Interesting bit of news
Vladimir Putin and World Bank chief stage summit to save the tiger | Environment | The Guardian
Vladimir Putin and World Bank chief stage summit to save the tiger | Environment | The Guardian
Tiger conservation
- Thread starter arjaydee
- Start date
" Tiger numbers have declined by 97% in the past 100 years. They can be found in only 13 countries of Asia now, compared with 25 at the start of the 20th century. Photograph: Ho/AFP/Getty Images"
Tigers could be found in 25 countries?! I didn't think it was ever that many.
Tigers could be found in 25 countries?! I didn't think it was ever that many.
It indicates that the South China Tiger(amoyensis) became extinct in the wild in 1990's. But at the bottom it gives an estimated population for China.(40 or 50)
Is this for 'amoyensis' and therefore a contradiction, or does another subspecies also range into China?
Is this for 'amoyensis' and therefore a contradiction, or does another subspecies also range into China?
Panthera Puss
Well-Known Member
PT Altaica also range into China.
There are 40-50 (very inbred) amoyensis in Chinese zoos
Dicerorhinus
Well-Known Member
There is thought to be a small population of Siberian Tigers in the North East of China.
I have been told that the captive South China Tigers are genetically "polluted" with Siberian Tiger genes. (Look out for a paper soon)
Looks like we are back to 5 surviving sub-species.
***speaking of genetic pollution in tigers. I can't believe that a Hybrid animal (sourced from Twycross?) was introduced into a National Park in India. If I were running the program I would cull every tiger that has the potential to be a descendent.
I'm astounded that anyone seriously considering such an act would not have triple checked the candidate’s ancestry.
Makes me wonder what Howletts have done to the Clouded Leopard population in Cambodia with their totally unnecessary reintroduction.
I have been told that the captive South China Tigers are genetically "polluted" with Siberian Tiger genes. (Look out for a paper soon)
Looks like we are back to 5 surviving sub-species.
***speaking of genetic pollution in tigers. I can't believe that a Hybrid animal (sourced from Twycross?) was introduced into a National Park in India. If I were running the program I would cull every tiger that has the potential to be a descendent.
I'm astounded that anyone seriously considering such an act would not have triple checked the candidate’s ancestry.
Makes me wonder what Howletts have done to the Clouded Leopard population in Cambodia with their totally unnecessary reintroduction.
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Panthera Puss
Well-Known Member
Some Siberians & South Chinese were certainly crossed in Chinese zoos in the 1970s & 80s.
I hope the Tiger Summit will have changed the fate of world's wild tigers. This is literally the last chance to do this. China is the key; the effective enforcement of the ban on tiger trade is the single most important link in this chain. They can do it - if they really want to.
Yes, tigers used to be found in 26 countries. Here is a list of present 13 tiger range countries:
India, Russia, Nepal, Bhutan, Bangladesh, Myanmar, Thailand, Malaysia, Indonesia, Cambodia, Laos, Vietnam and China.
Tigers used to be found in another 13 countries:
Turkey, Iran, Iraq, Pakistan, Afghanistan, South Korea, North Korea, Kazakhstan, Turkmenistan, Uzbekistan, Tajikistan, Azerbaijan and Singapore.
The South China Tiger (amoyensis) is very probably extinct in the wild. There is a captive population of 60-70 individuals, all descendants of fewer than 7 founder individuals.
Here is the explanation of China's wild tiger numbers estimate: China has a handful of wild Amur (altaica) tigers in the north, possibly a few surviving Indochinese (corbetti) tigers in the south (the last and only camera trap image recorded three years ago), and a few Bengal (tigris) tigers in Tibet (recorded more than ten years ago).
These estimates may be optimistic, and both southern tiger populations may possibly be extinct by now. Perhaps they still exist, as China's law has very strict punishment for tiger poaching: theoretically, even death sentence; in the last recorded case of tiger poaching in the south, in 2008, the perpetrator was sentenced to 12 years in prison.
Captive South China tigers have been "polluted" with Indochinese (corbetti) tiger genes. I haven't heard of them mixing with Amur (altaica) tigers, though it is possible. Nevertheless, they are all we have left of the South China tiger, and they should be preserved and perpetuated. It is quite possible that more Indochinese tigers will eventually have to be mixed in, as the inbred population deteriorates.
As for the hybrid (tigris x altaica) that was introduced in Dudhwa in India more than 30 years ago, yes, it was a mistake - no hybrid tiger should have been introduced into the Bengal tiger range. However, there is hardly any harm done, and there are even certain benefits from a genetical standpoint (mixing invigorates populations, in all species, including humans).
I would certainly not go so far as to cull its descendants (although the game warden of Dudhwa has indeed killed some of them in his time). Like all other protected areas in India, Dudhwa is a small reserve, and its breeding population is hovering around 20 individuals. If it weren't for the occasional wanderings of tigers from Katerniaghat and Kishanpur, this would be a very inbred population, possibly even extinct. Yet even so, the entire remaining Uttar Pradesh and Western Nepal metapopulation has less than a hundred adult tigers combined. It has no links to Central India, severed links to Chitwan (the habitat break is around Butwal town), and very little (if any) contact with the Corbett metapopulation. The culling of any number of tigers from there (or anywhere) would be a terrible waste, and it would further erode the genetic variability of tigers there. As proven in the case of Ngorongoro lions (as well as Gir lions, Ranthambhore tigers and Amur tigers), the perpetual inbreeding results in reduced fertility - eventually killing off the entire population.
Yes, tigers used to be found in 26 countries. Here is a list of present 13 tiger range countries:
India, Russia, Nepal, Bhutan, Bangladesh, Myanmar, Thailand, Malaysia, Indonesia, Cambodia, Laos, Vietnam and China.
Tigers used to be found in another 13 countries:
Turkey, Iran, Iraq, Pakistan, Afghanistan, South Korea, North Korea, Kazakhstan, Turkmenistan, Uzbekistan, Tajikistan, Azerbaijan and Singapore.
The South China Tiger (amoyensis) is very probably extinct in the wild. There is a captive population of 60-70 individuals, all descendants of fewer than 7 founder individuals.
Here is the explanation of China's wild tiger numbers estimate: China has a handful of wild Amur (altaica) tigers in the north, possibly a few surviving Indochinese (corbetti) tigers in the south (the last and only camera trap image recorded three years ago), and a few Bengal (tigris) tigers in Tibet (recorded more than ten years ago).
These estimates may be optimistic, and both southern tiger populations may possibly be extinct by now. Perhaps they still exist, as China's law has very strict punishment for tiger poaching: theoretically, even death sentence; in the last recorded case of tiger poaching in the south, in 2008, the perpetrator was sentenced to 12 years in prison.
Captive South China tigers have been "polluted" with Indochinese (corbetti) tiger genes. I haven't heard of them mixing with Amur (altaica) tigers, though it is possible. Nevertheless, they are all we have left of the South China tiger, and they should be preserved and perpetuated. It is quite possible that more Indochinese tigers will eventually have to be mixed in, as the inbred population deteriorates.
As for the hybrid (tigris x altaica) that was introduced in Dudhwa in India more than 30 years ago, yes, it was a mistake - no hybrid tiger should have been introduced into the Bengal tiger range. However, there is hardly any harm done, and there are even certain benefits from a genetical standpoint (mixing invigorates populations, in all species, including humans).
I would certainly not go so far as to cull its descendants (although the game warden of Dudhwa has indeed killed some of them in his time). Like all other protected areas in India, Dudhwa is a small reserve, and its breeding population is hovering around 20 individuals. If it weren't for the occasional wanderings of tigers from Katerniaghat and Kishanpur, this would be a very inbred population, possibly even extinct. Yet even so, the entire remaining Uttar Pradesh and Western Nepal metapopulation has less than a hundred adult tigers combined. It has no links to Central India, severed links to Chitwan (the habitat break is around Butwal town), and very little (if any) contact with the Corbett metapopulation. The culling of any number of tigers from there (or anywhere) would be a terrible waste, and it would further erode the genetic variability of tigers there. As proven in the case of Ngorongoro lions (as well as Gir lions, Ranthambhore tigers and Amur tigers), the perpetual inbreeding results in reduced fertility - eventually killing off the entire population.
Do you now if this 'pollution' is recognised by the studbook holders for 'amoyensis' and whether any tigers in the captive population that are known to be impure are being prevented from breeding any further, or does it affect the overall population?
Re the female Tiger that was released in Dudwa NP. 'Tara' was obtained by Billy Arjun Singh from Twycross Zoo UK as an experiment in 'rewilding' a Tiger born in a zoo. I don't know what percentage of 'altaica' there was in her ancestry, but in the 1970's tiger genetics was not the advanced science it is today and I believe there was no awareness at the time that she was in fact (and unfortunately) not a purebred Indian tiger.
re amoyensis: no clue as yet. What I do know is that in the case of the small founder base for amoyensis, I would suspect that introduction of a genetic contribution from - to my mind - the closest ssp. corbetti is not necessarily a bad thing.
re bengalensis/altaica hybrid. Even the potential harm done here may be marginal at best. I have not come to know any genetic studies on the Dudwha Bengal tiger population and what percentage genetic pollution is altaica in origin. This - however - concerns an introduction avant-la-lettre and as such would constitute a valuable exercise for any planned re-introductions in P.R. China, Iran and elsewhere for altaica and amoyensis.
So, not all is lost ... I guess!
Yes, they are aware of it. Here are quotes from one study:
"The three South China tigers from the Suzhou Zoo, China, that had clustered with P. t. corbetti I by mtDNA (Pti-217, Pti-218, and Pti-222) also associated more closely with P. t. corbetti I from northern Indochina by microsatellite analysis (Figure 4). The two distinct (by mtDNA) P. t. amoyensis individuals (Pti-219 and Pti-220) from the Chongqing Zoo, China, likewise formed a distinct lineage in the microsatellite analysis (Figure 4)."
"Of the five individuals originally designated as P. t. amoyensis, three were genetically indistinguishable from P. t. corbetti I, resulting in an inadequate sample size for a meaningful estimation of population variation."
"The ultimate classification of tigers of the southern China and northern Indochina region is further complicated by the poor definition of the geographic boundary between P. t. corbetti I and P. t. amoyensis, and because the South China tiger subspecies is represented only by captive-born animals of imprecise origin. One of the two phylogenetic lineages in this captive population (Pti-217, Pti-218, and Pti-222) was indistinguishable from northern Indochinese tigers (see Figures 3 and 4), perhaps as a consequence of introgression of the northern Indochinese tigers into the Chinese captive population or a more-northern distribution of the Indochinese tigers than had previously been recognized. A comprehensive morphological and genetic assessment of the captive population (around 50 individuals) (Tilson et al. 2004), of historic samples, and of additional wild tigers from southern China, in the context of subspecies patterns seen here would be useful to resolve remaining uncertainties and to inform in situ and ex situ management strategies."
"the adequacy of traditional subspecies designations is tentative at best, since morphological distinctions in many cases have been based on a few specimens, and because subsequent studies have failed to affirm these distinctions. Herrington (1987) and Kitchener (1999) have revealed a wide range of morphological variations within the subspecies and, to some extent, overlapping among the subspecies. A previous molecular genetic assessment of 28 tigers has indicated a low level of genetic variation, revealing little evidence for subspecies distinctiveness (Wentzel et al. 1999). Moreover, ecological analyses of tiger habitat (Kitchener and Dugmore 2000) indicate that there have been few geographic barriers (e.g., mountain ranges and deserts) to migration and gene flow that would have been sufficient for subspecies isolation.
However, we cannot rule out the possibility that some of the current population subdivision, particularly in the case of the divergence of P. t. altaica and P. t. amoyensis/P. t. corbetti I, could be related to the disruption of an isolation-by-distance pattern caused by the recent extinction of intermediate populations; this hypothesis can be tested only when a larger geographic sampling is available.
The age of the most recent common ancestor for tiger mtDNA was estimated to be 72,000–108,000 y, relatively younger than some other Panthera species. Overall, tigers had moderate levels of mtDNA diversity (Table 6), substantially less than leopards (P. pardus) (Uphyrkina et al. 2001), Geoffroy’s cat (Oncifelis geoffroyi), Pampas cat (O. colocolo), or tigrina (Leopardus tigrinus) (Johnson et al. 1999), but comparable to pumas (Puma concolor)
Our results also show that, although modern tigers have a relatively young history, ecological, demographic, and biogeographic factors have led to recognizable subdivisions among otherwise closely related populations. We therefore might expect that more extensive geographic sampling would reveal additional phylogenetic divisions among populations, especially in the Indian Subcontinent and the Indochina bioregions, or alternatively, would blur the apparent phylogenetic subdivisions and reveal a clinal distribution of genetic variation across different subspecies. Further sampling of modern and historic specimens will also help clarify whether the patterns we have observed are attributable to the recent substantial population decline throughout the range in tigers, or whether the observed differentiations among tigers occurred earlier."
Source:
PLoS Biology: Phylogeography and Genetic Ancestry of Tigers (Panthera tigris)
As for Tara, I absolutely agree, things today would be done differently. But we must not forget that, if it weren't for Billy Arjan Singh, Dudhwa wouldn't even exist today. If one looks at the Gangetic plain and India's border areas with Nepal on Google Earth today, one can clearly see the few remaining islands of forest in the sea of agricultural land.
Btw. I just had a look at IUCN/SSC Nowell et al: Wild Cats: Status Survey and Conservation Action Plan, and saw that Georgia, too, was a tiger range state once (tiger killed near Tbilisi in 1922).
"The three South China tigers from the Suzhou Zoo, China, that had clustered with P. t. corbetti I by mtDNA (Pti-217, Pti-218, and Pti-222) also associated more closely with P. t. corbetti I from northern Indochina by microsatellite analysis (Figure 4). The two distinct (by mtDNA) P. t. amoyensis individuals (Pti-219 and Pti-220) from the Chongqing Zoo, China, likewise formed a distinct lineage in the microsatellite analysis (Figure 4)."
"Of the five individuals originally designated as P. t. amoyensis, three were genetically indistinguishable from P. t. corbetti I, resulting in an inadequate sample size for a meaningful estimation of population variation."
"The ultimate classification of tigers of the southern China and northern Indochina region is further complicated by the poor definition of the geographic boundary between P. t. corbetti I and P. t. amoyensis, and because the South China tiger subspecies is represented only by captive-born animals of imprecise origin. One of the two phylogenetic lineages in this captive population (Pti-217, Pti-218, and Pti-222) was indistinguishable from northern Indochinese tigers (see Figures 3 and 4), perhaps as a consequence of introgression of the northern Indochinese tigers into the Chinese captive population or a more-northern distribution of the Indochinese tigers than had previously been recognized. A comprehensive morphological and genetic assessment of the captive population (around 50 individuals) (Tilson et al. 2004), of historic samples, and of additional wild tigers from southern China, in the context of subspecies patterns seen here would be useful to resolve remaining uncertainties and to inform in situ and ex situ management strategies."
"the adequacy of traditional subspecies designations is tentative at best, since morphological distinctions in many cases have been based on a few specimens, and because subsequent studies have failed to affirm these distinctions. Herrington (1987) and Kitchener (1999) have revealed a wide range of morphological variations within the subspecies and, to some extent, overlapping among the subspecies. A previous molecular genetic assessment of 28 tigers has indicated a low level of genetic variation, revealing little evidence for subspecies distinctiveness (Wentzel et al. 1999). Moreover, ecological analyses of tiger habitat (Kitchener and Dugmore 2000) indicate that there have been few geographic barriers (e.g., mountain ranges and deserts) to migration and gene flow that would have been sufficient for subspecies isolation.
However, we cannot rule out the possibility that some of the current population subdivision, particularly in the case of the divergence of P. t. altaica and P. t. amoyensis/P. t. corbetti I, could be related to the disruption of an isolation-by-distance pattern caused by the recent extinction of intermediate populations; this hypothesis can be tested only when a larger geographic sampling is available.
The age of the most recent common ancestor for tiger mtDNA was estimated to be 72,000–108,000 y, relatively younger than some other Panthera species. Overall, tigers had moderate levels of mtDNA diversity (Table 6), substantially less than leopards (P. pardus) (Uphyrkina et al. 2001), Geoffroy’s cat (Oncifelis geoffroyi), Pampas cat (O. colocolo), or tigrina (Leopardus tigrinus) (Johnson et al. 1999), but comparable to pumas (Puma concolor)
Our results also show that, although modern tigers have a relatively young history, ecological, demographic, and biogeographic factors have led to recognizable subdivisions among otherwise closely related populations. We therefore might expect that more extensive geographic sampling would reveal additional phylogenetic divisions among populations, especially in the Indian Subcontinent and the Indochina bioregions, or alternatively, would blur the apparent phylogenetic subdivisions and reveal a clinal distribution of genetic variation across different subspecies. Further sampling of modern and historic specimens will also help clarify whether the patterns we have observed are attributable to the recent substantial population decline throughout the range in tigers, or whether the observed differentiations among tigers occurred earlier."
Source:
PLoS Biology: Phylogeography and Genetic Ancestry of Tigers (Panthera tigris)
As for Tara, I absolutely agree, things today would be done differently. But we must not forget that, if it weren't for Billy Arjan Singh, Dudhwa wouldn't even exist today. If one looks at the Gangetic plain and India's border areas with Nepal on Google Earth today, one can clearly see the few remaining islands of forest in the sea of agricultural land.
Btw. I just had a look at IUCN/SSC Nowell et al: Wild Cats: Status Survey and Conservation Action Plan, and saw that Georgia, too, was a tiger range state once (tiger killed near Tbilisi in 1922).
Panthera Puss
Well-Known Member
For a reference to Siberian x South Chinese hybrids (138-9 and ff):
Tigers of the world: the biology ... - Google Books
Two South Chinese - Siberian hybrids were living at IOW Zoo in the UK until recently, they came from Italy. One was DNA tested & found to be a 1/8 Amoyensis 7/8 Siberian mix.
Tigers of the world: the biology ... - Google Books
Two South Chinese - Siberian hybrids were living at IOW Zoo in the UK until recently, they came from Italy. One was DNA tested & found to be a 1/8 Amoyensis 7/8 Siberian mix.
Hi,
About introduced tigress to Dudhwa:
It is not even proven that this tigress ever raised young in the wild. It was already adult when introduced, so short lifespan, and wild tigressess are known to be hostile to newcomers, and turnover of individuals is indeed high, so likely no hybrid tigers remain in Dudhwa area.
About South Chinese tigers:
Current inbred population in China are the only animals on the planet, so they need to be protected as-it-is, in the same way as Lowland-Caucasian Wisents are protected (no purebred Caucasian animals exist). The goal should be to breed maximal number of young and selecting stronger ones for breeding, to remove inbreeding effect. Possibly, even futher Indochinese or Siberian founders might need to be introduced to prevent further inbreeding.
About status and distribution of amoyensis and origin of captive animals:
Subspecific designations of tigers (and almost all wild animals, indeed) is a mystery. The founders were not sampled from all localities in China, indeed most museum specimens were not sampled and they are difficult to get (Chinese are famously non-cooperative). So we don't know how borders went between South Chinese subspecies and Siberian to the north and Indochinese to the south. We don't know the extent of hybridization on the border, we don't know variability (genetic and external) within subspecies. Further strudy might reveal part of it. Others disappeared forever together with wild Chinese tigers.
About subspecies in general:
Subspecies are not uniform and separated units. So, there is likely that genetic structure of captive amoyensis is different from historic Chinese populations. Indeed, recovering exactly the same genetic structure might be impossible and not matter in conservation in general. Even if wild population of animals re-expands after decline, it may be that different genetic vatriants started to dominate.
Tiger is also interesting situation: genetically relatively uniform (as is puma) it created at least several conservation units which are biologically irrepraceable - simply because short-haired tropical subspecies couldn't survive cold winters in temperate climate. So here, interesting is that genetics and morphology has to be both taken into account.
About introduced tigress to Dudhwa:
It is not even proven that this tigress ever raised young in the wild. It was already adult when introduced, so short lifespan, and wild tigressess are known to be hostile to newcomers, and turnover of individuals is indeed high, so likely no hybrid tigers remain in Dudhwa area.
About South Chinese tigers:
Current inbred population in China are the only animals on the planet, so they need to be protected as-it-is, in the same way as Lowland-Caucasian Wisents are protected (no purebred Caucasian animals exist). The goal should be to breed maximal number of young and selecting stronger ones for breeding, to remove inbreeding effect. Possibly, even futher Indochinese or Siberian founders might need to be introduced to prevent further inbreeding.
About status and distribution of amoyensis and origin of captive animals:
Subspecific designations of tigers (and almost all wild animals, indeed) is a mystery. The founders were not sampled from all localities in China, indeed most museum specimens were not sampled and they are difficult to get (Chinese are famously non-cooperative). So we don't know how borders went between South Chinese subspecies and Siberian to the north and Indochinese to the south. We don't know the extent of hybridization on the border, we don't know variability (genetic and external) within subspecies. Further strudy might reveal part of it. Others disappeared forever together with wild Chinese tigers.
About subspecies in general:
Subspecies are not uniform and separated units. So, there is likely that genetic structure of captive amoyensis is different from historic Chinese populations. Indeed, recovering exactly the same genetic structure might be impossible and not matter in conservation in general. Even if wild population of animals re-expands after decline, it may be that different genetic vatriants started to dominate.
Tiger is also interesting situation: genetically relatively uniform (as is puma) it created at least several conservation units which are biologically irrepraceable - simply because short-haired tropical subspecies couldn't survive cold winters in temperate climate. So here, interesting is that genetics and morphology has to be both taken into account.
:
Illegal tiger-farm discovered in Thiland ( and other animal-species, among them a douc 
) :
TRAFFIC - Wildlife Trade News - Thai seizure of a dozen captive tigers resurrects farming threat
) :TRAFFIC - Wildlife Trade News - Thai seizure of a dozen captive tigers resurrects farming threat
Are Tigers counted the right way in India ? :
India’s tigers seem to be a massive success story — many scientists aren’t sure
India’s tigers seem to be a massive success story — many scientists aren’t sure
Article about the possibility of re-introduce tigers in Cambodia :
The Society for Conservation Biology
The Society for Conservation Biology
Jungle Man
Well-Known Member
Wow There have been many victories for the tigers in recent years, hopefully in some years they will be more and more stable.
Bad news for the Malayan tiger in Malaysia :
The Last Days of the Malayan Tiger | UNRESERVED | Intelligence Is Sexy
:The Last Days of the Malayan Tiger | UNRESERVED | Intelligence Is Sexy