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posted by chromas on Thursday March 29 2018, @02:56AM   Printer-friendly
from the left-to-bear-arms dept.

Hunting laws in many countries and U.S. states prevent mother bears from being hunted while they are accompanied by their cubs. In Sweden, that seems to have artificially selected for mother bears that spend an extra year raising their cubs:

Female bears generally spend either 1.5 or 2.5 years with their young. In many ways, the pressures of bear life favor the shorter option — a mother with cubs cannot mate, so the more time she spends with each litter, the fewer offspring she'll have over her lifetime.

But a new study [open, DOI: 10.1038/s41467-018-03506-3] [DX] of brown bears in Sweden has found a surprising trend: More and more mothers are spending the extra year with their cubs.

"There's about a 30 percent increase in females staying to care for young for an extra year," explains Fanie Pelletier, an ecologist at Sherbrooke University in Quebec, and an author on the study published Tuesday in the journal Nature Communications. "Early on, in the '80s, almost all females stayed with their young for 1 year and a half," she says. "It's only since 2005 that we have witnessed this increase in the population [that are] staying with their young the extra year."

The trend is tied to a hunting regulation that protects family groups from hunters. It's illegal to shoot mother or cubs when they are together.

"For females, if you leave your cubs at one year and a half, then you become a target during the next hunting season," explains Pelletier. But "if you stay for a bit longer with your cubs, you're protected an extra year. The hunting is filtering out the females that keep their young for a smaller amount of time."

Abstract:

As an important extrinsic source of mortality, harvest should select for fast reproduction and accelerated life histories. However, if vulnerability to harvest depends upon female reproductive status, patterns of selectivity could diverge and favor alternative reproductive behaviors. Here, using more than 20 years of detailed data on survival and reproduction in a hunted large carnivore population, we show that protecting females with dependent young, a widespread hunting regulation, provides a survival benefit to females providing longer maternal care. This survival gain compensates for the females' reduced reproductive output, especially at high hunting pressure, where the fitness benefit of prolonged periods of maternal care outweighs that of shorter maternal care. Our study shows that hunting regulation can indirectly promote slower life histories by modulating the fitness benefit of maternal care tactics. We provide empirical evidence that harvest regulation can induce artificial selection on female life history traits and affect demographic processes.


Original Submission

 
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  • (Score: 2) by marcello_dl on Thursday March 29 2018, @06:45AM (3 children)

    by marcello_dl (2685) on Thursday March 29 2018, @06:45AM (#659866)

    >When you consider how short the time span these hunting laws have been on the books the change in behavior happening this quickly is pretty amazing.

    Only if you insist in not considering concepts like karma and providence, implying that all mutation is random and selection a function of time. This has nothing to do with religion, in fact it becomes about religion only when you pick Darwin over Lamarck because it makes less assumptions. Everything should be made "as simple as possible, but not simpler".

    Let's face it, when you get old enough, something about the random impersonal universe does not compute.

    Starting Score:    1  point
    Karma-Bonus Modifier   +1  

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  • (Score: 1, Funny) by Anonymous Coward on Thursday March 29 2018, @07:25AM (1 child)

    by Anonymous Coward on Thursday March 29 2018, @07:25AM (#659879)

    Let's face it, when you get old enough, something about the random impersonal universe does not compute.

    That's just selection bias, the rest of us just die young in nihilistic apathy.

    • (Score: 2) by Bot on Friday March 30 2018, @11:19PM

      by Bot (3902) on Friday March 30 2018, @11:19PM (#660599) Journal

      > That's just selection bias providence: the rest of us just die young in nihilistic apathy.

      FTFY

      --
      Account abandoned.
  • (Score: 3, Interesting) by stormreaver on Thursday March 29 2018, @12:03PM

    by stormreaver (5101) on Thursday March 29 2018, @12:03PM (#659925)

    This has nothing to do with religion...

    Since the notion of Karma and Providence are religious nonsense (Karma less so than Providence, as an argument can be made linking Karma and Conscience), your posting has everything to do with religion.

    Unless bears have a heretofore unknown understanding of human hunting laws, this is most likely the result of hunters reducing the number of bears that possess a weaker genetic predisposition to raise their young over longer periods; leaving a larger pool of reproducing bears with a stronger genetic predisposition to raise their young over longer periods.

    In other words: Darwinian Evolution.