Onychorhynchus coronatus
Well-Known Member
Sorry about that @Arizona Docent ! I wasn't aware of that, just saw the article and remembered the thread so posted.
The Black Panther Thread
- Thread starter Arizona Docent
- Start date
Sorry about that @Arizona Docent ! I wasn't aware of that, just saw the article and remembered the thread so posted.
No problem. It's an excellent book (stunning photos) if anyone is interested in the topic.
toothlessjaws
Well-Known Member
I think your argument is pretty dismissive of the significance of melanism in leopards.11% of the population is not a rare aberration as melanism is in many other other organisms. I think its definitely accurate to describe melanism as an established part of the leopard morphology - as most authors do. I also disagree that melanism is not advantageous. It's surely slightly advantageous in some scenarios otherwise it wouldn't have proliferated throughout the leopard gene pool the way it has.
If you accept these things, then it's only logical that you accept its a mutation of value to the leopard species and therefore worthy of being preserved within its insurance populations.
11% of what population?
It could also be common just because those are the animals that are able to breed, or the mutation has occurred multiple times in different populations... there's numerous reasons for it. Slightly advantageous in some scenarios means almost nothing when a subspecies is already critically endangered. There are plenty of things that meet those parameters - body size, hunting skill, primarily source of food, health conditions. We don't place any emphasis on those different traits for preservation, why should color be any different?
What evidence do you have that the subspecific captive populations have unviable founder populations?
I also question whether there is proper space to manage a generic population alongside multiple subspecific programs. It would likely take away valuable space that otherwise would be used to expand subspecific populations and slow the loss of genetic diversity.
Melanism in leopards is recessive, so many non-melanistic animals can be carriers of the mutation. Thus, managing a population with a high number of melanistic individuals may not be necessary to retain the allele. As has been pointed out, there are at least two black Amur leopards in the US population; if their genes aren't lost in subsequent generations, then the phenotype can reoccur.
Except that the subspecific captive populations in most countries (such as Amur) are subspecies where the frequency of that mutation is very low (and are probably still present to some degree anyway - re: recessive alleles).
This is a good point as well. It is exceedingly difficult for humans to judge which adaptations are advantageous, and even more so to predict if they will be at any given time or in any given environment. Better to let natural selection take its course rather than spending considerable resources on trying to preempt it. Genetic diversity is the objective; trying to preserve specific mutations is a wash when you're talking about actively preventing an entire species or population from disappearing (which would likely be the case in a hypothetical reintroduction scenario).
toothlessjaws
Well-Known Member
The simple fact that there aren't even enough of some subspecies (javan, Sri lankan) in captivity (especially outside their ranges) to have viable founder populations. And no doubt many of these animals are related and descended from even less.
I've made a point continuously of stressing that genetic leopards will be needed unless zoos acquire more founders of pure subspecies.
Yes, I know how it works. I still think it's fair to have concern that some of the pure subspecies kept in zoos have such low founder populations that the mutation might not be represented in that population.
I have always black panthers represent around 11% of the overall leopard population and in certain areas (including large areas in southern Asia) black leopards outnumber spotted leopards. I would argue natural selection itself has declared rather clearly that its advantageous or at the very least, neutral. In any event it's an established morph of the species and thats worth keeping around.
Yes. Which is why I keep stating that firstly, zoos are not providing viable insurance populations of all the leopard subspecies. So in light of this, i'm concerned that its counter productive to phase out zoo hybrids that potentially have much genetic value in preserving the species.
As a follow up point, I felt that potentially since some pure subspecies in zoos have such low founder bases, that it's possible, even likely, that in some subspecies the melanistic gene might be lost. And thats undesirable in my opinion.
That doesn't really clarify anything for me, as I still don't know what your benchmark is for "viable" and have no idea how you're determining that threshold. Also, how do you know that the captive generic population of leopards is any genetically better off than the captive subspecies populations? The latter have been carefully managed and expanded somewhat, while the former is not managed and seems to be declining, at least in public sector zoos.
I don't understand what you are trying to convey. You seem to be arguing that there should be a generic captive population with melanistic individuals represented in case the subspecies populations fail, but are fine with not having that if more subspecies founders can be acquired? And how exactly would a generic population be kept going as a backup when they occupy space that is needed for the subspecies populations to survive long-term in the first place? (though as an aside, I'm not sure generic leopards are really occupying a ton of usable space for breeding programs in the first place)
In any case, a generic leopard population is not going to be considered of conservation or reintroduction value by the vast majority of the scientific community anytime soon. Some leopard populations are in danger of going extinct imminently, but not the entire species. Generic leopards just occupy space that could otherwise be used to protect the specific populations that are in critical condition currently.
These are two completely different conclusions: one implies importance that needs to be preserved, the other implies non-importance that doesn't need to be preserved.
Except that I already stated that most of the pure subspecies in zoos already have very low frequencies of the mutation? In any case, adding more founders doesn't guarantee that the allele won't be lost in the captive population (or indeed introduced to it at all).
The 11% claim seems to track back to an article from two years ago, and is made by Nick Pilfold. He doesn't offer any basis for this claim. I think it's a pretty wild claim to make, given no one has good estimates on the overall number of leopards alive. Even the IUCN has very little population data available.
As for the southern Asia statement, it comes from a 2010 paper by Kae Kawanishi (https://zslpublications.onlinelibrary.wiley.com/doi/abs/10.1111/j.1469-7998.2010.00731.x). I don't have access to the entire paper, but the number of estimated animals total is extremely low.
toothlessjaws
Well-Known Member
Correct.
April 13, 2021, three black Amur leopard cubs were born at Tanganyika Wildlife Park (USA).
Tanganyika Wildlife Park Celebrates the Birth of Three Amur Leopards - the Most Endangered Big Cat Species in the World - Tanganyika Wildlife Park (twpark.com)
Tanganyika Wildlife Park Celebrates the Birth of Three Amur Leopards - the Most Endangered Big Cat Species in the World - Tanganyika Wildlife Park (twpark.com)
The Amur leopard is not a species
You are correct - good catch. It does bring the credibility of Tanganyinka into question when they make erroneous statements like this.