Header

UZH-Logo

Maintenance Infos

Effect of high population density of eastern black rhinoceros, a mega‐browser, on the quality of its diet


Okita‐Ouma, Benson; Pettifor, Richard; Clauss, Marcus; Prins, Herbert H T (2021). Effect of high population density of eastern black rhinoceros, a mega‐browser, on the quality of its diet. African Journal of Ecology, 59(4):826-841.

Abstract

High density of herbivore populations can lead to intense foraging competition and depletion of food consequently lowering diet quality and population performance. We tested for the effects of the density of eastern black rhinoceros (Diceros bicornis michaeli) in nine in situ populations of 0.01–0.7 individuals per km2 density range on the quality of their diet while controlling for plant available moisture and plant available nutrients. We used faecal calcium, phosphorus, copper and zinc concentrations as proxy indices for dietary quality from 473 fresh faecal samples obtained from 77 adult animals in situ, after determining a positive faeces-diet mineral correlation in feeding trials with black rhinoceros in zoos. Some populations surpassed 70%–80% of their estimated maximum stocking densities expected to cause impact on forage. However, we did not find significant correlation between rhino population density and dietary quality, as measured via faecal mineral nutrient content. This suggests that black rhinoceros may have sufficient behavioural plasticity to adjust their diet to cover their nutritional requirements when density increases. Instead, 1-month lagged plant available moisture, reflecting precipitation over the 4 weeks preceding each sampling effort, significantly explained the mineral concentrations in the faeces. By contrast, plant available nutrients had no effect.

Abstract

High density of herbivore populations can lead to intense foraging competition and depletion of food consequently lowering diet quality and population performance. We tested for the effects of the density of eastern black rhinoceros (Diceros bicornis michaeli) in nine in situ populations of 0.01–0.7 individuals per km2 density range on the quality of their diet while controlling for plant available moisture and plant available nutrients. We used faecal calcium, phosphorus, copper and zinc concentrations as proxy indices for dietary quality from 473 fresh faecal samples obtained from 77 adult animals in situ, after determining a positive faeces-diet mineral correlation in feeding trials with black rhinoceros in zoos. Some populations surpassed 70%–80% of their estimated maximum stocking densities expected to cause impact on forage. However, we did not find significant correlation between rhino population density and dietary quality, as measured via faecal mineral nutrient content. This suggests that black rhinoceros may have sufficient behavioural plasticity to adjust their diet to cover their nutritional requirements when density increases. Instead, 1-month lagged plant available moisture, reflecting precipitation over the 4 weeks preceding each sampling effort, significantly explained the mineral concentrations in the faeces. By contrast, plant available nutrients had no effect.

Statistics

Citations

Dimensions.ai Metrics
3 citations in Web of Science®
3 citations in Scopus®
Google Scholar™

Altmetrics

Downloads

32 downloads since deposited on 16 Nov 2021
15 downloads since 12 months
Detailed statistics

Additional indexing

Item Type:Journal Article, refereed, original work
Communities & Collections:05 Vetsuisse Faculty > Veterinary Clinic > Department of Small Animals
Dewey Decimal Classification:570 Life sciences; biology
630 Agriculture
Scopus Subject Areas:Life Sciences > Ecology, Evolution, Behavior and Systematics
Uncontrolled Keywords:Ecology, Evolution, Behavior and Systematics
Language:English
Date:1 December 2021
Deposited On:16 Nov 2021 08:18
Last Modified:26 May 2024 01:48
Publisher:Wiley-Blackwell Publishing, Inc.
ISSN:0141-6707
OA Status:Hybrid
Publisher DOI:https://doi.org/10.1111/aje.12893
Project Information:
  • : FunderZoological Society of London
  • : Grant ID
  • : Project Title
  • : FunderMohamed bin Zayed Species Conservation Fund
  • : Grant ID
  • : Project Title
  • Content: Published Version
  • Language: English
  • Licence: Creative Commons: Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0)