Possible Consequences of Inbreeding in Amur Leopards

This is probably a dumb question but what happens when a indvidual (or a few members) of a particular species found a new population, say, by arrival on a new continent or island? Examples might include goats, rats and cats. Do these populations suffer the same inbreeding problems? Or does reproductive rate have some influence on things?

Another question: I know that some massive disease among the big cats left many species crippled several thousand years ago, including cheetahs and tigers.

(well, that's what I read back in college)

Anyway, is this why the Amur Leopard is so endangered, or are there other reasons?

Well Zack, First of all did you even read the article?
Yes it is true the leapords, along with many other big cats
suffered from a disease which I'ven ever heard of, and which I cannot mention based on limited information. I think sport-killing the leopards is the main reason they are so endangered. It's pretty much the same thing that happened in Canada about 200 years ago, but they were bigger wilder animals full of meat called "Buffalo". Noble white guys eh ;)

Zwirko; That's not a dumb question at all, and what you're essentially talked about was termed the "Founder Effect." This sort of effect was observed after the famous eruptions of Krakatoa in 1883, devastating the wildlife on the island (and subsequent activity helping to form a new island, Anak Krakatau). The effect inbreeding has in cases like the (re)population of islands depends on a number of things, namely the number of organisms of each sex of a given species, the presence of potentially harmful recessive traits among those animals, and whether there is population flow (i.e. are more organisms of that species arriving and at what rate?). If a small breeding population is in isolation and has a number of harmful recessive traits in the gene pool, then there's a good chance that the population will suffer the adverse consequences of inbreeding, especially if there are no new arrivals to add diversity. Even if such consequences of inbreeding do not occur, inbreeding reduces genetic variability and makes the population more susceptible to diseases, making it very easy for disease to wipe out the population if there are no organisms that are resistant due to lack of variation.

Zach; I don't know of any population bottlenecks among leopards, and this seems to make sense given the large range of the cats (as far as I know they're the widest-ranging species of big cat, from Africa through Indonesia). The Amur population has declined primarily due to habitat fragmentation and hunting, their pelts being especially thick and so highly prized among hunters. Their current inbreeding makes them vulnerable to disease (and cheetahs still are vulnerable even though their numbers have been doing better), which may ultimately push them over the edge even if conservation practices can increase their numbers (they need variability to survive, not just large population size).

John; Zach asked a perfectly reasonable question; there's no reason to be sarcastic if you can't answer the question about disease.

Zwirko, Interesting question, not at all dumb. however the 'liger' of all things has become a new species. When they made the cat who knew what to expect, it came out twice the size of a Tiger, and had the strength and endurance of a Lion. It's interesting but, the cat has become an outkast. If we shall do this to all the big cats, whats going to happen with the originals?
Now that my friends, is a Question.
Leopards inbreeding might have a dramatic effect on their way of nature. They may become more vulnerable to human contact. Which of course is no biggy, seeing as how their pretty much a minority in their own land. If they continue to inbreed the cats may develop new traits, they may become more violent, they may be born slightly deformed, or their brain may not develop the way it normally should. All of which have devastating effects against them. So cross-breeding an animal will introduce another new species of cat. I don't know what the whole outcome of this dilemma may be, but I only hope for the best. When we can no longer breed them in captivity, what will happen?

Good Point Laelaps.

Thanks for the answer, Brian. I'd like to mention that inbreeding is also threatening the wild cheetah population, as well. Tigers and lions seem to have bounced back from the feline disease, but cheetahs took an enormous hit. Because their individual territories are so large, and their breeding cycles are slow, they could also face extinction.

(again, that's mostly from my college days)

Perhaps the gentlemen involved out there should consider breeding them with other cats. Time for a simple solution. Seems like through out time everything goes extinct. Life is life and a name is just a name. Maybe we can call the breed, "amur evolution". Is it true that we evolved?

John T: Just a slight correction; the liger is hardly a "new" species. It is just a hybrid, a curiosity, but definitely not a unique species in the same sense that tigers, leopards and lions are different species.

Z Pather: The thing is, we just don't know just what will happen if we end up breeding them with other leopard subspecies. Will we end up with a population of 'mongrelized' leopards? If we breed them with say, Chinese leopards, we probably stand to lose quite a bit of the Amur leopard gene pool.

The problem with outbreeding, even within the same species, is that you lose a great deal of the genetic diversity that allowed the creature to adapt to its environment in the first place. While hybridisation between subspecies definitely occurs, especially where one subspecies intergrades with another, we are interested in preserving the subspecies or species as a unique taxon, not a mishmash of various subspecies thrown together.

In essence, it's about quality, not quantity. Conservationists are not so much interested in churning out more leopards (after all, most cat species can and do produce pretty large litters in captivity), but rather protecting as much of the existing gene pool as possible. Which means in situ conservation, since even the best zoos can only preserve but a tiny fraction of the genetic diversity of a taxon. For even though the Amur leopard is 'only' one of several subspecies of leopard, it is unique in its own way, having adapted to its environment, and is worthy of protection as a distinct and unique entity, same with other leopard subspecies like the Sri Lankan or Javan or Arabian leopard. Mixing them all together simply because they're all leopards and will breed together is a grave disservice to the variability and uniqueness of the taxon, and probably does not benefit the various subspecies in the long run.

Besides, we never know if future research would have determined that maybe the differences between subspecies are great enough to warrant separation into distinct species, just like how the clouded leopards of mainland Asia and the islands of Indonesia are now two distinct species.

Any subspecies which is lost is lost forever, even if it might have close relatives, or even if its physical traits can be brought back through careful breeding. Which is why although we have supposedly recreated the aurochs and tarpan through backbreeding, and are on the way to doing the same for the quagga, we have not actually brought them back from extinction, we have merely created simulations and approximations, probably not even close to the 'originals' which were shaped by the environment and natural selection.

I would accept outbreeding with other leopard populations if for example, say, new and solid research determined that Amur leopards were actually part of another subspecies. Just like how the extant tiger subspecies of mainland Asia are increasingly thought to show clinal variation and adaptation to different environments and prey availability, rather than actually being evolutionarily distinct subpopulations. Though this is still not exactly widely accepted, and most of the material I have found still tends to separate the tigers into Bengal, Siberian, South China, Indochinese and Malayan subspecies. And incidentally, this same research indicates that the Sumatran tiger is distinct enough to possibly be a different species. So crossing a Bengal tiger with an Indochinese tiger = hmm, maybe not that bad after all, but crossing a Siberian with a Sumatran = definite no-no.

Another possibility would be if inbreeding was so severe that an infusion of genes from a closely related subspecies might help 'reinvigorate' the endangered subspecies, just as how the critically endangered Florida panther has received genes from Texan cougars. Though recent research suggests that all North American puma populations are recently evolved, having descended from South or Central American migrants that recolonised the continent after the North American pumas were wiped out at the end of the Late Pleistocene, so in that case, maybe it's a moot point anyway, and Florida panthers and Texan cougars might turn out be close enough to be part of a single subspecies.

But in general, the aim of conservation, especially where it comes to protecting particular subspecies, is to preserve the existing gene pool, especially since these are the genes that have been shaped over millennia of natural selection to enable the creatures to survive. The Mexican wolf and Asiatic lion are examples of endangered subspecies which have had recovery programs fraught with problems, especially with lousy keeping of records and careless hybridisation with other subspecies.

Sure, we could always release wolves from Minnesota into Arizona to replace the Mexican wolf, or lions from Botswana into India to replace the Asiatic lion, or Namibian cheetahs into Iran to replace the Asiatic cheetah, or southern white rhino from South Africa to Congo to replace the critically endangered northern white rhino. Sure, they'll probably settle down eventually and prosper, become the ecological equivalent of the native, and maybe adapt and even breed with what few locals survive. But we won't be 'bringing back' a once endangered or extinct form. We'll merely be replacing a taxon shaped by the forces of nature with a 'mongrel' of our creation, a mere ghost of what once lived in that environment.

I quote William Oliver:

"I am not really sure why, but species are generally regarded as being somehow more important than subspecies and, hence, merit higher conservation priority. I confess I can�t swallow this view without a good deal of choking and spluttering � particularly if one considers that a polytypic species � being an abstracted sum of its parts � doesn�t actually exist. In fact, the adoption of this view can be (and often is) positively unhelpful, in that subspecies are all too often ignored and species� conservation priorities are thus �loaded� in favour of the least threatened subspecies or populations � a patently ridiculous (and arguably irresponsible) situation"

Hi, im Jonny & i have a couple of theories. It seems as if most, if not all conservationists, would prefer inbreeding, as apposed to cross-breeding so to speak. For example breeding an amur leopard with an african leopard would produce healthy, but 'impure' cubs. Whereas breeding two related amur leopards would produce pure, but (very likely) unhealthy cubs. in my opinion, i think cross breeding sounds much more ideal. Sure you don't have a pure wild species, but you do have a healthy wild species. Is it not better for the animal to be healthy? All leopards originated in Africa anyway, so who's to say they cannot adapt to the conditions of the far east like they did once before...?

If it dies what kind of impact will it have on the environment and food chain?