Experimental evidence that effects of megaherbivores on mesoherbivore space use are influenced by species' traits
(2021) In Journal of Animal Ecology 90(11). p.2510-2522- Abstract
The extinction of 80% of megaherbivore (>1,000 kg) species towards the end of the Pleistocene altered vegetation structure, fire dynamics and nutrient cycling world-wide. Ecologists have proposed (re)introducing megaherbivores or their ecological analogues to restore lost ecosystem functions and reinforce extant but declining megaherbivore populations. However, the effects of megaherbivores on smaller herbivores are poorly understood. We used long-term exclusion experiments and multispecies hierarchical models fitted to dung counts to test (a) the effect of megaherbivores (elephant and giraffe) on the occurrence (dung presence) and use intensity (dung pile density) of mesoherbivores (2–1,000 kg), and (b) the extent to which the... (More)
The extinction of 80% of megaherbivore (>1,000 kg) species towards the end of the Pleistocene altered vegetation structure, fire dynamics and nutrient cycling world-wide. Ecologists have proposed (re)introducing megaherbivores or their ecological analogues to restore lost ecosystem functions and reinforce extant but declining megaherbivore populations. However, the effects of megaherbivores on smaller herbivores are poorly understood. We used long-term exclusion experiments and multispecies hierarchical models fitted to dung counts to test (a) the effect of megaherbivores (elephant and giraffe) on the occurrence (dung presence) and use intensity (dung pile density) of mesoherbivores (2–1,000 kg), and (b) the extent to which the responses of each mesoherbivore species was predictable based on their traits (diet and shoulder height) and phylogenetic relatedness. Megaherbivores increased the predicted occurrence and use intensity of zebras but reduced the occurrence and use intensity of several other mesoherbivore species. The negative effect of megaherbivores on mesoherbivore occurrence was stronger for shorter species, regardless of diet or relatedness. Megaherbivores substantially reduced the expected total use intensity (i.e. cumulative dung density of all species) of mesoherbivores, but only minimally reduced the expected species richness (i.e. cumulative predicted occurrence probabilities of all species) of mesoherbivores (by <1 species). Simulated extirpation of megaherbivores altered use intensity by mesoherbivores, which should be considered during (re)introductions of megaherbivores or their ecological proxies. Species' traits (in this case shoulder height) may be more reliable predictors of mesoherbivores' responses to megaherbivores than phylogenetic relatedness, and may be useful for predicting responses of data-limited species.
(Less)
- author
- organization
- publishing date
- 2021-06-30
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- African savanna, biotic interactions, competition, elephant, facilitation, giraffe, megafauna, trophic rewilding
- in
- Journal of Animal Ecology
- volume
- 90
- issue
- 11
- pages
- 2510 - 2522
- publisher
- Wiley-Blackwell
- external identifiers
-
- pmid:34192343
- scopus:85109746840
- ISSN
- 0021-8790
- DOI
- 10.1111/1365-2656.13565
- language
- English
- LU publication?
- yes
- additional info
- Funding Information: The authors thank the Government of Kenya for granting permission to conduct this research. They thank Mpala Research Centre for its staff and logistical support. They thank S. Lima, G. Busenei, M. Mohamed and S. Ekale for their invaluable assistance in the field. KLEE plots were built and maintained by grants from the James Smithson Fund of the Smithsonian Institution, The National Geographic Society (Grants 4691‐91, 9106‐12 and 9986‐16) and the National Science Foundation (LTREB BSR 97‐07477, 03‐16402, 08‐16453, 12‐56004, 12‐56034 and 19‐31224). UHURU plots were built with an NSERC Discovery Grant and are maintained by grants from the US National Science Foundation (DEB 1547679 and 1930763). They thank the organizers of the November 2020 virtual HMSC course. Publisher Copyright: © 2021 The Authors. Journal of Animal Ecology published by John Wiley & Sons Ltd on behalf of British Ecological Society. Copyright: Copyright 2021 Elsevier B.V., All rights reserved.
- id
- 6ba70e98-11d8-41fc-8daf-1821f2cfb551
- date added to LUP
- 2021-07-30 18:42:23
- date last changed
- 2024-06-15 13:43:39
@article{6ba70e98-11d8-41fc-8daf-1821f2cfb551,
abstract = {{<p>The extinction of 80% of megaherbivore (>1,000 kg) species towards the end of the Pleistocene altered vegetation structure, fire dynamics and nutrient cycling world-wide. Ecologists have proposed (re)introducing megaherbivores or their ecological analogues to restore lost ecosystem functions and reinforce extant but declining megaherbivore populations. However, the effects of megaherbivores on smaller herbivores are poorly understood. We used long-term exclusion experiments and multispecies hierarchical models fitted to dung counts to test (a) the effect of megaherbivores (elephant and giraffe) on the occurrence (dung presence) and use intensity (dung pile density) of mesoherbivores (2–1,000 kg), and (b) the extent to which the responses of each mesoherbivore species was predictable based on their traits (diet and shoulder height) and phylogenetic relatedness. Megaherbivores increased the predicted occurrence and use intensity of zebras but reduced the occurrence and use intensity of several other mesoherbivore species. The negative effect of megaherbivores on mesoherbivore occurrence was stronger for shorter species, regardless of diet or relatedness. Megaherbivores substantially reduced the expected total use intensity (i.e. cumulative dung density of all species) of mesoherbivores, but only minimally reduced the expected species richness (i.e. cumulative predicted occurrence probabilities of all species) of mesoherbivores (by <1 species). Simulated extirpation of megaherbivores altered use intensity by mesoherbivores, which should be considered during (re)introductions of megaherbivores or their ecological proxies. Species' traits (in this case shoulder height) may be more reliable predictors of mesoherbivores' responses to megaherbivores than phylogenetic relatedness, and may be useful for predicting responses of data-limited species.</p>}},
author = {{Wells, Harry B.M. and Crego, Ramiro D. and Opedal, Øystein H. and Khasoha, Leo M. and Alston, Jesse M. and Reed, Courtney G. and Weiner, Sarah and Kurukura, Samson and Hassan, Abdikadir A. and Namoni, Mathew and Ekadeli, Jackson and Kimuyu, Duncan M. and Young, Truman P. and Kartzinel, Tyler R. and Palmer, Todd M. and Pringle, Robert M. and Goheen, Jacob R.}},
issn = {{0021-8790}},
keywords = {{African savanna; biotic interactions; competition; elephant; facilitation; giraffe; megafauna; trophic rewilding}},
language = {{eng}},
month = {{06}},
number = {{11}},
pages = {{2510--2522}},
publisher = {{Wiley-Blackwell}},
series = {{Journal of Animal Ecology}},
title = {{Experimental evidence that effects of megaherbivores on mesoherbivore space use are influenced by species' traits}},
url = {{http://dx.doi.org/10.1111/1365-2656.13565}},
doi = {{10.1111/1365-2656.13565}},
volume = {{90}},
year = {{2021}},
}