1
|
Kamaru DN, Palmer TM, Riginos C, Ford AT, Belnap J, Chira RM, Githaiga JM, Gituku BC, Hays BR, Kavwele CM, Kibungei AK, Lamb CT, Maiyo NJ, Milligan PD, Mutisya S, Ng'weno CC, Ogutu M, Pietrek AG, Wildt BT, Goheen JR. Disruption of an ant-plant mutualism shapes interactions between lions and their primary prey. Science 2024; 383:433-438. [PMID: 38271503 DOI: 10.1126/science.adg1464] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2022] [Accepted: 12/01/2023] [Indexed: 01/27/2024]
Abstract
Mutualisms often define ecosystems, but they are susceptible to human activities. Combining experiments, animal tracking, and mortality investigations, we show that the invasive big-headed ant (Pheidole megacephala) makes lions (Panthera leo) less effective at killing their primary prey, plains zebra (Equus quagga). Big-headed ants disrupted the mutualism between native ants (Crematogaster spp.) and the dominant whistling-thorn tree (Vachellia drepanolobium), rendering trees vulnerable to elephant (Loxodonta africana) browsing and resulting in landscapes with higher visibility. Although zebra kills were significantly less likely to occur in higher-visibility, invaded areas, lion numbers did not decline since the onset of the invasion, likely because of prey-switching to African buffalo (Syncerus caffer). We show that by controlling biophysical structure across landscapes, a tiny invader reconfigured predator-prey dynamics among iconic species.
Collapse
Affiliation(s)
- Douglas N Kamaru
- Department of Zoology & Physiology and Program in Ecology & Evolution, University of Wyoming, Laramie, WY, USA
- Ol Pejeta Conservancy, Private Bag 10400, Nanyuki, Kenya
| | - Todd M Palmer
- Department of Biology, University of Florida, Gainesville, FL, USA
| | - Corinna Riginos
- Department of Zoology & Physiology and Program in Ecology & Evolution, University of Wyoming, Laramie, WY, USA
- The Nature Conservancy, Lander, WY, USA
| | - Adam T Ford
- Department of Biology, University of British Columbia, Kelowna, BC, Canada
| | - Jayne Belnap
- Southwest Biological Science Center, US Geological Survey, Moab, UT, USA
| | - Robert M Chira
- School of Biological Sciences, University of Nairobi, Nairobi, Kenya
| | - John M Githaiga
- School of Biological Sciences, University of Nairobi, Nairobi, Kenya
| | | | - Brandon R Hays
- Nicholas School of the Environment, Duke University, Durham, NC, USA
| | - Cyrus M Kavwele
- School of Mathematics & Statistics and School of Biodiversity, University of Glasgow, Glasgow, Scotland
- School of Natural Resources, Karatina University, Nyeri, Kenya
| | | | - Clayton T Lamb
- Department of Biology, University of British Columbia, Kelowna, BC, Canada
| | - Nelly J Maiyo
- Ol Pejeta Conservancy, Private Bag 10400, Nanyuki, Kenya
| | - Patrick D Milligan
- Ol Pejeta Conservancy, Private Bag 10400, Nanyuki, Kenya
- Department of Biology, University of Nevada, Reno, NV, USA
| | - Samuel Mutisya
- Ol Pejeta Conservancy, Private Bag 10400, Nanyuki, Kenya
| | | | - Michael Ogutu
- Ol Pejeta Conservancy, Private Bag 10400, Nanyuki, Kenya
| | - Alejandro G Pietrek
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Salta, Argentina
| | - Brendon T Wildt
- Department of Zoology & Physiology and Program in Ecology & Evolution, University of Wyoming, Laramie, WY, USA
| | - Jacob R Goheen
- Department of Zoology & Physiology and Program in Ecology & Evolution, University of Wyoming, Laramie, WY, USA
| |
Collapse
|
2
|
Kimuyu DM, Veblen KE, Riginos C, Chira RM, Githaiga JM, Young TP. Influence of cattle on browsing and grazing wildlife varies with rainfall and presence of megaherbivores. Ecol Appl 2017; 27:786-798. [PMID: 27935669 DOI: 10.1002/eap.1482] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2016] [Revised: 10/25/2016] [Accepted: 11/15/2016] [Indexed: 06/06/2023]
Abstract
In many savanna ecosystems worldwide, livestock share the landscape and its resources with wildlife. The nature of interactions between livestock and wildlife is a subject of considerable interest and speculation, yet little controlled experimental research has been carried out. Since 1995, we have been manipulating the presence and absence of cattle and large mammalian herbivore wildlife in a Kenyan savanna in order to better understand how different herbivore guilds influence habitat use by specific wildlife species. Using dung counts as a relative assay of herbivore use of the different experimental plots, we found that cattle had a range of effects, mostly negative, on common mesoherbivore species, including both grazers and mixed feeders, but did not have significant effects on megaherbivores. The effect of cattle on most of the mesoherbivore species was contingent on both the presence of megaherbivores and rainfall. In the absence of megaherbivores, wild mesoherbivore dung density was 36% lower in plots that they shared with cattle than in plots they used exclusively, whereas in the presence of megaherbivores, wild mesoherbivore dung density was only 9% lower in plots shared with cattle than plots used exclusively. Cattle appeared to have a positive effect on habitat use by zebra (a grazer) and steinbuck (a browser) during wetter periods of the year but a negative effect during drier periods. Plots to which cattle had access had lower grass and forb cover than plots from which they were excluded, while plots to which megaherbivores had access had more grass cover but less forb cover. Grass cover was positively correlated with zebra and oryx dung density while forb cover was positively correlated with eland dung density. Overall these results suggest that interactions between livestock and wildlife are contingent on rainfall and herbivore assemblage and represent a more richly nuanced set of interactions than the longstanding assertion that cattle simply compete with (grazing) wildlife. Specifically, rainfall and megaherbivores seemed to moderate the negative effects of cattle on some mesoherbivore species. Even if cattle tend to reduce wildlife use of the landscape, managing simultaneously for livestock production (at moderate levels) and biodiversity conservation is possible.
Collapse
Affiliation(s)
- Duncan M Kimuyu
- Department of Natural Resources, Karatina University, Karatina, Kenya
- Mpala Research Centre, P.O. Box 555, Nanyuki, Kenya
| | - Kari E Veblen
- Mpala Research Centre, P.O. Box 555, Nanyuki, Kenya
- Department of Wildland Resources and Ecology Center, Utah State University, Logan, Utah, 84322, USA
| | - Corinna Riginos
- Mpala Research Centre, P.O. Box 555, Nanyuki, Kenya
- Department of Zoology and Physiology, University of Wyoming, Laramie, Wyoming, 82071, USA
| | - Robert M Chira
- School of Biological Sciences, University of Nairobi, Nairobi, Kenya
| | - John M Githaiga
- School of Biological Sciences, University of Nairobi, Nairobi, Kenya
| | - Truman P Young
- Mpala Research Centre, P.O. Box 555, Nanyuki, Kenya
- Department of Plant Sciences, University of California, Davis, California, 95616, USA
| |
Collapse
|
3
|
McCauley DJ, Dawson TE, Power ME, Finlay JC, Ogada M, Gower DB, Caylor K, Nyingi WD, Githaiga JM, Nyunja J, Joyce FH, Lewison RL, Brashares JS. Carbon stable isotopes suggest that hippopotamus‐vectored nutrients subsidize aquatic consumers in an East African river. Ecosphere 2015. [DOI: 10.1890/es14-00514.1] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Affiliation(s)
- Douglas J. McCauley
- Department of Ecology, Evolution and Marine Biology, University of California, Santa Barbara, California 93106 USA
| | - Todd E. Dawson
- Department of Environmental Science, Policy, and Management, University of California, Berkeley, California 94720 USA
- Department of Integrative Biology, University of California, Berkeley, California 94720 USA
| | - Mary E. Power
- Department of Integrative Biology, University of California, Berkeley, California 94720 USA
| | - Jacques C. Finlay
- Department of Ecology, Evolution, and Behavior, University of Minnesota, Saint Paul, Minnesota 55108 USA
| | - Mordecai Ogada
- Conservation Solutions Afrika, P.O. Box 880, Nanyuki 10400 Kenya
| | - Drew B. Gower
- Department of Civil and Environmental Engineering, Princeton University, Princeton, New Jersey 08544 USA
| | - Kelly Caylor
- Department of Civil and Environmental Engineering, Princeton University, Princeton, New Jersey 08544 USA
| | - Wanja D. Nyingi
- National Museums of Kenya, Ichthyology Section, P.O. Box 40658-00100, Nairobi, Kenya
| | - John M. Githaiga
- School of Biological Sciences, University of Nairobi, P.O. Box 30197, Nairobi, Kenya
| | - Judith Nyunja
- Kenya Wildlife Service, Wetlands Program, P.O. Box 40241-00100, Nairobi, Kenya
| | - Francis H. Joyce
- Department of Ecology, Evolution and Marine Biology, University of California, Santa Barbara, California 93106 USA
| | - Rebecca L. Lewison
- Department of Biology, San Diego State University, San Diego, California 92182-4614 USA
| | - Justin S. Brashares
- Department of Environmental Science, Policy, and Management, University of California, Berkeley, California 94720 USA
| |
Collapse
|