I walk a lot in a park in a suburban area. There’s quite a bit of open territory including the park itself, adjacent greenspaces, church property, undeveloped land, and parking lots for office buildings. There are usually many birds swooping around, including hawks.
Last summer I noticed what I think was the same redtail hawk with a smaller bird following close behind it, matching its flight. I’d see them, or other similar pairs, at all times during the day or evening — whenever I’d be down there walking. Now this summer I see a crow flying around with a similar buddy — or pest.
Why do these birds pair up like this? They are quite clearly different birds so I’m positive it isn’t mating behavior.
Smaller birds diving at or following larger ones is not unknown, and is called mobbing. I frequently see blue jays mobbing crows, and have seen crows mobbing an owl. That might have been what you saw happening.
I hope Colibri will come along and give us a definitive answer. Meanwhile, I have seen and read about this behavior. What I read is that smaller birds will harass hawks to drive them away from their nests during the time when young offspring are learning to fly.
Would you want a predator in your neighborhood? And if you’re a predator yourself, would you want an alpha predator getting all the goods? Crows mob hawks and owls in an attempt to make them move on. And other birds will mob crows (because crows will steal eggs and probably young birds).
I’ve also seen redwing blackbirds divebombing egrets, probably for the same reason. I bet an egret would regard a baby redwing blackbird as a tasty change from minnows.
You can pretty much tell mobbing behaviour as it’s clearly hostile toward the other bird. And I’ve never seen it just be one bird, as the OP seems to be describing.
Birds also mob cats. In my youth I saved many a cat from Blue Jays and Robins.
The closest I’ve seen to what the OP describes is the sea gull / pelican relationship. I have seen gulls follow pelicans, when I lived in Florida. Obviously in that case they are trying to steal the fish the pelicans catch. Each gull seems to attach itself to a particular pelican and follow it.
It’s an interesting relationship as the pelicans are much bigger and you have to admire the pelicans for not just beating up the gulls and you have to admire the gulls for their nerve.
I’ve never seen more than one bird following along. I can believe it’s trying to drive off the larger bird, though — the littler bird always appears to be chasing.
If the predator is perched in a tree, you’ll often see a whole bunch of smaller bird species ganging up on it, making quite a racket all the while. Predators are pretty much hard-coded to attack via surprise, but become relative wimps once the potential prey turns the tables on them.
Yes, this kind of mobbing behavior is common among birds. Larger birds like hawks generally rely on surprise to capture their prey. If a small bird is aware of its presence, they are just not maneuverable enough to catch it.
Some small birds like kingbirds will chase almost any other bird, even when alone or in just a pair. (In fact, this is how kingbirds got their name.) Other birds join into groups to “mob” predators when they find them in a roost, and try to drive them out of the area. This includes hawks, owls, etc.; they will also mob other predators like snakes, cats, foxes, and so on.
One good way to find owls in a daytime roost is to listen for the mobbing calls of other birds (which can be distinctive). Also, counter-intuitively, one can attract small birds by giving the call of an owl like the pygmy-owl; they will often rush up to see if they can spot the predator.
Though it has roots in past activities, it’s actually a fairly modern practice–it’s the rise and ubiquitousness of inexpensive digital cameras and easy file sharing. The birds do all sorts of silly, pre-choreographed routines (singing in unexpected locations is a popular one) to get your attention and film your reaction. I think the species Anatidae Donaldus x popularized the no-pants gag.
I’m in south-central Texas and have seen grackles, mockingbirds, and some wren-like birds mob vultures, hawks, cats and dogs. Sometimes it was a single bird attacking the predator, sometimes it was multiple birds who took turns attacking and sometimes it was a large group of birds simultaneously attacking the predator.
There is a nesting pair of hawks in my neighborhood and sometimes the grackles perch in nearby trees and “yell at” the hawks when they’re on their nest.
I’ve heard owls calling at night, but have never seen or heard any other birds harassing them.
Other birds don’t harass owls at night - they’re at too much of an advantage then due to their superior nocturnal vision. They only mob owls when they find them at a roost during the day.
