Reptile & Amphibian Forums

Over time I have seen this occur with three or four different P ruthveni females over several seasons. I am not claiming it as a fact or anything "scientific" BUT-
the females I have seem to prefer to breed with smaller males. This week I put an '04 female in with an '03 stud. all things being equal, I expected for him to be all over her but nothing doing. So I replace him with an '05 "worm" and he's got the female by the back of the head doing their thing. I tried another big boy with her and again, no interest by either.
I first noticed this in '05, the year after my numero uno male unexpectedly keeled over. I didn't have a certain number two/back up because the other holdbacks were "small" and unproven. after some thinking I realized numero uno was smaller than the girls and decided to give the smaller guys a chance. bang. success! with the exception of one pair that is like an old couple, the other girls dig little guys.

just my observations, and I'd say that it's not such a bad thing to hang onto a few up and coming males on occasion.
anyone see this with other pits?

daveb

Dave,
I've observed this with many pits for many years. That's why I tend to keep my males on the smaller size. John Meltzer

John,
I am glad to hear you've had success with this approach. I didn't think it was an original concept but at the time ('05) after a proven breeder expired unexpectedly, I was looking for any answer to find a successful breeding solution.
I don't know what others' positions are on keeping holdbacks, but having some young guns around has worked well. In the future I would like to see how well this works with other "difficult" colubrids like some drymarchon ssp.
dave b

Seems to me she's a cradle robbing cougar.

Interesting observation. I can not say that I have never observed this phenomenon but I should note that I generally only keep single pairs of snakes as space is limited and for the most part my males are all bigger that their females. The females will go through reproductive stress each year where as the males do not have that metabolic drain and seem to out grow the females. I generally feed the males less but they still overtake the females and I have never experienced any female refusal of big male breeding issues. Several years ago I successfuly bred a very large (7') male jani to a slender 40" female w/o issue. As an ecologist I wonder what advantage a female would have by choosing a smaller, presumably less well established, male when given a choice? The times that I have seen Cratalid breeding in the wild the males were always larger than the females. I have heard of studies where males that lost during male on male combat interactions would not breed even if removed from the presence of that winner male. The act of being beaten would change their psychology enough that they would remain "loosers" for the remainder of that breeding season.

I wonder if it is a male pheramone issue? In other words if you put the small males in first followed by the larger males would the females "accept" or "select' the larger males?

This would be an interesting study to set up and follow through on. You would have to have a sample of say 15 or 20 females, test all the males for fertility, and choose study males for each female that are significantly different in size.Since we don't always see copulation we would have to genetically trace the offspring back to the successful males. It sound like a bunch of work but I think you could test the hypothesis that way. Again, I can not see of an advantage for the female to choose a "lesser" male over a "well established" ,larger, successful male. In the world of snakes the bigger you get equals the longer you have been around surviving the pressures of selction which equals biologic success. I could however be looking at the topic from the wrong perspective?

Dave, thanks for the thoought provoking topic!

this could be a captive condition, I don't know. most times i have not preintroduced a larger male. my first successful breeder in '03 and '04 was smaller than the girls, and that is where the idea came from. obviously not a new thought as John M has shown but it has worked well here, too.
these animals are in need of a lot more field study or more of the studies in the field need to be published.
i think possibly in an environment where an animal specializes in one type of prey as ruthveni are known to do with pocket gophers, it may come down to resource allocation and interspecific competition(?). a clutch of 4-6 eggs weighs 400-600 g. I don't know how many kcals ( or joules is it these days?) are in each egg but its a few. small males using less resources ( or maybe an entirely different habitat?) may be more attractive ( i know that is phrased a little odd, but...).

I do have a pair, both are big and they are like an old happy couple each spring. So not all of the successful pairings are big girl small guy.

anytime you want to work on an experiment with 15- 20 pairs of ruthveni, I'm in!

Cheers,
Dave
PS -are those mugitus going to breed this year? Please be sure to sign me up for a pair!

inTRAspecific competition.

I've definitely noticed this in boas, where smaller, younger males are often much better breeders than large individuals.
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Brad Chambers
WWW.HCU-TX.ORG

The Avalanche has already started-it is too late for the pebbles to vote....

so Brad,

I have heard that but I haven't bred boas. what do you propose for small male boas being more attractive to females?

How many bulls are you keeping now? do you see anything like this in your pit collection?

daveb

so Brad,

How many bulls are you keeping now? do you see anything like this in your pit collection?

Well, for one thing I don't think that in boas there is any male to male combat, so small male size and larger female size should be selected for. The reason for this is twofold-first, a larger female can produce more offspring, and second, a smaller male will not compete much with females for resources. They will seek out different categories/sizes of prey animals.

I don't have that many bulls-my stillwater hypos, some double het stillwater X patternless, and my locality Trans-Pecos bull/sonoran intergrades. I can't say I've seen it as yet-last year I only bred my Trans-Pecos bulls, and that male is a few inches longer than the female (right on six ft.). They successfully produced 8 good eggs....
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Brad Chambers
WWW.HCU-TX.ORG

The Avalanche has already started-it is too late for the pebbles to vote....

is that correct- stillwater HYPO x patternless double hets? That has the potential to be a very interesting combo. keep me posted.
btw,how are the gtp's doing in texas?
daveb

Stillwater hypo X Patternless (from homegrown herps). They won't breed till next season, but I'm anxiously awaiting the event.

My Chondros are doing fine down here-of course I have to be religious about their misting schedule. My oldest Wamena and an Aru type male have beed hooking up recently, and she has been showing signs of building follicles, so I'm hopeful....
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Brad Chambers
WWW.HCU-TX.ORG

The Avalanche has already started-it is too late for the pebbles to vote....