Cryptic Sexual Selection

[mtolypetsupply]

Was watching a show on PBS last night about sexual selection of different species. It was awesome, because there was a segment about Garters, Red-Sideds specifically. I think they were at the Narcisse Dens from the writhing mass of breeding balls that made the ground come alive!

Anyway, they talked about "cryptic sexual selection". It's "cryptic" because it is not observable- it happens within the dam.

We know what happens:

Garters emerge from dens, males first, who then lay in wait for the females to emerge. When they do, the horny little buggers pile on, and whomever manages to get the hemipenes where they need to be gets to breed her. The lady, indignant from the assault, high-tails it away from the group of horny boys, with a sperm plug preventing further mating at that time.

After 36 hours or so, the plug falls out, and she again becomes attractive to males. Now, however, she's warmer, and smarter, and attempts to select a mate from the suitors that find her. Still, often upwards of 10 males can find her and attempt breeding. Now that she has her wits about her, she challenges them by racing away. Whomever can keep up, or whatever other criteria they use to choose a mate, gets to mate with her. After their mating, she may mate with more males, after the plug falls out, etc. etc. etc.

Now, here's the coolest part, IMO.

The biologists say that now that she has sperm from two or more males, somehow, (they didn't explain how) she can CHOOSE which sperm to use. They didn't get into mechanics, or whether it's truly conscious choice, or a function of something else entirely. The "choice" has evolved as a mechanism so that the early breedings, which may just be an undesirable male who truly "got lucky" and took advantage of her slow metabolism, can be discarded in favor of a superior mate.

They also did not get into whether or not, if bred by only one unacceptable male, she could reject the sperm and not fertilize the eggs.

Does anyone else have info on this? Does this apply to other genus? I'll do some poking around the net.

[drache]

that is so cool, Stephi
thanks a ton
do you remember the title of the show?
- was trying to find it on their site

[mtolypetsupply]

Okay, here's the link:

Video: Full Episode - What Males Will Do - Mating and Sexual Selection | Nature

Chapter 4 is what talks about the garter and cryptic selection

[guidofatherof5]

Very interesting.

[mtolypetsupply]

Very interesting.

LOL I have an image of the old school Laugh In, Artie whats-his-name in a german outfit saying "Very Innnnnteresting"

LOLOL!

[drache]

can't wait to see it
while we're on the subject . . .
I just picked up "Dr Tatiana's Sex Advice to all Creation" from someone's "free" box
I don't think garters are mentioned in it though, or at least not sufficiently to make it into the index

[Nafun]

"Dr Tatiana's Sex Advice to all Creation" sounds like a porno.

[drache]

"Dr Tatiana's Sex Advice to all Creation" sounds like a porno.

well, yeah . . .
except I don't think it's not got that much on human sex, but I could be wrong
the impression I got, as the dog was pulling me on to the next smelly spot, was that it's more about the weird mating strategies of other species. Who knows - there may be analogies drawn to our species at some point
I'll let you know if it turns out to be truly exciting despite the lack of garters

[ConcinusMan]

That was a very cool video. I think it might be a little misleading? I think perhaps the female holds off on ovulation, ejects the sperm, mates again, then ovulates, thus fertilizing her eggs with the second mating.

T.ordinoides have been found to mate up to 3 times in spring, then ovulate, then having babies from 3 different fathers in one litter in mid summer! Some of them skip the spring mating, and mate in fall, hold the sperm, ovulate in late winter, then have late spring babies.

[drache]

at last got to watch it - very cool
I have to say that I'm a bit entranced with the lyre bird - especially when it makes the camera shutter sounds