Do zoo‐housed primates retreat from crowds? A simple study of five primate species

Abstract

An animal's welfare state is directly influenced by the mental state, which is shaped by experiences within the environment throughout the animal's life. For zoo-housed animals, visitors to the zoo are a large part of that environment and a fluctuating influence within it. This study examines the impact of zoo visitors on the space use of five species of zoo-housed primates (Eastern black-and-white colobus monkeys, Colobus guereza, n = 5, Allen's swamp monkeys, Allenopithecus nigroviridis, n = 2, DeBrazza's monkeys, Cercopithecus neglectus, n = 3, Bolivian gray titi monkeys, Callicebus donacophilus, n = 3, and crowned lemurs, Eulemur coronatus, n = 3). Specifically, we considered whether primates' distance from visitor areas changed as crowd sizes increased. Data were collected using the ZooMonitor app. Observers recorded spatial coordinates for each animal over periods ranging from 12 to 32 months. Data were analyzed using two types of regression models (linear and logistic) to examine the influence of visitors on the location of the primates. Both analyses revealed a statistically significant but small decrease in primate distance from visitor viewing glass as the number of visitors increased. Behavioral indicators of welfare were also unaffected by the presence of visitors. These results suggest that, with additional validation, distance from visitors may be one promising, simple way to evaluate the influence of visitors on primate welfare.

Comparing Space Use and Fecal Glucocorticoid Concentrations during and after the COVID-19 Closure to Investigate Visitor Effects in Multiple Species

“…Gorillas and chimpanzees (Pan troglodytes) did not vary their use of a zone within 1m of the viewing glass based on crowd size [23]. Eastern black-and-white colobus, Allen's swamp monkeys, DeBrazza's monkeys, Bolivian gray titi monkeys, and crowned lemurs showed an increase in proximity to viewing windows, both with larger crowd sizes and when the zoo was open than during the COVID-19 closure [12]. Other COVID-19 studies also examined proximity to guests as an indicator of visitor effects.…”

“…Nile crocodiles (Crocodylus niloticus) spent more time in proximity to conspecifics when the zoo was open compared to closed [10], and Japanese macaques (Macaca fuscata) seemed to prefer completing trials in testing booths closest to the public when the zoo reopened [11]. Five primate species, including Eastern black-and-white colobus (Colobus guereza), Allen's swamp monkeys (Allenopithecus nigroviridis), DeBrazza's monkeys (Cercopithecus neglectus), Bolivian gray titi monkeys (Callicebus donacophilus), and crowned lemurs (Eulemur coronatus), showed a slight but significant increase in proximity to the glass when open versus closed [12]. Catalina Island rattlesnakes (Crotalus catalinensis) showed more social and investigative behaviors after reopening [13].…”

“…Overall, however, most studies conducted during COVID-19 closures reported entirely or mainly neutral effects that suggest a minimal impact from visitors. There were no significant differences in behavior between the closures and open periods reported for western lowland gorillas (Gorilla gorilla gorilla) [19], African penguins [16], greater flamingos (Phoenicopterus roseus) [18], Amur leopards (Panthera pardus orientalis), snow leopards (Panthera uncia), Rothschild giraffes (Giraffa camelopardalis), Chapman's zebras (Equus quagga chapmani), nyala (Tragelaphus angasii), swamp wallabies (Wallabia bicolor) [20], Eastern black-and-white colobus, Allen's swamp monkeys, DeBrazza's monkeys, Bolivian gray titi monkeys, or crowned lemurs [12]. Additionally, Nile crocodiles [10], greater and Chilean flamingos [18], Amur leopards, snow leopards, Rothschild giraffes, Chapman's zebras, nyala, swamp wallabies, and Chinese gorals (Naemorhedus griseus) [20] showed no difference in space use between open and closed periods.…”

Primatology in zoos: Studying behavior, cognition, and welfare

“…This over‐representation of apes reflects patterns identified in previous reviews of zoo‐based primate research (Cronin et al, 2017; Hopper, 2017; Lewis & Krupenye, 2022; Melfi, 2005, 2007; Stoinski et al, 1998), but does not reflect the population of primates living in zoos: only 15% of the primates housed in North American AZA‐accredited zoos are great apes ( Gorilla, Pan , and Pongo ) (Species360, 2021). Accordingly, for this special issue I wanted to invite contributions from researchers studying zoo‐housed monkeys and prosimians (e.g., Cairo‐Evans et al, 2022; Hayden et al, 2022; Spiezio et al, 2022) in addition to those studying apes (e.g., Laméris et al, 2022; Martin & Shumaker, 2022; Motes‐Rodrigo & Tennie, 2022; Vonk, 2022; Yamanashi et al, 2022).…”

“…for this special issue I wanted to invite contributions from researchers studying zoo-housed monkeys and prosimians (e.g., Cairo-Evans et al, 2022;Hayden et al, 2022;Spiezio et al, 2022) in addition to those studying apes (e.g., Laméris et al, 2022;Martin & Shumaker, 2022;Motes-Rodrigo & Tennie, 2022;Vonk, 2022;Yamanashi et al, 2022).…”