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1.
J Wildl Dis ; 60(3): 703-713, 2024 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-38679922

RESUMEN

Rabies is a highly virulent viral disease that has been associated with large-scale population declines of the endangered African wild dog (Lycaon pictus). Rabies vaccination may be a valuable conservation tool in this species, but studies indicate that a single dose does not always confer protective immunity. We examined 47 serum samples from 22 captive African wild dogs (sampled opportunistically for other purposes) to assess whether serum antibody levels after vaccination correlated with the number of doses received and whether other factors affected outcomes. Results of the fluorescent antibody virus neutralization test showed that median antibody titers were 0.085 IU/mL prevaccination, 0.660 IU/mL after a single vaccination, and 22.150 IU/mL after a booster vaccination. Antibody titers above 0.5 IU/mL, internationally accepted as the threshold for seroconversion, were found in none of the samples taken prevaccination, 66.67% of samples taken after primary vaccination, and 90.90% of samples collected after booster vaccination. This study illustrates the probable protective benefit a rabies booster vaccination may provide in African wild dogs and serves as a basis for future research to improve vaccination protocols contributing to the conservation of this endangered species.


Asunto(s)
Anticuerpos Antivirales , Canidae , Inmunización Secundaria , Vacunas Antirrábicas , Rabia , Animales , Vacunas Antirrábicas/inmunología , Vacunas Antirrábicas/administración & dosificación , Rabia/prevención & control , Rabia/veterinaria , Anticuerpos Antivirales/sangre , Inmunización Secundaria/veterinaria , Animales Salvajes , Femenino , Masculino , Vacunación/veterinaria
2.
J Vet Med Sci ; 86(5): 596-599, 2024 May 25.
Artículo en Inglés | MEDLINE | ID: mdl-38583979

RESUMEN

There are few studies on diseases affecting endangered African wild dogs. We report our findings on malignant tumors in two African wild dogs. Case 1 was a 6-year-old intact female diagnosed with inflammatory mammary carcinoma with pulmonary metastasis. Case 2 was an 11-year-old male diagnosed with primary hemangiosarcoma of the left atrial coronary sulcus with metastasis to multiple organs. Additionally, the tumor had grown through the cardiac wall, causing cardiac tamponade. The identification of disease incidence trends provides important information which will allow for the early detection and treatment of malignant tumors, and aid in the conservation of this species.


Asunto(s)
Canidae , Hemangiosarcoma , Neoplasias Mamarias Animales , Animales , Hemangiosarcoma/veterinaria , Hemangiosarcoma/patología , Femenino , Neoplasias Mamarias Animales/patología , Masculino , Carcinoma/veterinaria , Carcinoma/patología , Neoplasias Cardíacas/veterinaria , Neoplasias Cardíacas/patología , Neoplasias Cardíacas/secundario , Neoplasias Pulmonares/veterinaria , Neoplasias Pulmonares/patología , Neoplasias Pulmonares/secundario
3.
J Appl Anim Welf Sci ; 27(1): 180-191, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-36597253

RESUMEN

Glucocorticoids are regulated by the hypothalamic-pituitary-adrenal (HPA) axis and are important in responding to various psychological and physiological stressors. For the African wild dog (Lycaon pictus) only one aspect of the HPA axis has been investigated with no information present on cortisol insufficiency. Here, a pilot study involving both HPA feedback mechanisms is characterized by dynamic function tests (i.e., stimulation and suppression) and a cutoff value for a stressed state is established. Results showed a mean plasma cortisol increase of 40.7% after the administration of Synacthen from initial values, with females recording higher concentrations than males. Using Youden's index, this adaptive response was able to determine a cutoff value of 80.72 ng/ml that infers a stress state. The observed response in the suppression test was similar to that reported in domestic dogs. These results expand the basic knowledge of adrenal function in this endangered species and provide a means in which to determine whether animals are stressed or not. The method used also has application to other species in gauging the degree of stress they are experiencing, which can assist in improving welfare outcomes for captive animals.


Asunto(s)
Dexametasona , Sistema Hipotálamo-Hipofisario , Masculino , Femenino , Animales , Sistema Hipotálamo-Hipofisario/fisiología , Hidrocortisona , Retroalimentación , Proyectos Piloto , Sistema Hipófiso-Suprarrenal/fisiología
4.
J Comp Pathol ; 207: 59-65, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-37967496

RESUMEN

This retrospective study documents the occurrence of single and multiple cutaneous apocrine gland tumours (CATs) on the dorsal midline of 16 captive African wild dogs (AWDs, Lycaon pictus) derived from 161 submissions to diagnostic laboratories in South Africa, France and Germany between 1997 and 2022. Animals included in the study came from zoological institutions in South Africa (n = 2), France (n = 5) and Germany (n = 1) and ranged from 5 to 14 years of age. Fifteen affected animals were female (94%) and one was male. CATs presented as raised, hairless, multilobular, grey firm masses, consistently located along the dorsal midline. Apart from a single cutaneous apocrine adenoma and a cystadenoma occurring concurrently with two non-cystic adenocarcinomas, neoplasms were consistent with malignant cutaneous apocrine adenocarcinomas with lymphatic spread and visceral metastases. Advanced age and female sex were identified as risk factors. A genetic component or association with the increasing use of GnRH agonist contraceptives was suspected but could not be established. This study highlights the need for close clinical monitoring of AWDs over the age of 5 years for the development of CATs along the dorsal midline and supports early surgical intervention. More research is needed to determine the role of inbreeding, endocrine changes and husbandry factors that may play a role in the development of CATs on the dorsal midline of AWDs.


Asunto(s)
Adenocarcinoma , Canidae , Animales , Masculino , Femenino , Glándulas Apocrinas , Estudios Retrospectivos , Sudáfrica/epidemiología , Adenocarcinoma/veterinaria
5.
PeerJ ; 11: e15253, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37159833

RESUMEN

Temporal partitioning in large carnivores have previously been found to be one of the main factors enabling co-existence. While activity patterns have been investigated separately at artificial waterholes and e.g., game trails, simultaneous comparative analyses of activity patterns at artificial waterholes and game trails have not been attempted. In this study, camera trap data from Maremani Nature Reserve was used to investigate whether temporal partitioning existed in a carnivore guild of four species (spotted hyena, leopard, brown hyena and African wild dog). Specifically, we investigated temporal partitioning at artificial waterholes and on roads and trails an average of 1,412 m away from an artificial waterhole. Activity patterns for the same species at artificial waterholes and roads/game trails were also compared. We found no significant differences in temporal activity between species at artificial waterholes. Temporal partitioning on game trails and roads was only found between spotted hyena (nocturnal) and African wild dog (crepuscular). Between nocturnal species (spotted hyena and leopard) no temporal partitioning was exhibited. Only African wild dog exhibited significantly different activity patterns at waterholes and roads/game trails. This indicates artificial waterholes may be a location for conflict in a carnivore guild. Our study highlights the impact of anthropogenic landscape changes and management decisions on the temporal axis of carnivores. More data on activity patterns at natural water sources such as ephemeral pans are needed to properly assess the effect of artificial waterholes on temporal partitioning in a carnivore guild.


Asunto(s)
Canidae , Hyaenidae , Panthera , Animales , Ligando de CD40 , Existencialismo
6.
Data Brief ; 45: 108685, 2022 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-36425977

RESUMEN

In this present article the draft sequence data for Clostridium perfringens FA, which was isolated from the faecal material of a critically endangered African Wild dog, is reported. The bacterium is widely distributed in the environment and in the normal intestinal flora of humans and animals. The genome of strain C. perfringens FA was assembled into 21 contigs with a total length of 3, 044, 349 bp and a GC content of 28.20%. There are 2742 CDS, 70 tRNAs and 5 rRNAs. Five putative virulence genes were detected. There were no plasmid replicons found. The genome of few environmental isolates has been sequenced. The draft genome of strain FA can be compared to disease causing isolates cultured from humans to aid in a better understanding of the pathogenesis of the bacterium.

7.
Mov Ecol ; 10(1): 16, 2022 Mar 31.
Artículo en Inglés | MEDLINE | ID: mdl-35361272

RESUMEN

BACKGROUND: Prey depletion is a threat to the world's large carnivores, and is likely to affect subordinate competitors within the large carnivore guild disproportionately. African lions limit African wild dog populations through interference competition and intraguild predation. When lion density is reduced as a result of prey depletion, wild dogs are not competitively released, and their population density remains low. Research examining distributions has demonstrated spatial avoidance of lions by wild dogs, but the effects of lions on patterns of movement have not been tested. Movement is one of the most energetically costly activities for many species and is particularly costly for cursorial hunters like wild dogs. Therefore, testing how top-down, bottom-up, and anthropogenic variables affect movement patterns can provide insight into mechanisms that limit wild dogs (and other subordinate competitors) in resource-depleted ecosystems. METHODS: We measured movement rates using the motion variance from dynamic Brownian Bridge Movement Models (dBBMMs) fit to data from GPS-collared wild dogs, then used a generalized linear model to test for effects on movement of predation risk from lions, predictors of prey density, and anthropogenic and seasonal variables. RESULTS: Wild dogs proactively reduced movement in areas with high lion density, but reactively increased movement when lions were immediately nearby. Predictors of prey density had consistently weaker effects on movement than lions did, but movements were reduced in the wet season and when dependent offspring were present. CONCLUSION: Wild dogs alter their patterns of movement in response to lions in ways that are likely to have important energetic consequences. Our results support the recent suggestion that competitive limitation of wild dogs by lions remains strong in ecosystems where lion and wild dog densities are both low as a result of anthropogenic prey depletion. Our results reinforce an emerging pattern that movements often show contrasting responses to long-term and short-term variation in predation risk.

8.
Ecology ; 103(10): e3576, 2022 10.
Artículo en Inglés | MEDLINE | ID: mdl-34714927

RESUMEN

Group living in species can have complex consequences for individuals, populations, and ecosystems. Therefore, estimating group density and size is often essential for understanding population dynamics, interspecific interactions, and conservation needs of group-living species. Spatial capture-recapture (SCR) has been used to model both individual and group density in group-living species, but modeling either individual-level or group-level detection results in different biases due to common characteristics of group-living species, such as highly cohesive movement or variation in group size. Furthermore, no SCR method currently estimates group density, individual density, and group size jointly. Using clustered point processes, we developed a cluster SCR model to estimate group density, individual density, and group size. We compared the model to standard SCR models using both a simulation study and a data set of detections of African wild dogs (Lycaon pictus), a group-living carnivore, on camera traps in northern Botswana. We then tested the model's performance under various scenarios of group movement in a separate simulation study. We found that the cluster SCR model outperformed a standard group-level SCR model when fitted to data generated with varying group sizes, and mostly recovered previous estimates of wild dog group density, individual density, and group size. We also found that the cluster SCR model performs better as individuals' movements become more correlated with their groups' movements. The cluster SCR model offers opportunities to investigate ecological hypotheses relating group size to population dynamics while accounting for cohesive movement behaviors in group-living species.


Asunto(s)
Ecosistema , Simulación por Computador , Densidad de Población , Dinámica Poblacional
9.
Arch Microbiol ; 204(1): 42, 2021 Dec 21.
Artículo en Inglés | MEDLINE | ID: mdl-34932157

RESUMEN

The African wild dog (AWD) (Lycaon pictus) is a critically endangered species. These animals are hypercarnivores, hunting mostly medium-sized antelope. In this study, using bacterial tag-encoded FLX-Titanium amplicon pyrosequencing (bTEFAP®), the microbiota in the fecal material of AWDs living in the Great Plains Zoo & Delbridge Museum of Natural History was investigated. In both samples, the most predominant bacterial phylum was the Firmicutes with members of the genus Blautia spp. being the most dominant bacteria.


Asunto(s)
Canidae , Microbiota , Animales , Canidae/microbiología , Especies en Peligro de Extinción , Heces
10.
Genes (Basel) ; 12(10)2021 09 22.
Artículo en Inglés | MEDLINE | ID: mdl-34680858

RESUMEN

African painted dogs (Lycaon pictus, APD) are highly endangered, with fewer than 7000 remaining in nature. Captive breeding programs can preserve a genetically diverse population and provide a source of individuals for reintroductions. However, most programs are initiated from few founders and suffer from low genetic diversity and inbreeding. The aims of this study were to use molecular markers to assess genetic variation, inbreeding, and relatedness among APDs in the North American captive population, to use these data to realign studbook records, and to compare these data to wild populations and to the European captive population to facilitate the development of a global management plan. We sequenced mitochondrial and major histocompatibility (MHC) class II loci and genotyped 14 microsatellite loci from 109 APDs from 34 institutions in North America. We identified three likely studbook errors and resolved ten cases of uncertain paternity. Overall, microsatellite heterozygosity was higher than reported in Europe, but effective population size estimates were lower. Mitochondrial sequence variation was extremely limited, and there were fewer MHC haplotypes than in Europe or the wild. Although the population did not show evidence of significant inbreeding overall, several individuals shared high relatedness values, which should be incorporated into future breeding programs.


Asunto(s)
Perros/genética , Variación Genética , Animales , Femenino , Marcadores Genéticos/genética , Masculino , América del Norte , Linaje
11.
Animals (Basel) ; 11(6)2021 May 27.
Artículo en Inglés | MEDLINE | ID: mdl-34072227

RESUMEN

Thirty-six species of canid exist globally, two are classified as critically endangered, three as endangered, and five as near threatened. Human expansion and the coinciding habitat fragmentation necessitate conservation interventions to mitigate concurrent population deterioration. The current conservation management of wild canids includes animal translocation and artificial pack formation. These actions often cause chronic stress, leading to increased aggression and the suppression of the immune and reproductive systems. Castration and pharmaceutical treatments are currently used to reduce stress and aggression in domestic and captive canids. The undesirable side effects make such treatments inadvisable during conservation management of wild canids. Pheromones are naturally occurring chemical messages that modulate behaviour between conspecifics; as such, they offer a natural alternative for behaviour modification. Animals are able to distinguish between pheromones of closely related species through small compositional differences but are more likely to have greater responses to pheromones from individuals of the same species. Appeasing pheromones have been found to reduce stress- and aggression-related behaviours in domestic species, including dogs. Preliminary evidence suggests that dog appeasing pheromones (DAP) may be effective in wild canids. However, the identification and testing of species-specific derivatives could produce more pronounced and beneficial behavioural and physiological changes in target species. In turn, this could provide a valuable tool to improve the conservation management of many endangered wild canids.

12.
Int J Parasitol Parasites Wildl ; 14: 335-340, 2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-33898235

RESUMEN

Reports in the literature indicate that species of Hepatozoon commonly occur in African wild dog (AWD) or painted wolf (Lycaon pictus) populations. These findings were based on examination of blood smears by microscopy, and specific identity of the Hepatozoon sp. gamonts seen could not be confirmed. We present the first in-depth molecular data on the prevalence of species of Hepatozoon in a free-ranging AWD population. In a general health survey of AWDs in the Kruger National Park, blood specimens (n = 74) collected from 54 individuals were examined for the presence of Hepatozoon spp. At first sampling, specimens from 42 of 54 individuals (77.7%) were positive, based on the primer set HepF300 and HepR900. Twenty individuals were resampled between 51 and 69 days after first sampling; one of these was resampled twice. Samples from six individuals that had tested negative previously now reacted positive. Assuming that all 54 individuals were still alive, the prevalence had therefore increased to 48 individuals infected, or 88.8%. Resultant 18S rDNA sequences isolated from these specimens share high similarity to other Hepatozoon canis genotypes. Phylogenetic analysis recovered the Hepatozoon sp. isolated from AWDs within the H. canis cluster, which includes species of Hepatozoon from other canid and tick hosts.

13.
Transbound Emerg Dis ; 68(4): 2581-2588, 2021 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-33900034

RESUMEN

It has recently been discovered that Mycobacterium bovis (M. bovis) causes disease in the endangered African wild dog (Lycaon pictus) in areas endemic for bovine tuberculosis (bTB), including the Kruger National Park (KNP). However, information on M. bovis infection dynamics within this species is limited and requires investigation as M. bovis can cause conservation consequences due to movement restrictions, crucial for genetic management. This study had two aims: firstly, to investigate mycobacterial shedding in free-ranging wild dogs from KNP by culturing oropharyngeal swab (OS) and bronchoalveolar lavage (BAL) samples. Secondly, to determine the relationship between ante-mortem culture and interferon gamma release assay (IGRA) results as well as agreement between OS culture and BAL culture results. Mycobacterial culture revealed that 6 of 173 (3.5%) OS samples and 1 of 32 (3.1%) BAL samples (from 7 different wild dogs) were M. bovis culture positive, suggesting that wild dogs can shed M. bovis through respiratory secretions. However, the possibility of contamination by ingestion of infected prey cannot be excluded in wild dogs with positive OS culture results. Furthermore, the test outcomes between IGRA and culture (OS and BAL) differed substantially. Samples from 172 wild dogs were available for IGRA screening and 134 had positive results (detectable M. bovis immune sensitization). Seven wild dogs had culture-positive results, which included one additional wild dog that did not have an IGRA result (total 173 wild dogs). Out of these 7 M. bovis culture-positive wild dogs, 3 were IGRA positive initially, however, after repeat sampling and testing, 5 out of 7 were IGRA positive. These findings suggest that intraspecies transmission of M. bovis may be possible among wild dogs. Although the risk of intraspecies transmission is currently unknown, this knowledge is important for assessing the risk of M. bovis transmission from infected wild dogs to uninfected populations during translocations.


Asunto(s)
Enfermedades de los Bovinos , Mycobacterium bovis , Tuberculosis Bovina , Tuberculosis , Animales , Bovinos , Ensayos de Liberación de Interferón gamma/veterinaria , Parques Recreativos , Tuberculosis/diagnóstico , Tuberculosis/epidemiología , Tuberculosis/veterinaria
14.
Vet Parasitol ; 291: 109381, 2021 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-33667987

RESUMEN

In sub-Saharan Africa, babesiosis in domestic dogs is caused primarily by Babesia rossi. Black-backed jackals (Canis mesomelas), which are subclinical carriers of B. rossi, were a likely reservoir host from which infection passed to domestic dogs. The role of other indigenous canids, e.g. African wild dogs (Lycaon pictus), as reservoirs of B. rossi has not been elucidated. The question also arises whether genetic differences have arisen between B. rossi infecting domestic dogs and "ancestral" B. rossi in jackals. In a previous study we found that nearly one-third (27 of 91) of jackals were infected with B. rossi; this was confirmed by 18S rDNA sequence analysis. In this study, the near full-length B. rossi 18S rRNA gene was successfully amplified from 6 domestic dogs and 3 black-backed jackals. The obtained recombinant sequences were identical (100 %) to previously described B. rossi sequences of black-backed jackals in South Africa, and 99 % similar to B. rossi from dogs in South Africa and the Sudan. Although blood specimens from 5 (10 %) of 52 free-ranging African wild dogs (from Kruger National Park, South Africa, reacted with the B. rossi probe on RLB hybridisation, the presence of B. rossi could not be confirmed by amplification and sequencing, nor by multiplex, real-time PCR. Although African wild dogs they can be infected with B. rossi without showing clinical signs, our findings suggest that they are apparently not important reservoir hosts of B. rossi.


Asunto(s)
Babesiosis/epidemiología , Canidae/parasitología , Especificidad del Huésped , Animales , Babesia/genética , Babesiosis/parasitología , Enfermedades de los Perros/parasitología , Perros , Chacales/parasitología , Reacción en Cadena de la Polimerasa , Sudáfrica/epidemiología
15.
Ecology ; 102(5): e03319, 2021 05.
Artículo en Inglés | MEDLINE | ID: mdl-33636010

RESUMEN

Competitively dominant carnivore species can limit the population sizes and alter the behavior of inferior competitors. Established mechanisms that enable carnivore coexistence include spatial and temporal avoidance of dominant predator species by subordinates, and dietary niche separation. However, spatial heterogeneity across landscapes could provide inferior competitors with refuges in the form of areas with lower competitor density and/or locations that provide concealment from competitors. Here, we combine temporally overlapping telemetry data from dominant lions (Panthera leo) and subordinate African wild dogs (Lycaon pictus) with high-resolution remote sensing in an integrated step selection analysis to investigate how fine-scaled landscape heterogeneity might facilitate carnivore coexistence in South Africa's Hluhluwe-iMfolozi Park, where both predators occur at exceptionally high densities. We ask whether the primary lion-avoidance strategy of wild dogs is spatial avoidance of lions or areas frequented by lions, or if wild dogs selectively use landscape features to avoid detection by lions. Within this framework, we also test whether wild dogs rely on proactive or reactive responses to lion risk. In contrast to previous studies finding strong spatial avoidance of lions by wild dogs, we found that the primary wild dog lion-avoidance strategy was to select landscape features that aid in avoidance of lion detection. This habitat selection was routinely used by wild dogs, and especially when in areas and during times of high lion-encounter risk, suggesting a proactive response to lion risk. Our findings suggest that spatial landscape heterogeneity could represent an alternative mechanism for carnivore coexistence, especially as ever-shrinking carnivore ranges force inferior competitors into increased contact with dominant species.


Asunto(s)
Canidae , Carnívoros , Leones , Animales , Ecosistema , Telemetría
16.
J Comp Neurol ; 528(18): 3245-3261, 2020 12 15.
Artículo en Inglés | MEDLINE | ID: mdl-32720707

RESUMEN

The African wild dog is endemic to sub-Saharan Africa and belongs to the family Canidae which includes domestic dogs and their closest relatives (i.e., wolves, coyotes, jackals, dingoes, and foxes). The African wild dog is known for its highly social behavior, co-ordinated pack predation, and striking vocal repertoire, but little is known about its brain and whether it differs in any significant way from that of other canids. We employed gross anatomical observation, magnetic resonance imaging, and classical neuroanatomical staining to provide a broad overview of the structure of the African wild dog brain. Our results reveal a mean brain mass of 154.08 g, with an encephalization quotient of 1.73, indicating that the African wild dog has a relatively large brain size. Analysis of the various structures that comprise their brains and their topological inter-relationships, as well as the areas and volumes of the corpus callosum, ventricular system, hippocampus, amygdala, cerebellum and the gyrification index, all reveal that the African wild dog brain is, in general, similar to that of other mammals, and very similar to that of other carnivorans. While at this level of analysis we do not find any striking specializations within the brain of the African wild dog, apart from a relatively large brain size, the observations made indicate that more detailed analyses of specific neural systems, particularly those involved in sensorimotor processing, sociality or cognition, may reveal features that are either unique to this species or shared among the Canidae to the exclusion of other Carnivora.


Asunto(s)
Animales Salvajes/anatomía & histología , Encéfalo/anatomía & histología , Canidae/anatomía & histología , África del Sur del Sahara , Animales , Evolución Biológica , Perros , Imagen por Resonancia Magnética , Filogenia , Especificidad de la Especie
17.
J Anim Ecol ; 89(10): 2356-2366, 2020 10.
Artículo en Inglés | MEDLINE | ID: mdl-32654130

RESUMEN

Reliable estimates of birth, death, emigration and immigration rates are fundamental to understanding and predicting the dynamics of wild populations and, consequently, inform appropriate management actions. However, when individuals disappear from a focal population, inference on their fate is often challenging. Here we used 30 years of individual-based mark-recapture data from a population of free-ranging African wild dogs Lycaon pictus in Botswana and a suite of individual, social and environmental predictors to investigate factors affecting the decision to emigrate from the pack. We subsequently used this information to assign an emigration probability to those individuals that were no longer sighted within their pack (i.e. missing individuals). Natal dispersal (i.e. emigration from the natal pack) showed seasonal patterns with female dispersal peaking prior to the mating season and male dispersal peaking at the beginning of the wet season. For both sexes, natal dispersal rate increased in the absence of unrelated individuals of the opposite sex in the pack. Male natal dispersal decreased with increasing number of pups in the pack and increased in larger packs. Female natal dispersal decreased with increasing number of pups in larger packs, but increased with increasing number of pups in smaller packs. Individuals of both sexes were less likely to exhibit secondary dispersal (i.e. emigration from a pack other than the natal pack) if they were dominant and if many pups were present in the pack. Our models predicted that 18% and 25% of missing females and males, respectively, had likely dispersed from the natal pack, rather than having died. A misclassification of this order of magnitude between dispersal and mortality can have far-reaching consequences in the evaluation and prediction of population dynamics and persistence, and potentially mislead conservation actions. Our study showed that the decision to disperse is context-dependent and that the effect of individual, social and environmental predictors differs between males and females and between natal and secondary dispersal related to different direct and indirect fitness consequences. Furthermore, we demonstrated how a thorough understanding of the proximate causes of dispersal can be used to assign a dispersal probability to missing individuals. Knowledge of causes of dispersal can then be used within an integrated framework to more reliably estimate mortality rates.


Asunto(s)
Canidae , Animales , Botswana , Femenino , Masculino , Dinámica Poblacional , Reproducción
18.
Oecologia ; 191(3): 531-540, 2019 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-31535256

RESUMEN

There are several hypotheses that could explain territory size in mammals, including the resource dispersion hypothesis (RDH), the intruder pressure hypothesis (IPH), and the intraguild predation hypothesis (IGPH). In this study, we tested predictions of these three hypotheses regarding territories of 19 packs of endangered African wild dogs (Lycaon pictus) over 2 years in the Kruger National Park, South Africa. If territory size was supported by the RDH, then we would observe (1) wild dog territories would be larger when resource patches were more dispersed, (2) pack sizes would be larger when resource patches were rich, and (3) pack size would not affect territory size. If supported by the IPH, then we would observe (4) larger territories would experience less intrusions, and (5) there would be an increase in territory overlap in areas of low resource dispersion. Finally, if supported by the IGPH, we would observe (6) territories would be larger in areas of higher lion (Panthera leo) density, as evidence of a spatial avoidance strategy. We found that the IGPH was fully supported (6), the IPH half supported (5), and the RDH partially supported (1 and 3), where we found spatial partitioning of wild dogs with lions, potentially mediated by resources and territory overlap with conspecifics. Ultimately, our results show that subordinate carnivores must balance a trade-off between dominant interspecific competitors and conspecifics to successfully coexist in areas with dominant carnivores.


Asunto(s)
Carnívoros , Leones , Animales , Ecosistema , Conducta Predatoria , Sudáfrica
19.
Emerg Infect Dis ; 25(7): 1425-1427, 2019 07.
Artículo en Inglés | MEDLINE | ID: mdl-31211936

RESUMEN

We screened African wild dogs (Lycaon pictus) in Kruger National Park, South Africa, for Mycobacterium bovis infection using an interferon-gamma release assay. We detected M. bovis sensitization in 20 of 21 packs; overall apparent infection prevalence was 83%. These animals experience high infection pressure, which may affect long-term survival and conservation strategies.


Asunto(s)
Enfermedades de los Perros/epidemiología , Enfermedades de los Perros/microbiología , Mycobacterium bovis , Tuberculosis/veterinaria , Animales , Animales Salvajes , Perros , Geografía Médica , Vigilancia en Salud Pública , Sudáfrica/epidemiología
20.
J S Afr Vet Assoc ; 89(0): e1-e13, 2018 Apr 26.
Artículo en Inglés | MEDLINE | ID: mdl-29781673

RESUMEN

Both domestic and wild carnivore species are commonly diagnosed with rabies virus (RABV) infection in South Africa. Although the majority of confirmed rabies cases in wild carnivore species are reported from the yellow mongoose (Cynictis penicillata), the rest are from other wild carnivores including the highly endangered wild dog (Lycaon pictus). Lyssavirus infection was confirmed in two wild dogs and a spotted hyaena (Crocuta crocuta) in the Madikwe Game Reserve, North West province in South Africa, in 2014 and 2015, using a direct fluorescent antibody test and immunohistochemistry. There had been no new wild dog introductions to the Madikwe Game Reserve for many years and the wild dogs were last vaccinated against rabies approximately 11 years prior to the incident. The first euthanised wild dog was the last surviving of a break-away pack of 6, and the second was the last of a larger pack of 18, the rest of which died with no carcasses being found or carcasses too decomposed for sampling. Subsequent antigenic typing of the lyssaviruses indicated that they were canid RABVs. The RABVs originating from 22 wild carnivore species, 7 dogs, and a caprine, mostly from the North West province, were genetically characterised by targeting a partial region of the nucleoprotein gene. The nucleotide sequence analyses of these viruses and two previously characterised RABVs confirmed that the outbreak viruses were also canid rabies, phylogenetically clustering with virus isolates originating from black-backed jackals recovered between 2012 and 2015 from the North West province, and domestic dogs from neighbouring communal areas. The source(s) of the mortalities and possible reservoir host(s) for the virus could only be speculated upon from data on specific predator numbers, movements and behaviour, kills, park management and the changing environmental ecology, which were monitored closely in Madikwe over several years. The most likely rabies sources were from boundary fence contacts between wild carnivores within the park, with domestic dogs or cats and/or naturally occurring wild carnivores outside the park. The associated risk of zoonotic infection and threat to important and endangered predators may be mitigated through regional rabies control primarily in domestic dogs and cats, as well as by preventative vaccination of at-risk park employees and their pets. The importance of ongoing prophylactic rabies protection by regular vaccination of highly endangered wildlife carnivores and the submission of carcasses for rabies diagnosis of any wild or domestic animals behaving uncharacteristically or found dead is emphasised.


Asunto(s)
Animales Salvajes/virología , Canidae/virología , Hyaenidae/virología , Infecciones por Rhabdoviridae/veterinaria , Animales , Animales de Zoológico , Encéfalo/virología , Brotes de Enfermedades/prevención & control , Perros , Especies en Peligro de Extinción , Humanos , Inmunoquímica , Lyssavirus/aislamiento & purificación , Masculino , Rabia , Vacunas Antirrábicas , Infecciones por Rhabdoviridae/diagnóstico , Infecciones por Rhabdoviridae/epidemiología , Infecciones por Rhabdoviridae/prevención & control , Sudáfrica/epidemiología , Zoonosis/prevención & control
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