Research Articles (Centre for Veterinary Wildlife Studies)

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Does sex matter in the cheetah? Insights into the skeletal muscle of the fastest land animal
(Company of Biologists, 2024-08) Kohn, Tertius Abraham; Knobel, Samantha; Donaldson, Byron; Van Boom, Kathryn Merle; Blackhurst, Dee M.; Peart, James M.; Jensen, Jorgen; Tordiffe, Adrian Stephen Wolferstan
The cheetah is considered the fastest land animal, but studies on their skeletal muscle properties are scarce. Vastus lateralis biopsies, obtained from male and female cheetahs as well as humans, were analysed and compared for fibre type and size, and metabolism. Overall, cheetah muscle had predominantly type IIX fibres, which was confirmed by the myosin heavy chain isoform content (mean±s.d. type I: 17±8%, type IIA: 21±6%, type IIX: 62±12%), whereas humanmuscle contained predominantly type I and IIA fibres (type I: 49±14%, type IIA: 43±8%, type IIX: 7±7%). Cheetahs had smaller fibres than humans, with larger fibres in the males compared with their female counterparts. Citrate synthase (16±6 versus 28±7 μmol min−1 g−1 protein, P<0.05) and 3-hydroxyacyl co-enzyme A dehydrogenase (30±11 versus 47 ±15 μmol min−1 g−1 protein, P<0.05) activities were lower in cheetahs than in humans, whereas lactate dehydrogenase activity was 6 times higher in cheetahs (2159±827 versus 382±161 μmolmin−1 g−1 protein, P<0.001). The activities of creatine kinase (4765±1828 versus 6485 ±1298, P<0.05 μmol min−1 g−1 protein) and phosphorylase (111±29 versus 216±92 μmol min−1 g−1 protein) were higher in humans, irrespective of the higher type IIX fibres in cheetahs. Superoxide dismutase and catalase,markers of antioxidant capacity, were higher in humans, but overall antioxidant capacity was higher in cheetahs. To conclude, fibre type, fibre size andmetabolismdiffer between cheetahs and humans, with limited differences between the sexes.
The hearts of large mammals generate higher pressures, are less efficient and use more energy than those of small mammals
(Company of Biologists, 2024-10) Snelling, Edward P.; Seymour, Roger S.; edward.snelling@up.ac.za
A prevailing assumption in the cardiovascular field is that the metabolic rate of the heart is a constant proportion of a mammal’s whole-body aerobic metabolic rate. In this Commentary, we assemble previously published cardiovascular, metabolic and body mass data from matched terrestrial mammalian species, at rest and during heavy exercise, and reveal scaling relationships that challenge this assumption. Our analyses indicate that the fractional metabolic cost of systemic perfusion compared with whole-body metabolic rate increases significantly with body size among resting mammals, from ∼2.5% in a mouse to ∼10% in an elephant. We propose that two significant body size-dependent effects contribute to this conclusion; namely, that larger species generate higher mean systemic arterial blood pressure and that their myocardium operates with lower external mechanical efficiencies compared with those of smaller species. We discuss potential physiological and mechanical explanations, including the additional energy needed to support the arterial blood column above the heart in larger species, especially those with long necks, as well as the possible sources of greater internal energy losses from the heart of larger species. Thus, we present an updated view of how increasing blood pressure and decreasing efficiency of the myocardium result in an increasing fractional metabolic cost of perfusion as body size increases among resting mammals.
Measurement of microclimates in a warming world : problems and solutions
(Company of Biologists, 2024-07) Mitchell, Duncan; Maloney, Shane K.; Snelling, Edward P.; Fonseca, Vinı́cius de França Carvalho; Fuller, Andrea
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.
Unravelling the maternal evolutionary history of the African leopard (Panthera pardus pardus)
(PeerJ Inc., 2024-04) Morris, Declan R.; McWhorter, Todd J.; Boardman, Wayne S.J.; Simpson, Gregory J.G.; Wentzel, Jeanette Maria; Coetzee, Jannie; Moodley, Yoshan
The African leopard (Panthera pardus pardus) has lost a significant proportion of its historical range, notably in north-western Africa and South Africa. Recent studies have explored the genetic diversity and population structure of African leopards across the continent. A notable genetic observation is the presence of two divergent mitochondrial lineages, PAR-I and PAR-II. Both lineages appeared to be distributed widely, with PAR-II frequently found in southern Africa. Until now, no study has attempted to date the emergence of either lineage, assess haplotype distribution, or explore their evolutionary histories in any detail. To investigate these underappreciated questions, we compiled the largest and most geographically representative leopard data set of the mitochondrial NADH-5 gene to date. We combined samples (n = 33) collected in an altitudinal transect across the Mpumalanga province of South Africa, where two populations of leopard are known to be in genetic contact, with previously published sequences of African leopard (n = 211). We estimate that the maternal PAR-I and PAR-II lineages diverged approximately 0.7051 (0.4477–0.9632) million years ago (Ma). Through spatial and demographic analyses, we show that while PAR-I underwent a mid-Pleistocene population expansion resulting in several closely related haplotypes with little geographic structure across much of its range, PAR-II remained at constant size and may even have declined slightly in the last 0.1 Ma. The higher genetic drift experienced within PAR-II drove a greater degree of structure with little haplotype sharing and unique haplotypes in central Africa, the Cape, KwaZulu-Natal and the South African Highveld. The phylogeographic structure of PAR-II, with its increasing frequency southward and its exclusive occurrence in south-eastern South Africa, suggests that this lineage may have been isolated in South Africa during the mid-Pleistocene. This hypothesis is supported by historical changes in paleoclimate that promoted intense aridification around the Limpopo Basin between 1.0–0.6 Ma, potentially reducing gene flow and promoting genetic drift. Interestingly, we ascertained that the two nuclear DNA populations identified by a previous study as East and West Mpumalanga correspond to PAR-I and PAR-II, respectively, and that they have come into secondary contact in the Lowveld region of South Africa. Our results suggest a subdivision of African leopard mtDNA into two clades, with one occurring almost exclusively in South Africa, and we identify the potential environmental drivers of this observed structure. We caution that our results are based on a single mtDNA locus, but it nevertheless provides a hypothesis that can be further tested with a dense sample of nuclear DNA data, preferably whole genomes. If our interpretation holds true, it would provide the first genetic explanation for the smaller observed size of leopards at the southernmost end of their range in Africa.
Promoting rhinoceros welfare during transit : veterinarians' perspectives on transportation practices
(Medpharm Publications, 2024-11) Macha, E.S.; Meyer, Leith Carl Rodney; Leiberich, Marion; Hofmeyr, M.; Hooijberg, Emma Henriette; emma.hooijberg@up.ac.za
Despite translocation being a useful conservation strategy in rhinoceros management, morbidities and mortalities occurring during transportation pose a significant concern to rhinoceros managers, veterinarians, and scientists. The objectives of this study were to better understand the effects of transport on rhinoceros and to gain insights from veterinarians involved in rhinoceros translocations about current practices and potential interventions that could improve welfare. A weblink and QR code to an online questionnaire with a total of 46 questions in Google Forms was sent to veterinarians who had experience in African rhinoceros transportation, through personal emails and social network forums. Results demonstrated that despite dehydration and negative energy balance being reported as the major causes of morbidities and mortalities during transport and post-release, most veterinarians (30/35; 86%) involved in rhinoceros translocation did not offer water, parenteral fluids, or feed to transported animals, for logistical reasons and the knowledge or perception of rhinoceros' resistance to taking ad lib food and water during transport. However, 52% (15/29) and 41% (15/34) of participants suggested that parenteral fluids could be used as an intervention to mitigate dehydration and negative energy balance respectively. To reduce stress, 94% (33/35) of respondents suggested the use of tranquilisers and sedatives. This study is the first to systematically investigate and report on practices by veterinarians involved in rhinoceros translocations globally. The study highlights that further research is required to explore optimal and pragmatic techniques in the field to mitigate reported welfare challenges in rhinoceros during transport.
Genetic characterization of diagnostic epitopes of cardiac troponin I in African rhinoceros
(Sage, 2025-03) Rautenbach, Yolandi; Parsons, Sven David Charles; Loots, Angelika Katrin; Goddard, Amelia; Meyer, Leith Carl Rodney; Buss, Peter Erik; Hooijberg, Emma Henriette
African rhinoceros undergo chemical immobilization and prolonged transport during translocations for conservation purposes and, hence, experience several pathophysiologic changes, including skeletal muscle injury. Potential concurrent myocardial injury has not been investigated due to a lack of validated immunoassays. We aimed to use inferred cardiac troponin I (cTnI) amino acid sequences of southern white (Ceratotherium simum simum) and southern-central black (Diceros bicornis minor) rhinoceros to assess the potential usefulness of several commercial cTnI immunoassays for detecting cTnI in African rhinoceros. We extracted RNA from the myocardium of deceased rhinoceros (2 white, 1 black rhinoceros) followed by primer design, cDNA synthesis via RT-PCR, and Sanger sequencing. The inferred cTnI amino acid sequences were obtained from the mRNA transcript sequences. The homology of epitope binding sites recognized by capture and detection antibodies in 6 human immunoassays was visually evaluated using aligned inferred rhinoceros cTnI amino acid sequences. Percentage identity between white and black rhinoceros cDNA nucleotide sequences was 99%; inferred amino acid sequences were identical. There were 5 amino acid differences between humans and rhinoceros in the epitope binding sites of immunoassay antibodies; 5 assays contained antibodies against epitopes that were not conserved. For one assay, the single capture antibody targeted a short heterologous epitope (residue 87–91), and cross-reactivity with rhinoceros cTnI was deemed unlikely. For the other 5 assays, complete antibody-epitope homology, or the inclusion of multiple detection or capture antibodies, or targeting of long epitopes, indicated that these assays could be suitable for further investigation of cTnI measurement in African rhinoceros.
Clinical Coxiella burnetii infection in sable and roan antelope in South Africa
(AOSIS, 2024-07-26) Wiedeman, Wikus; Glover, Akorfa B.; Steyl, Johan Christian Abraham; O'Dell, Jacques Henry; Van Heerden, Henriette; henriette.vanheerden@up.ac.za
Various zoonotic microorganisms cause reproductive problems such as abortions and stillbirths, leading to economic losses on farms, particularly within livestock. In South Africa, bovine brucellosis is endemic in cattle, and from 2013–2018, outbreaks of Brucella melitensis occurred in sable. Coxiella burnetii, the agent responsible for the zoonotic disease known as Q-fever and/or coxiellosis, also causes reproductive problems and infects multiple domestic animal species worldwide, including humans. However, little is known of this disease in wildlife. With the expansion of the wildlife industry in South Africa, diseases like brucellosis and coxiellosis can significantly impact herd breeding success because of challenges in identifying, managing and treating diseases in wildlife populations. This study investigated samples obtained from aborted sable and roan antelope, initially suspected to be brucellosis, from game farms in South Africa using serology tests and ruminant VetMAX™ polymerase chain reaction (PCR) abortion kit. The presence of C. burnetii was confirmed with PCR in a sable abortion case, while samples from both sable and roan were seropositive for C. burnetii indirect enzyme-linked immunosorbent assay (iELISA). This study represents the initial report of C. burnetii infection in sable and roan antelope in South Africa. Epidemiological investigations are crucial to assess the risk of C. burnetii in sable and roan populations, as well as wildlife and livestock in general, across South Africa. This is important in intensive farming practices, particularly as Q-fever, being a zoonotic disease, poses a particular threat to the health of veterinarians and farm workers as well as domestic animals.
Case report : discovery of tuberculosis caused by Mycobacterium bovis in free-ranging vervet monkeys in the Greater Kruger Conservation Area
(Frontiers Media, 2024-12) De Klerk-Lorist, Lin-Mari; Miller, Michele A.; Mitchell, Emily P.; Lorist, Rudolf; Van Dyk, David Schalk; Mathebula, Nomkhosi; Goosen, Louise; Dwyer-Leonard, Rebecca; Ghielmetti, Giovanni; Streicher, Elizabeth M.; Kerr, Tanya J.
Animal tuberculosis (TB) has been reported in several wildlife species in the Greater Kruger Conservation Area (GKCA), South Africa. This report describes the discovery of clinical tuberculosis, caused by Mycobacterium bovis (M. bovis), in free-ranging vervet monkeys (Chlorocebus pygerythrus). The “One Health” concept is especially relevant to TB since this is a multi-host disease with zoonotic potential and is endemic in GKCA. Vervet monkeys have become habituated to humans in tourist areas and may be a source of infection through close contact. Indirect transmission of M. bovis through environmental sources has also been suspected to present a risk of spread between host species. Clinically diseased monkeys present in two tourist areas in the GKCA, that died (n = 1) or were euthanized (n = 5), were submitted for diagnostic necropsies. The presence of pathological lesions, Ziehl-Neelsen-stained impression smears, Xpert® MTB/RIF Ultra (GXU) assay, mycobacterial culture and speciation by genomic regions of difference PCR, were used to confirm the diagnosis of M. bovis infection in these monkeys. The finding of multiple cases necessitates further investigation of TB in monkey troops living within the GKCA tourist areas to determine the source of infection and assess the risk of transmission to other animals and humans.
Ketamine-butorphanol-medetomidine for the immobilisation of free-living hyenas (Crocuta crocuta)
(Medpharm Publications, 2024-03) Roug, Annette; Meyer, Leith Carl Rodney; Netshitavhadulu, L.; Leiberich, Marion; Buss, Peter
Free-ranging spotted hyenas (Crocuta crocuta) are immobilised for a variety of purposes, including wildlife-human conflict mitigation, research, and veterinary treatment. Combinations of tiletamine-zolazepam (Zoletil) and medetomidine are commonly used for immobilisation of hyenas, however, recovery times are long. In this descriptive study, a total of 20 adult or subadult free-ranging hyenas were immobilised near Skukuza in the Kruger National Park using ketamine, butorphanol, and medetomidine. The goal of the study was to evaluate a suitable dose and measure cardiorespiratory effects of this combination. The quality of induction and recovery were scored using an established scoring system from 1 (excellent) to (poor). Twelve of the 20 hyenas were given an induction score of 1 (excellent), five an induction score of 2 (good), and three an induction score of 3 (fair). Of the animals with induction score = 1, the mean drug dose was 1.17 mg/kg ketamine, 0.25 mg/kg butorphanol and 0.03 mg/kg medetomidine, and the mean induction time and time to handling 6:25 minutes and 9:46 minutes respectively. The mean recovery time (from reversal to standing) was 10:16 min, which is shorter than what has been reported for tiletaminezolazepam- based combinations in hyenas. Most hyenas were bradycardic (< 40 beats per minute) and the mean PaO2 69.5 mmHg. Three hyenas, one with induction score = 2, and two with induction scores = 3 spontaneously recovered at 33, 44 and 56 minutes post approach respectively. Regardless of induction time, all hyenas reached a level of surgical anaesthesia while immobilised. Overall, ketamine-butorphanol-medetomidine (KBM) was effective in immobilising hyenas but induction times varied, and animals were bradycardic during immobilisation.
Comparison of the immobilisation and cardiorespiratory effects of thiafentanil-azaperone versus thiafentanil-medetomidine-azaperone in African buffalo (Syncerus caffer)
(Medpharm Publications, 2024-03) Faber, Vanessa; Burroughs, Richard E.J.; Meyer, Leith Carl Rodney; Hansen, H.J.; Gerber, D.; Koeppel, Katja Natalie
African buffalo (Syncerus caffer) are frequently immobilised for veterinary interventions, disease screening and translocations. Concerns over user and animal safety, costs, and irregularities in opioid supply, have led to the development of alternative immobilisation protocols. This study compared immobilisation of 12 boma-habituated African buffalo with thiafentanil-azaperone (TA) vs. thiafentanil-medetomidine-azaperone (TMA) in a randomised crossover study. Each buffalo received a combination of thiafentanil (6–7 mg) + azaperone (40 mg) and thiafentanil (1 mg) + medetomidine (3–4 mg) + azaperone (40 mg) with a three-week washout period between immobilisations. Induction and recovery times were recorded, quality of induction and immobilisation were scored subjectively, and physiological variables were monitored. The TMA combination induced immobilisation with 1/7th of the TA thiafentanil dose and at a quarter of the cost. Induction times for the TA combination were significantly faster at 5.7 ± 1.6 min and more reliable compared to the TMA combination at 10.95 ± 3.9 min. Both combinations resulted in severe hypoxaemia, however hypoxaemia was overall more pronounced in the TMA (PaO2 44 ± 14 mmHg) combination compared to the TA (PaO2 51 ± 13,33 mmHg) combination and resulted mainly from decreased pulmonary oxygen exchange rather than hypoventilation; PaCO2 values were mostly within the normal expected physiological range. Supplementary oxygen and close monitoring of blood oxygenation is considered essential with either combination. Although the reduction in costs could be beneficial for the wildlife industry, longer induction times, and risks from severe hypoxaemia need to be taken into consideration when the TMA combination is used.
Animal rabies in Mozambique : a retrospective study with focus on dog rabies and vaccination coverage
(Medpharm Publications, 2024-10) Bilaide, S.; Nicolau, Q.; Mapaco, L.; Rodrigues, F.; Pondja Junior, A.; Deve, J.; Sabeta, Claude Taurai; Bauhofer, A.; Chilundo, A.; Fafetine, J.; Abernethy, D.A. (Darrell); Mapatse, M.
Rabies, a highly preventable zoonotic disease, remains a major public health problem in Mozambique with approximately 50 human fatalities per annum due to dog-mediated rabies. This study analysed animal rabies cases and dog vaccination coverage, confirmed between 2001 and 2021, based on history, clinical signs, and/or diagnostic tests. During this period, 955 animal rabies cases were reported with the highest occurrence in Maputo (n = 283; 29.6%) and the lowest from Zambézia and Sofala provinces (n = 30; 3.1%). A significant number of animal rabies cases occurred in 2005 (n = 180; 18.8%). Most cases were identified in domestic dogs (n = 766; 80.2%). During the same period, 4.6 million dogs were vaccinated against rabies and the countrywide coverage was 10.4%. The total number of vaccinations administered increased over the 21-year period, from 46 301 in 2001 to a peak of 464 780 in 2018 before slightly declining in subsequent years. Rabid dogs are still important reservoirs and vectors species in Mozambique. More effective control measures, surveillance, reporting and enhanced awareness programmes are needed to address this neglected disease and consequently meet the global strategic plan to end human deaths due to dog-mediated rabies by 2030.
Cutaneous plasmacytoma with systemic metastases in a Cape serotine bat (Laephotis capensis)
(MDPI, 2024-02-05) Van der Weyden, Louise; Avenant, Alida; O'Dell, Nicolize; nicolize.odell@up.ac.za
Despite their relatively long life-spans, reports of neoplasia in bats are rare and are limited to a handful of cases. In this report, we describe a 2-year-old female wild Cape serotine bat (Laephotis capensis) that had been caught by a domestic cat and presented with a skin mass over the chest area. Histopathological analysis of a subsequent biopsy revealed proliferating sheets of neoplastic round cells, occasionally appearing to form packets, supported by a fine, fibrovascular stroma. Marked nuclear pleomorphism was seen, as well as a high mitotic count. Immunohistochemistry displayed positive labelling for MUM1 in the neoplastic cells. The diagnosis was extramedullary plasmacytoma (EMP); a neoplasm consisting of plasma cells derived from B lymphocytes. Due to a deteriorating condition, the bat was anaesthetised, and the mass was surgically removed two weeks later. However, the bat succumbed under the anaesthetic. Histopathological examination of the mass showed the same neoplastic cell population as observed in the biopsy; in addition, there was a locally extensive infiltration of neoplastic cells in the spleen and a mild presence of neoplastic cells in circulation. This is the first report of an EMP in a bat, and we compare the findings with that seen in dogs and cats.
The recolonisation of the Piketberg leopard population : a model for human-wildlife coexistence in a changing landscape
(MDPI, 2024-06) McManus, J.S.; Smit, Albertus J.; Faraut, Lauriane; Couldridge, Vanessa; Van Deventer, Jaco; Samuels, Igshaan; Devens, C.H. (Carolyn); Smuts, Bool
Important metapopulation dynamics are disrupted by factors such as habitat loss, climate change, and human-induced mortality, culminating in isolated wildlife populations and threatening species survival. Source populations, where birth rates exceed mortality and connectivity facilitates dispersal, contrast with sink populations, where mortality outstrips births, risking localised extinction. Recolonisation by individuals from source populations is pivotal for species survival. The leopard is the last free-roaming apex predator in South Africa and plays an important ecological role. In the Eastern and Western Cape provinces in South Africa, leopard populations have low densities and fragmented population structures. We identified a leopard population that, after being locally extinct for a century, appeared to recolonise an ‘island’ of mountainous habitat. We aimed to understand potential factors driving this recolonisation using recent camera trapping surveys and historical statutory destruction permits. We employed spatially explicit capture–recapture (SECR) methods to estimate the leopard density and explore potential factors which best explain density. We found that the recently recolonised Piketberg population now exhibits some of the highest densities reported in the region (~1.8 leopards/100 km2 ; CI 1.4–2.5). Livestock, human presence, elevation, and the camera trap grid appeared to explain leopard detection rates. When considering the historic data, the re-emergence of leopards in the Piketberg coincided with the cessation of the extensive state-sponsored and state-enabled culling of the species, and the change in land use from livestock production to crop agriculture, which likely contributed to the recolonisation. Elucidating these factors deepens our understanding of leopard metapopulation dynamics in relation to land use and species management and highlights the crucial role of private land and state agencies and associated policies in species persistence.
A portable fluid administration system for prolonged intravenous fluid administration in subadult and adult white rhinoceroses (Ceratotherium simum)
(Wiley, 2024-12) Leiberich, Marion; Hooijberg, Emma Henriette; Van Heerden, Bill; Meyer, Leith Carl Rodney
While translocations of white rhinoceroses have become an important conservation tool, dehydration during long-distance transports has been identified as a welfare concern. Intravenous (iv) fluid administration might therefore be useful to mitigate dehydration; however, special requirements need to be met to make iv fluid administration suitable for large, wild rhinoceroses during transport. Requirements include a portable and robust system that is capable of delivering high flow rates, is easy to set up, and remains patent and operating for long periods of time while allowing the animals to freely stand or lay down in the transport crates. Due to the lack of suitable fluid administration systems, we developed a custom-made system consisting of 8 L drip bags, a three-part, 4.4-m–long, large bore and partially coiled administration set, and a robust, battery-operated infusion pump, which allowed us to successfully administer iv fluids at a maintenance rate of 1–2 mL/kg/h to eight rhinoceroses for 24 h during a mock transport. While iv fluid administration in transported rhinoceroses is time intensive and the large amount of drip bags required during lengthy transports might pose a limitation, the developed system may be useful for the long-distance transport of small groups of rhinoceroses. Furthermore, this system would be of value for injured or sick rhinoceroses, which require parenteral fluid therapy when commercially available infusion pumps cannot provide the large fluid volumes needed. RESEARCH HIGHLIGHTS : We describe the development of a portable, robust iv fluid administration system for white rhinoceroses during a 24-h transport. It consists of 8 L drip-bags, a three-part, 4.4-m–long, large bore and partially coiled administration set, and a robust, battery-operated infusion pump.
Spatial patterns of large African cats : a large-scale study on density, home range size, and home range overlap of lions Panthera leo and leopards Panthera pardus
(Wiley, 2023-04) NAms, Vilis; Parker, Dan M.; Weise, Florian Johannes; Patterson, Bruce D.; Buij, Ralph; Wageningen, P.B.; Radloff, Frans G.T.; Vanak Ashoka, Abi Tamim; Tumenta, Pricelia N.; Hayward, Matt W.; Swanepoel, Lourens H.; Funston, Paul J.; Bauer, Hans; Power, R. John; O'Brien, John; O'Brien, Timothy G.; Tambling, Craig; DeIongh, Hans H.; Ferreira, Sam M.; Owen‑Smith, Norman; Cain, James W.; Fattebert, Julien; Croes, Barbra M.; Spong, Goran F.; Loveridge, Andrew J.; Houser, Ann Marie; Golabek, Krytyna A.; Begg, Colleen M.; Grant, Tanith; Trethoman, Paul; Musyoki, Charles; Menges, Vera; Creel, Scott; Balme, Guy A.; Pitman, Ross T.; Bissett, Charlene; Jenny, David; Schuette, Paul; Wilmers, Christopher C.; Hunter, Luke T.B.; Kinnaird, Margaret F.; Begg, Keith; Owen, Cailey R.; Steyn, Villiers; Bockmuehl, Dirk; Munro, Stuart J.; Mann, Gareth K.H.; DuPreez, Byron D.; Marker, Laurie L.; Huqa, Tuqa J.; Cozzi, Gabriele; Frank, Laurence G.; Nyoni, Phumuzile; Stein, Andrew B.; Kasiki, Samuel M.; MacDonald, David W.; Martins, Quinton, E.; VanVuuren, Rudie J.; Stratford, Ken; Bidner, Laura R.; Oriol-Cotteril, Alayne; Maputla, N.W. (Nakedi Walter); Maruping-Mzileni, Nkabeng; Parker, Tim; Van't Zelfde, Maarten; Isbell, Lynne A.; Beukes, Otto B.; Beukes, Maya; nwmaputla@zoology.up.ac.za
1. Spatial patterns of and competition for resources by territorial carnivores are typically explained by two hypotheses: 1) the territorial defence hypothesis and 2) the searching efficiency hypothesis. 2. According to the territorial defence hypothesis, when food resources are abundant, carnivore densities will be high and home ranges small. In addition, carnivores can maximise their necessary energy intake with minimal territorial defence. At medium resource levels, larger ranges will be needed, and it will become more economically beneficial to defend resources against a lower density of competitors. At low resource levels, carnivore densities will be low and home ranges large, but resources will be too scarce to make it beneficial to defend such large territories. Thus, home range overlap will be minimal at intermediate carnivore densities. 3. According to the searching efficiency hypothesis, there is a cost to knowing a home range. Larger areas are harder to learn and easier to forget, so carnivores constantly need to keep their cognitive map updated by regularly revisiting parts of their home ranges. Consequently, when resources are scarce, carnivores require larger home ranges to acquire sufficient food. These larger home ranges lead to more overlap among individuals’ ranges, so that overlap in home ranges is largest when food availability is the lowest. Since conspecific density is low when food availability is low, this hypothesis predicts that overlap is largest when densities are the lowest. 4. We measured home range overlap and used a novel method to compare intraspecific home range overlaps for lions Panthera leo (n = 149) and leopards Panthera pardus (n = 111) in Africa. We estimated home range sizes from telemetry location data and gathered carnivore density data from the literature. 5. Our results did not support the territorial defence hypothesis for either species. Lion prides increased their home range overlap at conspecific lower densities whereas leopards did not. Lion pride changes in overlap were primarily due to increases in group size at lower densities. By contrast, the unique dispersal strategies of leopards led to reduced overlap at lower densities. However, when human-caused mortality was higher, leopards increased their home range overlap. Although lions and leopards are territorial, their territorial behaviour was less important than the acquisition of food in determining their space use. Such information is crucial for the future conservation of these two iconic African carnivores.
Life-history and genetic relationships in cooperatively breeding dwarf mongoose groups
(Royal Society, 2024-10) Arbon, Josh J.; Morris-Drake, Amy; Kern, Julie M.; Howell, Gabrielle M.K.; Wentzel, Jeanette Maria; Radford, Andrew N.; Nichols, Hazel J.
Cooperatively breeding societies show distinct interspecific variations in social and genetic organization. Long-term studies provide invaluable data to further our understanding of the evolution and maintenance of cooperative breeding but have also demonstrated how variation exists within species. Here we integrate life-history, behavioural and genetic data from a long-term study of dwarf mongooses Helogale parvula in South Africa to document mating, breeding, dispersal and relatedness patterns in this population and compare them to those found in a Tanzanian population at the other extreme of the species’ range. Our genetic data reveal high levels of reproductive skew, above that expected through observational data. Dispersal was male-biased and was seen more frequently towards the onset of the breeding season, but females also regularly switched between groups. These patterns of breeding and dispersal resulted in a genetically structured population: individuals were more related to groupmates than outsiders, apart from the unrelated dominant pair, ultimately resulting in reduced inbreeding risk. Our results also demonstrate that dwarf mongooses are largely consistent in their social structure across their sub-Saharan distribution. This work demonstrates the direct and indirect pathways to reproductive success for dwarf mongooses and helps to explain the maintenance of cooperative breeding in the species.
Case Report : cutaneous melanocytic schwannoma with concomitant melanocytoma in a canine
(F1000 Research Ltd, 2024-08) Monakali, Olwam H.; O'Dell, Nicolize; Van der Weyden, Louise; olwam.monakali@up.ac.za
Schwannoma is a nerve sheath tumour arising from differentiated Schwann cells, and melanocytic schwannoma (MS) is a rare variant where the Schwan cells produce melanin pigment. MS is typically associated with spinal nerve roots and there have been only ~20 reports of cutaneous or subcutaneous MS to-date in humans. In canines, there have only been two reports of MS, both associated with spinal root nerves. In this report, we describe a 7-year-old Weimaraner cross breed dog that presented with two pigmented lesions on the eyelids. The lesions were surgically removed and histological analysis revealed well-circumscribed, non-encapsulated, expansile, neoplasms that were displacing most of the dermis and adnexa. The first lesion was composed of spindloid cells arranged in short interlacing streams with large amounts of pale eosinophilic cytoplasm that sometimes contained fine melanin granules. In areas there were spindle cells arranged in verocay bodies which led to a diagnosis of MS. In contrast, the second lesion was composed of polygonal cells arranged in thick sheets with large amounts of pale eosinophilic cytoplasm that sometimes contained fine melanin granules. The diagnosis was melanocytoma (which is one of the macroscopic differential diagnoses for MS). Whilst melanocytoma is a commonly occurring cutaneous lesion in canines and surgical removal is considered curative, due to little being known about MS in dogs, the outcome remained guarded, as MS in humans has an unpredictable nature, and recurrence and metastasis have been reported.
Reliability, clinical performance and trending ability of a pulse oximeter and pulse co-oximeter, in monitoring blood oxygenation, at two measurement sites, in immobilised white rhinoceros (Ceratotherium simum)
(BMC, 2024-07) Mtetwa, Thembeka Kim; Snelling, Edward P.; Buss, Peter Erik; Donaldson, Ashleigh C.; Roug, Annette; Meyer, L.C.R. (Leith Carl Rodney); thembeka.mtetwa@up.ac.za
BACKGROUND: Monitoring blood oxygenation is essential in immobilised rhinoceros, which are susceptible to opioid induced hypoxaemia. This study assessed the reliability, clinical performance and trending ability of the Nonin PalmSAT 2500 A pulse oximeter’s and the Masimo Radical-7 pulse co-oximeter’s dual-wavelength technology, with their probes placed at two measurement sites, the inner surface of the third-eyelid and the scarified ear pinna of immobilised white rhinoceroses. Eight white rhinoceros were immobilised with etorphine-based drug combinations and given butorphanol after 12 min, and oxygen after 40 min, of recumbency. The Nonin and Masimo devices, with dual-wavelength probes attached to the third-eyelid and ear recorded arterial peripheral oxygen-haemoglobin saturation (SpO2) at pre-determined time points, concurrently with measurements of arterial oxygen-haemoglobin saturation (SaO2), from drawn blood samples, by a benchtop AVOXimeter 4000 co-oximeter (reference method). Reliability of the Nonin and Masimo devices was evaluated using the Bland-Altman and the area root mean squares (ARMS) methods. Clinical performance of the devices was evaluated for their ability to accurately detect clinical hypoxemia using receiver operating characteristic (ROC) curves and measures of sensitivity, specificity, and positive and negative predictive values. Trending ability of the devices was assessed by calculating concordance rates from four-quadrant plots. RESULTS: Only the Nonin device with transflectance probe attached to the third-eyelid provided reliable SpO2 measurements across the 70 to 100% saturation range (bias −1%, precision 4%, ARMS 4%). Nonin and Masimo devices with transflectance probes attached to the third-eyelid both had high clinical performance at detecting clinical hypoxaemia [area under the ROC curves (AUC): 0.93 and 0.90, respectively]. However, the Nonin and Masimo devices with transmission probes attached to the ear were unreliable and provided only moderate clinical performance. Both Nonin and Masimo devices, at both measurement sites, had concordance rates lower than the recommended threshold of ≥90%, indicating poor trending ability. CONCLUSIONS: The overall assessment of reliability, clinical performance and trending ability indicate that the Nonin device with transflectance probe attached to the third-eyelid is best suited for monitoring of blood oxygenation in immobilised rhinoceros. The immobilisation procedure may have affected cardiovascular function to an extent that it limited the devices’ performance.
Orthognathic surgery to improve malocclusion in a chimpanzee (Pan troglodytes)
(Wiley, 2024-03) Steenkamp, Gerhardus; Hoogendijk, Christiaan Fritz; Ruiz, José Carlos Almansa; Koeppel, Katja Natalie; gerhard.steenkamp@up.ac.za
Malocclusion is a common finding in both companion animals and humans due to dental or maxillofacial discrepancies. Treatment depends on the complications and the species it presents in. In humans, orthognathic surgery is commonly performed to address skeletal malocclusions. A male chimpanzee born in 2002 and orphaned due to the bush meat pet trade was rescued in 2010 by Chimp Eden, a chimpanzee sanctuary. In 2017, it presented with inappetence and weight loss of 6-month duration. After a computed tomography scan was performed and full mouth impressions were made, a diagnosis of asymmetry of the mandible with the left side markedly shorter and rotated along its long axis was made (malocclusion class IV in a side-to-side direction). A bilateral sagittal split operation was performed to correct the malocclusion and improve its feeding. At the time of writing this report, it was eating freely and no complications were seen on multiple post-operative radiographs.
Speculating on transverse grooves in African elephant tusks
(International Union for Conservation of Nature and Natural Resources, 2023-10) Parker, Ian S.C.; Theleste, Erwan; Steenkamp, Gerhardus
No abstract available.

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