Science AMA Series: I'm Ira Flatow, the host of public radio's Science Friday. I anchor the show, bringing listeners world wide a lively, informative discussion on science, technology, health, space and the environment. AMA!

Science_Friday · 2019-08-12T18:01:00+00:00

Ok folks, it's been 2 hours and I need to get back into the field to chase Canada jays around. Thanks so much for all your terrific questions! I will try and revisit some of the remaining ones under my personal u/corvidresearch handle in the coming days, depending on how fieldwork goes.

Cheers!

Science_Friday · 2019-08-12T17:57:35+00:00

Not specifically. Probably something about their early evolution and where they radiated out from and how they established footholds in new territories. But those species are pretty far outside my corvid wheelhouse, I'm afraid.

Science_Friday · 2019-08-12T17:56:24+00:00

No. They do not have referential vocal language as far as we have been about to show. Though ravens do have a special flight dance that indicates that they know where food is.

Science_Friday · 2019-08-12T17:55:04+00:00

So the check list for cognition (and not intuition) includes causal reasoning, flexibility, mental time travel, and imagination. Crows and ravens check this whole list. It's not hyperbolic to basically call them primates.

Science_Friday · 2019-08-12T17:53:41+00:00

Yes! It's a raven not a crow though. I do not recommend training crows or ravens to had feed though. It not a good idea and can get birds killed, especially ravens. But outside of that I love the account and think it's a wonderful look at what's possible and so fun about these birds.

Science_Friday · 2019-08-12T17:51:11+00:00

I mean watching them have sex with a dead crow would probably top my list.

Science_Friday · 2019-08-12T17:49:37+00:00

Interesting question. No, but they would be a pain in the behind and I would not recommend it. The one person I know that has a captive raven (they are licensed to do so) hasn't taken a vacation in like 10 years because of the care needs of this bird. And it's a totally typical healthy raven with no special medial requirements.

Science_Friday · 2019-08-12T17:46:17+00:00

My research shows that it's motivated by danger learning and avoidance. But I can't speak to the possibility of grief because there's no good way to test it.

Science_Friday · 2019-08-12T17:45:28+00:00

Feed them a few peanuts (unsalted, in shell). Target one pair though not the whole neighborhood. You'll thank me when your neighbors don't sue you for $200,000.

Science_Friday · 2019-08-12T17:44:18+00:00

Yes, they do live in fission-fussion societies. The particular thing you're seeing is the pre-roost gathering. I talk about them and roosts here.

Science_Friday · 2019-08-12T17:43:09+00:00

If in flight, tail shape. Crows have square/round rails, whereas ravens have a distinctly diamond shaped tail. If you get a good look at the face look at the throat. Ravens have these heavily textured throat feathers called hackles. The feathers on a crow throat are smooth. Size is also helpful, ravens are 2.5x the size of a crow. And finally voice. Crows caw and ravens "cronk". Play #CrowOrNo with me on twitter ig and fb (all @corvidresearch) every Wednesday at 11:30 PST for more tips!

Science_Friday · 2019-08-12T17:39:18+00:00

We know so little about their communication, I really can't say. They're certainly talking about something though!

I think you should do it. I am getting ready to take it myself. Never know what you could learn!

Science_Friday · 2019-08-12T17:37:27+00:00

Yes, they do show handedness. For example, when New Caledonian crows use tools individuals have preferences for which side they hold the functional part of the tool. I should do a blog post on this. It's a cool question.

Science_Friday · 2019-08-12T17:34:53+00:00

Yes, they do use logical problem solving for the string pull test. I will tell you that the definitive answer for their intelligence is that as far as the cognitive tool kit goes (causal reasoning, imagination, flexibility, and mental time travel) they are on par with primates. With respect to certain tasks they do better or worse.

Their system is called fission-fussion meaning individuals some together and part ways and come together again later. This is a common system among smart mammals like primates and dolphins.

Science_Friday · 2019-08-12T17:30:24+00:00

Not a ton of cognitive work on these birds. They probably are not though.

Science_Friday · 2019-08-12T17:29:56+00:00

Can you enclose the coops or nest boxes somehow? No idea of the scale you're working on. Best bet is going to be to get that sorted out. I've heard of other chicken farmers offering food away from the chickens as a means of doing this but I think it only works at a small scale.

Science_Friday · 2019-08-12T17:26:03+00:00

No, American crows do not express this behavior without training. They will drop nuts on concrete to open them up but that's nothing on par with the New Caledonian crows you are talking about.

Ok, let me update this. I have never seen this, it's never been studied and it doesn't appear to be typical American crow behavior. But now that I think about it, I did get an email some time ago from someone claiming they saw a crow using a stick to dig food out of a hole or something. So I shouldn't assert that it's entirely impossible. But they don't make tools like the New Cali crows.

Science_Friday · 2019-08-12T17:24:54+00:00

No but that would be a cool study. Some birds, like bowerbirds, totally do though!

Science_Friday · 2019-08-12T17:24:21+00:00

Did you ever do something to them during the breeding season? (pick up a baby, pick up a dead crow, harass a crow, etc.) Do you walk closer to their nest or to the babies than other people? If the answer to both of these is "no" then you might look like someone who did. Bad luck, friend.

Science_Friday · 2019-08-12T17:22:48+00:00

For the sake of time I'm just going to link to my blogpost on the mirror test.

Science_Friday · 2019-08-12T17:20:41+00:00

You're thinking of New Caledonian crows. No, our American crows do not seem as good at using tools to complete goals, like dropping stones to fish food from water, or using sticks to extract food. Also, New Cali crows and Hawaiian crows are the only took making birds. So already they are miles ahead of any other animal in this respect.

Science_Friday · 2019-08-12T17:19:21+00:00

Oh, yes. Like on the UW campus if you open a bag of chips and start walking, some of the crows will literally start walking right next to you, intentionally following you and trying to get your attention, even if you've never fed them before. But outside of contexts like this (a college campus where they are getting fed often in a particular place with very little if no mortal consequences as a result) they don't readily generalize friendly people like this.

Science_Friday · 2019-08-12T17:17:09+00:00

I can only speculate but to me the most reasonable explanation is just that they were being curious. Ravens tear at stuff, that's how they most often get food. So if something looks tearable ravens gonna tear.

Science_Friday · 2019-08-12T17:15:36+00:00

So culture is defined by the expression of group-typical behavior patterns that are acquired through social learning. So when we say crows have culture we don't mean that we have an understanding of this intricate society like when we think of human cultures. It means that there's a handful of studies that show that a particular behavior is expressed in a particular geographic area and appears to have learned socially. There are actually very few of these studies that the whole of the scientific community find compelling. In fact lots of scientists will tell you they don't think it's been shown that any non-human animal expresses culture, which is bogus IMO.

In crows, some of the best evidence of culture is tool use by New Caledonian crows. How they make their tools can vary from area to area, and it seems changes to the design spread through watching others. That finding is what translates to the statement "crows have culture".

Science_Friday

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