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Chapter 22: Pygmy hog Porcula salvania (Hodgson, 1847)and unsuitable for intraperitoneal insertion. The limited battery
life of the radio implants also necessitated their insertion only a
few days before the intended release of the hogs. Unfortunately,
the experiments failed, largely due to technical problems in the
transmitter/battery, and in 2012 also on account of the health
complications they caused. With further miniaturization and
improvements in transmitter technology it may be prudent
to experiment with newer implants provided the device can
be inserted into the hog’s body through tiny endoscopic holes
that would heal rapidly under semi-wild conditions in the pre-
release facility. Ear tags have been tried on pygmy hogs in 2014,
2015 and 2016 and appear to be a more promising approach
so far. However, despite repeated improvements in design, the
external transmitter antennae continue to break within days
or weeks. Although the trials demonstrated the suitability of
ear tags, this may work only if a durable transmitter antenna is
found. However, any device will be useful only if the battery lasts
for about a year and the radio signals can be detected from a dis-
tance of 500 m or more in order to monitor the hogs in the wild
in different seasons and in the dense, tall grass habitat (Narayan
& Deka 2015).
Reintroductions
Twenty-one social groups with a total of 100 captive-bred pygmy
hogs were released into the wild at three different sites in Assam
between 2008 and 2016: 35 in Sonai Rupai, 59 in Orang, and six
in Barnadi.
In May 2008, 16 (seven male and nine female) hogs were
released in Gelgeli grasslands of Sonai Rupai Wildlife Sanctuary.
Post-release monitoring indicated that most of the released
animals survive, and successful reproductions were recorded
on several occasions. The released groups and their progenies
also dispersed to other parts of the sanctuary, up to 3.5 km from
their original release sites. Camera-trap images revealed healthy
animals with shiny coats, unlike the somewhat emaciated hogs
captured from the wild in Manas in 1996. Some of these individ-
uals were identified by hair-clipping marks on their body before
release. That they appeared to be in good health despite harsh
weather and sometimes difficult foraging conditions even nine
months after their release suggested their successful adaptation
to the wild (Narayan et al. 2008, 2010). More hogs were released
in Sonai Rupai – nine (four male and five female) in two groups
in 2009, and 10 (seven males and three females) in three groups
in 2010. Thus, a total of 35 (18 male and 17 female) hogs in eight
social breeding groups were released in the sanctuary. Although
they continued to thrive until 2011, surveys in the following
years suggest a decline in population growth due to deteriora-
tion of habitat quality. With the worsening of the security situ-
ation in the area, the protection and management of grassland
seems to have suffered.
In 2011, the reintroduction operations were shifted to the
next agreed priority site, Orang National Park. Under similar
protocol, 13 (five male and eight female) hogs in three social
groups were released in the Magurmari grasslands of Orang
in 2011, followed by the release of 12 (eight male and four
female) in two social groups. When monitoring by project per-
sonnel and reports from Park staff suggested increase in hog
population and their dispersal to adjacent areas, it was decided
to continue the release operations for the next three years given
the size and availability of suitable habitat and enthusiasm of
the Park staff in management of grasslands in Orang. Thus, in
2013, three groups with 14 (five male and nine female) hogs; in
2014, two groups with 11 (five male and six female) hogs; and
finally in 2015, two groups with nine (three male and six female)
hogs were released in Orang. The released hogs are being moni-
tored with encouraging results – young hoglets born in the wild
have been recorded every year after release. Radio tracking has
revealed that the released hogs are dispersing up to 3 km and
they continue to breed and disperse. Estimation through nest
surveys in 2016 indicated that the reintroduced population in
Orang had grown to over 120 or more.
With the release of six (three male and three female) hogs
in May 2016 and eight (four male and four female) hogs in May
2017 in the restored grasslands of Barnadi Wildlife Sanctuary,
the project has crossed the milestone of reintroducing more
than a hundred (108) hogs into the wild.Capture Operations (2013)
As mentioned under ‘Capture operations (1996)’ above, permis-
sion was given to start the conservation breeding with only six
wild-caught hogs. However, after making several representa-
tions about the need for more wild blood in order to improve
the heterozygosity and survivability of the captive and future
reintroduced populations, the authorities gave permission to
catch six more hogs from Manas. The facts that the breeding
programme was highly successful and dozens of captive-bred
hog were reintroduced by the project helped.
The second capture operation was mounted in March 2013
and efforts were taken to replicate the 1996 operations for a com-
parative population estimate by counting flushed hogs. Altogether
72 drives were conducted using 13–15 elephants and about 25–30
personnel at several locations, but pygmy hogs were flushed
only in an area of about 6–7 km^2 around Kuri Beel camp under
Bansbari Range. This area was part of the slightly larger area from
where the hogs were captured in 1996. After several attempts the
project team managed to capture a male and two females and the
operations were called off as it ran out of options. Sixty of these
drives were conducted in the above area and only 15 pygmy hogs
were flushed, including the three that were trapped.
The 2013 capture operations strongly indicated that the popula-
tion of the species and its distribution in Manas had declined steeply
over the intervening two decades. As mentioned above, 56 drives
were conducted in the first capture operations in the same area and
in the same season with similar efforts, number of elephants and
people, and 42 hogs were flushed of which 11 were captured.Population Status and Future Plans
Even conservative estimates suggest that the reintroduced pop-
ulation at the three sites has crossed the 150 mark, and it can be
safely assumed that, along with the captive population of 50–60
hogs, about 50 per cent of the world population of this species is
either at the release site or in captivity, as the last naturally sur-
viving wild population of the species in Manas probably num-
bers less than 200 individuals (Narayan & Oliver 2015)..02412:46:11