Research

 

The Chinese Tiger Project has supported research projects across many disciplines such as prey consumption rate assessment, cheetah reintroduction and monitoring, and camera-tracking photogrammetry.

Important and comprehensive research programs have been conducted since 2012 by Dr. Maria Fabregas, Dr. Henk Bertschinger, Dr. Gary Koehler, Petri Viljoen and the University of Pretoria. Key research program goals are: an assessment of hunting performance of rewilded South China tigers and pregnancy and pseudo-pregnancy assessment in breeding female tigers. Each of these goals has 3 components.

Hunting performance of rewilded South China tigers:


1. To assess mean meat intake of rewilded tigers through determination of their kill rate.

Rewilded tigers must be able to hunt frequently enough to provide themselves with the appropriate meat intake if their reintroduction to protected areas in China wants to succeed.


2. Develop a logistic regression model to predict kill sites of ungulate prey from GPS data.

Once the tigers are released back in China, determination of their kill rate and therefore chances of survival, will only be possible through GPS data evaluation.


3. To determine the biological and environmental variables related to hunting success in South China tigers.


Biological variables such as age, sex, rewilding experience, etc and environmental variables such as cover density, slope, wind, distance to water body, etc associated with hunting success should be among the criteria to choose candidate sites to establish protected areas where the tigers will be later reintroduced, as this will contribute to increased survival rates of reintroduced tigers.

Breeding stage in South China tigers to assess pregnancy and pseudopregnancy state in the species.

Male and female captive tigers are kept apart because of their solitary nature, and just brought together for breeding purposes. Given that a main priority of Save China's Tigers is to breed as fast as possible to go through the genetic bottleneck, it is important to determine whether a female is pregnant or not as soon as possible, if she is not, the male can be put back together to try to mate again. However, pregnancy in tigers is not obvious to the naked eye until the very last stage.


1. Behavioral changes related to pregnancy/pseudo pregnancy stage.

Determining behavioral changes (if any) related to pregnancy or pseudo-pregnancy is a non-invasive method that would enable the assessment of female reproductive phase at an early stage, and plan accordingly.


2. Hormonal profile of female tigers throughout pregnancy.

To monitor faecal progesterone levels in females is a non-invasive way to confirm ovulation, pregnancy and pseudopregnancy, and to be able to predict expected date of partus, which would enable the assessment of female reproductive phase at an early stage, and plan accordingly.


3. Pregnancy assessment through gain weight measured with photogrammetry.

The monitoring of female reproductive state (pregnant, pseudo-pregnant, not pregnant) through gain weight measured by photogrammetry is a non-invasive method that would enable the assessment of female reproductive phase at an early stage, and plan accordingly. Moreover, it could be used in field camera stations once the tigers are reintroduced in China.


Preliminary results of the groundbreaking research being conducted by Dr. Maria Fabregas are indeed very positive, showing that the evaluated tigers are able to hunt frequently enough to meet their energetic requirements, but most importantly, they show a high level of adaptability in their hunting behaviour. Dr. Fabregas indicated that, "the fact that they are flexible in their hunting strategies depending on environment is very encouraging, as the habitat where they will be reintroduced in China will be very different from what they experience here in South Africa. Being able to adapt to different environments is crucial for their survival."

reintroduced in China.


Rewilding Research

Photogrammetry

Knowledge of changes in body size or mass is fundamental to our ability to assess how an environment may affect the health of an individual. Take as an example the human obsession with keeping our weight within certain limits. This is not principally driven by a need to 'look good' (although that is one aspect of relevance for humans specifically), but rather with an ingrained desire to be relatively healthy and ensure better chances for survival and performance. For humans, this is fairly easy to do: just jump on a scale at suitable intervals. However, for large mammal ecologists, such basic knowledge is not easily collected because of the obvious difficulties associated with actually weighing large animals. Moreover, for any meaningful trends to be identified, large samples of animals need to be repeatedly weighed.


In an effort to ease the logistical impediments to assessing size and mass of large mammals repeatedly over time, a group from the University of Pretoria's Mammal Research Institute (http://www.up.ac.za/zoology/?q=user/137/research) is fine-tuning techniques that use photographs to 'weigh' large terrestrial mammals. Using photographs to measure objects is known as photogrammetry, and has various applications. In zoology it has seen some steady recent development for assessment of animal body size and mass. Variations of a technique originally developed to estimate the mass of giant southern elephant seals (http://www.int-res.com/articles/ab2009/5/b005p031.pdf) are now being tested in various terrestrial scenarios.  


At Laohu Valley Reserve, specifically at the South China tiger rewilding facility, an exciting development in these techniques known as "camera-trapping photogrammetry" has been pioneered by the same team from the University of Pretoria. The method is essentially a combination of traditional camera-trap methodology and the above photogrammetric technique. The beauty of this system is that animals are free to roam through an arena of cameras and need not be immobilised for the photogrammetric procedure. Essentially, a three-dimensional model of an animal (in this case the tiger) is constructed from a series of photographs, which is then used to estimate volume allowing an accurate estimation of the weight of an individual.  The development of this technique promises exciting advances in the field of large mammal research.




Cheetah Reintroduction

Cheetahs Return to Loahu Valley Reserve & The Free State


Another significant milestone for the Laohu Valley Reserve and the Free State province in South Africa is the return of wild cheetahs to the lands of the reserve as part of a special partnership project of Conservation Finance International and the Endangered Wildlife Trust.


The two male cheetahs were provided by the Endangered Wildlife Trust which is dedicated to conserving threatened species and ecosystems in southern Africa to the benefit of all people. Vincent van der Merwe of the EWT said: "The two males were born in July 2010 on Amakhala Private Game Reserve. They will reach reproductive age soon after arriving at Laohu Valley. They were born in a free ranging environment on a 5700ha reserve, implying that their movements are constrained only by reserve fencing." He added the males, "…were originally part of a litter of 5 (4 males & 1 female). Before the Metapopulation Project was launched in June 2011, 24% of all cheetahs born on small fenced cheetah reserves in South Africa were sold into captivity."


The cheetahs had radio collars attached for GPS tracking and successfully hunted an antelope in a matters of days. Stuart Bray of Conservation Finance International and co-founder of Save China's Tigers, said:  "I would like to personally thank the EWT for their assistance in this reintroduction.  Without the EWT, this would not have been possible.  This is truly a historic day for the Free State and a milestone in the effort to restore Laohu Valley Reserve to its natural state."

Remote Monitoring

The Project team needs to frequently and closely monitor the tigers for several reasons including health monitoring, research, and breeding management. One of the challenges of rewilding tigers is achieve this monitoring while restricting human interaction and allowing tigers to free-range in the large camps.  Due to the large wilderness-like camps and the need to not disturb a new mother, it is sometimes weeks of careful monitoring before staff can confirm the birth of a tiger cub in the underbrush.


Besides such basic methods as careful listening and watching with binoculars and telephoto lenses, the Chinese Tiger Project team uses a number of techniques and new technologies for monitoring. The Project has been using radio collars since 2005, not only for selected tigers but also to track patterns of prey species in the hunting camps. Aerial GPS mapping is also performed with specially equipped aircraft.

Project advisor, Petri Viljoen, a renowned ecologist and conservationist, member of the IUCN Antelope Specialist Group and Society of Ecological Restoration, has made significant progress on development of two technologies that offer new monitoring opportunities: a remote controlled 4x4 rock-climbing 'buggy' and sophisticated quadcopter drone that can observe from hundreds of feet in the air. Both systems have been tested and performed successfully. The rock buggy is alternatively equipped with GoPro or Canon dSLR cameras and the quadcopter with a GoPro, that offers HD video aerial surveillance.

Ecologist Petri Viljoen with radio collared tiger.

Preliminary results of the groundbreaking research being conducted by Dr. Maria Fabregas are indeed very positive, showing that the evaluated tigers are able to hunt frequently enough to meet their energetic requirements, but most importantly, they show a high level of adaptability in their hunting behaviour. Dr. Fabregas indicated that, "the fact that they are flexible in their hunting strategies depending on environment is very encouraging, as the habitat where they will be reintroduced in China will be very different from what they experience here in South Africa. Being able to adapt to different environments is crucial for their survival."

reintroduced in China.


GoPro equipped quadcopter.

Rewilding Research Paper Published

The answer to this question is critical for future conservation of endangered animals that are extinct in the wild but have surviving populations in zoos and reserves. If these pampered captives cannot survive in the wild, then efforts to re-establish wild populations are fruitless.


A new paper by conservation scientists documents the first empirical evidence that captive-born tigers can successfully hunt free-ranging prey adequately to meet their energy demands – a critical factor of their being able to survive in the wild and validating the use of captive animals to recover wild populations provided other reintroduction criteria are met. Entitled: “Hunting performance of captive-born South China tigers (Panthera tigris amoyensis) on free-ranging prey and implications for their reintroduction”, the paper published in Biological Conservation, a leading international science journal, documents the study of the SCT’s South China tigers’ hunting performance and their suitability for reintroduction into the wilds of China.


The paper was authored by a multidisciplinary team of researchers: Maria Fabregas, a wildlife scientist at the University of Pretoria who has conducted post-doctoral research on hunting performance and breeding activity of the South China tiger; Geoffrey Fosgate  a statistician at the University of Pretoria that collaborates with SCT in the analysis an interpretation of complex data; and Gary Koehler, a carnivore specialist that has been advising SCT since the inception of the tiger project and has broad experience in tiger behavior.


The South China tiger, is listed by the IUCN as critically endangered and is regarded as probably extinct in the wild, leaving captive-born animals as the only stock available for reintroductions. However, reintroduced tigers will not survive in the wild unless they can proficiently hunt and the authors aimed to determine whether captive-born tigers were able to hunt free-ranging prey and to evaluate their hunting performance as a criterion for reintroduction.


Other relevant variables were explored that effected subsequent hunting success, such as the availability of stalking cover and the upbringing history of tigers while cubs. Twelve tigers over two years of age were fitted with GPS collars and placed individually in 100 ha enclosures to determine their kill rate of Blesbuck, a type of antelope, as a measure of their hunting performance.

The article reports that all the tigers but one, successfully hunted blesbuck and the tigers also killed other species indicating flexibility in their hunting behavior and showed higher kill rates where cover was more abundant, confirming the importance of stalking cover in hunting success for this species. Results showed that the presence of the mother during cub development was not necessary for cubs to hunt later in life, although it had a positive effect on kill rate.


Moreover, that tigers’ ability to adapt to the African veld ecoregion suggests they should be able to adapt back to southern China where opportunities for stalking and ambush are more numerous.


Read more: http://conservationmagazine.org/2015/10/captive-tigers-can-learn-to-hunt/  

May be purchased at: http://www.sciencedirect.com/science/article/pii/S0006320715300987  

Or requests will be considered: info@savechinastigers.org   



Can captive-born tigers survive in the wild?

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