Wednesday, October 5, 2011

Katydid Nupital Gifts

This article is right in line with what was discussed last class. Males offering other gifts other than his sperm to the females. Females choosing mate based on best gift. Best gift = best male/genes for healthy offspring.

More nutrients for the young, something to occupy the female during insemination. Yay Sexual Selection!


A new study of katydids in the latest issue of the Proceedings of the Royal Society B -- co-authored by U of T Mississauga professor Darryl Gwynne -- supports a theory that females will search if males offer a lot more than just sperm.

"In this beast [in this study], it's a big cheesy, gooey substance that the male ejects when he copulates," says Gwynne. "It's attached to his sperm packet, so while she's being inseminated, she can reach back and grab this mating gift and eat it."

"Males mostly do the searching, because the Darwinian sexual selection process is typical stronger in males; they're competitive, says Gwynne." As a consequence of their eagerness to get to the females, the females just hang out waiting for the males to come to them."

And from the male's perspective, a large food gift not only potentially benefits his offspring, but distracts the female long enough to ensure that he has time for a full insemination. Otherwise, says Gwynne, "she's hungry...if he didn't give her this gift, she'd just pull off the sperm packet and snack on that like a little hors d'oeuvre."

Ryan M. Pfeiffer.

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