Why robins arrive north when the weather is still cold and snowy.
Why do robins arrive at their summer homes when winter weather is often at its worst? It's a question I've wondered about every year when I spy the first robin of the season, but never tried to answer -- till today.
The temperature in Boston finally climbed above freezing today for the first time in weeks, so my husband and I got out and walked around town for an hour or more. Down near the Charles River (frozen over), we saw a big fat robin standing in the snow.
At that moment I made up my mind that this year I'd either find an authoritative answer on the Web or I'd call the Audubon Society. I already knew that the early robins were generally males who were scouting homes for the summer. And that obviously the reason is that, as the saying goes, the early bird gets the worm, or, in this case, his choice of accommodations.
But why fly in with snow on the ground, temps barely above freezing, and more winter weather surely on tap, this being New England?
Well, you can chalk some if it up to instinct, says bird expert Sam Fried on GORP, in answer to a question from someone in Massachusetts about 25 robins arriving just before a snowstorm: "Probably triggered by lengthening daylight hours and internal hormones, American robins surge north from their wintering grounds in the southern United States, regardless of the local weather conditions."
But how do they find food when the ground is frozen and mostly covered with snow? It's not exactly a worm paradise out there. Well, occasionally early robins don't find enough food, Fried says, but mostly they survive on berries, fruits, and rose hips left from the previous year.
I realize I'm projecting human feelings onto a bird, but I'll have to say the robin we saw was pretty cocky. He looked at us as though he was the king of all he surveyed. You got the feeling he knew exactly what he was doing and he felt good about it.
I also found some information about American robins wintering as far north as Minnesota and Ontario -- why they do it and how they survive -- on the Journey North site, a global study of wildlife migration (for students, I think, although interesting to anyone with curiosity).
One of the answers includes this, which I thought was interesting: "Cold temperatures don't hurt most birds -- as long as they have food. As nights grow cooler during fall, northern birds start growing more down feathers close to their bodies. These feathers work like a down jacket. The down feathers insulate the birds, keeping the heat of their bodies inside. The robins make their body heat by shivering; as long as they have food to give them energy, they can survive extreme cold."
So maybe "my" robin was bulked up with a down jacket!
After the post earlier this week about birds, I received an e-mail asking me to tell you about BirdNote, a daily two-minute radio program that airs on a number of radio stations across the United States. There's also a website with all the episodes available and a search function. Folks can subscribe to the daily podcast as well.
My review of the bird cam is still in the works. Look for it later this week.
(NOTE: We invite you to visit the main page of the Monitor's gardening site, where you can find many articles, essays, and blog posts on various garden topics.)