the young males learn their songs?
Even if the father does sing a little, off and on, while the nestlings
are being raised, that's not very much time to learn.
Suppose the adults started singing again in the fall
before the family disperses. Wouldn't that be an advantage to the
young males who are just learning their songs? If a fledgling,
off the nest and mostly able to care for himself, is "babbling",
trying exploratory notes while learning what sounds he can make,
wouldn't it be helpful to have a few nearby males who occasionally
burst into song even if it's out of season?
Maybe the "Autumnal Recrudescence" isn't birds being confused about
the weather at all. Maybe it's an evolutionary aid to help the young
birds crystallize their songs before heading into their first winter.
By singing in autumn, the males help their sons crystallize their
songs for the next year, which helps the sons be more successful
when it's time to look for a mate next spring.
Just a theory ... but I think it makes some sense, and I'll be listening
to this autumn's chorus with new interest.
[ 11:57 Aug 18, 2013
More nature/birds |
permalink to this entry |