Exploring Seasonal Behavior, Metal Exposure, and Reproductive Dynamics in Captive Vultures

Abstract

Vultures are scavengers that play a crucial role in maintaining ecosystem stability, making their conservation essential. The decline of vulture populations in South Asia, including southwest Asia, began in the 1990s due to the widespread use of the veterinary drug diclofenac, with populations plummeting by the early 2000s. To restore critically endangered White-rumped Vultures (Gyps bengalensis) in the ecosystem, the Punjab Wildlife Department, in collaboration with WWF, has established the Changa Manga Vulture Conservatory in Punjab, Pakistan. The White-rumped Vultures (Gyps bengalensis) are kept in captivity for breeding and conservation efforts. To investigate the presence of heavy metals in captive vultures, a non-invasive method was employed to collect meat, water, fecal and feather samples. The behavior of vultures within the captive environment was also observed. The samples were washed, properly labelled and underwent chemical digestion using aqua regia, followed by analysis through PerkinElmer AAnalyst 200 Atomic Absorption Spectrometer and examined the quantity of 12 specific metals: (Pb, Cd, Cu, Cr, Al, As, Mg, Mn, Fe, K, Na and Zn). The metals were further categorized as heavy metals (Pb, Cd, Cr, Al, and As) and essentials metals (Cu, Mg, Mn, Fe, K, Na and Zn). The study aimed to find the metals exposure and its accumulation in captive vultures. Samples of meat, feathers, and feces revealed seasonal variations in metal concentrations. Notably, elements like Al, As, and Pb showed higher levels in winter compared to summer. In behavior vultures displayed signs of fear and alarm when humans approached within 10 feet, likely due to the confined environment and lack of social interaction, which are crucial for vultures in the wild. The seasonal behavioral patterns of vultures revealing distinct shifts between summer and winter. In winter, breeding activities like nest building and mating become prominent, along with increased aggression due to territorial instincts. In contrast, summer was characterized by decreased feeding and a preference for walking behavior. These findings raise concerns about the potential impact of captivity on vulture behavior and physiology, suggesting that captive environments might not fully meet the birds' ecological and social needs. Moreover, reproductive dynamics of vultures from 2 to 36 showed success of this rehabilitation center. It was also concluded that further research is required to emphasize the importance of exploring ambient air and to find sources of contamination other than meat and water. Moreover, further research will be required to prioritize vulture well-being and population sustainability.