Evolution
As
a parent, you want to teach your children about the dangers of the
world and how to stay safe from them. The cricket is no different -
except it can do this despite abandoning its eggs.
To
determine whether the mother's predation risk would influence the
behaviour of her offspring, researchers Jonathan Storm (Uni of South
Carolina Upstate) and Steven Lima (Indiana State Uni) placed pregnant crickets
in an enclosure with a wolf spider. The fangs of the spider had been
covered with wax to prevent it eating the crickets, but it could still
stalk them. When eggs had been laid and hatched, those offspring and a
control group (whose mothers were not exposed to predators) were placed
in a new enclosure with another wolf spider - a very hungry one with
usable fangs.
They found that the control group of offspring
were eaten much quicker than those whose mothers had lived with the
spider. The experimental offspring stayed hidden over 100% longer than
the control, aiding their survival. Another experiment demonstrated they
were more likely to freeze when they encountered spider silk or faeces -
behaviour that would give them a significant survival advantage. This
difference has also been noted between crickets from predator-light
environments and those in predator rich habitats. Storm suggests it's
possible that stressed mothers release a hormone which affects their
offspring, but more research is needed before we can say for sure.
Photo credit: iStockphoto/Joseph Calev
http://www.sciencedaily.com/
And for the paper itself:
http://www6.svsu.edu/~gmlange/
As
a parent, you want to teach your children about the dangers of the
world and how to stay safe from them. The cricket is no different -
except it can do this despite abandoning its eggs.
To determine whether the mother's predation risk would influence the behaviour of her offspring, researchers Jonathan Storm (Uni of South Carolina Upstate) and Steven Lima (Indiana State Uni) placed pregnant crickets in an enclosure with a wolf spider. The fangs of the spider had been covered with wax to prevent it eating the crickets, but it could still stalk them. When eggs had been laid and hatched, those offspring and a control group (whose mothers were not exposed to predators) were placed in a new enclosure with another wolf spider - a very hungry one with usable fangs.
They found that the control group of offspring were eaten much quicker than those whose mothers had lived with the spider. The experimental offspring stayed hidden over 100% longer than the control, aiding their survival. Another experiment demonstrated they were more likely to freeze when they encountered spider silk or faeces - behaviour that would give them a significant survival advantage. This difference has also been noted between crickets from predator-light environments and those in predator rich habitats. Storm suggests it's possible that stressed mothers release a hormone which affects their offspring, but more research is needed before we can say for sure.
Photo credit: iStockphoto/Joseph Calev
http://www.sciencedaily.com/
And for the paper itself:
http://www6.svsu.edu/~gmlange/
To determine whether the mother's predation risk would influence the behaviour of her offspring, researchers Jonathan Storm (Uni of South Carolina Upstate) and Steven Lima (Indiana State Uni) placed pregnant crickets in an enclosure with a wolf spider. The fangs of the spider had been covered with wax to prevent it eating the crickets, but it could still stalk them. When eggs had been laid and hatched, those offspring and a control group (whose mothers were not exposed to predators) were placed in a new enclosure with another wolf spider - a very hungry one with usable fangs.
They found that the control group of offspring were eaten much quicker than those whose mothers had lived with the spider. The experimental offspring stayed hidden over 100% longer than the control, aiding their survival. Another experiment demonstrated they were more likely to freeze when they encountered spider silk or faeces - behaviour that would give them a significant survival advantage. This difference has also been noted between crickets from predator-light environments and those in predator rich habitats. Storm suggests it's possible that stressed mothers release a hormone which affects their offspring, but more research is needed before we can say for sure.
Photo credit: iStockphoto/Joseph Calev
http://www.sciencedaily.com/
And for the paper itself:
http://www6.svsu.edu/~gmlange/
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