New question for MarkB

kap10cavy · 05-18-05, 10:35 PM

I was watching a show awhile back and all this talk about multiclutching made me remember something.
The show had to do with swarms, the locust swarms were the parts that caught my intrest. A comment was made by the narrator about the amount of food that just flew in would make a big impact on the breeding season.
In your opinion, could a large abundance of food like this cause a wild monitor to multiclutch?
I know, I watch too much TV and think too much.

Scott

crocdoc · 05-19-05, 06:31 PM

Hey, Scott,

I know I'm not Mark, but since he hasn't responded yet, I'll add my thoughts if you don't mind.

That's a good question/idea you've posted regarding locust swarms. We've had a couple of big years for those here in NSW recently.

Most locust swarms are short lived affairs. They come into an area, raize it, then move on. I've seen the damage they have done to pasture land on a friend's property - there's nothing left, to they point where he had to sell off his cattle to avoid having to hand feed them.

Birds benefit from these swarms because they can fly in, get all of the food they need, then fly off again to wherever their nest is. The animals local to that area that aren't flying in and out (such as the reptiles) get a huge hit of food for a short period, but once the locusts are gone there isn't enough forage left to support any other insects so the reptiles probably get really badly hit. That's conjecture.

So, is that short lived rush of locusts enough to allow the monitors to multiclutch? Maybe it is, maybe it isn't. So far, though, there hasn't been any evidence of wild monitors multiclutching.

Funnily enough, I didn't actually enter the debates on multiclutching when those 'discussions' (read 'bunfights') occurred on the other forums. In my view, it's possible but not probable (certainly not in the two local species, V varius and V rosenbergi). Even if someone did document it occurring it wouldn't then become the 'norm' but an exception.

kap10cavy · 05-19-05, 07:19 PM

I always figured if it did happen in the wild, it would be with some of the larger tropical species. Something that has an abundance of food year round. If I was to pick an Aussie lizard to do this is the wild, I would try to plan my studies around mertens, just because of they way they hunt for fish and such.
That, and they seem like such fun lizards to watch.

Scott

crocdoc · 05-19-05, 07:37 PM

I'm not convinced that any species has an abundance of food year 'round, as even in the tropics there are wet and dry seasons with differing food availabilities.

However, a species like mertens which gets much of its food from underwater is probably less affected by this than those living away from water, so it would be a good choice. Tropical species also have a longer period during which food is available.

See? It's possible to have a sensible logical conversation about this without it disintegrating into personal attacks. I could never understand why people get so worked up about topics like this on other forums.

kap10cavy · 05-19-05, 07:42 PM

And just think, lil' ole me came up with this all on my own.
I have never written a paper, studied them in the wild or hatched one single monitor egg.
Some people just think too hard and get stuck in a rut.
Never happen with me, I don't know enough to be convince one way or the other. hahaha
Maybe my thinking is too simple for others to understand.

Scott

mbayless · 05-19-05, 07:50 PM

Hi Scott and DK,
Hahahaha = Coincidence? Yes, the hatchling V. exanthematicus hatch right when the Harmattan winds die down, and the locust blooms burst across West Africa out of the North-west from Mali/Niger areas into lower lying regions of West Africa - and they raise the ground flat - these blooms are a vital sources of food for the V. exanthematicus, and many other animals during their brief visitation.... as for double-clutching - it does happen in captivity, but I cannot for the life of me figure out why = I think it has something related to diet.

there are some terrific books on African locusts/blooms out there. I have 1970's editions, but it is essentially the same idea now, but with more devastation and crisis to West Africa as the people are worse off now than before...
markb
markb

crocdoc · 05-19-05, 08:11 PM

Quote:

Originally posted by kap10cavy
And just think, lil' ole me came up with this all on my own.
I have never written a paper, studied them in the wild or hatched one single monitor egg.
Some people just think too hard and get stuck in a rut.
Never happen with me, I don't know enough to be convince one way or the other. hahaha
Maybe my thinking is too simple for others to understand.

Scott

Ah.. but before you get too excited and self-congratulatory, it is all still conjecture and for all of the examples we can think of where it may feasibly occur, there still is no evidence of multiclutching having occurred in the wild.

kap10cavy · 05-19-05, 09:38 PM

True, I am just amazed that noone has seemed to mention these things as a possibilty to study.
Hey, I am just a hick from Alabama and like things simple.
I get a headache when Mark and Shvar use all those big words.
I do my best to keep things civil and fun.
I am not afraid to throw out an idea, no matter how ridiculous it might seem if it makes sese to me.

Scott

mbayless · 05-20-05, 12:34 AM

I have given this double-clutch thing a lot of thought, and seen it myself in V. exanthematicus years ago - it hurts my head too - and I can think of only 1 piece of evidence for wild populations that could remotely be related to it, and it comes from breeding records in 1876!

Alfred Gogga Brown (1834-1920) worked with V. albigularis for 40 years near Aliwal, RSA, Africa. He once reported a female V. albiuglaris depositing her eggs on top of a nest of eggs previously made by her - in the same nest - could this be evidence for double-clutching in the wild. The monitors lived outdoors, only corraled by Gogga Brown - they lived essentially wild.

markb

crocdoc · 05-20-05, 12:50 AM

Quote:

Originally posted by mbayless
He once reported a female V. albiuglaris depositing her eggs on top of a nest of eggs previously made by her - in the same nest - could this be evidence for double-clutching in the wild. The monitors lived outdoors, only corraled by Gogga Brown - they lived essentially wild.
markb

Did he feed them? If he did (and he would have had to, if they had no freedom to forage), it would still be a captive situation and they may still be responding to the abundance of food.

crocdoc · 05-20-05, 12:54 AM

Funnily enough, I think eventually someone somewhere WILL come up with evidence of a wild female double clutching. It would have to happen somewhere at some stage, when the conditions are just right and there's a male living near by. Will it change our world view of wild monitor reproduction, though, or would it still be rare instance in which an animal took advantage of an unusual set of circumstances?

kap10cavy · 05-20-05, 06:20 AM

I figure if someone makes a discovery of wild monitors multiclutching, they will be living near a year yound food source.
Maybe a chicken farm. Hey Dave, know any chicken farmers in your area?

Scott

mbayless · 05-20-05, 03:42 PM

Yeah the reports I have of capive V. albiogularis and V. exanhematicus are extensive, and a few of them are double-clutch events, depositing two groups of eggs from the single female within 40 days of each deposition.... interesting. It is diet related, and perhaps related to fat-storage too....

markb