P
ygmy hogs are one of the rare and
endangered animals listed by the International Union for the Conservation of Nature (IUCN), and designated as a schedule 1 species under the Indian Wildlife Protection Act, 1972. It is one of the very few mammals that build its own home, or nest, complete with a roof. Its present population, including reintroduced animals, is estimated to be less than 300 in wild. The original population, which became restricted to a single locality, the Manas National Park in Assam, India, may number less than 50.
Efforts to save this species from extinction include the protection of its only habitat and by breeding the animals in captivity. These are undertaken by the Pygmy Hog Conservation Program (PHCP), which is a collaborative project with the Ministry of Environment and Forests, Government of India, IUCN/SSC Wild Pig Specialist Group, and Forest Department, Government of Assam, as the key partners.
Since 1996, over 500 pygmy hogs have been bred successfully and 142 captive-born have been released into the wild as part of the conservation programme. However, all these captive individuals were offspring of just seven wild-caught individuals. One of the major challenges of a long-term captive breeding program is to maintain genetic diversity within a population, over several generations. The genetic diversity can be lost from inbreeding due to mating between related individuals within a population, established with very few founders.
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A study was recently conducted by the PHCP and the Laboratory for Conservation of Endangered Species at the Council of Scientific and Industrial Research’s Centre for Cellular and Molecular Biology (CSIR-CCMB-LaCONES) to examine the reproductive and genetic fitness of these captive-bred individuals. The research group headed by Dr. G. Umapathy of CSIR-CCMB LaCONES studied genetic changes in 36 captive-bred pygmy hogs over time across eight consecutive generations. They also tested the association between genetic diversity and reproductive success to account for any fitness loss.
The study found no overall signs of genetic inbreeding between individuals across different generations. Dr. Umapathy said “This was possible because of the strict scientific conservation breeding protocol followed by the programme. But, the recent generations show slightly increased relatedness. We, therefore, recommend the introduction of a few wild individuals to the breeding pool”.
Dr. Goutam Narayan of PHCP and EcoSystems-India, said- “We carefully selected unrelated mates and bred them in separate family lines. We are glad that this study has provided evidence that it is possible to avoid genetic inbreeding in a small captive population even if the founder population is very small, if a strict protocol is followed year after year”.
Dr. Vinay K Nandicoori, Director, CCMB, said, “This is the first such study on Indian animals to understand genetics effect of long-term captive breeding of endangered animals. The outcomes of the study will guide the management and optimization of the breeding protocol in PHCP and other similar conservation breeding programmes”.
The lead author of the study was Dr. Deepanwita Purohit and the other authors include S. Manu, M. S. Ram, S. Sharma, and H. C. Patnaik from CCMB, and Parag J. Deka from Pygmy Hog Conservation Programme.