Playing Cupid to conserve the remaining pygmy hogs in Assam
by Sahana Ghosh on 30 March 2018 |
Pygmy hogs' survival is intricately linked to grassland habitats.
Successful reintroduction into the wild entails habitat restoration, genetic analysis to pair individuals and monitoring.
Between 2008 and 2016, 100 pygmy hogs have been reintroduced into the wild at three different places in Assam: Sonai Rupai, Orang and Barnadi.
Smallest among wild pigs, the shy and secretive pygmy hogs (Porcula salvania) are found nowhere else in India except in Assam and number only a few hundred. To ensure their survival, conservationists are playing match-makers aided by cutting-edge genetic analysis tools, pairing up individuals in the world's sole pygmy hog captive breeding programme.
Once thought to be extinct, the 100th captive-bred pygmy hog was re-introduced into the wild in 2016, thanks to the tenacity of conservationists Goutam Narayan and Parag Deka, associated with the Pygmy Hog Conservation Programme (PHCP) that is trying to save the species and its habitat.
The plight of these 25 cm-high animals and how they have made an amazing comeback was recently made into a documentary "Durrell's Underhogs."
A pygmy hog mother with her piglets. Photo by Tammo Buss.
"Although exact numbers are not known it is estimated that there may be only a few hundred, probably less than 300, pygmy hogs left in the wild. One of the reasons why they are disappearing is due to the decimation of the tall grasslands, which is their habitat," Parag Deka, project director, PHCP, Durrell Wildlife Conservation Trust, told Mongabay-India at its Guwahati-based centre.
Pygmy hogs are listed as Critically Endangered in the IUCN Red List.
Indicator species for the health of grasslands
Conservation breeding of pygmy hogs, which act as indicator species for health of grasslands, forms the core of PHCP's activities.
"The species is very elusive. Before we know all about them in a scientific manner, they can disappear from the world so that is why it is advisable to at least start a conservation-breeding programme. The idea is to capture pygmy hogs from the wild, increase their population by breeding them at the centre and reintroduce them into the wild after habitat restoration," Deka said.
Maintaining the health of the grasslands is essential for the survival of the pygmy hogs. Photo by Goutam Narayan.
PHCP is a collaborative project of Durrell Wildlife Conservation Trust, IUCN/SSC Wild Pig Specialist Group, Assam Forest Department and India's Ministry of Environment, Forest & Climate Change, and with EcoSystems-India and Aaranyak as local partners.
Currently the programme maintains about 60 hogs in captivity – 22 in the Nameri centre, 37 in Guwahati centre, two in Guwahati zoo. They are called 'nal gahori' or 'takuri borah' in Assamese, 'oma thakri' in Bodo, and 'sano banel' in Nepali.
Playing cupid
It is not just elbow grease and painstaking tracking and monitoring that is keeping these diminutive brownish-black pygmy hogs' extinction at bay. Successful reintroduction into the wild entails a bit of 'playing Cupid', says Deka, programme manager, Aaranyak Threatened Species Recovery Programme.
This means mastering a gamut of activities involving metrics: sophisticated data gathering and storage tools such as the Single Population Analysis and Record Keeping Systems (SPARKS) and Population Management (PMx) that help in managing the demographic and genetic qualities of small captive populations.
"In the human context, this is somewhat like a profile on a matrimonial matchmaking site," Deka explained on a lighter note.
A pygmy hog pair in an enclosure. Photo by Sahana Ghosh / Mongabay.
"If you do not perform these analysis then how do you decide who to pair with whom? For conservation breeding you have to think of the long-term genetic goal to maximise genetic diversity. For the first three to four years, you can track which animal is from which generation, you can pair them up but when three to four generations come and if you want to pair them, it is difficult to know without genetic planning," Deka explained.
SPARKS was designed to ease the work of studbook keepers in managing small captive populations of animals. The programme stores information about life histories and events of each individual.
Both can crunch data on population size, growth rate, fecundity, mortality parameters as well as inbreeding coefficients for proposed pairings. PMx goes a step ahead and offers the chance to visualise potential outcomes: pairings, introduction of founders, increasing generation length etc.
PHCP assiduously maintains data of each individual hog and all the animals are identified with a rice-grain size microchip that is inserted under the skin. The hogs breed only once a year and have four or five piglets each year.
"All the data goes to SPARKS and from there I will migrate the date to PMx. Through the latter, I will find out the best pair (match). Then I check them physically, their last breeding performance and then they are put together. They start to know each other (by smelling etc.). In some cases they are not compatible; say, the male is not interested in the female, so we put another male in the site and so the former becomes aggressive and pays attention to the female as a result of competition," commented Deka with a twinkle in his eye.
Meanwhile, around 2,500 km away at the Laboratory for the Conservation of Endangered Species (LaCONES) at CSIR-Centre for Cellular and Molecular Biology in Hyderabad, G. Umapathy and colleagues are busy understanding genetic and reproductive potential of captive and reintroduced animals.
To aid the conservation programme, they have developed techniques for reproductive monitoring of pygmy hog using fecal sample.
"We use non-invasive sampling (fecal) method to identify pygmy hog from other species in the wild and also distinguish between individuals. We have also developed a similar method to identify pregnancy status of animals in wild and captivity," G. Umapathy told Mongabay-India.
In the past, hogs are believed to have ranged across a narrow belt of grassland in the south of Himalayan foothills in Uttar Pradesh, Nepal, Bihar, north Bengal, Assam and possibly extending into contiguous habitats in southern Bhutan.
Pygmy hogs being release from their enclosure into their natural habitat. Photo by Goutam Narayan.
Even till 1990, they were present in a few places outside Manas National Park, such as in the Barnadi Wildlife Sanctuary but now, only Manas supports the last known viable wild population of this critically endangered species.
Information on their distribution before 1970s is scanty and the species was never reported to be plentiful. By the 1960s it was feared to be extinct. After the species was rediscovered in 1971 following a fire in the Barnadi Wildlife Sanctuary, an attempt (which later failed) was made to breed them in captivity.
"A tea plantation manager took the first group of 14 hogs into a private captive collection and called on Durrell's Jeremy Mallinson for advice on husbandry techniques," according to information on the programme's website.
The tides turned in favour of these 25 cm-tall animals with the establishment of an official conservation-led captive population at custom-built facilities in Basistha near Guwahati following the inception of the PHCP in 1995.
As the population shot up by over 600 percent, a new breeding facility was established at Potasali in Nameri straddling the border between Assam and Arunachal Pradesh, to house the increasing population.
Between 2008 and 2016, 100 of the beleaguered creatures were reintroduced into the wild at three different places in Assam: Sonai Rupai, Orang and Barnadi. There are no confirmed records of the species from Bhutan in the recent past.
Grassland habitats are intricately linked to the survival of the sensitive hogs. So, in parallel to the captive breeding, the PHCP team is studying these habitats to understand how to manage them better.
"Improper grassland management or absence of grassland management degraded the habitat which made it unfit for hogs and other grassland-dependent species," Deka says, adding, human beings and cattle are mainly responsible for the disappearance and disturbance of grassland habitats.
"Most of the tall grasslands were converted into cultivation fields, grazing grounds, farms and villages. In addition, one has to consider the natural succession process by which it transforms to forests. If you don't manage it properly, it becomes a woodland," Deka said.
Habitat restoration and reintroduction is a continuous process and they go hand-in-hand, according to Deka.
A pygmy hog nest in the grasslands. Photo by Parag Deka.
"When it comes to reintroduction, we have to go for a soft release as we cannot introduce them directly from the breeding centre," Deka adds.
For this the animals are "pre-conditioned" for eventual re-introduction in a specially constructed 'pre-release' facility in Potasali, on the outskirts of Nameri National Park, east of Sonai Rupai Wildlife Sanctuary.
"They are maintained in three separate social groups, in simulated natural habitats intended to encouraging natural foraging, nest-building and other behaviours," according to a Darwin Initiative Final Report.
Placed under minimal human contact, they are encouraged to forage naturally and their supplementary diet is gradually reduced to less than a fourth of daily requirement. Their behaviour is closely monitored and it is seen the pygmy hogs start behaving like wild animals and learn to survive in the wild within a couple of months.
After about five months in the pre‐release enclosures the hogs are taken to the reintroduction site where they are kept in a smaller enclosure for two to three days before being allowed to escape to the wild.
Deka says the programme is working closely with the forest department officials in Assam to ensure grassland habitats are maintained and the pygmy hogs can be saved.
"Conservative estimates suggest the reintroduced populations at the three sites have crossed 150. Efforts are on to identify new sites in the past distribution range for potential re-introduction but the success of these efforts depend on grassland management, security situation in the state and also financial sustainability. So a lot rests on generating awareness for the pygmy hogs," Deka said.
Narayan, G., & Deka, P. J. (2017). Pygmy Hog Porcula salvania (Hodgson, 1847). Ecology, Conservation and Management of Wild Pigs and Peccaries, 234.
Article published by S. Gopikrishna Warrier
Animals, Conservation, Endangered species, Forests, Grasslands, Habitat Fragmentation, Habitat Loss, Mammals, National Parks, Technology and Conservation, Wildlife Sanctuary