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Vermeulen MM, Fritz H, Strauss WM, Hetem RS, Venter JA. Seasonal activity patterns of a Kalahari mammal community: Trade-offs between environmental heat load and predation pressure. Ecol Evol 2024; 14:e11304. [PMID: 38628919 PMCID: PMC11019135 DOI: 10.1002/ece3.11304] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2023] [Revised: 03/24/2024] [Accepted: 04/04/2024] [Indexed: 04/19/2024] Open
Abstract
Mammals in arid zones have to trade off thermal stress, predation pressure, and time spent foraging in a complex thermal landscape. We quantified the relationship between the environmental heat load and activity of a mammal community in the hot, arid Kalahari Desert. We deployed miniature black globe thermometers within the existing Snapshot Safari camera trap grid on Tswalu Kalahari Reserve, South Africa. Using the camera traps to record species' activity throughout the 24-h cycle, we quantified changes in the activity patterns of mammal species in relation to heat loads in their local environment. We compared the heat load during which species were active between two sites with differing predator guilds, one where lion (Panthera leo) biomass dominated the carnivore guild and the other where lions were absent. In the presence of lion, prey species were generally active under significantly higher heat loads, especially during the hot and dry spring. We suggest that increased foraging under high heat loads highlights the need to meet nutritional requirements while avoiding nocturnal activity when predatory pressures are high. Such a trade-off may become increasingly costly under the hotter and drier conditions predicted to become more prevalent as a result of climate change within the arid and semi-arid regions of southern Africa.
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Affiliation(s)
- Mika M. Vermeulen
- Department of Conservation ManagementNelson Mandela UniversityGeorgeWestern CapeSouth Africa
| | - Hervé Fritz
- Sustainability Research UnitNelson Mandela UniversityGeorgeWestern CapeSouth Africa
- International Research LaboratoryREHABS, CNRS – Université de Lyon 1 – Nelson Mandela UniversityGeorgeWestern CapeSouth Africa
| | - W. Maartin Strauss
- School of Biological SciencesUniversity of CanterburyChristchurchNew Zealand
| | - Robyn S. Hetem
- School of Biological SciencesUniversity of CanterburyChristchurchNew Zealand
- School of Animal, Plant and Environmental SciencesUniversity of the WitwatersrandJohannesburgGautengSouth Africa
| | - Jan A. Venter
- Department of Conservation ManagementNelson Mandela UniversityGeorgeWestern CapeSouth Africa
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Bernstein-Kurtycz LM, Dunham NT, Evenhuis J, Brown MB, Muneza AB, Fennessy J, Dennis PM, Lukas KE. Evaluating the effects of giraffe skin disease and wire snare wounds on the gaits of free-ranging Nubian giraffe. Sci Rep 2023; 13:1959. [PMID: 36737637 PMCID: PMC9898309 DOI: 10.1038/s41598-023-28677-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Accepted: 01/23/2023] [Indexed: 02/05/2023] Open
Abstract
Giraffe skin disease (GSD), a condition that results in superficial lesions in certain giraffe (Giraffa spp.) populations, has emerged as a potential conservation threat. Preliminary findings suggested that individuals with GSD lesions move with greater difficulty which may in turn reduce their foraging efficiency or make them more vulnerable to predation. A current known threat to some giraffe populations is their mortality associated with entrapment in wire snares, and the morbidity and potential locomotor deficiencies associated with wounds acquired from snares. The goal of our study was to quantify the locomotor kinematics of free-ranging Nubian giraffe (G. camelopardalis camelopardalis) in Murchison Falls National Park (MFNP), Uganda, and compare spatiotemporal limb and neck angle kinematics of healthy giraffe to those of giraffe with GSD lesions, snare wounds, and both GSD lesions and snare wounds. The presence of GSD lesions did not significantly affect spatiotemporal limb kinematic parameters. This finding is potentially because lesions were located primarily on the necks of Nubian giraffe in MFNP. The kinematic parameters of individuals with snare wounds differed from those of healthy individuals, resulting in significantly shorter stride lengths, reduced speed, lower limb phase values, and increased gait asymmetry. Neck angle kinematic parameters did not differ among giraffe categories, which suggests that GSD neck lesions do not impair normal neck movements and range of motion during walking. Overall, MFNP giraffe locomotor patterns are largely conservative between healthy individuals and those with GSD, while individuals with snare wounds showed more discernible kinematic adjustments consistent with unilateral limb injuries. Additional studies are recommended to assess spatiotemporal limb kinematics of giraffe at sites where lesions are found predominantly on the limbs to better assess the potential significance of GSD on their locomotion.
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Affiliation(s)
- L M Bernstein-Kurtycz
- Division of Conservation and Science, Cleveland Metroparks Zoo, 4200 Wildlife Way, Cleveland, OH, 44109, USA.,Department of Biology, Case Western Reserve University, Cleveland, OH, USA.,Little Rock Zoo, Little Rock, AR, USA
| | - N T Dunham
- Division of Conservation and Science, Cleveland Metroparks Zoo, 4200 Wildlife Way, Cleveland, OH, 44109, USA. .,Department of Biology, Case Western Reserve University, Cleveland, OH, USA.
| | - J Evenhuis
- Department of Biology, Case Western Reserve University, Cleveland, OH, USA.,College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO, USA
| | - M B Brown
- Giraffe Conservation Foundation, P.O. Box 86099, Eros, Namibia.,Smithsonian National Zoo and Conservation Biology Institute, Front Royal, VA, 22630, USA.,Department of Biological Sciences Program in Ecology, Evolution, Ecosystems, and Society, Dartmouth College, Hanover, NH, USA
| | - A B Muneza
- Giraffe Conservation Foundation, P.O. Box 86099, Eros, Namibia
| | - J Fennessy
- Giraffe Conservation Foundation, P.O. Box 86099, Eros, Namibia
| | - P M Dennis
- Division of Conservation and Science, Cleveland Metroparks Zoo, 4200 Wildlife Way, Cleveland, OH, 44109, USA.,Department of Biology, Case Western Reserve University, Cleveland, OH, USA.,Department of Veterinary Preventive Medicine, The Ohio State University, Columbus, OH, USA
| | - K E Lukas
- Division of Conservation and Science, Cleveland Metroparks Zoo, 4200 Wildlife Way, Cleveland, OH, 44109, USA.,Department of Biology, Case Western Reserve University, Cleveland, OH, USA
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