Exploring seasonal behavior, metal exposure, and reproductive dynamics in captive vultures

Vultures are vital scavengers that help maintain ecosystem balance, making their conservation crucial. In South Asia, particularly since the 1990s, vulture populations have declined drastically due to the veterinary use of diclofenac, with severe drops by the early 2000s. To aid recovery, the Punjab Wildlife Department, in collaboration with WWF, established the Changa Manga Vulture Conservatory in Punjab, Pakistan, focusing on the conservation of critically endangered White-rumped Vultures (Gyps bengalensis). Captive vultures were studied using non-invasive sampling of meat, water, feces, and feathers to assess heavy metal exposure. The samples were washed, labeled, digested using aqua regia, and analyzed using a PerkinElmer AAnalyst 200 Atomic Absorption Spectrometer. Twelve metals were quantified, categorized as heavy metals (Pb, Cd, Cr, Al, As) and essential metals (Cu, Mg, Mn, Fe, K, Na, Zn). Seasonal variations were observed, with Al, As, and Pb showing higher concentrations in winter. Behavioral observations revealed fear and alarm responses when humans approached closely, likely due to confinement and limited social interaction. Seasonal behavioral shifts were noted; winter prompted breeding behaviors like nesting and mating, alongside increased aggression due to territoriality, while summer saw reduced feeding and more walking activity. These behavioral patterns suggest captivity may not fully support vultures' natural ecological and social needs. Reproductive success was recorded, with the number of vultures rising from 2 to 36, indicating some success in rehabilitation. However, the study highlights the need for further research into environmental factors such as ambient air and additional contamination sources. Emphasis should also be placed on enhancing captive conditions to support vulture well-being and ensure long-term population sustainability.