Late Summer Means The Bird Migration Is Near
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Tue, 08/24/2010 - 10:00am
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Late_Summer_Migration.mp3 | 10.99 MB |
Chel Anderson is a botanist and plant ecologist for the Minnesota Department of Natural Resources. She lives here in Cook County and joins us periodically to talk about phenology or what’s going on in the woods right now. Welcome back!
Anderson: Hi, Jay.
Now, I know some birds have started to migrate—in fact, probably quite a few of them. Where are we in the annual migration ritual?
Anderson: Well, we’re definitely dealing with the early birds, but it is starting, you know, and it always amazes me that already things are responding to changes in what’s going on in the phenology of other living things and doing what they need to do to take care of themselves in that regard. In particular, birds that rely on insects to maintain and sustain themselves over the course of their lives need to be taking action right now because, I don’t know about you, but I’ve been enjoying the lack of biting insects of late.
I was going to say, Chel, we haven’t had a lot of insects, and have been able to actually sit outside and enjoy it. Is that a problem for migrating birds right now?
Anderson: Well, I’m sure it’s making it harder to find easy pickings, so to speak, but these birds are really good at what they do, but if you were an adult trying to feed your fledglings and help them, or if you’re a new bird and you’re just learning the ropes on how to find these things, yeah, definitely having fewer bugs out there of different kinds, insects out there to potentially eat is going to be a challenge for you. Yeah, I’m sure it does have an impact.
Well, who’s moving through?
Anderson: Yeah, well, among the first—and there’s so many, there’s too many to talk about individually, but I definitely want to mention one particular bird that is the Common Nighthawk. I think it’s an underappreciated bird. It is an insect feeder and this is the time of year that one can observe them in flocks as they start their migration to the south, following insect availability. Nighthawks are kind of charcoal-gray, not very large, maybe around the size of a sharp-shinned hawk. They really are exceptionally good flyers, because they have to be able to pursue insects, flying insects. They don’t eat insects that are, you know, hanging out under leaves, they are only after insects that are in flight, so they have tremendous acrobatic prowess in flight. This is the time of year when you might actually get to observe that. They are crepuscular feeders, so beginning in the evening, as the light gets low and then again in the morning. If you’re in a place where there are lights at night, in the Twin Cities, even here in Grand Marais, if they happen to be in-town area where there’s enough light, they’ll be feeding at night and you can here them calling back and forth to each other with this kind of loud, piercing call that they have that sounds like a “beeearrr, beeearrr.” And, they use that to, you know, kind of keep together and let each other know where they are. And, they go around basically flying at high speed with their mouths wide open raking in anything they can come across. Despite their name, including the word “hawk,” they have very little in common with hawks other than, say, a Merlin, which also are sharp-shinned which can fly very quickly and turn quickly and dive and faint. That’s what Nighthawks can do, but they have very weak feet, no big talons like a hawk, and their beaks are very small, not hooked, not for flesh tearing. So, their mouths, instead, are these big, gaping mouths with very course, stiff hairs lining the edges of them that help them rake in and collect insects as they fly through the air. So, they’re looking for, you know, groups of insects that are hovering together or moving together for mating purposes or whatever, but in the air, and trying to hit these groups and then just whisking around as quick as they can to try to sweep them into their mouths. I had a wonderful experience last year about this time. I was down along the lake, Lake Superior, and I had a good view kind of inland, but also out over the lake, and I saw this bird at a distance come kind of soaring down from inland right to the lake shore and as soon as it got to the lake shore and as soon as it got to the edge of the lake, it turned and started circling above the lake shore. And I thought, “Oh, what’s that?” So, I fished out my binoculars and I’m looking. I was pretty far away, so I wasn’t absolutely sure for awhile. And, as I was trying to figure it out, I saw yet another one come and another one come. Well, eventually there were about 30 of these birds in a group and by then I was close enough and they had moved a little bit down the shore towards me, so I could identify them for sure as nighthawks. It was just a spectacular aerial display watching these birds pursuing insects and being careful though. They didn’t have any need to go out over the lake. There probably weren’t very many flying insects out over Lake Superior, but they were using the lake just like most of our migrating birds do, to make their way down the shore. You know, not going out over the lake, but just following the shore. It was just spectacular.
Before I let you go, what about birdfeeder birds? I mean, should we be looking for anything in particular coming through, migrating through the area right now?
Anderson: Birdfeeders, probably the main thing would be hummingbirds that are already starting to move, also. So, hummingbirds that aren’t from your little neighborhood there would be coming through and they will be utilizing our hummingbird feeders right until the very bitter end, kind of, of their migration. And of course, young birds will leave later than the adult birds, because they need to put on more bulk and get more fit for their migration, so they’ll be staying around a little bit longer. But, adults, once they’ve kind of finished their work of raising some fledglings, they’ll get started on heading south and they’ll be replaced by other adults that are coming through from other places.
Chel Anderson, DNR botanist and plant ecologist. Thanks for helping us understand what’s going on around us this late summer.
Anderson: You’re welcome.
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