Tadoba Welcomes White-rumped Vultures

Most millennials and Gen-Z kids today are unlikely to have seen a vulture. Talk to anyone older, though, and they’ll tell you that back in the day, vultures or “giddh” were a common sight across the country. What happened to these vultures? Where did they disappear?

Vulture population crashes in the 1990s

Since the mid-1990s, vulture populations across the Indian subcontinent faced severe decline. In 2000, of the nine vulture species resident in India, three — long-billed vulture (Gyps indicus), slender-billed vulture (Gyps tenuirostris), and white-rumped vulture (Gyps bengalensis) — were assessed as critically endangered as per the IUCN Red List. Later, the red-headed vulture (Sarcogyps calvus) was added to the list. Populations of vultures declined by 95 per cent, with species like the white-rumped vulture pushed to the brink of extinction. Scientists and ornithologists from around the subcontinent rallied together to discover that the use of the drug diclofenac (a non-steroidal anti-inflammatory drug) to treat ailments in cattle was the reason for the vulture population crash.

Vultures are primarily scavengers, and feeding on cattle carcasses laced with diclofenac causes renal failure and eventual death in the birds. A ban on the use of diclofenac for cattle treatment was implemented, and substitutes were introduced. The ban slowed the decline of vulture populations, but irreversible damage had already been done.

Do vultures matter?

Would the average human be affected if vultures across the country go extinct? The answer lies in the ecosystem services that vultures provide. Vultures are biologically equipped to feed on dead and decaying animal carcasses, and through scavenging, they speed up the process of nutrient recycling in the ecosystem. Rotting carcasses are also breeding grounds for a host of pathogens that can severely impact humans living in the area. By feeding on these carcasses, vultures break down the organic matter faster and control disease spread. The removal of vultures from an ecosystem can make people vulnerable to the spread of zoonotic epidemics.

Captive breeding of vultures for eventual rewilding

While banning diclofenac was a crucial first step for vulture recovery, it was unlikely that vulture populations would recover naturally. Without human intervention, the remaining vultures would likely perish over time. To that end, the South Asia Vulture Recovery Plan was formulated in 2004. It recommended setting up conservation breeding programmes for three species of critically endangered Gyps vultures. The plan was to attain the long-term survival of vultures by periodically augmenting natural vulture populations with captive-bred individuals. Consequently, the first Vulture Conservation Breeding Centre (VCBC) was set up in Pinjore, Haryana, in 2004, and it was called the Jatayu VCBC. Soon after, several other VCBCs were established across India as a collaborative effort between the Forest Department, the Central Zoo Authority, the Bombay Natural History Society (BNHS) and the Royal Society for the Protection of Birds (RSPB), a UK-based bird conservation organisation.

However, captive breeding vultures is not enough to ensure vulture recovery. The natural next step is reintroducing them into the wild to assimilate with wild vulture populations. Critical thought is integral to the choice of vulture reintroduction sites. Given the efforts invested in captive breeding, the viability of reintroduction is dependent on the survival of captive-bred vultures in the wild. Protected Areas (PAs) across the country have been identified as potential sites for vulture reintroduction because diclofenac continues to be used (illegally) for treating livestock in rural areas, and the availability of wild prey carcasses inside PAs may serve as a safer source of forage for the birds.

In Maharashtra, two tiger reserves — Tadoba-Andhari Tiger Reserve (TATR) and Pench Tiger Reserve (PTR) (which spreads into neighbouring MP) were identified as potential sites for rewilding captive-bred vultures. These sites were selected based on data collected during the All-India Tiger Estimation Effort (AITE), which suggested they had high densities of wild prey like sambar, chital, nilgai, gaur, and wild pigs. TATR was chosen as an ideal site for rewilding white-rumped vultures since these vultures are tree-nesting birds, and TATR has this habitat.

Reintroduction of white-rumped vultures in Tadoba

Ten captive-bred white-rumped vultures aged two or more years were selected from VCBC Pinjore for translocation to TATR. Unrelated individuals were chosen to ensure genetic diversity. The birds were placed in individual wooden cages and transported by road.

The “soft release” method was chosen for the reintroduction, where the birds would initially be introduced to a pre-release aviary for acclimatisation to the new environment. The vultures were brought to TATR on 21st January 2024 and will be released into the wild later in the year. Before releasing the birds into the aviary, the birds were given a thorough health checkup and marked using coloured bands.

 

Life in the pre-release aviary

The pre-release aviary is 30x9x6 m and has been constructed using bird-friendly materials to ensure the vultures are not hurt. The aviary has double-door protection, a food hatch, and two water troughs, and it is big enough for the birds to fly around and exercise their wings. The area around the aviary and the monitoring room has been fenced off (with an electrical fence) to deter the movement of wild animals. Footage from CCTV cameras inside the aviary can be accessed from a remote-control room. The entire operation is powered by solar panels.

Twice a week, the birds are fed goat carcasses. The feeding schedule is intentionally erratic to prepare them for life in the wild. They are fed on different days with varying quantities of meat. Once a day, a forest department worker enters the aviary to clean the water troughs and may remove any remaining bones after a while.

Vulture safe zone surveys

Vultures travel great distances (up to 100 km) in search of food. Therefore, a 100 km radius surrounding the release site must be secured as a vulture-safe zone to ensure the birds’ safety post-release. Some surveys are being conducted in this zone, including the estimation of food and habitat availability and the population estimation of wild vultures. Pharmacy surveys are to be conducted to ensure that none of the medical shops in the region are dispensing banned vulture-toxic drugs. 

Current status and the way forward

Currently, the birds are in the pre-release aviary and will be released in a few months. All ten individuals are healthy and adapting well to their new environment. The vulture safe zone surveys were ongoing in April 2024. Before the birds can be released, both wings will be fitted with GSM-based microchips and patagial tags, which will allow scientists to monitor them once they are released. The long-term viability of vulture reintroduction in the landscape is contingent on these individuals surviving in the wild. If these birds do well and assimilate with natural populations from the region, additional captive-bred vultures can be released in the reserve in a phased manner.

While efforts undertaken by the TATR management team and BNHS are crucial to the well-being of the vultures in the wild, local communities are equally responsible for their survival. Avoiding vulture-toxic drugs and taking ownership for vulture conservation may be the kindest way for local communities to welcome their new winged neighbours.