(However, in the interest of "accuracy in blogging," what Tweety Bird himself (herself?) actually said was,
Tweety Bird |
"I tawt I taw a puddy tat!" "I did! I did taw a puddy tat!" )
One thing that still works pretty good on my almost "used up"
body are my ears. And this morning I woke up to a sound
that I haven't heard since last year at this time:
The chirping of birds returning from their winter vacation
down South.
And how do they know that it's time to leave their tropical
vacation paradise and return North?
Because it's getting warmer up here?
Nope.
It has nothing to do with the temperature. It's because the
length of daylight is increasing.
Anyway that's what the experts say. Furthermore they say the
reason the birds take the long return journey back, instead
of staying in their tropical paradise, is because it ain't really
so great down there...for birds:
'Unfortunately, despite what the Jimmy Buffett song indicates, life in the tropics is not as ideal as it might seem. For one thing, the tropics are not chock-full of unused food resources. The migrants from the north have to compete with a huge variety of tropical species that live there year-round. A more subtle issue is that warmer climates also tend to be home to a great many more infectious diseases and parasites.
It also turns out that there are some real advantages to making the trip north. Spring migrants time their return to coincide with a virtual explosion of food resources. As New England emerges from the grip of winter, virtually every local plant and animal begins to reproduce, and it’s not long before there is a huge abundance of seeds, fruits and invertebrates. Migrant species take advantage of these resources to have their own young.
What’s more, day length is more favorable during northern summers. In the tropics, there is little seasonal variation in the number of hours of daylight. As you travel farther north, summer days get longer and longer—in fact, above the Arctic Circle, there are weeks when the sun never sets. These longer summer days mean that there are more hours of daylight in which migrant birds can gather food and feed the hungry mouths of their rapidly growing young. ' -Bird Expert
ELCOME, welcome, little stranger,