Hybrid pythons killed by wildlife department

[adder]

Dear all, I copy and paste an Australian news story from today for informational purposes.
I cannot vouch for it's accuracy.
All the best

http://www.news.com.au/breaking-new...nakes-euthanased/story-e6frfku9-1226438825334
Cross-bred snakes euthanased
TWENTY snakes have been euthanased after they were found to be a hybrid of two native species.
Environment officials in Adelaide say the snakes were advertised for sale by a licensed breeder and were found to be a cross between Bredi pythons and coastal carpet pythons.
Cross-breeding native species is illegal.
"We don't like to have to euthanase animals, but there are a number of problems associated with cross-breeding of species," SA fauna permits unit manager Sonya Nicholls said.
"We are not trying to stop people from keeping or selling protected natives.
"But it is very important that everyone who does this understands their legal requirements, as well as their social and environmental obligations."
Ms Nicholls said it was important that breeders maintained the purity of genetic stock to ensure the long-term survival of Australia's native species.
If a species becomes extinct in the wild it might become necessary to use captive animals to reintroduce it to its native habitat.

 

[ladymedusa218]

this is pretty interesting. soooooo what if they find wild hybrids? its well documented that cross-breeding happens in the wild of similar species(ex: texas rat snake X black rat snake, or everglades ratsnake X grey rat snake).

 

[snowgyre]

Interesting. Genetic contamination is a very serious concern with wildlife biologists. We are aware that hybridization does happen occasionally in the wild, but there is increasing worry that changes we are bringing upon the landscape are making this a more common occurrence due to range shifts, increasing distances between habitat patches, etc.

A good example of human-induced wildlife hybridization is between golden- and blue-winged warblers. Golden-winged warblers typically occupy high-elevation early successional habitats, created by fire, hurricane damage, tornadoes, etc. Blue-winged warblers typically inhabit lower-elevation habitats. However, due to increased human development that reduces habitat at lower elevations, blue-winged warblers are shifting their ranges to occupy higher elevations, causing them to encounter and interbreed with golden-winged warblers. Considering golden-winged warblers are suffering extensive declines throughout their range, hybridization with blue-winged warblers due to human activities is reducing the number of pure golden-wings out there. In the next century or so, golden-winged warblers could very well be extinct as a distinct species.

There are examples like this throughout the world. I'm primarily an avian biologist, so those are the examples I typically think of. Mallard introductions are causing similar problems, since they hybridize freely with American black ducks, or even something as exotic and highly endangered as the New Zealand blue duck.

I sympathize with the Australian breeder who had to get his hybrids euthanized, but I think Australian law is pretty strict but straightforward. If he hybridized, he probably did so in full knowledge that he was violating the law.

 

[adder]

OK, now noting that many reptiles are getting carted about by people, either as escaped pets, released pets, hitch-hikers in building supplies shipments and the like, the long term prognosis is more wild hybridization in the wild.
Add to that the general decline of species and habitats, I ask, is it really a waste of time being a genetic purist, or are we really pissing against the wind, taking a long-term position (hundreds of years).

All the best

 

[natsamjosh]

"Genetic contamination is a very serious concern with wildlife biologists."

Why is it assumed to be "contamination" rather than basic evolution?



"human-induced wildlife hybridization..."

Humans are part of nature, are they not? If hybridization of the birds you cited were caused by animal(s) other than Homo sapiens, would it be a problem or not?


Just curious...

 

[hadenglock]

While hybridization does occur in nature on occassion, there have been issues with humans hybridizing animals and then having them released into the wild. Domestic Cats are a great example of this.......

 

[salottimc]

I'm interested to know everyone's thoughts on how selective breeding can damage a species?

 

[hadenglock]

Selective breeding will cause genetic deterioration overtime. Look at all the albino snakes that are born missing eyes. I think certain ball python morphs carry genetic disorders because of heavy selective breeding too (corkscrewing in spider ball morphs) Selective breeding often results in inbreeding as well, and that can cause obvious problems too. Certain dog breeds carry genetic disorders like hip displaysia, eye problems, etc..... Overall selective breeding is destined to destroy a species genetic makeup. Im not bashing anyone who loves to breed for selectivity, im only stating what will happen if it spirals out of control and there is no sort of control to keep it in check (I.E. introducing new genes into a gene pool).

 

[Helenthereef]

Selective breeding by its very nature usually results in diminished genetic variety within each animal. Wild "orginals" carry much more genetic variation and therefore are more able to produce adaptations when conditions alter (such as climate change).

Also I think you have to be aware of how sensitive the Australians are to "Introduced" animals, as they are now living with the legacy of plagues of rabbits etc, introduced in less educated times.

 

[jellyfishrhythm]

The entire argument of selective breeding, especially in favor of simple recessive traits, is misunderstood by far too many people in our "industry" - I think the bigger problem lies in the lack of patience exhibited by breeders to create the next "epic super rare ultra mega foxy snake" or the most super-hypo-transluscent-silkback-dunner-paradox bearded dragon. So many of these recessive genes (and we know that most of them are recessive) have never been raised out into adulthood (adulthood not necessarily correlating with "breeding size") prior to combining them with 2+ OTHER simple recessives to create something else. Honestly, how do we know as a reptile community that all Pumas (in terms of ball pythons) don't die at 6 years old? We don't. It's a long shot, I know, but I think my point is obvious.

The same occurs in terms of things like the spider morphs in balls and the enigma morphs in leopard geckos. These genes (codominant/dominant, respectively) are KNOWN to carry neurological comorbidities along with them, yet still, they're being bred over, and over, and over, and over again - to the detriment of the animal and the species as a whole. Artificially weakening the gene pool is the last thing you really want to do as a responsible reptile breeder. I know that most people have no qualms breeding these genetic combos, but anyone saying that "well, the parents had no signs of the spider wobble or enigma syndrome, thus, the babies will show even fewer phenotypical symptoms, and eventually, we'll be able to breed it out" has clearly never taken a genetics course in their entire life. It doesn't work that way.

There is a LOT to be said for selective breeding in the realm of creating visually stunning animals, and I'm not a hypocrite, I do it too, but I believe beyond a shadow of a doubt that it has to be done responsibly. When you can show me a 12-year old female hypotrans microscale leather dunner bearded dragon that dies of old age and natural causes, then I'll be OK with the idea of breeding them. The reptile business has become a game of "keeping up with the Joneses" (or the Trempers, or the Dovenbargers, and so on and so forth) - pioneers of the industry are just that: pioneers, but they've done the necessary backpedaling and maintained enough patience to know that what they're producing and selling is genetically sound.

Too many basement breeders thinking they're geneticists.

OK, rant = over.

As for euthanizing the hybrids, I'm torn on the subject. If it DOES happen naturally, that's fine and dandy, but allowing any kind of release of these hybridized animals into the wild (in other words, pawning off your self-created weakened gene pool onto an already genetically sound ecosystem) is not only reprehensible, but irresponsible. I'm not a fan of hybrids either (as I'm sure you've probably deduced already) - and I agree with Helen, Australia is a very special case. Rabbit and cane toad epidemics have RAVAGED many of the naturally occurring ecosystems due to lack of natural predation, niche assignment, etc - why contribute to the problem? People have proven time and time again that they cannot be trusted to keep captive breeding in captivity, and regardless of bioethics, on the most basal level, they don't know how to keep their freaks of nature (don't scoff at the terminology, that's what they are, love them or hate them) in their living room. A few bad apples ruin it for the entire bunch, and I fear this will be a problem that our beloved reptile community will grapple with for many many years.

Case in point: have you seen the (awful) special on the Discovery Channel/Animal Planet about the supposed naturally occuring Burmese x African Rock python super-hybrid? - I'm just saying, it's not cool to play puppeteer with live, reproducing, and genetically interdependent puppets. Especially not ones with zero Darwinian checks and balances placed upon them.

 

[salottimc]

Don't get me started on Animal Planet hype.

I think some of the products of selective breeding are quite beautiful, but in the end, I always find myself gravitating back to the basic critters. I've looked at ball python breeds, but find myself liking the normals (or ones with slightly crisper colors) more. Same goes with other snakes as well (jungle carpet pythons, red tail boas, corn snakes). Just my opinions.

 

[sschind]

Too many basement breeders thinking they're geneticists.

OK, rant = over.

I agree with what you said but its not just the basement breeders that are causing the problems you brought up. Most of the big time breeders do the same thing. They may know more about genetics than the little guy and they may have a better idea what certain pairings will produce but they have no more idea about potential health issues associated with those pairings than anyone else. On top of that I haven't seen too many that are against selling those morphs that do have issues. Some, but not many, most of them make the excuses like those you mentioned. I'm sure there are a lot of breeders who are knowledgeable about genetics but I doubt many of them are geneticists.

 

[snowgyre]

"Genetic contamination is a very serious concern with wildlife biologists."

Why is it assumed to be "contamination" rather than basic evolution?

"human-induced wildlife hybridization..."

Humans are part of nature, are they not? If hybridization of the birds you cited were caused by animal(s) other than Homo sapiens, would it be a problem or not?

Just curious...

<begin long essay, you're warned >

Oops, missed updates to this thread until now. Basic evolution occurs in response to basic environmental processes, including both stochastic and biological processes. Stochastic processes are those which are not directly controllable by the animal, such as environmental disasters (hurricanes, floods, etc.), or long-term effects such as climate change. Biological processes include density dependence effects (disease, food shortages, predator densities, etc.) and sexual selection (which ultimately drives sexual differences and reproductive success). All in all, these factors all combine into a single facet of evolution: survival. The longer you survive, the more opportunities you have to have offspring, and the more your genes will be present in the environment.

Humans break these rules, while all other species on earth are still bound by them. Are humans a part of nature? Yes. But, arguably, we are no longer limited by traditional evolutionary pressures. This, in combination with our incredible ability to affect unprecedented environmental change instantly (think mountain top removal for coal in the Appalachians, which destroys mountains which have been there since the last glaciation in little under a year), we're placing an incredible amount of strain on every other organism on Earth. Evolution can only help a species survive over eons, not over months, decades, or even centuries. No species on Earth, including arguably ourselves, have the evolutionary tools to deal with such sudden and dramatic environmental changes.

And this all ties into genetics, believe it or not.

Essentially, the entire argument can be boiled down into one simple philosophical construct: we, as humans, are the gardeners of the Earth. We have the unprecedented power to change our world at the global scale. Do we want to take the easy way out and let the weeds grow in our garden (e.g. invasive species, hybrids, pest species), or do we want to do the right but sometimes unpopular thing and try to protect and conserve as much as we can (e.g. endangered species, genetic diversity, specialists instead of generalists, etc.)?

Just so you know my thoughts aren't completely baseless, these ideas were spearheaded by Aldo Leopold in the early 20th Century. He was the founder of modern wildlife and land management and was the first professor in the field. In his seminal works, A Sand County Almanac (1949) and Game Management (1933), he established ethics that scientists today use to influence wildlife and land management decisions. Here are two quotes from him that effectively summarize (through correlation, Aldo Leopold was of a time prior to modern genetics concerns) why genetic diversity seems to be underplayed among people who don't understand its importance and also explain why we should be concerned about conserving it.

"One of the penalties of an ecological education is that one lives alone in a world of wounds. Much of the damage inflicted on land is quite invisible to laymen. An ecologist must either harden his shell and make believe that the consequences of science are none of his business, or he must be the doctor who sees the marks of death in a community that believes itself well and does not want to be told otherwise."

"The outstanding scientific discovery of the twentieth century is not television, or radio, but rather the complexity of the land organism. Only those who know the most about it can appreciate how little we know about it. ...If the biota, in the course of aeons, has built something we like but do not understand, then who but a fool would discard seemingly useless parts? To keep every cog and wheel is the first precaution of intelligent tinkering."

</long essay from a professor in wildlife ecology and management>

 

[adder]

Yes I always subscribed to the following:
""The outstanding scientific discovery of the twentieth century is not television, or radio, but rather the complexity of the land organism. Only those who know the most about it can appreciate how little we know about it. ...If the biota, in the course of aeons, has built something we like but do not understand, then who but a fool would discard seemingly useless parts? To keep every cog and wheel is the first precaution of intelligent tinkering."" but now things have changed a bit in that I was recently told that biodiversity can be "manufactured" by humans and genetic engineers.
Where does this leave us?

 

[snowgyre]

Not quite sure what you're getting at, Ray. I don't know who told you that biodiversity can be "manufactured," because it can't. We can't invent new genes, we can only tweak what is already provided in nature. And, arguably, incorporating genes of different organisms together through genetic engineering equals hybridization, which equals a decrease in genetic diversity.

If you ever wanted a term that us wildlife biologist/ecologist types wish had never been invented, it's the term "biodiversity." It's a real anathema to scientists, not least because it doesn't have a single unifying definition, and most because it means different things to different people. Managing for "biodiversity" is always a trick, because if that's a goal of a specific organization instead of a more targeted goal of, say, managing an endangered or threatened species, then you could actually be working against yourself.

For a real life example, let's say I'm interested in managing spotted owls in the forests of the Pacific Northwest. Those forests have unique species, but relatively low "biodiversity" when compared with other habitat types. I could actually increase local and regional biodiversity by clear cutting sections of forests, which would increase the amount of edge and grassland habitats (we call these early successional habitats, which are known to support the greatest diversity of species). However, if I did that, then species that need large tracks of intact but relatively species poor stands of old growth forest would decline (such as spotted owls, northern goshawks, marbled murrelet, etc.). Now do you see where we run into issues with managing for biodiversity? It's not a one-size fits-all management scheme, but unfortunately far too many laypersons think that managing for increased biodiversity at all costs is the best thing we could possibly do. On a global scale? Sure. Even regional I could buy... sometimes, depending upon location. But on the local scale? Definitely not all the time.

If anybody wants a decent read on what biodiversity actually means, you can go here: http://philsci-archive.pitt.edu/269/1/Biodiversity.pdf

 

[Helenthereef]

<begin long essay, you're warned >

</long essay from a professor in wildlife ecology and management>

with all of it....

As a marine ecologist I'm currently watching coral reefs adapt to warming oceans, and many unappreciated or unknown coral species are coming to the fore as conditions change. These species are only there because of the huge variation within the natural genepool.

To compare with the Australian Python situation under discussion here, if aquarium keepers "released" the few coral species that have been cultivated in the controlled and favourable environment of tanks, they may initially grow so rapidly that they came to dominate the reefs, and this might look like a success of human genetic intervention.

However, if a future disease or climate change event happened, because those few species would have less variation in their genes, they would be less likely to have descendents that could survive the change, and those reefs would be more likely to die and not recover than those in a natural state.

Hope that didn't make it more complicated.........

 

[jellyfishrhythm]

Thank you (Helen and Vanessa, particularly) for giving me hope that intelligent scientists/ecologists/geneticists (or even non-professional science-types that are well read) still matriculate within the reptile world.

I agree completely about the term "biodiversity" - there are far too many interpretations of the word on the tongues of both scientists and politicians alike, and unfortunately, far too often, the definition is tweaked to suit the purposes of the individual who *thinks* they know what it means. I subscribed to the meaning of biodiversity being a purely numeric value (or so I was taught by my ecology/evolution of animal form professors in college) genuinely representing the total number of species within a given area (a sort of take on population density) - which in turn leads to the conundrum that "more" doesn't always mean "most sustainable" - some of the oldest existing ecosystems thrive in the presence of only 10 identifiable ("identifiable" being the keyword here) species, while some of the most biodiverse (sticking with my original definition) areas are most adversely affected by "ecological pressures" (read: homo sapiens sapiens)

I suggest that the NON-science types reading this thread take some time off and experience a little Stephen Jay Gould. It'll do you a world of good ;-)

 

[Helenthereef]

I suggest that the NON-science types reading this thread take some time off and experience a little Stephen Jay Gould. It'll do you a world of good ;-)

Or try some Richard Dawkins, one of the worlds great science interpreters!

 

[killimike]

This thread has gotten a bit off the topic of the killing of privately owned snakes.

Wildlife conservation issues are one thing, but it is crazy to seriously suggest that hybridization of pythons by a private breeder has any relevance what so ever to wild populations. Those animals were never going to be re-released into the wild. Serious purists who were concerned about having locality pure animals should never put themselves in the position of buy (unwittingly or no) one of these animals or its progeny.

This is just a case of a government department, run by ideologues who believe that private ownership of wildlife is a great sin, trying to justify its existence.

The sad thing is that, because we must be licenced to keep our own native reptiles here, the government has the means and legal right to force keepers to comply with whatever regulations it desires, with no recourse for the keeper. Conditions of the licence are subject to change, as happened with the NSW licence and broad headed snakes recently. So the sad truth is, this breeder did violate the terms of his licence, and did so knowingly, as he was not supposed to hybridize. So they have him on the ropes.

I hope those in the US see this as a cautionary tale!! I'm not sure that you guys realise some times the degree of control the government has over our reptile keeping. Most states require you to report every one of your sales, down to the last gecko hatchling, with full details. You must have all your animals at one physical address, you must only keep what the government has bothered to add to the allowable species list, you must get a permit (and pay for it in my state!) to sell -any- reptile across state lines.... The list goes on. I make the point at length in the hope of driving home how invasive and restrictive it is over here.

Please don't let it happen over there.

 

[rhatfield]

As to killing the hybrids. It is a law, the person broke the law and unfortunately, innocents died. I don't like it but can understand the law. I am a biologist and a science teacher. Australia is very protective of its species. if they produce fertile off spring - The hybrids well escape, they will breed with local animals, and will "pollute" the species.


As to hybridization, it is very rare and when an animal is given choice of mates of the same verses a different species or subspecies, it will choose the same species subspecies which has the correct signals, pheromones or what have you. In captivity this can be over come and will produce animals who will on their own mate with what either species, being similar the wild ones may

Of course I thought one of the definitions of species is that if mated, they will produce no or sterile offspring. But I understand that may not be.