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How a hawk learned to use traffic signals to hunt more successfully

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Re: How a hawk learned to use traffic signals to hunt more successfully

#31

Post by lloeki »

pdabbadabba wrote: post #23
lloeki wrote: post #13

> Cooper’s hawk is on a rather short list of bird of prey species that have successfully adapted to life in cities. A city is a difficult and very dangerous habitat for any bird, but particularly for a large raptor specializing in live prey: you have to avoid windows, cars, utility wires, and countless other dangers while catching something to eat every day. Peregrine falcons adapted quite well, and they're much more…

> Peregrine falcons adapted quite well, and they're much more sizeable. I'm not sure what you mean. As far as I am aware -- and according to every source I've looked at in the last few minutes -- Peregrine falcons and Cooper's hawks are about the same size (length and wingspan are within 1-2 inches).

> according to every source I've looked at in the last few minutes

I may be mistaken but that's what I found:

https://en.wikipedia.org/wiki/Peregrine_falcon

> The peregrine falcon has a body length of 34 to 58 cm (13–23 in) and a wingspan from 74 to 120 cm (29–47 in)

> Males weigh 330 to 1,000 g (12–35 oz) and the noticeably larger females weigh 700 to 1,500 g (25–53 oz)

https://en.wikipedia.org/wiki/Cooper%27s_hawk

> Total length of full-grown birds can vary from 35 to 46 cm (14 to 18 in) in males and 42 to 50 cm (17 to 20 in) in females. Wingspan may range from 62 to 99 cm (24 to 39 in), with an average of around 84 cm (33 in)

> In northern Florida, males averaged 288 g (10.2 oz) and females averaged 523 g (1.153 lb). In general, males may weigh anywhere from 215 to 390 g (7.6 to 13.8 oz) and females anywhere from 305.8 to 701 g (0.674 to 1.545 lb), the lightest hawks generally being juveniles recorded from the Goshutes of Nevada, the heaviest known being adults from Wisconsin

(not putting the full regional rundown, just the biggest entry)

Re: How a hawk learned to use traffic signals to hunt more successfully

#32

Post by vikingerik »

throwanem wrote: post #30
krisoft wrote: post #6

I have a similar story. I was taxiing a Cessna 152 at LHBS. It is a big grassy field. On that day there were a large flock of black birds sitting on the grass. I made the usual radio call to announce that I'm leaving the runway and taxiing to the tie-downs when the birds flitted away just between my airplane's nose and my destination. The birds outside of that "road" by roughly a wingspan distance remained on the gro…

I see pigeons and sparrows dodge cars by inches, too. For that matter I do the same myself! Sparrows hawk insects out of the air, and I believe starlings also. Predicting motion would need to be second nature, I think. Like skillfully catching a ball, but much more so and between your teeth...

Well, there is survivor bias there, of course; you don't see the ones that didn't learn to dodge...

Re: How a hawk learned to use traffic signals to hunt more successfully

#33

Post by KineticLensman »

Etheryte wrote: post #15
lloeki wrote: post #13

> Cooper’s hawk is on a rather short list of bird of prey species that have successfully adapted to life in cities. A city is a difficult and very dangerous habitat for any bird, but particularly for a large raptor specializing in live prey: you have to avoid windows, cars, utility wires, and countless other dangers while catching something to eat every day. Peregrine falcons adapted quite well, and they're much more…

Plus pigeons are not exactly known for being incredibly smart or agile, so if you're big enough to take one down, you probably won't struggle too much for food.

Pigeons fly surprisingly fast and can outfly smaller raptors in a straight line. A stooping (diving) Peregrine will usually win. Its strike may decapitate the pigeon which tends to minimise the struggling

Re: How a hawk learned to use traffic signals to hunt more successfully

#34

Post by lloeki »

throwanem wrote: post #25
pdabbadabba wrote: post #23

Earlier quoted context omitted.

> Peregrine falcons adapted quite well, and they're much more sizeable. I'm not sure what you mean. As far as I am aware -- and according to every source I've looked at in the last few minutes -- Peregrine falcons and Cooper's hawks are about the same size (length and wingspan are within 1-2 inches).

Peregrines are somewhat smaller and much more lightly built. I live in a nesting pair's territory which often sees transitory Cooper's; they're easy to distinguish both in flight and at rest. Male Cooper's are more peregrine-sized and hard to tell from sharp-shinned hawks sometimes, but that is an ordinary enough sexual dimorphism in birds. Interestingly, while peregrines and accipiters like Cooper's share a habit of…

Sadly we don't have Cooper's around here so I have no experience with them, hence why I looked them up (see nearby comment) and according to that source found out they were on the smaller size and much smaller weight.

Around here the only ones who would dare mob a peregrine would be crows.

Re: How a hawk learned to use traffic signals to hunt more successfully

#35

Post by lloeki »

hackeraccount wrote: post #28
lloeki wrote: post #13

> Cooper’s hawk is on a rather short list of bird of prey species that have successfully adapted to life in cities. A city is a difficult and very dangerous habitat for any bird, but particularly for a large raptor specializing in live prey: you have to avoid windows, cars, utility wires, and countless other dangers while catching something to eat every day. Peregrine falcons adapted quite well, and they're much more…

There are Peregrine falcons in my city. I remember walking downtown one time and seeing one on the sidewalk with a pigeon in its talons. All the commuters and I just walked around it. Really weird somehow.

Interesting, around here raptors hunt high, and if prey falls to the ground they abandon it; too dangerous to go down in the streets.

Re: How a hawk learned to use traffic signals to hunt more successfully

#36

Post by vidarh »

hackeraccount wrote: post #28
lloeki wrote: post #13

> Cooper’s hawk is on a rather short list of bird of prey species that have successfully adapted to life in cities. A city is a difficult and very dangerous habitat for any bird, but particularly for a large raptor specializing in live prey: you have to avoid windows, cars, utility wires, and countless other dangers while catching something to eat every day. Peregrine falcons adapted quite well, and they're much more…

There are Peregrine falcons in my city. I remember walking downtown one time and seeing one on the sidewalk with a pigeon in its talons. All the commuters and I just walked around it. Really weird somehow.

London apparently has a high density of them (but high density still only means something like 40 breeding pairs), and some people are all excited about the prospect that they can do something about the rapidly rising wild parakeet population...

Re: How a hawk learned to use traffic signals to hunt more successfully

#37

Post by stanmancan »

vikingerik wrote: post #32
throwanem wrote: post #30

Earlier quoted context omitted.

I see pigeons and sparrows dodge cars by inches, too. For that matter I do the same myself! Sparrows hawk insects out of the air, and I believe starlings also. Predicting motion would need to be second nature, I think. Like skillfully catching a ball, but much more so and between your teeth...

Well, there is survivor bias there, of course; you don't see the ones that didn't learn to dodge...

We call that evolution

Re: How a hawk learned to use traffic signals to hunt more successfully

#39

Post by im3w1l »

vikingerik wrote: post #32
throwanem wrote: post #30

Earlier quoted context omitted.

I see pigeons and sparrows dodge cars by inches, too. For that matter I do the same myself! Sparrows hawk insects out of the air, and I believe starlings also. Predicting motion would need to be second nature, I think. Like skillfully catching a ball, but much more so and between your teeth...

Well, there is survivor bias there, of course; you don't see the ones that didn't learn to dodge...

But it makes you wonder why they cut it that close. What benefit they get from it. I can think of several plausible reasons but none that is self-evidently true.

Re: How a hawk learned to use traffic signals to hunt more successfully

#40

Post by fullstop »

im3w1l wrote: post #39
vikingerik wrote: post #32

Earlier quoted context omitted.

Well, there is survivor bias there, of course; you don't see the ones that didn't learn to dodge...

But it makes you wonder why they cut it that close. What benefit they get from it. I can think of several plausible reasons but none that is self-evidently true.

Perhaps for the same reason that people skydive or engage in other risky behavior.
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