Dan got me thinking with his comment in the castration thread. It's not just Gorillas that have the problem male situation. l went to ISIS Randomly selected. Bison 210.394 hamadryas Baboon 341.509 Chimpanzee 362.610 There is something seriously wrong and correct me if l am wrong. And l know you will but don’t all 3 of these animals have 50/50 birth ratio. Or is it common knowledge that these males are euthanized! Maybe sold or transfered to non isis registered zoos.Maybe killed by dominant males? Just really seems suss to me.
Maybe aselect animalimports by zoos? Please don't forget that the days that zoos bought animals are not that long (or not entirely??) over. If you want a species where the living conditions require a dominant male that doesn't accept other grown males, that's what you buy.
@zooman: Well, I can tell You where quite a bunch of surplus Bisons end up-in the slaughterhouse (maybe with a more or less long detour to a bison ranch)... In regard to the primates-some of Your assumptions are correct: many if not most specimens of these two primate species nowadays go to zoos that are not ISIS- registered. Additionally, there is a higher male mortality rate in several species-which is influenced both by a more aggressive, risky life style as well as by a higher susceptibility to diseases. Especially in terms of gonosome related hereditary defects, males miss the second "compensating" X-chromosome. Prime example in humans: Hemophilia A In fact, similar to humans, one would expect a slighly higher number of males due to the lighter weight of Y-chromosome carrying sperms. However, due to the factors mentioned above, the sex ratio balances itself more or less. Officially, in serious modern zoos, euthanasia is the very, very last resort of how to deal with an unwanted, surplus animal-especially when it comes to popular species like apes, elephants, big cats etc. In some countries, the criteria to justify this are strict, excluding "surplus-ness" as a reason. @Elly: The days of animal trade with zoos involved are far from over. A large number of small mammal, fish, amphibian, reptile and bird species kept in zoos are not bred there, but acquired from private/commercial breeders or wild-caught (Neon tetras, for example).
Most parks in the Netherlands don't really make a big secret about where their surplus hoofstock ends up. Parks like Amersfoort, Beekse Bergen and Blijdorp (even on their website) are pretty open about killing a few animals (specially bison/watussi) and feeding them to their big predators. Some monkeys are also killed as surplus (some zoos get rid of their baboons that way), others end up in smaller non-ISIS parks (many macaque species).
Maybe that's what happened to the very large herd of Swamp Deer- a hundred or two animals- at Port Lympne's Combe Farm( the African experience area). Despite being an endangered species, they don't seem to have them anymore, just a small group of about 8 in the main park. Presumably nowhere else would take such a big number.
Hmmm...that is definetely interesting. Especially considering the below numbers looking at traditional "solitary" animals in zoos... Tigers: 119.128 Grizzly Bear: 30.42 Polar Bear: 84.93 Moose: 14.16 Definetely more like the expected 50:50 ratio...although most of the above animals are probably too valuable to trade to a non-accredited zoo/slaughterhouse....>.<
The husbandry of these species are the same for both sexes. It's not like you need a bigger/better enclosure to keep either sex. There's also no herd structure involved where females can live together and males can't. Usually it's these animals that end up skewed (herd-like hoofstock or elephants for example)...
I raised the subject of euthanasia in zoos when I was new to the forum, when I "broke into" this thread: http://www.zoochat.com/2/bear-breeding-23342/ However, I managed to do it in a very clumsy and perhaps even offensive way (not deliberatly, but...). I also promised to get back to the subject but hasn´t done it so far. Will do it on of these days. Please join the discussion when that happens, zooman!
Few ungulates are euthanised, many males kill each other or themselves, some animals are exported to small zoos, sometimes females are more often imported. With apes who live 40 years you really talk about historic situation.
Dan, Dan, Dan. I think from reading the posts here we are all enjoying ourselves and sharing our views and experiance.
Yeah mostly agreeing what was kinda said before that guys are usually more dominant and aggressive, in a group situation being that you'd want less conflict as possible and I'm the males enjoy being able to spend their time with the females without having to deal with other guys!
mmmm. I wonder. The case of Port Lympne's disappearing Swamp Deer herd- from treble figures now reduced to just a small group of 8- is still a very drastic reduction and to me it obviously indicates what happened to the rest....though I can understand why too.
This doesn't answer the sex ratio question- but is it possible that the Swamp Deer herd contracted a disease, and the herd had to be euthanized as a result? Maybe hte 8 that are left are the survivors...?
@Leptonyx: Well, it does partly answer it: more males than females die "on the way", growing up/living-which explains why there are less males than females shown in the census...In the case of the Swamp Deer-see Jurek7's answer.
I am pretty sure that was not the case. For a start all animals would have been euthanased, not leaving any. Also the 8 'survivors' are a very 'neat' group of one male and seven females. Other ungulate species, particularly the other Asian deer such as Axis and Sambar which are still at the Park would surely have been affected too. I suspect the Swamp deer were all put down and possibly fed to the Carnivores. I have also obliquely received some hints that this is what happened.
