Robins – probably other birds as well – tend to swoop along only a foot or two off the ground. It seems like this is behavior that is really important to them, or it would have been bred out since the advent of automobiles. Why do they fly so low?
WAG: looking for food. That pretty much sums up why animals do most anything aside from boinking.
Good point.
To elaborate now that I’ve taken a minute to think about it, robins eat crawly insects and worms so they are probably scanning for those.
Possibly taking advantage of the ground effect. It’s important for some birds, I don’t know about Robins.
I’ve only ever observed Robins flying low in human inhabited areas. Could be because we mow our lawns.
Out in the country where the grass grows at least knee high, I’ve never seen a Robin plowing through the knee-high grass, just to get lower to the ground.
I’d imagine it also makes predation from hawks a lot more difficult.
Energy, why gain height and burn so much of your resources if you don’t need to.
Because it gives a really impressive sensation of speed :).
Still brooding about this. Okay, so they’re looking for bugs – but they don’t stop and eat the bugs. They tend to swoop from point A to point B – with said points being on opposite sides of busy streets, it seems like. When they’re feeding, OTOH, they seem to do it on foot (so to speak), hopping around on the lawn.
Robins are basically ground birds. They find their food mainly on the ground, so they tend not to fly any higher than necessary in moving around between points within their home ranges in search of it. That would be a waste of energy. Although they do most of their actual searching on foot, they move between search areas on the wing, but don’t usuall rise very high.
They don’t generally recognize cars as hazards, at least not until they are very close, so that they treat a streat much like any other non=grassy area.
Another fun fact about robins is that they’re highly territorial. So in the average back-garden scenario, maybe they fly along very low because they want to see if there are any other robins in their patch of the world. Or to make their presence very obvious to other robins who might have hopped over the fence for a bit. When another robin shuttles through one’s airspace, looking all stupid, it must set off alarm bells fairly easily.
I get the impression that nature has designed them specifically to Get Into Fights.
Also, they migrate, don’t they? I’m pretty sure some of them do, and I’m equally pretty sure that they don’t do it by barrelling along a couple of feet off the ground, so they must only do the near-ground flying when they’re doing something specific at home. Which would further imply some dark and nefarious purpose like hassling other robins.
They’re actually strafing neighborhood cats. 
Yes Robins migrate. And they fly “high” while doing so.
As Colibri said, they’re ground birds by nature; to detail a bit, their bodies are pretty heavy as songbirds go, so expending energy in flight when they don’t have to is a good strategy.
Anectdotely: working in a wildlife rehabilitation center, learning the grueling routine of feeding baby birds: robin babies are the most voracious messy little gluttons of the songbird spectrum. I’d say the parents, after the first brood, are just plain exhausted. “Where’s that damned worm??? Bleah, fly, schmy…”
Thanks, Colibri, I was hoping you’d show up. (And thanks to everyone else as well.) Ground birds. :smack: Makes sense.
If it is windy, there is a strong wind gradient near the ground…it is much calmer the first few feet, and the wind increases steadily (but at a lower rate) up to 100’ or so. This is why wind generators are on tall towers, and why airplane pilots increase thier approach airspeed in windy conditions. (Airspeed drops significantly as ground is approached…bad thing)
Anyway, by flying low, birds are much less bothered by wind. I’ve seen many species taking advantage of this when going upwind.
I don’t think robins glide when they’re low enough to take advantage of that. Put differently, their wings aren’t long enough. The ground effect occurs within half a wingspan of the ground, and all the robins I’ve seen tend to flap too much at that altitude.
I see pelicans doing this a lot, because they have such long wings, and purple martins may do this for short distances when they’re flying half-an-inch above your lawn trolling for bugs (mouths wide open!). The black skimmer almost certainly does this too, since that’s its whole method of getting food.
