From LiveScience:
A new national park in Russia is an attempt to save the world’s rarest cat, the Amur leopard.
The park, announced Tuesday (April 10) by the World Wildlife Fund (WWF), encompasses 650,000 acres (262,000 hectares) of Amur leopard breeding area in Russia’s Far East. Now called the Land of the Leopard National Park, the park covers about 60 percent of the critically endangered cat’s habitat.
Fewer than 40 Amur leopards are believed to exist in the wild, according to the WWF. While most leopards stick to the savannas of Africa, the Amur leopard loves cold and high-elevation habitats, such as that found in the far east of Russia and in northern North Korea.
The new national park will help protect these large cats, which can reach 110 pounds (48 kilograms). The land will also become home to 10 Amur, or Siberian, tigers, another endangered species. Amur tigers were once in as dire a situation as Amur leopards, but their population is rebounding, with an estimated 360 tigers in the wild today.
This is good new for both Amur leopards and Amur tigers.
Amur tigers will likely be the last subspecies of tiger to go extinct in the wild. They just happen to live in an area where there aren’t many people, and it’s very hard for the people who are there to stalk tigers. The climate and terrain is for only the toughest and most resilient of poachers. Even though the black market for tigers still means that Amur tigers are being poached, this is not an easy undertaking. Plus, there is a culture of respect that exists between the people of the region and these tigers, which rarely attack people. (They do, however, like the taste of dog or wolf meat!)
Amur tigers derive from an estimated 50 cats that were roaming the wild when the species was offered full protection in 1947. The animals have very low genetic variation, but it has been estimated that these cats have always had low genetic variation. These cats experience a genetic bottleneck as the result of their post- Ice Age colonization of this part of Northeast Asia nearly 10,000 years ago. Through purging and natural selection, they do have a certain amount of inbreeding tolerance.
As habitat for these cats becomes more and more fragmented, they will likely become more and more inbred, and then it is possible that the effects of inbreeding could become more obvious. Tigers, like all solitary cats, have a mating system in which one male has a large territory that overlaps those of several females. The females are usually closely related, for female tigers disperse only a relatively short distance from their mothers. However, the male cubs are driven great distances from their mothers– usually by that dominant male– and this prevents inbreeding. If there are no territories for dispersing males to be driven into, then they will likely die or start problems with people. Inbreeding is also prevented because the dominant male’s tenure is very finite. Young challengers always slip in and eventually overthrow him. If a male remains the breeding male in a territory system for too long, it is very likely that he will be mating with his own daughters at some point. When tiger habitat becomes fragmented, inbreeding issue become more intensified.
It is not known if Amur leopards have evolved a similar inbreeding tolerance. We know very little about Amur leopards.
But it should not be assumed that they can withstand population bottlenecks.
This park will be very important in preserving the Amur leopard, but the population may or may not be sustainable.
Genetic rescue, which has essentially saved the Florida panther, has not been considered for either of these cats.
Florida panthers were saved through the introduction of wild Texas cougars, but it is not clear if any other leopard or tiger subspecies are appropriate for this region. There could be issues with an outbreeding depression if tropical subspecies were crossed with this frigid climate cats.
But establishing this park does give the cats a chance.
All the particulars need to be worked out from there.
This is a great news.
Btw, Russia was a leader in Polar Bear conservation also asking other 5 Arctic nations (USA, Canada, Norway and Denmark) to provide full protection to the Great white Bear as far back as in early 1960s. Unfortunately, all these first world countries chose to behave rather like underworld countries back then slamming the door on Russians.
Correct me if I’m wrong: if a breeding population survives a bottleneck, it may be that it’s rid itself of deleterious recessives. That’s the case with the cheetah – little genetic variation, but little that’s deleterious, too. The upside is that the animal can tolerate lots of inbreeding without inbreeding depression. The downside is may be too little variation to allow adaptation to changing circumstances.
OK, so in view of that, what is outcross depression? Thank you.
Another question. Playing devil’s advocate, here. I was dismayed awhile back when someone implied that it doesn’t matter whether we save the polar bear, because, after all, it’s nothing but a variation on the brown bear. Did I get that right? Doesn’t it matter to anyone that natural selection eked out of the bear genome, one that is not only white for life in polar regions, but one that stays in its polar regions and specializes in preying on aquatic mammals?
Russia is not my favorite country, but if they keep this up, I’ll have to consider them redeemed.
It depends upon the extent of the inbreeding and the rigors of selection.
Amur tigers are not as inbred as cheetahs, even now.
Cheetahs have survived an extreme genetic bottleneck. Skin grafts from one unrelated cheetah to another do not elicit an immune response. They are that closely related.
They may have purged their bad recessives, but they still suffer from an inbreeding depression– poor sperm counts and low fertility are the general rule with them.
Outbreeding depressions are easy to understand. I have a post on them in the works.
Thanks for clarifying.
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I believe that Bengal Tigers are considered appropriate for outbreeding purposes, if necessary, because they are capable of inhabiting cold weather climates and high altitudes. There is apparently not much variance genetically between Bengal and Amur tigers. Additionally, Bengal tigers from the northern part of their range rival Amur tigers, leading some to postulate that it is in fact the Bengal tiger that is the largest extant cat rather than the Amur tiger. I think it is very interesting that Amur tigers and the now extinct Caspian tigers were very, very closely related, perhaps even comprising the same subspecies – i.e., truly Siberian Tigers, as their range would have extended from the Amur River Valley in Far Eastern Russia to the Caspian Sea in Western Russia.
I would think that North Chinese Leopards (Panthera pardus japonensis) would be appropriate for outbreeding with Amur Leopards, since they inhabit fairly similar climates. Amur leopards have a longer winter coat and, if I’m not mistaken, are only slightly larger and lighter in coat color. So I would think that North Chinese Leopards are the logical go-to for outbreeding purposes. However, in zoos, even tropical subspecies of leopards seem to do fine during the winter, even in snow. So it may be possible for other subspecies to be used for outbreeding if/when it becomes necessary.
Devil’s advocate again – it’s about ideological drift. Looks like the Amur tiger has rebounded in numbers. Why worry about genetic crosses?
The leopard’s numbers should be watched closely. And, by the way, counting wildlife has its own problems. Why are we worried about out-crossing, while we accept uncritically the numbers we are given? But, if the numbers are correct, then, as Scottie says, fragmentation of the habitat is the issue. If we fix that, we give the animals a chance to save themselves.
It is possible for a highly inbred population to be maximally fit. If that’s the case, then you can’t improve it with out-crossing. You can, however, be guilty of introducing a less fit animal into a demanding situation, both from the standpoint of climate and from the standpoint of competition for available space.
The fact that large tropical animals can survive in northern zoos is, I think, beside the point. They are surviving with a lot of help, like all the rest of us who live near Guelph, so to speak. Fact is in nature a lot of these animals have northern and southern versions or subspecies. Furthermore, as Scottie says, the lack of genetic variation may be very old. It may be the result of genetic drift that occurred thousands of years ago when they first went north.
I say genetic tinkering should be the last resort, since we don’t know whether lack of variation is causing the declining numbers, assuming the numbers are really declining, and we don’t know what genetic evil we are turning loose in a population that may be capable of surviving on its own given enough space.
I think I may have been misunderstood. I don’t advocate crossing Bengal and Amur tigers, especially since there is ample genetic diversity in captivity to reinvigorate the wild population if/when needed. However, I don’t believe that the Amur Tiger population is in any way safe from extinction – but I don’t believe that inbreeding depression is going to be their downfall. The same is true with Amur Leopards. They are critically endangered, and whether or not they can be saved in the wild is not certain. Creation of a new national park is a great step, but unfortunately, these big cats are in big trouble. I do believe that there is a breaking point for inbred fitness, and highly inbred populations have a very difficult time remaining maximally fit. It doesn’t work in dogs, it doesn’t work in big cats. Whether 30 or 40 animals are actually enough to prevent inbreeding depression remains debatable, regardless of how far back the genetic bottleneck occurred. An ancient genetic bottleneck doesn’t necessarily mean that siblings were mating. But if we lose too many more Amur leopards, sibling and/or parent/offspring matings become much more likely, and that’s the beginning of the end. If that happens, and there are no reintroduction programs ready to release animals, then genetic outcrossing becomes much more appealing to save the subspecies.
My reference to genetic outcrosses was I guess twofold: 1. when it comes to saving species, I’m not a subspecies purist, and 2. even tropical subspecies of these two big cats have been shown to survive cold winters with very little difficulty.
Preserving subspecies as pure entities is ultimately the goal of conservation, but there are times when genetic rescues are necessary such as with the Florida Panther. I don’t know what the captive population of Amur Leopards looks like, so there may be genetic variation enough to keep the populations viable. But if genetic rescue does become necessary, there are other leopards from regions that experience cold winters. I would say with increased DNA analysis, and as taxonomists get a clearer picture of how subspecies are related, the most suitable genetic outcrosses would be with the most closely related extant subspecies.
Subspecies that inhabit similar climates should make suitable genetic outcross possiblitlies if necessary. Would I recommend crossing an Amur Tiger with a Malayan Tiger or an Amur Leopard with a Sri Lankan Leopard? Not particularly. But the fact that Bengal Tigers have been documented at elevations between 9,800ft to 13,500ft in Bhutan, where winters are cold, indicates that they are adaptable to the cold. North Chinese leopards inhabit areas that can get downright frigid as well. Animals that are typically considered tropical have shown in captivity time and again that they are perfectly suited to surviving in cold climates without support above and beyond what they get duing summer months – spotted hyenas, striped hyenas, cheetahs, African lions, and even Sumatran Tigers. Who knew that hyenas actually have fluffly winter coats when they need to? While specially heated rocks and such are sometimes provided, many smaller instituations don’t have the ability to provide additional support to these animals, and they do not have any problems surviving cold winters, so long as they get the basics that they need any other time of year.
The danger of introducing deleterious genes into a population by outcrossing is obviously something that should be considered before outcrosses are done. Since outcrosses are only done as last resorts, and in the specific cases of Amur tigers and Amur leopards, outcrosses do not seem to be needed, I don’t think this is a tremendous concern. I’d be more concerned about the big cats’ contracting something like Canine Distemper due to contact with domestic dogs than I would be about the deleterious effects of interspecific crossing. Also, if a subspecies is so low in number so as to warrant genetic rescue, then I don’t know that we should really be concerned about creating competion that ultimately harms the subspecies.
Thanks for replying. Yes, I believe the more tropical versions can survive cold winters. After all, the leopard, the hyena, the cheetah, are no more than 40,000 years away from life in a very cold Europe. I’m betting that they follow the prey and the prey survives or not depending on what’s growing under their feet. Oops, I’m getting close to the what-killed-the-pleistocene-megafauna question now and I don’t want to go there, where I have no competence whatsoever.
What I was trying to elicit was your first statement: “when it comes to saving species, I’m not a subspecies purist”. Thanks for putting it so simply and without equivocation. In your first post you sounded as though you were trying to establish your credentials for membership in the anti-purity league. Now that you have enlarged on your ideas it becomes apparent that you would advocate out-crossing only if necessary, as just one of an assortment of tools for saving an endangered population, and one to be applied only after careful consideration of all available options.
I’m not trying to be snarky here, but I fear ideological purity much more than I fear genetic purity. When we discard genetic purity as something real, tangible and absolute and a criterion by which we judge quality, we must take care not to substitute Impurity as a counter religion. There are, on the internet, people who look to “experts” for simple answers. Some of these people breed dogs. For them, I’d like to suggest a new mantra: There Are No Simple Answers.
About sub-species. This seems to be a big deal in conservation circles. I try not to think about sub-species. Too depressing. I fear when the outcome doesn’t suit us, we just tweak the definition of species or subspecies till it does. So, I think about populations and leave the sub-species questions to the biologists and the politicians. Example, red wolf. A beautiful and interesting animal. But, poof! it’s gone – nothing but a hybrid – defined out of existence. And the dingo. Poof!, it’s gone, too, as nothing but a domestic dog. Etc. The tendency to lump seems strange especially in view of who’s doing it. Has it occurred to you that the only people on earth who can’t distinguish between dog and wolf are the geneticists? Nobody else has that problem, maybe because the differences, while very small, are also very important. Which is a value judgment, for sure, unless we can give these differences scientific dignity as phenomena, such as “domestication”, or the adaptation of wolf to a new niche.
If you look up at the stars or into your fridge for micro-organisms you’ll find blobs of lookalike stuff. But the experts can distinguish between them: giants and dwarves, cocci and bacilli, etc. And at the next level, bugs arrange themselves into ecological zones and stars cluster into galaxies. Wow. As soon as the geneticists figure out how genes cluster and interact to form types, splitting will be back in vogue. That’s my prediction.
Anyway, thanks for being a good sport for letting me pick on you and for letting me piggy-back the first chapter of Kathy’s Manifesto on your post. And to think I was sober the whole time.