Pages in this blog

Friday, September 7, 2018

Knowledge of animal migration routes is passed on through social learning

Ed Yong, Humans Are Destroying Animals’ Ancestral Knowledge, The Atlantic, September 6, 2018:
In the 1940s, the Wyoming Game and Fish Department began trying to move bighorns back into their historic habitats. Those relocations continue today, and they’ve been increasingly successful at restoring the extirpated herds. But the lost animals aren’t just lost bodies. Their knowledge also died with them—and that is not easily replaced.

Bighorn sheep, for example, migrate. They’ll climb for dozens of miles over mountainous terrain in the spring, “surfing” the green waves of newly emerged plants. They learn the best routes from one another, over decades and generations. And for that reason, a bighorn sheep that’s released into unfamiliar terrain is an ecological noob. It’s not the same as an individual that lived in that place its whole life and was led through it by a knowledgeable mother.
Interesting, but seems a little confused:
“This changes how we think about wildlife habitats,” Kauffman adds. “Wildlife researchers have always focused on the physical landscape. How much grass is there? How many conifers? Then you can ask how good that habitat is for a sage grouse or a grizzly bear. But our work suggests that the true measure of habitat quality for mobile animals is both the physical attributes of the landscape and the knowledge that animals have of how to make a living there. Put naive animals into awesome habitats and they may perform really poorly, while animals that know how to exploit landscapes that have been degraded could do really well.”
It is certainly the case that one cannot define an ecological niche independently of the organism that occupies it [1]. It's not clear that "habit" is a synonym for "niche", but the thought seems to be the same. You can't define an animal's habitat independently of the animal's knowledge of it.

Habitat knowledge accumulates over generations:
That knowledge takes time to accrue, which the team showed by studying both the bighorns and five groups of translocated moose. The more time these animals spent in a new place, the better their surfing ability was, and the more likely they were to migrate. Jesmer thinks this process likely occurs over generations: Individuals learn to move through the world by following their mothers, and then augment that inherited know-how with their own experiences. “Each generation, you get this incremental increase in knowledge,” Jesmer says. For sheep, he says, learning how to effectively exploit their environment takes around 50 to 60 years. Moose need closer to a century.

That knowledge allows the animals to find plants early, when they’re young, tender, and more easily digested. And by eating high-quality plants, they can more easily pack on the fat and protein that gets them through harsh winters. “When they lose that knowledge, their populations will suffer,” Jesmer says.
* * * * *

[1] See these posts: "Lewontin: There is no niche without an organism", New Savanna, April 6, 2015, https://new-savanna.blogspot.com/2015/04/lewontin-there-is-no-niche-without.html

"'Pattern' as a term of art", New Savanna, July 5, 2014, https://new-savanna.blogspot.com/2014/07/pattern-as-term-of-art.html

No comments:

Post a Comment