Sexual and consumptive abstinence as a yard-stick for sapience?
August 31, 2017 9:49 PM   Subscribe

Are there any examples of non-human animals intentionally curtailing either resource consumption or reproduction in a way that would indicate a kind of understanding of ecology? Are there animals that, given super-abundance of resources and/or lack of predation will alter their behavior in such a way that obviates population boom and bust or general unbalancing of their ecosystem?

Trying to figure out if this is a biological universal. Certainly, alteration of behavior as a reaction to abundance wouldn't, by itself, prove that an animal had an ecological concept. But is there any evidence of such behaviou all outside of humanity?

You could also argue that humans haven't proven themselves entirely capable of curtailing consumption or procreation in any meaningful, effective way. But, c'mon, you know what I mean. We know lemmings don't really commit suicide. Do bears ever show restraint when man-made or natural effects produce a bumper crop of bunnies and dear? When the cats are away, do the mice ever forgo playing? Or does all of the fossil record and animal behaviorism just show us solipsistic specism?

The only situations that come to mind have to do with symbiosis and parasitism, but even there, it seems that ecological equilibrium only comes from eventual adaptation, rather than any type of cognitive strategy on the part of animals. Even in the case of highly adaptive or intelligent animals (elephants, crows, apes, dolphins?) is there any evidence of this in the animal kingdom?
posted by es_de_bah to Pets & Animals (19 answers total) 5 users marked this as a favorite
*Should read "Is there any evidence of such behavior at all, outside of humanity?
posted by es_de_bah at 9:53 PM on August 31, 2017

These lizards do;

These results suggest that female racerunners facing food restriction lay fewer offspring with unchanged body size and locomotor performance, and incur a cost in the form of poor postpartum body condition and immune function. The flexibility of maternal responses to variable food availability represents an important life strategy that could enhance the resistance of lizards to unpredictable environmental change.
posted by Homer42 at 10:34 PM on August 31, 2017 [1 favorite]

I like the idea and it is how I look at it intuitively, but honestly if I try to work it out this becomes somewhat circular.
Because lots of animals will refrain from doing stuff in certain situations.

Alligators don't munch on birds that pick their teeth clean and most fish won't make a meal of cleaner shrimp. Elk or deer that don't have enough resources won't grow antlers and basically opt out of the mating competition that year. Ants farm aphids. (Often) females or (occasionally) males will only mate with desirable partners. So different types of restraint abound.

But I would find arguments that any of these give count as evidence of sapience ridiculous. Simply because I know they aren't sapient.
posted by mark k at 10:47 PM on August 31, 2017 [1 favorite]

Homer42, what I'd be interested in would be almost the opposite response. That is, if the lizards in the HFT group actually had fewer offspring, so as not to overpopulate too far ouside the normal range. The scenario of a population overproducing during an unsual (often temporary) uptic in favorable conditions is common. Rather, as economic prosperity can lead to lower birth rates in humans, do animals ever show reserve in response to above average conditions?

Certainly, the maternal conditioning on display in these lizards COULD be a vector for such a response.
posted by es_de_bah at 10:56 PM on August 31, 2017

D'oh! Sorry. I responded to what I thought you said, not what you said.
posted by Homer42 at 1:51 AM on September 1, 2017

The closest thing I can think of is the fact that territoriality and hierarchy - present in a number of species - often keep numbers well below theoretical carrying capacity.

Standard thinking is that this happens because dominant individuals impose abstinence on other members of the group. Having excess resources in the territory that they control allows the dominant animals to grow bigger and stronger and smarter and socially better-connected, and thereby maintain both their control over their group and their control over their territory.

You could argue that this is more-or-less what humans do. You also see it in wolves, meerkats, hyenas, a bunch of bird and primate species, etc.

If you want to read more about the debate over why animals engage in territoriality - and whether population control is the intended consequence, or whether it's all about individual competition for control - you might find V. C. Wynne-Edwards interesting, and the criticism/reevaluation of his theories, and the re-reevaluation.
posted by clawsoon at 2:19 AM on September 1, 2017

You may or may not find it interesting, but there's a analogous debate in economics about the price-setting behaviour of firms. Do firms pursue maximum profit (analogous to a species consuming all available resources) or do they keep their prices below that limit? And if they do keep their prices below that limit, do they do it because they have a concern for the economy as a whole (analogous to a species being concerned with ecological collapse) or do they do it because it has some other advantage for them as an individual firm?
posted by clawsoon at 2:49 AM on September 1, 2017

Here's another re-reevaluation of Wynne-Edwards: Evolutionary Restraints: The Contentious History of Group Selection:
Tracing the history of biological attempts to determine whether selection leads to the evolution of fitter groups, Borrello takes as his focus the British naturalist V. C. Wynne-Edwards, who proposed that animals could regulate their own populations and thus avoid overexploitation of their resources. By the mid-twentieth century, Wynne-Edwards became an advocate for group selection theory and led a debate that engaged the most significant evolutionary biologists of his time, including Ernst Mayr, G. C. Williams, and Richard Dawkins. This important dialogue bled out into broader conversations about population regulation, environmental crises, and the evolution of human social behavior.
posted by clawsoon at 3:16 AM on September 1, 2017

Human females who are starving have difficulty conceiving; the same is true for other species. So sexual abstinence might not be necessary.
posted by mareli at 5:30 AM on September 1, 2017 [1 favorite]

You might be interested in this article by Holly Dunsworth and Anne Buchanan, on the evolutionary importance of connecting sex and reproduction.
posted by ChuraChura at 5:41 AM on September 1, 2017 [1 favorite]

I remember learning about this in Watership Down, that if conditions weren't right to have a littler a pregnant rabbit would "reabsorb" them and they would not be born. You can see a lot of internet talk about this concept but without more research I'm not sure if it's a real thing. It's clearly triggered by environmental things, however, I don't think sapience has anything to do with it. Just like how starving women won't menstruate. They don't consciously do this, their body does it for them.
posted by jessamyn at 6:41 AM on September 1, 2017

Urban foxes generally keep the population at around carrying capacity. If people start killing them in an area, litter sizes go up and age of first reproduction goes down. As the population stabilizes, the reverse happens.
posted by rockindata at 6:45 AM on September 1, 2017

rockindata, that's closer to what I'm talking about. My ladyfriend sent me this, which suggest such behavior in pack hunters and points out the difficulty of finding populations that remain stable enough to study across several species, due to human factors.

clawsoon, thankyou for all the great links!

The more I see, the more the question gets reversed: does the evidence actually suggest that HUMANS do this in any type of rational way, or is it just an illusion. The lense of economics is a super-interesting one there. Scary thought for our long-term viability: we may not have the biological OR social capacity for conservation.
posted by es_de_bah at 7:02 AM on September 1, 2017 [2 favorites]

Yeeeah, I don't think humans really do this in any sort of consistent, sustainable way.
posted by potrzebie at 7:25 AM on September 1, 2017 [1 favorite]

Kangaroos can control when they give birth. As can some other mammals too.

Kangaroos can actually pause an embryos development by pausing implantation (embryonic diapause). So Kangaroos during lean times they don't give birth, or during lush times or if the joey they are nursing dies off they literally have "one in the chamber" as it were to get going without having to find a male to impregnate them. So they can either breed continually if there is lots of food, seasonally if needed or not at all in times of drought.
posted by wwax at 8:51 AM on September 1, 2017 [3 favorites]

es_de_bah: The more I see, the more the question gets reversed: does the evidence actually suggest that HUMANS do this in any type of rational way, or is it just an illusion.

The chapter on wet nursing in Hrdy's (excellent, well worth reading if you're into this stuff) Mother Nature is a powerful comment on this. Dominant people literally take the milk of poor babies and give it to their own babies. This helps lower population growth, because the poor babies are much more likely to die. But is that a laudable conservation effort? Not so much.
posted by clawsoon at 7:00 PM on September 1, 2017 [2 favorites]

Are there any examples of non-human animals intentionally curtailing either resource consumption or reproduction in a way that would indicate a kind of understanding of ecology?

The problem with the question is the word intentionally. You have received excellent, knowledgeable responses, but there is no response that can tease out intentionality here.
posted by Joseph Gurl at 7:39 PM on September 1, 2017 [1 favorite]

ALL living and non-living processes do this. Reach equilibrium. Processes that don't reach equilibrium, don't persist. It doesn't require intentionality. Human population already does this on its own, and it has nothing to do with public policy or any intellectual awareness at an individual level (e.g., there is no human "overpopulation" problem as such).

When resources are plentiful, life flourishes. When resources are not plentiful, life contracts. Bears eating a bumper crop of bunnies isn't an ecological "problem", it's how the system self-balances.

Also, the question as you've asked it kind of depends on assuming that animals have the capacity for conscious decision making at some level, which... isn't really defined because consciousness isn't really defined. Like you can define "intentionality" however you want, so that anything can qualify.

The ability of humans to plan for long term outcomes, outcomes that wouldn't result from a natural equilibrium, seems unique.

Animals aren't more "ecological" than humans. Like, the stories of how predators in the wild don't kill more than they can eat... is a feel-good myth that isn't at all true.
posted by danny the boy at 12:59 PM on September 2, 2017

(And just for the record, bears don't eat bunnies, but you know what I mean.)
posted by danny the boy at 1:05 PM on September 2, 2017

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