Physiological stress in eastern black rhinoceros (Diceros bicornis michaeli) as influenced by their density, climatological variables and sexes

Benson Okita-Ouma, Gerrit Gort, Joshua J. Millspaugh, Herbert H.T. Prins

Research output: Contribution to journalArticlepeer-review

Abstract

It is important to understand the physiological stressors in animals especially for threatened species or intensively managed to improve their conservation and optimise their reproduction. We sought to understand changes in stress hormones (faecal glucocorticoid metabolites) in black rhinoceros (Diceros bicornis michaeli) in relation to population density and sex (intrinsic factors) and plant minerals, rainfall and land surface temperature (extrinsic factors). We used non-invasive faecal sampling techniques on animals of known sex, age and dominance in seven populations of contrasting population densities over 1 year. We measured variability in faecal corticosterone metabolites through radioimmunoassay and related them to population density, sex and faecal calcium, phosphorus, copper, zinc and potassium as characteristic of plant minerals, rainfall and temperature. We used linear mixed models (LMM) to analyse the data. We did not detect a significant relationship between physiological stress parameters and population density. However, we have indications that stress levels increased as rainfall and temperature increased and were correlated negatively and positively with concentration of faecal phosphorus and copper respectively; we found higher stress levels in females than in males. These results suggest that both intrinsic and extrinsic factors explain the variation in physiological stress observed in black rhinoceros.

Original languageEnglish
Article numbere13239
JournalAfrican Journal of Ecology
Volume62
Issue number1
DOIs
StatePublished - Jan 2024

Keywords

  • black rhinoceros
  • corticosterone
  • density
  • faecal minerals
  • physiological stress
  • rainfall
  • sex
  • temperature

Fingerprint

Dive into the research topics of 'Physiological stress in eastern black rhinoceros (Diceros bicornis michaeli) as influenced by their density, climatological variables and sexes'. Together they form a unique fingerprint.

Cite this