The Flying Forest

April 10, 2016 5:38 AM

"While crows and ravens get most of the attention, smaller members of the corvid family like jays and nutcrackers are out in the world busily building and rebuilding forests. Not on purpose, of course, but through a behavior charmingly called “scatter hoarding,” which basically involves stashing seeds around in various places for later devourment." And this allows the trees - oaks, chestnuts, beeches, hickories - to "borrow the wings of birds."

Mario B. Pesendorfer, T. Scott Sillett, Walter D. Koenig, and Scott A. Morrison (2016) Scatter-hoarding corvids as seed dispersers for oaks and pines: A review of a widely distributed mutualism and its utility to habitat restoration. The Condor: May 2016, Vol. 118, No. 2, pp. 215-237.

posted by ChuraChura (19 comments total)

Fantastic, thank you.
posted by sneebler at 6:46 AM on April 10, 2016

Symbiosis: It's what's for dinner. If you are a bird at least.
posted by Bringer Tom at 6:46 AM on April 10, 2016

(Had to Google it, but no, not Chekov. Carry on.)
posted by sexyrobot at 6:52 AM on April 10, 2016 [1 favorite]

Lovely illustrations, too.
posted by bobobox at 6:54 AM on April 10, 2016

I saw this on some David Attenborough show and it occurred to me that scatter hoarding is a lot like proto-farming. Obviously the trees don't mature within the birds' lifetimes, and trying to impute intention on the part of the birds to grow trees is a bit of a stretch, but it doesn't seem that far fetched to imagine that a similar kind of thing might have led humans to start planting things on purpose. Obviously I don't know what I'm talking about, but it's fun to think about.
posted by Dr. Send at 6:55 AM on April 10, 2016

Is intention imputed? I know what you mean, but these kinds of relationships arise all the time in nature. Causes and effects become difficult to separate, and then we get into evolutionary arguments where there's no clear evidence one way or another.
posted by sneebler at 7:12 AM on April 10, 2016 [1 favorite]

Honeybees cause wildflowers, and fig trees cause tiny wasps. If the antelope had known a workable population check maybe we wouldn't have had lions. It seems the decision, if one exists, is made above my pay grade.

Do we still believe that effect is necessarily linked to intention? Our puny brains run into a conundrum long before we get to the why beyond the how: monkeys to infinity, turtles all the way down, or some whitebeard with a wicked sense of humor playing dice with the universe. Hairy-tailed lab rats, for example, seem to leave the door open for those patient ones who like to make lists--the rats care nothing about the lists, they just want to get their tails warm. If I could understand what a billion times a billion of anything is like I might find it easier to connect the dots. Meanwhile, I get flowers.

My son can tell his grandchildren what bees were like.
posted by mule98J at 7:59 AM on April 10, 2016 [2 favorites]

I love the way they're exploiting the mutualism to restore forests.

Most trees have quite limited dispersal abilities, a real disadvantage when climate is rapidly changing. I imagine trees with far-traveling dispersers like birds will have an easier time of it.
posted by congen at 8:02 AM on April 10, 2016 [1 favorite]

I didn't mean to imply that TFA imputes intention on the part of the birds, just that to make the leap of calling it "farming" would seem to require that imputation. But that's what's interesting about it - is it necessary to talk about humans' intention in the context of our beginning to farm crops?
posted by Dr. Send at 8:17 AM on April 10, 2016

I would like to say that I love the word "devourment." Based on observing students in my library (and faculty at receptions), it's often a much better word than "eating" or even "consumption."
posted by GenjiandProust at 10:22 AM on April 10, 2016 [2 favorites]

"Let my armies be the rocks and the trees and the birds in the sky." - Henry Jones, Sr.
posted by lagomorphius at 11:05 AM on April 10, 2016

"Obviously I don't know what I'm talking about, but it's fun to think about." --Dr. Send

This sums up about 90% of my time online, and 100% of the joy I get from the World Wide Web.
posted by Snowden at 11:12 AM on April 10, 2016

I wonder personally if there isn't intentionality. I discovered a whole bunch of sunflowers growing up in some dirt pots and I and I was wondering what on earth was going on. Then I discovered there were the same seeds in the bird feeder quite a ways away. It doesn't make sense to me to bury seeds in the soil where they would grow when you could bury them in the rocks for better storage. We always try so hard to assume there's no possible way any other lifeform than humans could have any kind of intelligence. The excessive claims about lack of sensation, emotions, intent in any being but humans has in fact often been later found wrong. It's just an assumption and we like it the best because it allows humans to slaughter animals, cut down trees, experiment on living creatures and tell ourselves lies like that they don't feel pain or their pain is innately less worthy.
posted by xarnop at 12:48 PM on April 10, 2016 [1 favorite]

I read an SA article years ago about a study (conducted about as humanely as possible, as I recall) showing that seed-hiding blue jays had an independent memory of seed locations associated with each eye.
posted by jamjam at 1:06 PM on April 10, 2016

In case you were wondering what the larger corvids are doing while their cousins are planting trees, this Crow Vending Machine previously is quite entertaining.

I remember a similar story on a tv nature program many years ago* where an Indian guy had trained a group of magpies to come to his special whistle. His neighbours would hire him when they had insect infestations, and the magpies would follow him as he walked over to the field, where they would have a nice lunch.

* Is there a word for the "pre-Internet" era?
posted by sneebler at 4:21 PM on April 10, 2016 [1 favorite]

I wonder personally if there isn't intentionality.

Me too, even when I know these categories don't quite work. At one level, animals are just doing what they do. Here's a just-so story: Supposedly, sitting ducks need to turn their eggs occasionally so they're warmed evenly. How does the duck know when the egg needs to be turned? When the duck gets too hot.

(Personally, I think the contents stay embryo side up whether they're turned or not. Also, how do we know how the duck knows it's too hot?)

Maybe this Frans de Waal guy knows? He almost just came out with a book called Are We Smart Enough to Know How Smart Animals Are? that looks very interesting.
posted by sneebler at 4:34 PM on April 10, 2016

How does the duck know when the egg needs to be turned? When the duck gets too hot.

Wouldn't you bet that the egg heats up to keep it's underside from getting too cold, and that's what the duck feels?

In fact, I'd bet that the duck wouldn't continue to sit on an egg that stayed too cold for too long.
posted by jamjam at 5:05 PM on April 10, 2016

Niche construction, which can get to long-term mutualisms without intent.
posted by clew at 5:17 PM on April 10, 2016 [2 favorites]

Creepier version of this: I recall a story on CBC's Quirks and Quarks from a few years back in which scientists reported that some species of corvid - crows or magpies, I think it was - seemed to be "seeding" branches with ticks, at just the right spots for the ticks to attach themselves onto new moose and deer.

And later, presumably, the corvids would harvest their crop of ticks from the moose/deer.
posted by clawsoon at 7:05 PM on April 10, 2016 [1 favorite]