Recovery of vulture population in roosting and scavenging areas of Bastar and Bijapur , Chhattisgarh , India

Chhattisgarh is home to seven of the nine vulture species in India. One reason for this high vulture diversity is the presence of large herds of bovines numbering over 11 million individuals (ratio of human to bovine population is approximately 0.38), from which carcasses are disposed off in the open for scavengers. The late 1990s saw large scale decimation of vulture population, and since then there have been few studies with no sighting estimates available. In this study, concurrent sighting records were collected from different locations of southern Chhattisgarh and corroborated to develop conservative sighting estimates for sympatric populations of Gyps bengalensis and Gyps indicus. We present the first report on population recovery, with an estimated 30–35 Gyps bengalensis & 20–25 Gyps indicus in/ around Rudraram of Bijapur and 18 Gyps bengalensis & five Gyps indicus at Jamguda village of Bastar. Krishna Swami Gutta hill is identified as a nesting-roosting habitat for both species, for which six scavenging areas were identified in Bastar and Bijapur districts. The human/bovine population ratio for Bastar is 0.4, similar to the state ratio, while in Bijapur the ratio is 1.07, which justifies considering Bijapur as a conservation refuge. The few vultures that survived the diclofenac catastrophe in wild habitats most likely consumed wildlife carcasses that sustained a residual population. In these areas, the age-old practise of disposing off dead domesticated bovines away from settlements near reserve forests may also have supported the recovery of vulture population.


INTRODUCTION
Chhattisgarh is a land of dense forests, hill ranges, valleys, sheer cliffs, vast grasslands, agricultural land, waterfalls, and water-bodies. The estimated human population was 29 million for 2020 (Unique Identification Aadhar India updated 31 May 2019), with a rural population of about 22 million (i.e., 77 %). People generally maintain large herds of bovines totalling over 11 million animals (Livestock Census 2019) for agriculture and milk. The ratio of human to bovine population for Chhattisgarh state is approximately 0.38. Cattle are maintained largely on grazing, with basic shelters at night. Bovine death rates are relatively high owing to various factors. Many domestic bovines turn feral and enter forests, there are occasional outbreaks of disease since widespread vaccination is impractical, there are few veterinary personnel, many people prefer cheap traditional treatments over modern drugs, and most villages are far from the reach of emergency veterinary help. Dead animals are disposed off in a designated communal place on the outskirts of Bastar and Bijapur villages, where scavengers including vultures, feral carnivores and crows congregate.
Of Before the introduction of diclofenac (an antiinflammatory drug) in India during the 1990s vultures were recorded in large groups and were common sight in many localities, but the following years witnessed a continuous and drastic decline in vulture populations (Prakash et al. 2003). In 2004, Dr. Lindsay Oaks and his team found that diclofenac causes fatal renal failure in vultures. A simulation model demonstrated that if only 1 % of the carcasses were contaminated by diclofenac, Indian vulture populations could decline 60-90 % annually, and it was reported that 10 % of carcasses in India were contaminated (Green et al. 2004). In 2006, the Government of India banned the manufacture, marketing and use of diclofenac. Following this ban, the declining population of Gyps bengalensis slowed, but infrequent use of diclofenac continued (Prakash et al. 2012). Populations of White-rumped Vulture, Longbilled Vulture, and Slender-billed Vulture crashed during the mid-1990s throughout the Indian subcontinent, and the International Union for Conservation of Nature (IUCN) listed all of these species as 'Critically Endangered' (Birdlife International 2021). This study estimates vulture population in Bastar and Bijapur district of Chhattisgarh and attempts to correlate contributory factors for recovery post the decimation of the mid-1990s.
The White-rumped Vulture is identifiable by a conspicuous white ruff at base of neck, white inner thighs, a prominent broad white band on under-wings and 12 tail feathers. Head and neck are destitute of feathers and tinged pink, and the bill is dark at the tip and paler at the base with dark ceres. The nostril openings are slit-like. In flight, the white under-wing coverts are highly visible. The Long-billed Vultures is characterized by a narrow elongated head, long naked neck and head covered with woolly down sporting a prominent lanceolate ruff of feathers (longer in juvenile) at base of neck, and a long yellowish bill. It sports 14 tail feathers. The upper wings are sandy brown and darker head, have a buff ruff at the back of neck, feathers of back are sepia brown. Gyps indicus is smaller in size than Gyps bengalesis. Both are sociable, nest and roost communally on trees and cliffs (Grimmett et al. 2011;Naroji 2011). Both the species are medium-sized Old World vultures. White-rumped Vulture is native to southern and southeastern Asia. Long-billed Vulture is native to southern Asia.

MATERIALS AND METHODS
Opportunistic documentation of vultures in 2011-2016 gave the impetus to undertake dedicated surveys from June to October 2020, and in January 2021 in Bastar and Bijapur district of Chhattisgarh. Garmin GPSMap 78s was used to record the sighting position, Nikon Aculon A211 10-22 X 50 binoculars were used for spotting and identification of species. A Canon EOS 70D with an EF300mm f/4L IS USM lens and extender EF 1.4 X III were used for photographic documentation. The surveys were conducted in designated dead animal disposal places near villages. Concurrent sighting information was collected from different locations and corroborated to evolve conservative sighting estimates for vultures.

Study area
Two southern districts of Chhattisgarh; i.e., Bastar and Bijapur were covered to record the population of J TT vultures ( Figure 1). Bastar district covers an area of 6,596.90 km². The district is bounded on east by Odisha, north by Kondagaon district, west by Narayanpur and Dantewada, and south by Sukma. It is situated at a height of 606 m plateau from sea level. Kanger Ghati National Park (also called Kanger Valley National Park) is a protected area in the Bastar district of Chhattisgarh.
Bijapur district covers an area of 6562.48 km 2 . The district is bounded on east by Dantewada and Sukma districts, north by Narayanpur district and Maharashtra, west by Maharashtra and south by Telangana. The major river is Indravati and flows through Bastar, Dantewada and Bijapur uniting with Godavari near Bhadrakali River. The district is a rocky hilly terrain with an altitude ranging 177-599 m. District is covered by rich and thick dense mixed forest interspersed by moist and intermediated forest with diverse forest species. Indravati Tiger Reserve (Biosphere reserve), lies within this district with high and rocky hills.

Sightings of vultures in Bastar
Bastar district has a human population of 0.83 million as per 2011 census, and more than 70 % are tribal.

Sightings of vultures in Bijapur
Bijapur district has human population of 0.26 million (2011 census), and more than 70 % are tribal. The domesticated livestock population (cows and buffalos) is 0.28 million as per the 20 th Livestock Census, 2019. The ratio of human population to cattle population for Bastar district is approximately 1. Moderate/dense forest cover is 4,975 km 2 or 76 % (Indian State of Forest Report 2019). Frequent and regular sightings of White-Rumped Vulture and Indian Vulture have been made in this area.

Occasional Sightings of vultures in Dantewada
On 04 February 2020, one migrating sub-adult Himalayan Griffon found in Geedam (18.974°N, 81.399°E), a village in Dantewada district. A group of crows attacked the vulture which succumbed to injuries even after its treatment in the zoo. Table 1 presents chronological sighting records of vultures in Bastar and Bijapur (Image 4-8). Image 1, is GoogleEarth Map showing the sighting locations of Gyps bengalensis and Gyps indicus in Bastar and Bijapur districts. Figure 2, is a graphical presentation of vulture population in various roosting and scavenging sites.

DISCUSSION
Informal interviews with forest department personnel and local people of rural villages near Rudraram and Cherpalli revealed that vultures nest on Krishna Swami Gutta hill on the plain between the cliffs, 30-50 m above ground level. The hill is located south of Cherpalli in Bijapur district. Consistent sightings of vultures were documented in Bijapur district from March 2016, with photographic documentation and GPS co-ordinates.   In recent times vultures have been sighted in good numbers, often in the outskirts of remote villages surrounded with dense trees, higher cliffs and flattops on higher rocky hills, particularly near protected areas and far from urbanization. These habitats must have served as last refuges for those few vultures that survived the Diclofenac era. The factors contributing to the recovery of vulture population in Bastar and Bijapur district are: a) Conducive habitable places for resting and breeding in Bijapur district, is the first and foremost J TT important factor for survival and population recovery of vultures. The numbers of vultures were so low that not a single sighting report from this areas exists from 2005-2011 (Image 2 and 3 except for Gyps indicus by BirdLife International). b) Availability of adequate dead wildlife carcasses in these wild habitats (Indravati Tiger Reserve and Kanger Valley Tiger Reserve) likely sustained the decimated vulture population. Forest staff confirm that mortality of wild animals due to natural factors in protected areas is sufficient to sustain present vulture population. Carcasses of wild beasts and feral domesticated animals in the protected areas and peripheral remote village areas are generally free of Diclofenac contamination. This has ensured a safe and continuous source of food, but vigilance against misuse of Diclofenac is necessary to ensure conservation and recovery of vulture populations.
c) The ban on veterinary use of Diclofenac (i.e., from May 2006 till date) by the Indian Government might had a positive impact on recovery of vulture population, as witnessed in Bastar and Bijapur districts of southern Chhattisgarh. Two years after the ban, 1,150 of 1,251 liver samples from livestock carcasses collected across India between August 2007 and June 2008 were negative (Saini et al. 2012). Similarly, Cuthbert et al. (2011 reported that the concentration of diclofenac before and soon after the ban was 10.8-10.7 %, but had dropped to 6.5% in 31 months after the implementation of the ban, leading to a drop in the annual death rates of vultures from 80 % to 18 %. d) Traditional practises of disposing off dead bovines in designated communal sites in rural villages. An average of 10 bovines (i.e., 2-3 per month) are disposed in each village during the dry season, and 4-5 (i.e., 1-2 per month) in the wet and cold seasons. This is an important contributing factor for recent sightings of vultures in Bastar and Bijapur district.
The southern Chhattisgarh region is possibly a migratory route of vultures. On 04 February 2020, one migrating sub-adult Himalayan Griffon was recorded in Geedam village of Dantewada district. The repeated sightings of vultures around the same area and their nesting in the Krishna Swami Gutta hill is an opportunity to plan for the conservation of both species Gyps bengalensis and Gyps indicus vultures in India.

Suggestions
1. The traditional practise of disposing off dead bovines free of diclofenac contamination should be promoted in other designated communal sites instead of burying -to ensure a safe, constant source of food enabling vulture populations to grow further.
2. Camera traps should be fixed in nesting, roosting and scavenging areas to monitor inter and intra species interactions.
3. Long-term vulture monitoring projects should be undertaken; fitting of satellite telemeters on discrete population in roosting and scavenging areas for understanding movements, other parameters and physical challenges due to vast home range.
4. Krishna Swami Gutta hill must be designated as a 'Vulture Sanctuary' to protect the nesting sites of these vultures.
5. Vigilance and legal actions should be adopted on any diclofenac use in veterinary. Sensitization of chemists and drug associations, pharmacists, veterinary councils and farmers should be undertaken along www.threatenedtaxa.org The Journal of Threatened Taxa (JoTT) is dedicated to building evidence for conservation globally by publishing peer-reviewed articles online every month at a reasonably rapid rate at www.threatenedtaxa.org. All articles published in JoTT are registered under Creative Commons Attribution 4.0 International License unless otherwise mentioned. JoTT allows allows unrestricted use, reproduction, and distribution of articles in any medium by providing adequate credit to the author(s) and the source of publication.  Pp. 19985-19999