1
|
Hariohay KM, Hunninck L, Ranke PS, Fyumagwa RD, Palme R, Røskaft E. Between hunter and climate: the effects of hunting and environmental change on fecal glucocorticoid metabolite levels in two sympatric ungulate species in the Ruaha-Rungwa ecosystem, Tanzania. CONSERVATION PHYSIOLOGY 2023; 11:coad002. [PMID: 38026801 PMCID: PMC10660377 DOI: 10.1093/conphys/coad002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Revised: 11/22/2022] [Accepted: 01/31/2023] [Indexed: 12/01/2023]
Abstract
Understanding the drivers of animal population decline is a key focus of conservation biologists. Anthropogenic activities such as hunting have long been established as potentially detrimental to a population's persistence. However, environmental perturbations such as increased temperature variability, exacerbated by climate change, can also have important effects on animal populations. Animals can respond to these challenges by adjusting both their behavior and physiology. We measured fecal glucocorticoid metabolites (FGMs) of common impala (Aepyceros melampus) and greater kudu (Tragelaphus strepsiceros), both currently in stable populations, to examine effects of hunting, forage availability, daily variability in temperature and group size on their physiological stress response. The study was conducted across two adjacent protected areas, (i) one non-hunted area (Ruaha National Park; RNP) and (ii) one area used for trophy hunting (Rungwa Game Reserve; RGR). Both impala and kudu had significantly higher FGM levels in the area that allows hunting, while FGM levels decreased with increasing forage availability and increasing daily temperature. Moreover, impala (but not kudu) had lower FGM levels with larger group sizes. Our results indicate that the management regime can significantly alter the physiological state of wild ungulate populations. We also highlight the importance of considering the combined effects of anthropogenic, environmental and social contexts when studying the stress response of wild populations. Our results emphasize the value of protected areas and continued monitoring of hunting quota in order to maintain ungulate populations that are less vulnerable to population declines.
Collapse
Affiliation(s)
- Kwaslema Malle Hariohay
- Department of Wildlife Management, College of African Wildlife Management, Mweka, P. O. Box 3031, Moshi, Tanzania
- Department of Biology, Norwegian University of Science and Technology, Realfagbygget, NO-7491, Trondheim, Norway
| | - Louis Hunninck
- Department of Biology, Norwegian University of Science and Technology, Realfagbygget, NO-7491, Trondheim, Norway
- Department of Natural Resources and Environmental Sciences, University of Illinois Urbana-Champaign, Urbana, IL 61801, USA
| | - Peter S Ranke
- Department of Biology, Norwegian University of Science and Technology, Realfagbygget, NO-7491, Trondheim, Norway
- Center for Biodiversity Dynamics (CBD), Department of Biology, Norwegian University of Science and Technology, Realfagbygget, NO-7491, Trondheim, Norway
| | - Robert D Fyumagwa
- Department of Wildlife Management, Tanzania Wildlife Research Institute (TAWIRI), P.O. Box 661, Arusha
| | - Rupert Palme
- Department of Biomedical Sciences, University of Veterinary Medicine, Vienna
| | - Eivin Røskaft
- Department of Biology, Norwegian University of Science and Technology, Realfagbygget, NO-7491, Trondheim, Norway
| |
Collapse
|
2
|
Pasciu V, Sotgiu FD, Nieddu M, Porcu C, Berlinguer F. Measurement of fecal T3 metabolite levels in sheep: Analytical and biological validation of the method. Front Vet Sci 2022; 9:1011651. [PMID: 36504867 PMCID: PMC9733671 DOI: 10.3389/fvets.2022.1011651] [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: 08/04/2022] [Accepted: 11/10/2022] [Indexed: 11/27/2022] Open
Abstract
Introduction Biological sample collection from wild and farms animals is often associated with difficulties related to the handling and restraint procedures, and most of the time it could induce stress, altering the welfare and physiological homeostasis. The analysis of fecal T3 metabolites (FTMs) allows to test samples collected in a non-invasive manner, providing several information about the animal's physiological conditions and the effects related to environmental and nutritional variations. This procedure has found wide application in wild species, but less in domestic ones. Methods The aim of this work was to validate the use of an immuno-enzymatic competitive ELISA kit, designed for T3 quantification in human blood serum samples, for the assessment of FTMs in the sheep. For the analytical validation, precision, recovery and parallelism were evaluated; for biological validation the variations of FTMs in relation to age, sex and the physiological status of the animal were determined. Results After a verification of the precision (RSD % < 15%), mean recovery (75%) and parallelism (CV% < 10%), the kit was used to measure FTMs in cyclic, pregnant, and early lactating ewes as well as in rams and ewe lambs. The results showed that FTMs concentrations in pregnant ewes were significantly lower (p < 0.05) than in cyclic and early lactation ones. Furthermore, there were no significant differences in FTMs levels between ewes and rams, while in lambs FTMs levels were higher than in adults (p < 0.001). Conclusion In conclusion the present study demonstrates that FTMs can be reliably and accurately determined in sheep feces, using an ELISA kit formulated for human serum T3 assay. The application of this method in the livestock sector could allow to improve our knowledge about the response of animals to different physiological and environmental conditions, and thus assess their welfare.
Collapse
Affiliation(s)
- Valeria Pasciu
- Department of Veterinary Medicine, University of Sassari, Sassari, Italy,*Correspondence: Valeria Pasciu
| | | | - Maria Nieddu
- Department of Chemistry and Pharmacy, University of Sassari, Sassari, Italy
| | - Cristian Porcu
- Department of Veterinary Medicine, University of Sassari, Sassari, Italy
| | | |
Collapse
|
3
|
Pasciu V, Nieddu M, Baralla E, Muzzeddu M, Porcu C, Sotgiu FD, Berlinguer F. Non-invasive Assay for Measurement of Fecal Triiodothyronine (T3) Metabolite Levels in European Mouflon (Ovis aries musimon). Front Vet Sci 2022; 9:851794. [PMID: 35711806 PMCID: PMC9196329 DOI: 10.3389/fvets.2022.851794] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Accepted: 04/27/2022] [Indexed: 11/24/2022] Open
Abstract
Thyroid hormones (THs) are important indicators of metabolism and animal health. Traditionally, they have been determined from blood or urine samples. However, as their collection may be stressful and requires ethical approval, alternative non-invasive matrices are preferred when dealing with wild animals. Triiodothyronine (T3) is the active form of THs in blood and the major metabolite excreted in feces. This creates the ideal conditions for its assay in fecal samples. Fecal sampling eliminates the stress of the animals and the need to physically capture them. However, in wild species it is rare to find species-specific kits for the hormone assay. So, the objective of this work was to validate a method for the quantification of T3 metabolite (FTM) levels in feces of European mouflon by using an economic and easily available ELISA kit designed to quantify T3 in human plasma. Analytical and biological validations were performed in feces collected from 10 mouflons (5 ewes and 5 rams). An efficient liquid-extraction method was optimized. Precision, dilution linearity, parallelism, recovery and stability of T3 in fecal samples were calculated. Obtained data were considered acceptable according to international guidelines. The reliability of the results was verified comparing human plasma and mouflon fecal samples fortified with the same T3 standard solutions. The biological validation showed higher FTM levels in March compared to June, and no differences between mouflon ewes and rams. The validation of the present method provides a non-invasive and affordable tool for the quantification of FTM in European mouflon.
Collapse
Affiliation(s)
- Valeria Pasciu
- Department of Veterinary Medicine, University of Sassari, Sassari, Italy
- *Correspondence: Valeria Pasciu
| | - Maria Nieddu
- Department of Chemistry and Pharmacy, University of Sassari, Sassari, Italy
| | - Elena Baralla
- Department of Veterinary Medicine, University of Sassari, Sassari, Italy
| | - Marco Muzzeddu
- Agenzia Regionale FoReSTAS, Centro di Allevamento e Recupero della fauna Selvatica di Bonassai, Sassari, Italy
| | - Cristian Porcu
- Department of Veterinary Medicine, University of Sassari, Sassari, Italy
| | | | | |
Collapse
|
4
|
Malherbe M, McIntyre T, Hattingh TV, Leresche PM, Haussmann NS. Mammal road-type associations in Kruger National Park, South Africa: Common mammals do not avoid tar roads more than dirt roads. Ecol Evol 2021; 11:15622-15629. [PMID: 34824778 PMCID: PMC8601909 DOI: 10.1002/ece3.8190] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Revised: 09/10/2021] [Accepted: 09/13/2021] [Indexed: 11/11/2022] Open
Abstract
The majority of Africa's parks and conservation areas have a vast road network, facilitating motorized vehicle game viewing. These roads have an influence that is both road type- and species-specific, on the surrounding ecosystem. Due to their higher traffic volumes, we hypothesized that tar roads and their immediate surrounds within the Kruger National Park, South Africa, are avoided to a greater extent by medium-to-large mammals than comparable dirt roads in the park. We systematically recorded the presence of medium-to-large mammal species from our vehicle, recording data at 401 tar and 369 dirt road stops in the Kruger National Park. In addition to species presence, we also estimated the proximity of animals to the road, as well as herd sizes. Our results indicate an equal likelihood of viewing the commonly recorded medium-to-large mammal species from both road types. The likelihood of observing larger herd sizes was also similar between tar and dirt roads for the three most commonly observed species, African elephant (Loxodonta africana), impala (Aepyceros melampus), and plains zebra (Equus quagga), and the likelihood of viewing impala and zebra close to the road also did not differ between tar and dirt roads. However, elephant was observed more often close to tar roads, compared to dirt roads. We interpreted this as the result of potentially increased woody cover associated with more water runoff in close proximity to tar roads compared with dirt roads. Our results not only have ecological significance, supporting the notion that many of the park's species are habituated to human infrastructure, but also management implications, informing park officials about the influence of road traffic and road type on wildlife distributions.
Collapse
Affiliation(s)
- Misha Malherbe
- Department of Geography, Geoinformatics and MeteorologyUniversity of PretoriaHatfieldSouth Africa
| | - Trevor McIntyre
- Department of Life and Consumer SciencesUniversity of South AfricaFloridaSouth Africa
| | - Tarryn V. Hattingh
- Department of Geography, Geoinformatics and MeteorologyUniversity of PretoriaHatfieldSouth Africa
| | - Paige M. Leresche
- Department of Geography, Geoinformatics and MeteorologyUniversity of PretoriaHatfieldSouth Africa
| | - Natalie S. Haussmann
- Department of Geography, Geoinformatics and MeteorologyUniversity of PretoriaHatfieldSouth Africa
| |
Collapse
|
5
|
Lyamuya RD, Hariohay KM, Masenga EH, Bukombe JK, Mwakalebe GG, Mdaki ML, Nkwabi AK, Fyumagwa RD, Røskaft E. Magnitude, patterns and composition of wildlife roadkill in the Serengeti ecosystem, northern Tanzania. AFRICAN ZOOLOGY 2021. [DOI: 10.1080/15627020.2021.1952896] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Affiliation(s)
| | | | | | | | | | | | - Ally K Nkwabi
- Tanzania Wildlife Research Institute, Arusha, Tanzania
| | | | - Eivin Røskaft
- Department of Biology, Norwegian University of Science and Technology, Trondheim, Norway
| |
Collapse
|
6
|
Flølo LM, Hunninck L, May R, Jackson CR, Setsaas TH, Holmern T, Røskaft E. Behavioural and demographic changes in impala populations after 15 years of improved conservation management. Glob Ecol Conserv 2021. [DOI: 10.1016/j.gecco.2021.e01586] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
|
7
|
Influence of cereal harvest on adrenocortical activity in European hares (Lepus europaeus). EUR J WILDLIFE RES 2020. [DOI: 10.1007/s10344-020-01430-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
AbstractAnthropogenic disturbances, such as habitat modifications and machines, are associated with increased levels of faecal glucocorticoid metabolites (fGCMs) in mammals, an indicator of a stress response. One human-caused process provoking incisive habitat alterations is harvesting arable crops. We investigated the effect of cereal harvest on fGCM concentrations in European hares (Lepus europaeus) in arable landscapes in lower Austria during the year 2018 by collecting 591 faecal samples before, during and after cereal harvest. fGCMs were analysed using an enzyme immunoassay, and data were analysed using linear mixed-effects models. We found that neither cereal harvest nor farming practice (organic vs. conventional) caused an overall increase in the hares’ stress level. Lower vegetation density and higher proportions of bare ground were negatively correlated with fGCM concentrations, whereas the proportion of stubble fields was significantly positively correlated with fGCM concentrations in European hares. A change to more open landscapes might decrease time spent avoiding predation, and fallen grains may provide a beneficial additional food source for the hares. This indicates that European hares are well adapted to an opening up of the landscape and short-term disturbances such as cereal harvesting. In conclusion, cereal harvest had no large impact on European hares’ adrenocortical activity in an arable landscape with small average field size and enough available non-farmed areas.
Collapse
|
8
|
Monette VD, Kelly MJ, Buchholz R. Human disturbance and the activity patterns and temporal overlap of tapirs and jaguars in reserves of NW Belize. Biotropica 2020. [DOI: 10.1111/btp.12834] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
| | - Marcella J. Kelly
- Department of Fish and Wildlife Conservation Virginia Tech Blacksburg VA USA
| | - Richard Buchholz
- Department of Biology University of Mississippi, University MS USA
- Center for Biodiversity & Conservation Research University of Mississippi, University MS USA
| |
Collapse
|
9
|
Hunninck L, Palme R, Sheriff MJ. Stress as a facilitator? Territorial male impala have higher glucocorticoid levels than bachelors. Gen Comp Endocrinol 2020; 297:113553. [PMID: 32687935 DOI: 10.1016/j.ygcen.2020.113553] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/15/2019] [Revised: 06/12/2020] [Accepted: 07/14/2020] [Indexed: 11/25/2022]
Abstract
Territoriality is a common behavioural adaptation, widespread among ungulates. Here, we tested the hypothesis that territorial individuals have higher glucocorticoid concentrations than non-territorial bachelors, in wild impala (Aepyceros melampus) in the Serengeti ecosystem. We also investigated how the relationship between territoriality and glucocorticoid levels is influenced by environmental context, specifically, food quality, population density (i.e., territory defence intensity), and herd size (i.e., mate defence effort). We collected 139 faecal samples over 4 years and analysed these for faecal glucocorticoid metabolites (FGMs). We used Normalised Difference Vegetation Index (NDVI) as a proxy for food quality, and population density was based on aerial surveys. Territorial males had, on average, higher FGM concentrations than bachelors. Increased food quality did not affect FGM levels in territorial males, but decreased FGM levels in bachelors by 78%. Greater population density increased FGM levels by 47%, but this effect was not different between territorial and bachelor males. Herd size did not affect FGM levels in territorial males. While elevated GC levels are often suggested to be repercussions of being territorial, our findings support the hypothesis that elevated GC levels may be beneficial and act as a facilitator of a male's reproductive potential. The elevated GC levels may increase the ability of territorial males to maintain a territory by increasing energy mobilisation and metabolic rate, ultimately increasing their reproductive fitness. Appreciating that long-term increases in GC levels are not simply costly but may have an adaptive, potentially facilitating role in an animal's life history is key to understanding HPA-axis reactivity and its potential in eco-physiological studies.
Collapse
Affiliation(s)
- L Hunninck
- Norwegian University of Science and Technology, Norway; University of Massachusetts Dartmouth, United States.
| | - R Palme
- University of Veterinary Medicine, Austria
| | - M J Sheriff
- University of Massachusetts Dartmouth, United States
| |
Collapse
|
10
|
Hill JE, DeVault TL, Belant JL. A review of ecological factors promoting road use by mammals. Mamm Rev 2020. [DOI: 10.1111/mam.12222] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Affiliation(s)
- Jacob E. Hill
- Global Wildlife Conservation Center State University of New York College of Environmental Science and Forestry 1 Forestry Drive Syracuse NY13210USA
- Savannah River Ecology Laboratory University of Georgia PO Drawer E Aiken SC29802USA
| | - Travis L. DeVault
- Savannah River Ecology Laboratory University of Georgia PO Drawer E Aiken SC29802USA
| | - Jerrold L. Belant
- Global Wildlife Conservation Center State University of New York College of Environmental Science and Forestry 1 Forestry Drive Syracuse NY13210USA
| |
Collapse
|
11
|
Hunninck L, May R, Jackson CR, Palme R, Røskaft E, Sheriff MJ. Consequences of climate-induced vegetation changes exceed those of human disturbance for wild impala in the Serengeti ecosystem. CONSERVATION PHYSIOLOGY 2020; 8:coz117. [PMID: 32477568 PMCID: PMC7246078 DOI: 10.1093/conphys/coz117] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/02/2019] [Revised: 12/11/2019] [Accepted: 12/29/2019] [Indexed: 05/21/2023]
Abstract
In East Africa, climate change is predicted to reduce vegetation quality, and pervasive human disturbance has already resulted in significant declines in biodiversity. We studied the combined effects of reduced forage quality and human disturbance on faecal glucocorticoid metabolite (FGM) concentrations. We predicted that decreasing nutritional quality and increasing human disturbance would have an additive positive effect on FGM levels in wild impala (Aepyceros melampus). Employing a space-for-time approach, we used normalized difference vegetation index (NDVI) as a measure of forage quality, combined with spatially explicit proxies of human disturbance across areas of different protection management strategies in the Serengeti ecosystem. We collected 639 faecal samples, spread over 4 years, including both wet and dry seasons. Impala FGM levels increased significantly with declining NDVI and, to a lesser extent, with increasing proxies for human disturbance. However, we found no interaction between the two, such that impala had elevated FGM levels with low NDVI and low FGM levels with high NDVI regardless of human disturbance levels. This implies that impala will have high FGM levels if forage quality is poor, even with significant protection and reduced human disturbance. Understanding how animals respond to and cope with changes in forage quality and human land use across different protected areas is important for conservationists and managers to better protect species at risk and predict population viability.
Collapse
Affiliation(s)
- L Hunninck
- Department of Biology, Norwegian University of Science and
Technology, Høgskoleringen 5, 7034 Trondheim, Norway
- Corresponding author: NTNU, Høgskoleringen 1, 7491 Trondheim, Norway.
Tel: +47 474 43 361.
| | - R May
- Norwegian Institute for Nature Research, Høgskoleringen 9, 7034
Trondheim, Norway
| | - C R Jackson
- Norwegian Institute for Nature Research, Høgskoleringen 9, 7034
Trondheim, Norway
| | - R Palme
- Department of Biomedical Sciences, University of Veterinary
Medicine, Veterinärplatz 1, 1210 Vienna, Austria
| | - E Røskaft
- Department of Biology, Norwegian University of Science and
Technology, Høgskoleringen 5, 7034 Trondheim, Norway
| | - M J Sheriff
- Biology Department, University of Massachusetts, 285 Old Westport
Road, Dartmouth, MA 02747, USA
| |
Collapse
|
12
|
Jackson CR, Fossøy F, Røskaft E, May R. Do impala really avoid tourist roads? A response to Mulero‐Pázmány, D'Amico & González‐Suárez (2016). J Zool (1987) 2017. [DOI: 10.1111/jzo.12483] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- C. R. Jackson
- Norwegian Institute for Nature Research Trondheim Norway
| | - F. Fossøy
- Norwegian Institute for Nature Research Trondheim Norway
- Norwegian University of Science and Technology Trondheim Norway
| | - E. Røskaft
- Norwegian University of Science and Technology Trondheim Norway
| | - R. May
- Norwegian Institute for Nature Research Trondheim Norway
| |
Collapse
|
13
|
González‐Suárez M, D'Amico M, Mulero‐Pázmány M. Advancing road ecology in Africa with robust analyses and cautious inferences: a response to Jackson
et al
. (2017). J Zool (1987) 2017. [DOI: 10.1111/jzo.12484] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- M. González‐Suárez
- Ecology and Evolutionary Biology School of Biological Sciences University of Reading Reading UK
| | - M. D'Amico
- CIBIO/InBIO – Centro de Investigação em Biodiversidade e Recursos Genéticos Universidade do Porto Vairão Portugal
- CEABN/InBIO Instituto Superior de Agronomia Universidade de Lisboa Lisboa Portugal
| | - M. Mulero‐Pázmány
- Department of Natural Sciences Universidad Técnica Particular de Loja Loja Ecuador
| |
Collapse
|