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Mitchell D, Maloney SK, Snelling EP, Carvalho Fonsêca VDF, Fuller A. Measurement of microclimates in a warming world: problems and solutions. J Exp Biol 2024; 227:jeb246481. [PMID: 38958209 DOI: 10.1242/jeb.246481] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/04/2024]
Abstract
As the world warms, it will be tempting to relate the biological responses of terrestrial animals to air temperature. But air temperature typically plays a lesser role in the heat exchange of those animals than does radiant heat. Under radiant load, animals can gain heat even when body surface temperature exceeds air temperature. However, animals can buffer the impacts of radiant heat exposure: burrows and other refuges may block solar radiant heat fully, but trees and agricultural shelters provide only partial relief. For animals that can do so effectively, evaporative cooling will be used to dissipate body heat. Evaporative cooling is dependent directly on the water vapour pressure difference between the body surface and immediate surroundings, but only indirectly on relative humidity. High relative humidity at high air temperature implies a high water vapour pressure, but evaporation into air with 100% relative humidity is not impossible. Evaporation is enhanced by wind, but the wind speed reported by meteorological services is not that experienced by animals; instead, the wind, air temperature, humidity and radiation experienced is that of the animal's microclimate. In this Commentary, we discuss how microclimate should be quantified to ensure accurate assessment of an animal's thermal environment. We propose that the microclimate metric of dry heat load to which the biological responses of animals should be related is black-globe temperature measured on or near the animal, and not air temperature. Finally, when analysing those responses, the metric of humidity should be water vapour pressure, not relative humidity.
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Affiliation(s)
- Duncan Mitchell
- Brain Function Research Group, School of Physiology, University of the Witwatersrand, Parktown, 2193, Johannesburg, South Africa
- School of Human Sciences, University of Western Australia, Perth, WA 6009, Australia
| | - Shane K Maloney
- Brain Function Research Group, School of Physiology, University of the Witwatersrand, Parktown, 2193, Johannesburg, South Africa
- School of Human Sciences, University of Western Australia, Perth, WA 6009, Australia
| | - Edward P Snelling
- Brain Function Research Group, School of Physiology, University of the Witwatersrand, Parktown, 2193, Johannesburg, South Africa
- Department of Anatomy and Physiology, and Centre for Veterinary Wildlife Research, University of Pretoria, Pretoria 0110, South Africa
| | - Vinícius de França Carvalho Fonsêca
- Brain Function Research Group, School of Physiology, University of the Witwatersrand, Parktown, 2193, Johannesburg, South Africa
- Animal Biometeorology Laboratory, São Paulo State University, Jaboticabal, SP - CEP 01049-010, Brazil
| | - Andrea Fuller
- Brain Function Research Group, School of Physiology, University of the Witwatersrand, Parktown, 2193, Johannesburg, South Africa
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2
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Roos T, Purdon A, Boult V, Delsink A, Mitchell B, Kilian PJ. Movement patterns of two reintegrated African elephant ( Loxodonta africana) herds: transitioning from captivity to free-living. PeerJ 2024; 12:e17535. [PMID: 38854797 PMCID: PMC11162612 DOI: 10.7717/peerj.17535] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2023] [Accepted: 05/17/2024] [Indexed: 06/11/2024] Open
Abstract
With the escalating challenges in captive elephant management, the study of elephant reintegration emerges as a pivotal area of research, primarily addressing the enhancement of animal welfare. The term 'reintegration' refers to the process of rehabilitating captive elephants to a natural system, allowing them to roam freely without intensive human intervention. There is a relative paucity of research addressing the behavioural adaptations post-reintegration, despite reintegration of over 20 elephants across various fenced reserves in South Africa. Our study centres on two distinct herds of reintegrated African elephants, monitoring their movement patterns in two South African reserves over a 57-month period post-release. The primary goal of the study was to establish whether the flexibility and adaptability of movement behaviour of reintegrated elephants can be considered as one of the indicators of determining the success of such an operation. The second aim of our study was to investigate if the reintegrated elephants demonstrated an adaptability to their environment through their hourly, daily, and seasonal ranging patterns after a period of free roaming that exceeded 4 years. Our findings indicated that reintegrated elephants, much like their wild counterparts (movement based on literature), displayed notable seasonal and diurnal variations in key movement parameters, such as utilisation distribution areas and reserve utilization. These patterns changed over time, reflecting an adaptive shift in movement patterns after several years of free roaming. Notably, the trajectory of changes in movement parameters varied between herds, indicating unique adaptation responses, likely resulting from differences in the reintegration process (familiarity of reserve, season of release, presence of wild elephants). Although our study is constrained by the limited number of reintegrated herds available for analysis, it underscores the potential of captive elephants to successfully adapt to a free-living environment, emphasising the promising implications of reintegration initiatives.
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Affiliation(s)
- Tenisha Roos
- Elephant Reintegration Trust, Port Alfred, Eastern Cape, South Africa
| | - Andrew Purdon
- M.A.P Scientific Services, Pretoria, Gauteng, South Africa
| | - Victoria Boult
- Department of Meteorology, University of Reading, Reading, United Kingdom
| | - Audrey Delsink
- Humane Society International-Africa, Cape Town, South Africa
| | - Brett Mitchell
- Elephant Reintegration Trust, Port Alfred, Eastern Cape, South Africa
| | - Petrus Johannes Kilian
- Elephant Reintegration Trust, Port Alfred, Eastern Cape, South Africa
- !Khamab Kalahari Reserve, Tosca, North West, South Africa
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3
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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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4
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Andreasson F, Rostedt E, Nord A. Measuring body temperature in birds - the effects of sensor type and placement on estimated temperature and metabolic rate. J Exp Biol 2023; 226:jeb246321. [PMID: 37969087 PMCID: PMC10753514 DOI: 10.1242/jeb.246321] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2023] [Accepted: 11/08/2023] [Indexed: 11/17/2023]
Abstract
Several methods are routinely used to measure avian body temperature, but different methods vary in invasiveness. This may cause stress-induced increases in temperature and/or metabolic rate and, hence, overestimation of both parameters. Choosing an adequate temperature measurement method is therefore key to accurately characterizing an animal's thermal and metabolic phenotype. Using great tits (Parus major) and four common methods with different levels of invasiveness (intraperitoneal, cloacal, subcutaneous, cutaneous), we evaluated the preciseness of body temperature measurements and effects on resting metabolic rate (RMR) over a 40°C range of ambient temperatures. None of the methods caused overestimation or underestimation of RMR compared with un-instrumented birds, and body or skin temperature estimates did not differ between methods in thermoneutrality. However, skin temperature was lower compared with all other methods below thermoneutrality. These results provide empirical guidance for future research that aims to measure body temperature and metabolic rate in small bird models.
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Affiliation(s)
- Fredrik Andreasson
- Department of Biology, Section for Evolutionary Ecology, Lund University, Ecology Building, SE-223 62 Lund, Sweden
| | - Elin Rostedt
- Department of Biology, Section for Evolutionary Ecology, Lund University, Ecology Building, SE-223 62 Lund, Sweden
| | - Andreas Nord
- Department of Biology, Section for Evolutionary Ecology, Lund University, Ecology Building, SE-223 62 Lund, Sweden
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5
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Deacon F, Smit GN, Grobbelaar A. Resources and Habitat Requirements for Giraffes' ( Giraffa camelopardalis) Diet Selection in the Northwestern Kalahari, South Africa. Animals (Basel) 2023; 13:2188. [PMID: 37443986 DOI: 10.3390/ani13132188] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Revised: 06/24/2023] [Accepted: 06/28/2023] [Indexed: 07/15/2023] Open
Abstract
Diet selection concerning browse availability of giraffes (Giraffa camelopardalis) was studied over 15 months in an arid environment in South Africa. A global positioning system collar was fitted to a giraffe individual to assess the specific areas, consisting of different vegetation types, that the population utilised during different seasons. Results are provided on diet selection in relation to browse availability between seasons and vegetation types, including tree densities and the amount of the total evapotranspiration tree equivalents. Diet selections of the giraffe population changed in response to the availability of browse material from July to October. The availability of important resource areas had a significant (p < 0.05) effect on the spatial ecology, and an increase in home range size was noted. Information that is important for the well-being of giraffes was identified. This included nutritional stress and the limited variety of the most utilised tree species available for browsing, especially during critical dry periods. The results demonstrate the importance of assessment of giraffes' diet selection in relation to browse availability, especially before introduction to a new area, to limit the lack of population growth and underperformance. This study provides valuable information towards understanding the resources and habitats required for successful giraffe management.
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Affiliation(s)
- Francois Deacon
- Department of Animal Sciences, Faculty of Natural and Agricultural Sciences, University of the Free State, P.O. Box 339, Bloemfontein 9300, South Africa
| | - Gert Nicolaas Smit
- Department of Animal Sciences, Faculty of Natural and Agricultural Sciences, University of the Free State, P.O. Box 339, Bloemfontein 9300, South Africa
| | - Andri Grobbelaar
- Department of Animal Sciences, Faculty of Natural and Agricultural Sciences, University of the Free State, P.O. Box 339, Bloemfontein 9300, South Africa
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6
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Verzuh TL, Rogers SA, Mathewson PD, May A, Porter WP, Class C, Knox L, Cufaude T, Hall LE, Long RA, Monteith KL. Behavioural responses of a large, heat-sensitive mammal to climatic variation at multiple spatial scales. J Anim Ecol 2023; 92:619-634. [PMID: 36527180 DOI: 10.1111/1365-2656.13873] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Accepted: 11/23/2022] [Indexed: 12/23/2022]
Abstract
Climate warming creates energetic challenges for endothermic species by increasing metabolic and hydric costs of thermoregulation. Although endotherms can invoke an array of behavioural and physiological strategies for maintaining homeostasis, the relative effectiveness of those strategies in a climate that is becoming both warmer and drier is not well understood. In accordance with the heat dissipation limit theory which suggests that allocation of energy to growth and reproduction by endotherms is constrained by the ability to dissipate heat, we expected that patterns of habitat use by large, heat-sensitive mammals across multiple scales are critical for behavioural thermoregulation during periods of potential heat stress and that they must invest a large portion of time to maintain heat balance. To test our predictions, we evaluated mechanisms underpinning the effectiveness of bed sites for ameliorating daytime heat loads and potential heat stress across the landscape while accounting for other factors known to affect behaviour. We integrated detailed data on microclimate and animal attributes of moose Alces alces, into a biophysical model to quantify costs of thermoregulation at fine and coarse spatial scales. During summer, moose spent an average of 67.8% of daylight hours bedded, and selected bed sites and home ranges that reduced risk of experiencing heat stress. For most of the day, shade could effectively mitigate the risk of experiencing heat stress up to 10°C, but at warmer temperatures (up to 20°C) wet soil was necessary to maintain homeostasis via conductive heat loss. Consistent selection across spatial scales for locations that reduced heat load underscores the importance of the thermal environment as a driver of behaviour in this heat-sensitive mammal. Moose in North America have long been characterized as riparian-obligate species because of their dependence on woody plant species for food. Nevertheless, the importance of dissipating endogenous heat loads conductively through wet soil suggests riparian habitats also are critical thermal refuges for moose. Such refuges may be especially important in the face of a warming climate in which both high environmental temperatures and drier conditions will likely exacerbate limits to heat dissipation, especially for large, heat-sensitive animals.
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Affiliation(s)
- Tana L Verzuh
- Cooperative Fish and Wildlife Research Unit, Department of Zoology and Physiology, University of Wyoming, Laramie, Wyoming, USA
| | - Savannah A Rogers
- Bioinformatics and Computational Biology, University of Idaho, Moscow, Idaho, USA
| | - Paul D Mathewson
- Department of Integrative Biology, University of Wisconsin, Maddison, Wisconsin, USA
| | - Alex May
- Cooperative Fish and Wildlife Research Unit, Department of Zoology and Physiology, University of Wyoming, Laramie, Wyoming, USA
| | - Warren P Porter
- Department of Integrative Biology, University of Wisconsin, Maddison, Wisconsin, USA
| | - Corey Class
- Wyoming Game and Fish Department, Cheyenne, Wyoming, USA
| | - Lee Knox
- Wyoming Game and Fish Department, Cheyenne, Wyoming, USA
| | - Teal Cufaude
- Wyoming Game and Fish Department, Cheyenne, Wyoming, USA
| | - L Embere Hall
- Wyoming Game and Fish Department, Cheyenne, Wyoming, USA.,Department of Zoology and Physiology, University of Wyoming, Laramie, Wyoming, USA
| | - Ryan A Long
- Department of Fish and Wildlife Sciences, University of Idaho, Moscow, Idaho, USA
| | - Kevin L Monteith
- Cooperative Fish and Wildlife Research Unit, Department of Zoology and Physiology, University of Wyoming, Laramie, Wyoming, USA.,Haub School of the Environment and Natural Resources, University of Wyoming, Laramie, Wyoming, USA
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7
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Ortega Del Rosario MDLÁ, Beermann K, Chen Austin M. Environmentally Responsive Materials for Building Envelopes: A Review on Manufacturing and Biomimicry-Based Approaches. Biomimetics (Basel) 2023; 8:biomimetics8010052. [PMID: 36810383 PMCID: PMC9944834 DOI: 10.3390/biomimetics8010052] [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: 12/11/2022] [Revised: 01/21/2023] [Accepted: 01/23/2023] [Indexed: 01/28/2023] Open
Abstract
Buildings must adapt and respond dynamically to their environment to reduce their energy loads and mitigate environmental impacts. Several approaches have addressed responsive behavior in buildings, such as adaptive and biomimetic envelopes. However, biomimetic approaches lack sustainability consideration, as conducted in biomimicry approaches. This study provides a comprehensive review of biomimicry approaches to develop responsive envelopes, aiming to understand the connection between material selection and manufacturing. This review of the last five years of building construction and architecture-related studies consisted of a two-phase search query, including keywords that answered three research questions relating to the biomimicry and biomimetic-based building envelopes and their materials and manufacturing and excluding other non-related industrial sectors. The first phase focused on understanding biomimicry approaches implemented in building envelopes by reviewing the mechanisms, species, functions, strategies, materials, and morphology. The second concerned the case studies relating to biomimicry approaches and envelopes. Results highlighted that most of the existing responsive envelope characteristics are achievable with complex materials requiring manufacturing processes with no environmentally friendly techniques. Additive and controlled subtractive manufacturing processes may improve sustainability, but there is still some challenge to developing materials that fully adapt to large-scale and sustainability needs, leaving a significant gap in this field.
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Affiliation(s)
- Maria De Los Ángeles Ortega Del Rosario
- Faculty of Mechanical Engineering, Universidad Tecnológica de Panamá, Panama City 0819, Panama
- Sistema Nacional de Investigación (SNI), Clayton City of Knowledge Edf. 205, Panama City 0819, Panama
| | - Kimberly Beermann
- Geography Department, Birkbeck, University of London, London WC1E 6BT, UK
- International Association for Hydro-Environment Engineering and Research (IAHR), Panama Young Professionals Network (YPN), Panama City 0801, Panama
| | - Miguel Chen Austin
- Faculty of Mechanical Engineering, Universidad Tecnológica de Panamá, Panama City 0819, Panama
- Sistema Nacional de Investigación (SNI), Clayton City of Knowledge Edf. 205, Panama City 0819, Panama
- Centro de Estudios Multidisciplinarios en Ciencias, Ingeniería y Tecnología (CEMCIT-AIP), Panama City 0819, Panama
- Correspondence:
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8
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Burton-Roberts R, Cordes LS, Slotow R, Vanak AT, Thaker M, Govender N, Shannon G. Seasonal range fidelity of a megaherbivore in response to environmental change. Sci Rep 2022; 12:22008. [PMID: 36550171 PMCID: PMC9780231 DOI: 10.1038/s41598-022-25334-8] [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: 05/31/2022] [Accepted: 11/28/2022] [Indexed: 12/24/2022] Open
Abstract
For large herbivores living in highly dynamic environments, maintaining range fidelity has the potential to facilitate the exploitation of predictable resources while minimising energy expenditure. We evaluate this expectation by examining how the seasonal range fidelity of African elephants (Loxodonta africana) in the Kruger National Park, South Africa is affected by spatiotemporal variation in environmental conditions (vegetation quality, temperature, rainfall, and fire). Eight-years of GPS collar data were used to analyse the similarity in seasonal utilisation distributions for thirteen family groups. Elephants exhibited remarkable consistency in their seasonal range fidelity across the study with rainfall emerging as a key driver of space-use. Within years, high range fidelity from summer to autumn and from autumn to winter was driven by increased rainfall and the retention of high-quality vegetation. Across years, sequential autumn seasons demonstrated the lowest levels of range fidelity due to inter-annual variability in the wet to dry season transition, resulting in unpredictable resource availability. Understanding seasonal space use is important for determining the effects of future variability in environmental conditions on elephant populations, particularly when it comes to management interventions. Indeed, over the coming decades climate change is predicted to drive greater variability in rainfall and elevated temperatures in African savanna ecosystems. The impacts of climate change also present particular challenges for elephants living in fragmented or human-transformed habitats where the opportunity for seasonal range shifts are greatly constrained.
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Affiliation(s)
- Rhea Burton-Roberts
- grid.7362.00000000118820937School of Natural Sciences, Bangor University, Bangor, Gwynedd UK
| | - Line S. Cordes
- grid.7362.00000000118820937School of Ocean Sciences, Bangor University, Bangor, Gwynedd UK
| | - Rob Slotow
- grid.16463.360000 0001 0723 4123School of Life Sciences, University of KwaZulu-Natal, Pietermaritzburg, South Africa
| | - Abi Tamim Vanak
- grid.16463.360000 0001 0723 4123School of Life Sciences, University of KwaZulu-Natal, Pietermaritzburg, South Africa ,grid.464760.70000 0000 8547 8046Centre for Biodiversity and Conservation, Ashoka Trust for Research in Ecology and the Environment, Bangalore, India
| | - Maria Thaker
- grid.34980.360000 0001 0482 5067Centre for Ecological Sciences, Indian Institute of Science, Bangalore, India
| | - Navashni Govender
- grid.463628.d0000 0000 9533 5073Conservation Management, Kruger National Park, South African National Parks, Private Bag X402, Skukuza, 1350 South Africa ,grid.412139.c0000 0001 2191 3608School of Natural Resource Management, Nelson Mandela University, Private Bag X6531, George, 6530 South Africa
| | - Graeme Shannon
- grid.7362.00000000118820937School of Natural Sciences, Bangor University, Bangor, Gwynedd UK
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Smit JB, Searle CE, Buchanan‐Smith HM, Strampelli P, Mkuburo L, Kakengi VA, Kohi EM, Dickman AJ, Lee PC. Anthropogenic risk increases night‐time activities and associations in African elephants (
Loxodonta africana
) in the
Ruaha‐Rungwa
ecosystem, Tanzania. Afr J Ecol 2022. [DOI: 10.1111/aje.13083] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Affiliation(s)
- Josephine B. Smit
- Psychology, Faculty of Natural Sciences University of Stirling Stirling UK
- Southern Tanzania Elephant Program Iringa Tanzania
| | - Charlotte E. Searle
- Wildlife Conservation Research Unit, Department of Zoology The Recanati‐Kaplan Centre Tubney UK
- Lion Landscapes Iringa Tanzania
| | | | - Paolo Strampelli
- Wildlife Conservation Research Unit, Department of Zoology The Recanati‐Kaplan Centre Tubney UK
- Lion Landscapes Iringa Tanzania
| | - Lameck Mkuburo
- Southern Tanzania Elephant Program Iringa Tanzania
- Tanzanian Elephant Foundation Moshi Tanzania
| | | | | | - Amy J. Dickman
- Wildlife Conservation Research Unit, Department of Zoology The Recanati‐Kaplan Centre Tubney UK
- Lion Landscapes Iringa Tanzania
| | - Phyllis C. Lee
- Psychology, Faculty of Natural Sciences University of Stirling Stirling UK
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Imani N, Vale B. Developing a Method to Connect Thermal Physiology in Animals and Plants to the Design of Energy Efficient Buildings. Biomimetics (Basel) 2022; 7:biomimetics7020067. [PMID: 35735583 PMCID: PMC9220311 DOI: 10.3390/biomimetics7020067] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2022] [Revised: 05/18/2022] [Accepted: 05/19/2022] [Indexed: 12/04/2022] Open
Abstract
The literature shows that translating the thermal adaptation mechanisms of biological organisms to building design solutions can improve energy performance. In the context of bio-inspired thermoregulation several worthwhile attempts have been made to develop a framework for finding relevant thermal adaptation mechanisms in nature as inspiration for architectural design. However, almost all of these have followed a solution-based approach despite the problem-solving nature of architectural design. Given this, this research set out to take a problem-based approach to biomimetic design. The aim was to investigate the most effective way of accessing biological thermoregulatory solutions to assist architects in finding relevant biological inspirations for the thermal design of buildings. This required the development of an optimal structure for categorizing thermoregulatory mechanisms that could then be used as part of a framework for finding appropriate mechanisms for a particular architectural design problem. This development began with a three-step literature review to find, study, generalize and categorize a comprehensive list of thermal adaptation mechanisms used by animals and plants. This article describes how this literature review was carried out leading to the identification of nine main themes which were analysed for their practicality in informing the structure of the proposed framework. The selected themes were built around the common aspects of biology and architecture, and hence facilitated the categorization of biological thermoregulation mechanisms. This article thus explains the steps taken to develop a structure for generalizing and categorizing thermal adaptation strategies in nature. This article does not report on the list of thermal adaptation mechanisms identified in step 2 of the literature review. Instead, it presents the literature review workflow with a focus on step 3. Given that, discussion of the thermal adaptation mechanisms falls outside the scope of this article.
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11
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Kerley GIH, Monsarrat S. Shifted models cannot be used for predicting responses of biodiversity to global change: the African elephant as an example. AFRICAN ZOOLOGY 2022. [DOI: 10.1080/15627020.2022.2053883] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
Affiliation(s)
- Graham IH Kerley
- Centre for African Conservation Ecology, Nelson Mandela University, Gqeberha, South Africa
| | - Sophie Monsarrat
- Centre for African Conservation Ecology, Nelson Mandela University, Gqeberha, South Africa
- Center for Biodiversity Dynamics in a Changing World (BIOCHANGE) & Section for Ecoinformatics and Biodiversity, Department of Biology, Aarhus University, Aarhus City, Denmark
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12
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Sharpe LL, Prober SM, Gardner JL. In the Hot Seat: Behavioral Change and Old-Growth Trees Underpin an Australian Songbird’s Response to Extreme Heat. Front Ecol Evol 2022. [DOI: 10.3389/fevo.2022.813567] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Anthropogenic climate change is increasing the frequency and intensity of heat waves, thereby threatening biodiversity, particularly in hot, arid regions. Although free-ranging endotherms can use behavioral thermoregulation to contend with heat, it remains unclear to what degree behavior can buffer organisms from unprecedented temperatures. Thermoregulatory behaviors that facilitate dry heat loss during moderate heat become maladaptive once environmental temperatures exceed body temperature. Additionally, the costs associated with behavioral thermoregulation may become untenable with greater heat exposure, and effective cooling may be dependent upon the availability of specific microhabitats. Only by understanding the interplay of these three elements (responses, costs and habitat) can we hope to accurately predict how heat waves will impact wild endotherms. We quantified the thermoregulatory behaviors and microhabitat use of a small passerine, the Jacky Winter (Microeca fascinans), in the mallee woodland of SE Australia. At this location, the annual number of days ≥ 42°C has doubled over the last 25 years. The birds’ broad repertoire of behavioral responses to heat was nuanced and responsive to environmental conditions, but was associated with reduced foraging effort and increased foraging costs, accounting for the loss of body condition that occurs at high temperatures. By measuring microsite surface temperatures, which varied by up to 35°C at air temperatures > 44°C, we found that leaf-litter coverage and tree size were positively correlated with thermal buffering. Large mallee eucalypts were critical to the birds’ response to very high temperatures, providing high perches that facilitated convective cooling, the coolest tree-base temperatures and the greatest prevalence of tree-base crevices or hollows that were used as refuges at air temperatures > 38°C. Tree-base hollows, found only in large mallees, were cooler than all other microsites, averaging 2°C cooler than air temperature. Despite the plasticity of the birds’ response to heat, 29% of our habituated study population died when air temperatures reached a record-breaking 49°C, demonstrating the limits of behavioral thermoregulation and the potential vulnerability of organisms to climate change.
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13
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Nervo B, Roggero A, Isaia M, Chamberlain D, Rolando A, Palestrini C. Integrating thermal tolerance, water balance and morphology: An experimental study on dung beetles. J Therm Biol 2021; 101:103093. [PMID: 34879911 DOI: 10.1016/j.jtherbio.2021.103093] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Revised: 08/30/2021] [Accepted: 09/03/2021] [Indexed: 11/26/2022]
Abstract
The impacts of extreme and rising mean temperatures due to climate change can pose significant physiological challenges for insects. An integrated approach that focuses on mechanisms of body temperature regulation, water balance and morphology may help to unravel the functional traits underpinning thermoregulation strategies and the most relevant trade-offs between temperature and water balance regulation. Here, we focused on four species of tunneler dung beetles as important providers of ecosystem services. In this experimental research, we first quantified two traits related to desiccation resistance and tolerance via experimental tests, and subsequently defined two levels of resistance and tolerance (i.e. low and high) according to significant differences among species. Second, we identified morphological traits correlated with water balance strategies, and we found that desiccation resistance and tolerance increased with small relative size of spiracles and wings. High levels of desiccation tolerance were also correlated with small body mass. Third, by integrating thermal tolerance with functional traits based on desiccation resistance and desiccation tolerance, we found that the species with the highest survival rates under elevated temperatures (Euoniticellus fulvus) was characterized by low desiccation resistance and high desiccation tolerance. Our results suggest shared physiological and morphological responses to temperature and desiccation, with potential conflicts between the need to regulate heat and water balance. They also highlighted the sensitivity of a large species such as Geotrupes stercorarius to warm and arid conditions with potential implications for its geographic distribution and the provisioning of ecosystem services under a climate change scenario.
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Affiliation(s)
- Beatrice Nervo
- Department of Life Sciences and Systems Biology, University of Torino, Via Accademia Albertina 13, 10123, Torino, Italy.
| | - Angela Roggero
- Department of Life Sciences and Systems Biology, University of Torino, Via Accademia Albertina 13, 10123, Torino, Italy
| | - Marco Isaia
- Department of Life Sciences and Systems Biology, University of Torino, Via Accademia Albertina 13, 10123, Torino, Italy
| | - Dan Chamberlain
- Department of Life Sciences and Systems Biology, University of Torino, Via Accademia Albertina 13, 10123, Torino, Italy
| | - Antonio Rolando
- Department of Life Sciences and Systems Biology, University of Torino, Via Accademia Albertina 13, 10123, Torino, Italy
| | - Claudia Palestrini
- Department of Life Sciences and Systems Biology, University of Torino, Via Accademia Albertina 13, 10123, Torino, Italy
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14
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Omotoso O, Gladyshev VN, Zhou X. Lifespan Extension in Long-Lived Vertebrates Rooted in Ecological Adaptation. Front Cell Dev Biol 2021; 9:704966. [PMID: 34733838 PMCID: PMC8558438 DOI: 10.3389/fcell.2021.704966] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Accepted: 09/02/2021] [Indexed: 01/21/2023] Open
Abstract
Contemporary studies on aging and longevity have largely overlooked the role that adaptation plays in lifespan variation across species. Emerging evidence indicates that the genetic signals of extended lifespan may be maintained by natural selection, suggesting that longevity could be a product of organismal adaptation. The mechanisms of adaptation in long-lived animals are believed to account for the modification of physiological function. Here, we first review recent progress in comparative biology of long-lived animals, together with the emergence of adaptive genetic factors that control longevity and disease resistance. We then propose that hitchhiking of adaptive genetic changes is the basis for lifespan changes and suggest ways to test this evolutionary model. As individual adaptive or adaptation-linked mutations/substitutions generate specific forms of longevity effects, the cumulative beneficial effect is largely nonrandom and is indirectly favored by natural selection. We consider this concept in light of other proposed theories of aging and integrate these disparate ideas into an adaptive evolutionary model, highlighting strategies in decoding genetic factors of lifespan control.
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Affiliation(s)
- Olatunde Omotoso
- CAS Key Laboratory of Animal Ecology and Conservation Biology, Institute of Zoology, Beijing, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Vadim N Gladyshev
- Division of Genetics, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, United States
| | - Xuming Zhou
- CAS Key Laboratory of Animal Ecology and Conservation Biology, Institute of Zoology, Beijing, China
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15
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du Plessis K, Ganswindt SB, Bertschinger H, Crossey B, Henley MD, Ramahlo M, Ganswindt A. Social and Seasonal Factors Contribute to Shifts in Male African Elephant ( Loxodonta africana) Foraging and Activity Patterns in Kruger National Park, South Africa. Animals (Basel) 2021; 11:ani11113070. [PMID: 34827802 PMCID: PMC8614333 DOI: 10.3390/ani11113070] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Revised: 10/16/2021] [Accepted: 10/18/2021] [Indexed: 11/16/2022] Open
Abstract
African savannah elephants (Loxodonta africana) are well-known as ecosystem engineers with the ability to modify vegetation structure. The present study aimed to examine how male elephant foraging behaviour is affected across (a) season (wet versus dry); (b) time of day (before or after noon); (c) presence or absence of other elephants; and (d) reproductive state (musth versus no musth). Six radio-collared adult elephant bulls were observed twice per week from June 2007-June 2008 in Kruger National Park (KNP), South Africa. Using generalized linear mixed effect modeling, results indicate that elephant bulls graze more during the wet season and browse more during the dry season. To potentially offset the costs associated with thermoregulation during the heat of the day, KNP elephants spent more time foraging during the morning, and more time resting during the afternoon. Male elephants also foraged significantly less when they were associated with females compared to when they were alone or with other males. This is likely due to male-female associations formed mainly for reproductive purposes, thus impeding on male foraging behaviours. In contrast, the condition of musth, defined by the presence of related physical signs, had no significant effect on foraging behaviour.
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Affiliation(s)
- Kara du Plessis
- Mammal Research Institute, Department of Zoology and Entomology, University of Pretoria, Private Bag X20, Hatfield 0028, South Africa; (S.B.G.); (B.C.); (M.R.); (A.G.)
- Correspondence:
| | - Stefanie Birgit Ganswindt
- Mammal Research Institute, Department of Zoology and Entomology, University of Pretoria, Private Bag X20, Hatfield 0028, South Africa; (S.B.G.); (B.C.); (M.R.); (A.G.)
| | - Henk Bertschinger
- Veterinary Population Management Laboratory, Section of Reproduction, Department of Production Animal Studies, University of Pretoria, Private Bag X04, Onderstepoort 0110, South Africa;
| | - Bruce Crossey
- Mammal Research Institute, Department of Zoology and Entomology, University of Pretoria, Private Bag X20, Hatfield 0028, South Africa; (S.B.G.); (B.C.); (M.R.); (A.G.)
| | - Michelle Deborah Henley
- Applied Behavioural Ecology and Ecosystem Research Unit, School of Environmental Sciences, University of South Africa, Private Bag X5, Florida 1710, South Africa;
- Elephants Alive, P.O. Box 960, Hoedspruit 1380, South Africa
| | - Mmatsawela Ramahlo
- Mammal Research Institute, Department of Zoology and Entomology, University of Pretoria, Private Bag X20, Hatfield 0028, South Africa; (S.B.G.); (B.C.); (M.R.); (A.G.)
| | - André Ganswindt
- Mammal Research Institute, Department of Zoology and Entomology, University of Pretoria, Private Bag X20, Hatfield 0028, South Africa; (S.B.G.); (B.C.); (M.R.); (A.G.)
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16
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Peterson M, Jorge MLSP, Jain A, Keuroghlian A, Oshima JEF, Richard-Hansen C, Berzins R, Ribeiro MC, Eaton D. Temperature induces activity reduction in a Neotropical ungulate. J Mammal 2021. [DOI: 10.1093/jmammal/gyab092] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Abstract
Because global climate change results in increasingly extreme temperatures and more frequent droughts, behavioral thermoregulation is one avenue by which species may adjust. Changes in activity patterns in response to temperature have been observed in a number of mammal species, but rarely have been investigated in humid tropical habitats. Here we examine the relationship between activity patterns and microclimate temperatures for white-lipped peccaries (Tayassu pecari, Tayassuidae, Cetartiodactyla) in four distinct biomes—the Cerrado, the Pantanal, the Atlantic Forest, and the Amazon. From 2013 to 2017, we monitored 30 white-lipped peccaries fitted with GPS collars that included accelerometers and temperature sensors. White-lipped peccaries were primarily diurnal, with peaks of activity in the morning and late afternoon, except in the Amazon where activity was high throughout the day. Total time active did not vary seasonally. White-lipped peccaries were significantly less likely to be active as temperatures increased, with the probability of being active decreasing by >49% in all biomes between 30 and 40°C. Our findings indicate that white-lipped peccaries are likely to be adversely impacted by rising temperatures, through being forced to reduce foraging time during their prime active periods.
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Affiliation(s)
- Michaela Peterson
- Department of Earth and Environmental Sciences, Vanderbilt University, Nashville, Tennessee 37235, USA
| | - Maria Luisa S P Jorge
- Department of Earth and Environmental Sciences, Vanderbilt University, Nashville, Tennessee 37235, USA
| | - Avarna Jain
- Department of Earth and Environmental Sciences, Vanderbilt University, Nashville, Tennessee 37235, USA
| | | | - Júlia Emi F Oshima
- Programa de Pós-Graduação em Zoologia, Laboratório de Ecologia Espacial e Conservação—LEEC, Depto. de Ecologia, Instituto de Biociências, Universidade Estadual Paulista (UNESP), Av. 24-A, 1515, 13506-900, Rio Claro, São Paulo, Brasil
| | - Cécile Richard-Hansen
- Office français de la Biodiversité (OFB), Kourou-Campus agronomique—French Guyana, France
- UMR EcoFog, Kourou-Campus agronomique—French Guiana, France
| | - Rachel Berzins
- Office français de la Biodiversité (OFB), Kourou-Campus agronomique—French Guyana, France
| | - Milton Cezar Ribeiro
- Programa de Pós-Graduação em Zoologia, Laboratório de Ecologia Espacial e Conservação—LEEC, Depto. de Ecologia, Instituto de Biociências, Universidade Estadual Paulista (UNESP), Av. 24-A, 1515, 13506-900, Rio Claro, São Paulo, Brasil
| | - Don Eaton
- Peccary Project/IUCN/SSC Peccary Specialist Group, Campo Grande, Brazil
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17
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Field evidence supporting monitoring of chemical information on pathways by male African elephants. Anim Behav 2021. [DOI: 10.1016/j.anbehav.2021.04.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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18
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Development and validation of a spatially-explicit agent-based model for space utilization by African savanna elephants (Loxodonta africana) based on determinants of movement. Ecol Modell 2021. [DOI: 10.1016/j.ecolmodel.2021.109499] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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19
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Peeks M, Badarnah L. Textured Building Façades: Utilizing Morphological Adaptations Found in Nature for Evaporative Cooling. Biomimetics (Basel) 2021; 6:24. [PMID: 33805505 PMCID: PMC8103249 DOI: 10.3390/biomimetics6020024] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Revised: 03/23/2021] [Accepted: 03/25/2021] [Indexed: 11/16/2022] Open
Abstract
The overheating of buildings and their need for mechanical cooling is a growing issue as a result of climate change. The main aim of this paper is to examine the impact of surface texture on heat loss capabilities of concrete panels through evaporative cooling. Organisms maintain their body temperature in very narrow ranges in order to survive, where they employ morphological and behavioral means to complement physiological strategies for adaptation. This research follows a biomimetic approach to develop a design solution. The skin morphology of elephants was identified as a successful example that utilizes evaporative cooling and has, therefore, informed the realization of a textured façade panel. A systematic process has been undertaken to examine the impact of different variables on the cooling ability of the panels, bringing in new morphological considerations for surface texture. The results showed that the morphological variables of assembly and depth of texture have impact on heat loss, and the impact of surface area to volume (SA:V) ratios on heat loss capabilities varies for different surface roughness. This study demonstrates the potential exploitation of morphological adaptation to buildings, that could contribute to them cooling passively and reduce the need for expensive and energy consuming mechanical systems. Furthermore, it suggests areas for further investigation and opens new avenues for novel thermal solutions inspired by nature for the built environment.
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Affiliation(s)
- Megan Peeks
- The Department of Architecture and the Built Environment, Faculty of Environment and Technology, University of the West of England, Bristol BS16 1QY, UK;
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20
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Fuller A, Mitchell D, Maloney SK, Hetem RS, Fonsêca VFC, Meyer LCR, van de Ven TMFN, Snelling EP. How dryland mammals will respond to climate change: the effects of body size, heat load and a lack of food and water. J Exp Biol 2021; 224:224/Suppl_1/jeb238113. [PMID: 33627465 DOI: 10.1242/jeb.238113] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Mammals in drylands are facing not only increasing heat loads but also reduced water and food availability as a result of climate change. Insufficient water results in suppression of evaporative cooling and therefore increases in body core temperature on hot days, while lack of food reduces the capacity to maintain body core temperature on cold nights. Both food and water shortage will narrow the prescriptive zone, the ambient temperature range over which body core temperature is held relatively constant, which will lead to increased risk of physiological malfunction and death. Behavioural modifications, such as shifting activity between night and day or seeking thermally buffered microclimates, may allow individuals to remain within the prescriptive zone, but can incur costs, such as reduced foraging or increased competition or predation, with consequences for fitness. Body size will play a major role in predicting response patterns, but identifying all the factors that will contribute to how well dryland mammals facing water and food shortage will cope with increasing heat loads requires a better understanding of the sensitivities and responses of mammals exposed to the direct and indirect effects of climate change.
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Affiliation(s)
- Andrea Fuller
- Brain Function Research Group, School of Physiology, Faculty of Health Sciences, University of the Witwatersrand, Parktown 2193, South Africa .,Department of Paraclinical Sciences, Faculty of Veterinary Science, University of Pretoria, Onderstepoort 0110, South Africa.,Centre for Veterinary Wildlife Studies, Faculty of Veterinary Science, University of Pretoria, Onderstepoort 0110, South Africa
| | - Duncan Mitchell
- Brain Function Research Group, School of Physiology, Faculty of Health Sciences, University of the Witwatersrand, Parktown 2193, South Africa.,School of Human Sciences, Faculty of Science, University of Western Australia, Crawley 6009, WA, Australia
| | - Shane K Maloney
- Brain Function Research Group, School of Physiology, Faculty of Health Sciences, University of the Witwatersrand, Parktown 2193, South Africa.,School of Human Sciences, Faculty of Science, University of Western Australia, Crawley 6009, WA, Australia
| | - Robyn S Hetem
- Brain Function Research Group, School of Physiology, Faculty of Health Sciences, University of the Witwatersrand, Parktown 2193, South Africa.,School of Animal, Plant and Environmental Sciences, University of the Witwatersrand, Johannesburg 2000, South Africa
| | - Vinicius F C Fonsêca
- Brain Function Research Group, School of Physiology, Faculty of Health Sciences, University of the Witwatersrand, Parktown 2193, South Africa.,Innovation Group of Biometeorology and Animal Welfare (INOBIO-MANERA), Universidade Federal da Paraíba, Areia, 58397000, Brazil
| | - Leith C R Meyer
- Brain Function Research Group, School of Physiology, Faculty of Health Sciences, University of the Witwatersrand, Parktown 2193, South Africa.,Department of Paraclinical Sciences, Faculty of Veterinary Science, University of Pretoria, Onderstepoort 0110, South Africa.,Centre for Veterinary Wildlife Studies, Faculty of Veterinary Science, University of Pretoria, Onderstepoort 0110, South Africa
| | - Tanja M F N van de Ven
- Brain Function Research Group, School of Physiology, Faculty of Health Sciences, University of the Witwatersrand, Parktown 2193, South Africa
| | - Edward P Snelling
- Brain Function Research Group, School of Physiology, Faculty of Health Sciences, University of the Witwatersrand, Parktown 2193, South Africa.,Centre for Veterinary Wildlife Studies, Faculty of Veterinary Science, University of Pretoria, Onderstepoort 0110, South Africa.,Department of Anatomy and Physiology, Faculty of Veterinary Science, University of Pretoria, Onderstepoort 0110, South Africa
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21
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Dejene SW, Mpakairi KS, Kanagaraj R, Wato YA, Mengistu S. Modelling continental range shift of the African elephant (Loxodonta africana) under a changing climate and land cover: implications for future conservation of the species. AFRICAN ZOOLOGY 2021. [DOI: 10.1080/15627020.2020.1846617] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Affiliation(s)
- Sintayehu W Dejene
- College of Agriculture and Environmental Sciences, Haramaya University, Dire Dawa, Ethiopia
| | - Kudzai S Mpakairi
- Geo-information and Earth Observation Centre, Department of Geography and Environmental Science, University of Zimbabwe, Mount Pleasant, Harare
| | - Rajapandian Kanagaraj
- Helmholtz Centre for Environmental Research (UFZ), Department of Ecological Modelling, Leipzig, Germany
- French Institute of Pondicherry (IFP), Department of Ecology, Puducherry, India
| | | | - Sewnet Mengistu
- School of Biological Sciences, Haramaya University, Dire Dawa, Ethiopia
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22
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van Aarde RJ, Pimm SL, Guldemond R, Huang R, Maré C. The 2020 elephant die-off in Botswana. PeerJ 2021; 9:e10686. [PMID: 33510975 PMCID: PMC7808262 DOI: 10.7717/peerj.10686] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Accepted: 12/11/2020] [Indexed: 12/02/2022] Open
Abstract
The cause of deaths of 350 elephants in 2020 in a relatively small unprotected area of northern Botswana is unknown, and may never be known. Media speculations about it ignore ecological realities. Worse, they make conjectures that can be detrimental to wildlife and sometimes discredit conservation incentives. A broader understanding of the ecological and conservation issues speaks to elephant management across the Kavango–Zambezi Transfrontier Conservation Area that extends across Botswana, Namibia, Angola, Zambia, and Zimbabwe. Our communication addresses these. Malicious poisoning and poaching are unlikely to have played a role. Other species were unaffected, and elephant carcases had their tusks intact. Restriction of freshwater supplies that force elephants to use pans as a water source possibly polluted by blue-green algae blooms is a possible cause, but as yet not supported by evidence. No other species were involved. A contagious disease is the more probable one. Fences and a deep channel of water confine these elephants’ dispersal. These factors explain the elephants’ relatively high population growth rate despite a spell of increased poaching during 2014–2018. While the deaths represent only ~2% of the area’s elephants, the additive effects of poaching and stress induced by people protecting their crops cause alarm. Confinement and relatively high densities probably explain why the die-off occurred only here. It suggests a re-alignment or removal of fences that restrict elephant movements and limits year-round access to freshwater.
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Affiliation(s)
- Rudi J van Aarde
- Conservation Ecology Research Unit, Department of Zoology and Entomology, University of Pretoria, Hatfield, Gauteng, South Africa
| | - Stuart L Pimm
- Conservation Ecology Research Unit, Department of Zoology and Entomology, University of Pretoria, Hatfield, Gauteng, South Africa.,Nicholas School of the Environment, Duke University, Durham, NC, USA
| | - Robert Guldemond
- Conservation Ecology Research Unit, Department of Zoology and Entomology, University of Pretoria, Hatfield, Gauteng, South Africa
| | - Ryan Huang
- Nicholas School of the Environment, Duke University, Durham, NC, USA
| | - Celesté Maré
- Conservation Ecology Research Unit, Department of Zoology and Entomology, University of Pretoria, Hatfield, Gauteng, South Africa
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23
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Munyao M, Siljander M, Johansson T, Makokha G, Pellikka P. Assessment of human–elephant conflicts in multifunctional landscapes of Taita Taveta County, Kenya. Glob Ecol Conserv 2020. [DOI: 10.1016/j.gecco.2020.e01382] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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24
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Rozen-Rechels D, Valls-Fox H, Mabika CT, Chamaillé-Jammes S. Temperature as a constraint on the timing and duration of African elephant foraging trips. J Mammal 2020. [DOI: 10.1093/jmammal/gyaa129] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Abstract
In arid and semiarid environments, water is a key resource that is limited in availability. During the dry season, perennial water sources such as water pans often are far apart and shape the daily movement routines of large herbivores. In hot environments, endotherms face a lethal risk of overheating that can be buffered by evaporative cooling. Behavioral adjustments are an alternative way to reduce thermal constraints on the organism. The trade-off between foraging and reaching water pans has been studied widely in arid environments; however, few studies have looked into how ambient temperature shapes individual trips between two visits to water. In this study, we tracked during the dry season the movement of eight GPS-collared African elephants (Loxodonta africana) cows from different herds in Hwange National Park, Zimbabwe. This species, the largest extant terrestrial animal, is particularly sensitive to heat due to its body size and the absence of sweat glands. We show that most foraging trips depart from water at nightfall, lowering the average temperature experienced during walking. This pattern is conserved across isolated elephant populations in African savannas. We also observed that higher temperatures at the beginning of the trip lead to shorter trips. We conclude that elephants adjust the timing of foraging trips to reduce the thermal constraints, arguing that further considerations of the thermal landscape of endotherms are important to understand their ecology.
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Affiliation(s)
- David Rozen-Rechels
- Sorbonne Université, CNRS, IRD, INRA, Institut d’écologie et des sciences de l’environnement (IEES), Paris, France
| | - Hugo Valls-Fox
- SELMET, Univ de Montpellier, CIRAD, INRA, Montpellier Sup. Agro, Montpellier, France
| | - Cheryl Tinashe Mabika
- Scientific Services, Zimbabwe Parks and Wildlife Management Authority, Hwange National Park, Zimbabwe
| | - Simon Chamaillé-Jammes
- CEFE, Univ de Montpellier, CNRS, EPHE, IRD, Unive Paul Valéry Montpellier 3, Montpellier, France
- Mammal Research Institute, Department of Zoology and Entomology, Faculty of Natural and Agricultural Sciences, University of Pretoria, Hatfield, Pretoria, South Africa
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25
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Pontzer H, Rimbach R, Paltan J, Ivory EL, Kendall CJ. Air temperature and diet influence body composition and water turnover in zoo-living African elephants ( Loxodonta africana). ROYAL SOCIETY OPEN SCIENCE 2020; 7:201155. [PMID: 33391799 PMCID: PMC7735349 DOI: 10.1098/rsos.201155] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Accepted: 10/26/2020] [Indexed: 06/12/2023]
Abstract
African elephants, the largest land animal, face particular physiological challenges in captivity and the wild. Captive elephants can become over- or under-conditioned with inadequate exercise and diet management. Few studies have quantified body composition or water turnover in elephants, and none to date have examined longitudinal responses to changes in diet or air temperature. Using the stable isotope deuterium oxide (2H2O), we investigated changes in body mass, estimated fat-free mass (FFM, including fat-free gut content) and body fat in response to a multi-year intervention that reduced dietary energy density for adult African elephants housed at the North Carolina Zoo. We also examined the relationship between air temperature and water turnover. Deuterium dilution and depletion rates were assayed via blood samples and used to calculate body composition and water turnover in two male and three female African elephants at six intervals over a 3-year period. Within the first year after the dietary intervention, there was an increase in overall body mass, a reduction in body fat percentage and an increase in FFM. However, final values of both body fat percentage and FFM were similar to initial values. Water turnover (males: 359 ± 9 l d-1; females: 241 ± 28 l d-1) was consistent with the allometric scaling of water use in other terrestrial mammals. Water turnover increased with outdoor air temperature. Our study highlights the physiological water dependence of elephants and shows that individuals have to drink every 2-3 days to avoid critical water loss of approximately 10% body mass in hot conditions.
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Affiliation(s)
- Herman Pontzer
- Evolutionary Anthropology, Duke University, Durham, NC, USA
- Duke Global Health Institute, Duke University, Durham, NC, USA
| | - Rebecca Rimbach
- Evolutionary Anthropology, Duke University, Durham, NC, USA
- School of Animal, Plant & Environmental Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Jenny Paltan
- Department of Anthropology, Hunter College, New York, NY, USA
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26
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Beirne C, Meier AC, Brumagin G, Jasperse-Sjolander L, Lewis M, Masseloux J, Myers K, Fay M, Okouyi J, White LJT, Poulsen JR. Climatic and Resource Determinants of Forest Elephant Movements. Front Ecol Evol 2020. [DOI: 10.3389/fevo.2020.00096] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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27
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Szott ID, Pretorius Y, Ganswindt A, Koyama NF. Normalized difference vegetation index, temperature and age affect faecal thyroid hormone concentrations in free-ranging African elephants. CONSERVATION PHYSIOLOGY 2020; 8:coaa010. [PMID: 32577285 PMCID: PMC7297438 DOI: 10.1093/conphys/coaa010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2018] [Revised: 01/21/2020] [Accepted: 02/02/2020] [Indexed: 05/03/2023]
Abstract
Conservation biologists can use hormone measurements to assess animals' welfare, reproductive state, susceptibility to stressors, as well as energy expenditure. Quantifying hormone concentrations from faecal samples is particularly advantageous as samples can be collected without disturbing animals' behaviour. In order for an endocrine marker to be useful for wildlife managers, we need to understand how extrinsic and intrinsic factors affect hormone concentrations in free-ranging animal populations. Thyroid hormones are linked to basal metabolic rate and energy expenditure. Previous research demonstrated that triiodothyronine (T3) can be measured successfully in faecal matter of African elephants, Loxodonta africana. However, to our knowledge, research into factors affecting changes in elephant T3 levels has only been carried out in captive elephants so far. Thus, we present the first study of faecal T3 metabolite (mT3) concentrations of a large population of free-ranging African elephants. Over 15 months, we collected faecal samples from identified (n = 43 samples) and unidentified (n = 145 samples) individuals in Madikwe Game Reserve, South Africa. We investigated whether vegetative productivity [normalized difference vegetation index (NDVI)] in interaction with mean monthly temperature, age and sex affected mT3 concentrations. We found a significant negative interaction effect of NDVI and temperature. Increasing NDVI was related to higher concentrations of mT3, but increasing temperature was related to a decrease in mT3 concentrations in individually identified and unidentified elephants. In unidentified individuals, juvenile elephants had significantly higher mT3 concentrations compared to adult elephants. Faecal T3 can successfully be quantified in samples from free-ranging elephant populations and thus provides insight into energy expenditure in large herbivores.
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Affiliation(s)
- Isabelle D Szott
- School of Biological and Environmental Sciences, Liverpool John Moores University, Liverpool L3 3AF, UK
| | - Yolanda Pretorius
- Mammal Research Institute, University of Pretoria, Hatfield 0028, South Africa
- Southern African Wildlife College, Hoedspruit 1380, South Africa
| | - Andre Ganswindt
- Mammal Research Institute, University of Pretoria, Hatfield 0028, South Africa
- Endocrine Research Laboratory, Department of Anatomy and Physiology, University of Pretoria, Onderstepoort 0110, South Africa
| | - Nicola F Koyama
- School of Biological and Environmental Sciences, Liverpool John Moores University, Liverpool L3 3AF, UK
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28
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Mpakairi KS, Ndaimani H, Tagwireyi P, Zvidzai M, Madiri TH. Futuristic climate change scenario predicts a shrinking habitat for the African elephant (Loxodonta africana): evidence from Hwange National Park, Zimbabwe. EUR J WILDLIFE RES 2019. [DOI: 10.1007/s10344-019-1327-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Rozen‐Rechels D, Dupoué A, Lourdais O, Chamaillé‐Jammes S, Meylan S, Clobert J, Le Galliard J. When water interacts with temperature: Ecological and evolutionary implications of thermo-hydroregulation in terrestrial ectotherms. Ecol Evol 2019; 9:10029-10043. [PMID: 31534711 PMCID: PMC6745666 DOI: 10.1002/ece3.5440] [Citation(s) in RCA: 75] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Accepted: 06/17/2019] [Indexed: 02/06/2023] Open
Abstract
The regulation of body temperature (thermoregulation) and of water balance (defined here as hydroregulation) are key processes underlying ecological and evolutionary responses to climate fluctuations in wild animal populations. In terrestrial (or semiterrestrial) ectotherms, thermoregulation and hydroregulation closely interact and combined temperature and water constraints should directly influence individual performances. Although comparative physiologists traditionally investigate jointly water and temperature regulation, the ecological and evolutionary implications of these coupled processes have so far mostly been studied independently. Here, we revisit the concept of thermo-hydroregulation to address the functional integration of body temperature and water balance regulation in terrestrial ectotherms. We demonstrate how thermo-hydroregulation provides a framework to investigate functional adaptations to joint environmental variation in temperature and water availability, and potential physiological and/or behavioral conflicts between thermoregulation and hydroregulation. We extend the classical cost-benefit model of thermoregulation in ectotherms to highlight the adaptive evolution of optimal thermo-hydroregulation strategies. Critical gaps in the parameterization of this conceptual optimality model and guidelines for future empirical research are discussed. We show that studies of thermo-hydroregulation refine our mechanistic understanding of physiological and behavioral plasticity, and of the fundamental niche of the species. This is illustrated with relevant and recent examples of space use and dispersal, resource-based trade-offs, and life-history tactics in insects, amphibians, and nonavian reptiles.
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Affiliation(s)
- David Rozen‐Rechels
- Sorbonne Université, UPEC, CNRS, IRD INRAInstitut d'Écologie et des Sciences de l'Environnement, IEESParisFrance
| | - Andréaz Dupoué
- UMR 5321 CNRS-Université Toulouse III Paul SabatierStation d'Écologie Théorique et ExpérimentaleMoulisFrance
| | - Olivier Lourdais
- UMR 7372 CNRS-ULRCentre d'Études Biologiques de ChizéVilliers en BoisFrance
- School of Life SciencesArizona State UniversityTempeAZUSA
| | - Simon Chamaillé‐Jammes
- CNRS, Univ Montpellier, EPHE, IRD, Univ Paul Valéry Montpellier 3Centre d'Écologie Fonctionnelle et ÉvolutiveMontpellierFrance
| | - Sandrine Meylan
- Sorbonne Université, UPEC, CNRS, IRD INRAInstitut d'Écologie et des Sciences de l'Environnement, IEESParisFrance
- Sorbonne UniversitéESPE de ParisParisFrance
| | - Jean Clobert
- UMR 5321 CNRS-Université Toulouse III Paul SabatierStation d'Écologie Théorique et ExpérimentaleMoulisFrance
| | - Jean‐François Le Galliard
- Sorbonne Université, UPEC, CNRS, IRD INRAInstitut d'Écologie et des Sciences de l'Environnement, IEESParisFrance
- École normale supérieure, CNRS, UMS 3194Centre de recherche en écologie expérimentale et prédictive (CEREEP‐Ecotron IleDeFrance), Département de biologiePSL Research UniversitySaint‐Pierre‐lès‐NemoursFrance
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30
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Thapa K, Kelly MJ, Pradhan NMB. Elephant (Elephas maximus) temporal activity, distribution, and habitat use patterns on the tiger's forgotten trails across the seasonally dry, subtropical, hilly Churia forests of Nepal. PLoS One 2019; 14:e0216504. [PMID: 31083683 PMCID: PMC6513267 DOI: 10.1371/journal.pone.0216504] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2019] [Accepted: 04/17/2019] [Indexed: 11/19/2022] Open
Abstract
Understanding spatial distribution, habitat use, and temporal activity patterns is important for species conservation planning. This information especially is crucial for mega herbivores like elephants as their ranging patterns encompass a myriad of habitats types. Churia habitat is geological fragile yet important for wildlife in Nepal and India. We used camera trapping and sign surveys covering 536 km2 of Churia and surrounding areas within Chitwan National Park. Across 152 trapping locations, we accumulated 2,097 trap nights in a 60-day survey during the winter season of 2010-11. We used a non-parametric kernel density function to analyze winter activity patterns of elephants detected in camera-traps. Additionally, we walked 643 km over 76 grid cells in two surveys (winter and summer) to estimate elephant distribution and intensity of habitat use using an occupancy framework. Multi-season models allowed us to make seasonal (winter versus summer) inferences regarding changes in habitat use based on covariates influencing use and detection. We photographed 25 mammalian species including elephants with calves with a trapping rate of 2.72 elephant photos events per 100 trap nights. Elephant winter activity pattern was found to be mainly nocturnal, with crepuscular peaks. Covariates such as normalized differential vegetation index and terrain ruggedness positively influenced elephant spatial distribution and habitat use patterns within the Churia habitat. We also found lower elephant habitat use ([Formula: see text]) of Churia in winter 0.51 (0.02) than in summer 0.57 (0.02). Elephants heavily used the eastern portion of Churia in both seasons (67-69%). Overall, Churia habitat, which is often ignored, clearly is used by elephants, with increases in summer use in the west and high use year-round in the east, and thus should no longer be neglected or forgotten in species conservation planning.
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Affiliation(s)
| | - Marcella J. Kelly
- Department of Fish and Wildlife Conservation, Virginia Tech, Blacksburg, VA, United States of America
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31
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Buchholtz EK, Redmore L, Fitzgerald LA, Stronza A, Songhurst A, McCulloch G. Temporal Partitioning and Overlapping Use of a Shared Natural Resource by People and Elephants. Front Ecol Evol 2019. [DOI: 10.3389/fevo.2019.00117] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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32
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Miller, Jr WB, Torday JS. Reappraising the exteriorization of the mammalian testes through evolutionary physiology. Commun Integr Biol 2019; 12:38-54. [PMID: 31143362 PMCID: PMC6527184 DOI: 10.1080/19420889.2019.1586047] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Revised: 02/12/2019] [Accepted: 02/15/2019] [Indexed: 12/25/2022] Open
Abstract
A number of theories have been proposed to explain the exteriorization of the testicles in most mammalian species. None of these provide a consistent account for the wide variety of testicular locations found across the animal kingdom. It is proposed that testicular location is the result of coordinate action of testicular tissue ecologies to sustain preferential states of homeostatic equipoise throughout evolutionary development in response to the advent of endothermy.
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Affiliation(s)
| | - John S. Torday
- Department of Pediatrics, Harbor-UCLA Medical Center, Torrance, CA, USA
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33
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Thaker M, Gupte PR, Prins HHT, Slotow R, Vanak AT. Fine-Scale Tracking of Ambient Temperature and Movement Reveals Shuttling Behavior of Elephants to Water. Front Ecol Evol 2019. [DOI: 10.3389/fevo.2019.00004] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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34
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Purdon A, Mole MA, Chase MJ, van Aarde RJ. Partial migration in savanna elephant populations distributed across southern Africa. Sci Rep 2018; 8:11331. [PMID: 30054547 PMCID: PMC6063881 DOI: 10.1038/s41598-018-29724-9] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2017] [Accepted: 07/16/2018] [Indexed: 11/09/2022] Open
Abstract
Migration is an important, but threatened ecological process. Conserving migration requires the maintenance of functional connectivity across sufficiently large areas. Therefore, we need to know if, where and why species migrate. Elephants are highly mobile and can travel long distances but we do not know if they migrate. Here, we analysed the movement trajectories of 139 savanna elephants (Loxodonta africana) within eight clusters of protected areas across southern Africa to determine if elephants migrate, and if so, where, how and why they migrate. Only 25 of these elephants migrated. Elephants are a facultative partially migratory species, where only some individuals in a population migrate opportunistically, and not every year. Elephants migrated between distinct seasonal ranges corresponding to southern Africa’s dry and wet seasons. The timing of wet season migrations was associated with the onset of rainfall and the subsequent greening up of forage. Conversely, the duration, distance, and the timing of dry season migrations varied idiosyncratically. The drivers of elephant migration are likely a complex interaction between individual traits, density, and the distribution and availability of resources. Despite most migrations crossing administrative boundaries, conservation networks provided functional space for elephants to migrate.
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Affiliation(s)
- Andrew Purdon
- Conservation Ecology Research Unit, Department of Zoology and Entomology, University of Pretoria, Pretoria, 0028, South Africa
| | - Michael A Mole
- Conservation Ecology Research Unit, Department of Zoology and Entomology, University of Pretoria, Pretoria, 0028, South Africa
| | | | - Rudi J van Aarde
- Conservation Ecology Research Unit, Department of Zoology and Entomology, University of Pretoria, Pretoria, 0028, South Africa.
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35
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Mole MA, Rodrigues DÁraujo S, van Aarde RJ, Mitchell D, Fuller A. Savanna elephants maintain homeothermy under African heat. J Comp Physiol B 2018; 188:889-897. [DOI: 10.1007/s00360-018-1170-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2018] [Revised: 06/06/2018] [Accepted: 07/02/2018] [Indexed: 12/01/2022]
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36
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Mitchell D, Snelling EP, Hetem RS, Maloney SK, Strauss WM, Fuller A. Revisiting concepts of thermal physiology: Predicting responses of mammals to climate change. J Anim Ecol 2018; 87:956-973. [DOI: 10.1111/1365-2656.12818] [Citation(s) in RCA: 105] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2017] [Accepted: 01/17/2018] [Indexed: 11/29/2022]
Affiliation(s)
- Duncan Mitchell
- Brain Function Research Group; School of Physiology; Faculty of Health Sciences; University of the Witwatersrand; Johannesburg South Africa
- School of Human Sciences; University of Western Australia; Crawley WA Australia
| | - Edward P. Snelling
- Brain Function Research Group; School of Physiology; Faculty of Health Sciences; University of the Witwatersrand; Johannesburg South Africa
| | - Robyn S. Hetem
- Brain Function Research Group; School of Physiology; Faculty of Health Sciences; University of the Witwatersrand; Johannesburg South Africa
- School of Animal, Plant and Environmental Sciences; Faculty of Science; University of the Witwatersrand; Johannesburg South Africa
| | - Shane K. Maloney
- Brain Function Research Group; School of Physiology; Faculty of Health Sciences; University of the Witwatersrand; Johannesburg South Africa
- School of Human Sciences; University of Western Australia; Crawley WA Australia
| | - Willem Maartin Strauss
- Brain Function Research Group; School of Physiology; Faculty of Health Sciences; University of the Witwatersrand; Johannesburg South Africa
- Department of Environmental Science; University of South Africa; Johannesburg South Africa
| | - Andrea Fuller
- Brain Function Research Group; School of Physiology; Faculty of Health Sciences; University of the Witwatersrand; Johannesburg South Africa
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