Investigating the impact of large carcass feeding on the behavior of captive Andean condors (Vultur gryphus) and its perception by zoo visitors

Abstract

Naturalistic feeding methods, such as the provision of whole carcasses to zoo animals, are potentially controversial because zoo visitors might not approve of them. However, since several species of zoo animals feed from large carcasses in the wild, this food type could benefit their welfare in captivity compared to other less-natural food types. Scavengers in particular almost exclusively live on carcasses in nature; therefore, their welfare in captivity could significantly depend on the opportunity to express behaviors related to carcass feeding. In this study, we assessed the frequency of carcass feeding for vultures in North American zoos and investigated the effect of different food types on the behavior of zoo-housed Andean condors (Vultur gryphus). We also evaluated the opinion of North American zoo visitors about carcass feeding. Our results show that small whole carcasses (rats, rabbits) are part of the diet of vultures in most North American zoos, but large whole carcasses (ungulates) are rarely fed. Our behavioral study indicated that Andean condors appear to be more motivated to feed on more natural food types, which also seem to physically engage the birds more and occupy them longer. Most zoo visitors approved of carcass feeding for captive vultures over a range of prey animals, and the majority would also like to observe the vultures eat. Collectively, our results demonstrate that carcass feeding, particularly with larger prey, potentially enriches both zoo-housed vultures as well as the visitor experience.

Integrating Gut Bacterial Diversity and Captive Husbandry to Optimize Vulture Conservation

“…These inter-specific differences should be considered when evaluating host-microbiota interactions, especially for animals intended for release to the wild. The notable lack of large ungulate carcass feeding for captive vultures (Gaengler and Clum, 2015) is at odds with their evolved dietary specialization, and reliance on smaller whole prey species may introduce important, but as yet unquantified, differences in bacterial communities. Whilst it is possible that a captive-to-wild bacterial composition transition may occur following release, e.g., most recently evidenced in Tasmanian devil's (Sarcophilus harrisii) (Chong et al, 2019), this represents another acclimatization process, amongst a suite of other physiological and behavioral adaptations, incurred by released individuals.…”

“…Four Egyptian vultures (Neophron percnopterus) and 7 Griffon vultures (Gyps fulvus) housed at the Kalba Bird of Prey Centre (KBoPC) along with 4 Egyptian vultures housed at the Breeding Centre for Arabian Wildlife (BCEAW), both located in the United Arab Emirates (UAE), were used in this study ( Table 1). To represent typical captive dietary provision (Gaengler and Clum, 2015), two dietary conditions were implemented in a semi-randomized cross-over study design. Birds were fed either a sanitized diet (SD) comprising an overall weekly mixture of dressed quail, chicken and rat carcasses [i.e., skinned, partially eviscerated (gastrointestinal tract removed)] which were washed under tap water, or an un-sanitized diet (UD) of fully feathered/furred, intact whole carcass of the same prey species.…”

Food for Thought: Assessing Visitor Comfort and Attitudes toward Carcass Feeding at the ABQ BioPark Zoo

“…A recent hypothetical study by Gaengler and Clum (2015) also suggests that around 40% of zoo visitors in New York, New Jersey, Connecticut, and…”

“…Another 40-45% of visitors would approve of the feeding, but weren't sure if they would want to view it (Gaengler & Clum, 2015). The majority of visitors also approved of viewing a fish, chicken, rat, or rabbit carcass feeding with the same species (Gaengler & Clum, 2015).…”

“…The majority of visitors also approved of viewing a fish, chicken, rat, or rabbit carcass feeding with the same species (Gaengler & Clum, 2015).…”