Recumbence Behavior in Zoo Elephants: Determination of Patterns and Frequency of Recumbent Rest and Associated Environmental and Social Factors

PLoS One. 2016 Jul 14;11(7):e0153301. doi: 10.1371/journal.pone.0153301. eCollection 2016.

Abstract

Resting behaviors are an essential component of animal welfare but have received little attention in zoological research. African savanna elephant (Loxodonta africana) and Asian elephant (Elephas maximus) rest includes recumbent postures, but no large-scale investigation of African and Asian zoo elephant recumbence has been previously conducted. We used anklets equipped with accelerometers to measure recumbence in 72 adult female African (n = 44) and Asian (n = 28) elephants housed in 40 North American zoos. We collected 344 days of data and determined associations between recumbence and social, housing, management, and demographic factors. African elephants were recumbent less (2.1 hours/day, S.D. = 1.1) than Asian elephants (3.2 hours/day, S.D. = 1.5; P < 0.001). Nearly one-third of elephants were non-recumbent on at least one night, suggesting this is a common behavior. Multi-variable regression models for each species showed that substrate, space, and social variables had the strongest associations with recumbence. In the African model, elephants who spent any amount of time housed on all-hard substrate were recumbent 0.6 hours less per day than those who were never on all-hard substrate, and elephants who experienced an additional acre of outdoor space at night increased their recumbence by 0.48 hours per day. In the Asian model, elephants who spent any amount of time housed on all-soft substrate were recumbent 1.1 hours more per day more than those who were never on all-soft substrate, and elephants who spent any amount of time housed alone were recumbent 0.77 hours more per day than elephants who were never housed alone. Our results draw attention to the significant interspecific difference in the amount of recumbent rest and in the factors affecting recumbence; however, in both species, the influence of flooring substrate is notably important to recumbent rest, and by extension, zoo elephant welfare.

MeSH terms

  • Animal Husbandry
  • Animal Welfare*
  • Animals
  • Animals, Zoo
  • Behavior, Animal / physiology*
  • Elephants / physiology*
  • Environment
  • Female
  • Housing, Animal*
  • Rest / physiology*
  • Social Behavior*

Grants and funding

Funding for this work was provided by a National Leadership Grant to the Honolulu Zoological Society from the Institute of Museum and Library Services (www.imls.gov) grant number: LG-25-10-0033-10. This paper was completed while MRH was undertaking a Ph.D. in Biology at Portland State University and in receipt of funding from the Forbes-Lea Research Grant, Marie Brown Award, and Student Education Travel Grant. This study was also funded in part by a research grant from the Pittsburgh Zoo. Employers provided financial support in the form of authors' salaries as follows: Oregon Zoo (DS and MH); Disney’s Animal Kingdom (JS); Chicago Zoological Society-Brookfield Zoo (LM); Busch Gardens (JA). After the IMLS-funded period of performance (November 2010 – December 2013) AWARE Institute provided support in the form of salaries for author CM and JH. The specific roles of these authors are articulated in the ‘author contributions’ section. Neither the funders nor authors’ employers had any role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.