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Purple Martin Living Arrangements

Dear Bird Folks,

One of my favorite birds is the Purple Martin. I really like the way so many of them live in one big birdhouse. My question is about their roosting habits. I assume the mother bird sleeps in the nest with her babies, but what about the dad? Does he squeeze in the box too, or does he sleep someplace else?

– Ashley, fifth grade, Mashpee, MA


Good for you, Ashley,

It’s cool that you are so into birds. When I was in the fifth grade I didn’t know anything about birds. I was too busy trying to figure out how to put my shoes on the correct feet. Nike could have saved me a lot of trouble if they had invented a sneaker that would fit on either foot. Nike? What am I saying? I meant Buster Browns. That’s what I wore.

For the past thirty years I have been telling my customers that buying an expensive martin house is a waste of money. This is because there are no breeding Purple Martins on Cape Cod. And for the first twenty-seven years that was true. Then, around 2009, Mary Keleher, the former president of the Cape Cod Bird Club, discovered a small colony of martins living in a rundown birdhouse in your hometown of Mashpee. In fact, Mary also lives in Mashpee. Maybe I should introduce you two. She’s very nice.

After making her discovery, Mary put up a brand new house for the birds and then established a second colony a few miles away. Last week Mary invited me to accompany her as she tended her two martin colonies. It was a great experience. I wish I could invite the entire Cape to go see these martins, but both colonies are on fancy private golf courses, so Joe Public isn’t allowed. And while I’m not a big golf fan, and usually make a wise crack about golfers, I have to admit that after walking such beautiful grounds it made me want to join a country club. Both settings are gorgeous. Now I understand why birds and golfers hang out there…except for the golf part.

Martin houses are typically erected at the tops of very tall metal poles. Using a hand crank, Mary slowly lowered the first house so she could inspect all twelve apartments. She opened each cubicle and counted the eggs and chicks. One large nest contained seven very young and very hungry baby martins. The tiny chicks immediately opened their beaks in hopes that Mary would shove in some food, but she was fresh out of Purina Martin Chow. Mary worked quickly, recording ages and the number of eggs/chicks in each nest. All the counting and cranking was a lot of work for Mary, but fortunately she had plenty of help from her ten-year-old daughter. I mostly just got in their way.

When the work was done we all stood back and watched the adult martins, which had been hovering over us the entire time, fly into their respective nests, with mouths filled with food for their kids. What do martins eat? Most martin house manufacturers will tell you that martins eat thousands of mosquitoes. But the truth is, humans probably swallow more mosquitoes accidently than martins eat on purpose. Martins are fairly large birds and they prefer to capture larger prey. On this night the parents were shoving huge dragonflies and colorful butterflies into each baby’s pie hole. (Birds have pie holes, too, right? Yeah, I think so.)

After their evening meal the babies settled down for the night. Their mother snuggled with them to make sure they stayed nice and warm. Where the male birds go at night has been a bit of a mystery. And anytime there’s a mystery in nature there’s always a researcher somewhere who feels compelled to find out the answer. This case is no different. A paper published by the Cooper Ornithological Society (which I’m sure you read, Ashley), written by Charles Brown (yes, Charlie Brown), talks about this very topic. It turns out that like humans, martins’ sleeping arrangements are very complicated. According to Chuck’s study, here’s how things play out.

Most manmade martin houses have several compartments; a male martin will sometimes claim more than one. The female, the nest, the eggs and chicks all crowd into one apartment, while the male sleeps peacefully in the second apartment. (He knows what he’s doing.) He’s not alone for long, however. After about two weeks of growing, the kids become too big and too annoying. At this point, the female also leaves the chicks and cuddles up with her mate in his man cave. Some males can’t defend or aren’t able to afford an extra apartment. When this happens he will typically sleep with the rest of the family, but he’s not happy about it. In this last case, there is no second apartment for the adults to move into as the chicks grow. They must move someplace else. Sooner or later they end up spending their nights in a nearby tree, which serves as a communal roost for other adult martins, non-breeders and assorted losers.

It seems Purple Martins are like old married couples. Some of them sleep in the same room, while others don’t. As I said, it’s complicated. But I’m glad you are interested in birds, Ashley. Birding is a fun hobby. Although, I wouldn’t recommend it as a profession, the money’s not that great. The best way to make a lot of cash is to invent something, like a single sneaker that fits either the left or right foot. I’ll totally buy dozens of them.