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1.
PLoS One ; 16(3): e0248977, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33740027

RESUMEN

Various species of wild, adaptable, medium-sized carnivores occur outside of protected areas, often coming into contact with people and their domestic animals. Negative human-carnivore interactions can lead to antagonistic attitudes and behavior directed at such species. In the South African Karoo, a semi-arid rangeland, the predation of small-livestock by mesopredators is common and farmers typically use a combination of non-lethal and lethal methods to try and prevent livestock losses. We used ethnographic field observations and semi-structured interviews as part of a mixed methods approach, including the quantitative and qualitative analysis of farmers' narratives to illustrate the nuanced ways in which sheep farmers relate to the two mesopredators that consume the most livestock on their farms; black-backed jackal and caracal. Overall, farmers attributed negative characteristics to jackal and caracal but farmers' narratives provided evidence of complex perceptions in that the animals were admired as well as disliked. Both species were seen as charismatic due to traits such as their physical appearance, their "cunning" nature and their remarkable adaptability to human activities, including lethal control. Aesthetic appreciation was an important predictor of tolerance towards both species whereas negative attitudes were associated with the perception that mesopredators should only occur within protected areas. Attitudes towards jackals also appeared to have been affected by cultural representations of them as "thieves". We showed that perceiving mesopredators as beautiful increased the average marginal probability of a farmer tolerating them, and that this strong relationship held when controlling for other covariates such as livestock predation. We advocate the importance of understanding the cultural and aesthetic aspects of predators and considering existing positive dimensions of human-wildlife relationships that may encourage increased farmers' tolerance, which might promote coexistence.


Asunto(s)
Actitud , Canidae/fisiología , Estética , Agricultores/psicología , Chacales/fisiología , Animales , Geografía , Ganado , Modelos Logísticos , Conducta Predatoria/fisiología , Sudáfrica
2.
Anat Histol Embryol ; 46(1): 85-93, 2017 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-27477545

RESUMEN

Manipulation of the reproductive activity of jackals is dependent on a thorough understanding of the reproductive biology of this species. This study describes seasonal morphological changes in the adult testis of the black-backed jackal in relation to the immunoexpression of the basement membrane marker, laminin and the cytoskeletal proteins, cytokeratin, smooth muscle actin and vimentin. Laminin was immunolocalized in basement membranes surrounding seminiferous tubules, as well as in basement membranes associated with Leydig, peritubular myoid and vascular smooth muscle cells. Scalloped basement membranes enclosed seminiferous tubules in regressing testes. The seminiferous epithelium and interstitial tissue in all animals studied were cytokeratin immunonegative. Smooth muscle actin was demonstrated in vascular smooth muscle cells, as well as in peritubular myoid cells encircling seminiferous tubules. Vimentin immunoreactivity was exhibited in the cytoplasm of Sertoli cells, Leydig cells, vascular endothelial cells, vascular smooth muscle cells and fibrocytes. Vimentin immunostaining in Sertoli, Leydig and peritubular myoid cells varied depending on the functional state of the testis. The results of the study have shown that dramatic seasonal histological changes occur in the testes of the jackal. In addition, the use of immunohistochemistry accentuates these morphological changes.


Asunto(s)
Actinas/metabolismo , Proteínas del Citoesqueleto/metabolismo , Chacales/fisiología , Queratinas/metabolismo , Laminina/metabolismo , Testículo/metabolismo , Vimentina/metabolismo , Animales , Inmunohistoquímica/veterinaria , Células Intersticiales del Testículo/metabolismo , Masculino , Estaciones del Año , Túbulos Seminíferos/metabolismo , Células de Sertoli/metabolismo , Espermatozoides/citología , Testículo/anatomía & histología
3.
PLoS One ; 11(5): e0153858, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27144887

RESUMEN

Population monitoring is crucial for wildlife management and conservation. In the last few decades, wildlife researchers have increasingly applied bioacoustics tools to obtain information on several essential ecological parameters, such as distribution and abundance. One such application involves wolves (Canis lupus). These canids respond to simulated howls by emitting group vocalizations known as chorus howls. These responses to simulated howls reveal the presence of wolf litters during the breeding period and are therefore often used to determine the status of wolf populations. However, the acoustic structure of chorus howls is complex and discriminating the presence of pups in a chorus is sometimes difficult, even for experienced observers. In this study, we evaluate the usefulness of analyses of the acoustic energy distribution in chorus howls to identify the presence of pups in a chorus. We analysed 110 Iberian wolf chorus howls with known pack composition and found that the acoustic energy distribution is concentrated at higher frequencies when there are pups vocalizing. We built predictive models using acoustic energy distribution features to determine the presence of pups in a chorus, concluding that the acoustic energy distribution in chorus howls can be used to determine the presence of wolf pups in a pack. The method we outline here is objective, accurate, easily implemented, and independent of the observer's experience. These advantages are especially relevant in the case of broad scale surveys or when many observers are involved. Furthermore, the analysis of the acoustic energy distribution can be implemented for monitoring other social canids that emit chorus howls such as jackals or coyotes, provides an easy way to obtain information on ecological parameters such as reproductive success, and could be useful to study other group vocalizations.


Asunto(s)
Conducta Animal/fisiología , Reproducción/fisiología , Vocalización Animal/fisiología , Lobos/fisiología , Acústica , Animales , Conservación de los Recursos Naturales/métodos , Coyotes/fisiología , Ecosistema , Chacales/fisiología , Modelos Teóricos , Dinámica Poblacional
4.
Sci Rep ; 6: 24021, 2016 Apr 06.
Artículo en Inglés | MEDLINE | ID: mdl-27050564

RESUMEN

Animals disperse in response to poor resource conditions as a strategy of escaping harsh competition and stress, but may also disperse under good resource conditions, as these provide better chances of surviving dispersal and gaining fitness benefits such as avoiding kin competition and inbreeding. Individual traits should mediate the effect of resources, yielding a complex condition-dependent dispersal response. We investigated how experimental food reductions in a food-rich environment around poultry-growing villages interact with individual-traits (age, gender, body-mass) in two sympatric canids, red foxes and golden jackals, to jointly affect emigration propensity and survival during dispersal. Sub-adult foxes emigrated more frequently from the food-rich habitat than from the pristine, food-limited habitat, while adult foxes showed the opposite trend. During dispersal, adults exhibited lower survival while sub-adults did not experience additional mortality costs. Although fox mortality rates increased in response to food reduction, dispersal remained unchanged, while jackals showed strong dispersal response in two of the three repetitions. Jackal survival under food reduction was lowest for the dispersing individuals. While resources are an important dispersal determinant, different age classes and species experience the same resource environment differently and consequently have different motivations, yielding different dispersal responses and consequences.


Asunto(s)
Migración Animal/fisiología , Zorros/fisiología , Chacales/fisiología , Envejecimiento/fisiología , Animales , Ecosistema , Conducta Alimentaria , Femenino , Masculino , Modelos Biológicos , Probabilidad , Análisis de Supervivencia
6.
Behav Processes ; 92: 131-42, 2013 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-23124015

RESUMEN

We compare differences in the reproductive strategies of "free-living" dogs with their wild relatives in the genus Canis, of which the dog is a very recently evolved member. The members of this genus display a greater range of parental motor patterns than generally seen in other species of Carnivora, including pair-bonding and extended parental care; parents regurgitate to offspring and provision them with food for months to as long as a year. But the domestic dog does not routinely display these genus-typical behaviors. While this has generally been assumed to be a result of direct human intervention, humans have little reproductive control over the vast majority of domestic dogs. We analyze the low frequency of display of genus-typical behaviors and postulate that the dog's reproductive behaviors are an adaptation to permanent human settlement and the waste resources associated with it. Adaptation to this environment has decreased seasonality, increased the fecundity of unrestrained dogs and reduced the need for prolonged parental care. The consequences of greater fecundity and reduced parental care are compared to the reproductive behavior of other species of the genus.


Asunto(s)
Canidae/fisiología , Conducta Alimentaria/fisiología , Conducta Sexual Animal/fisiología , Animales , Coyotes/fisiología , Perros/fisiología , Chacales/fisiología , Apareamiento , Estaciones del Año , Lobos/fisiología
7.
J Zoo Wildl Med ; 39(4): 576-81, 2008 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-19110699

RESUMEN

Twenty-two free-ranging golden jackals (Canis aureus) were immobilized with a combination of 113 +/- 24 microg/kg medetomidine and 2.1 +/- 0.3 mg/kg ketamine (M-K) or 88 +/- 16 microg/kg medetomidine and 0.47 +/- 0.08 mg/ kg midazolam (M-M) by i.m. injection. Induction and recovery times were recorded. Pulse rate, respiratory rate, body temperature, systolic and diastolic blood pressures, and oxygen saturation were measured. Anesthesia depth indicators were observed. There was no significant difference between the M-K and the M-M groups regarding induction time (6:14 +/- 1:45 and 7:16 +/- 2:09 min, respectively). Both combinations provided safe and effective immobilization for at least 20-30 min. Pulse rate was significantly higher in the M-K group. There was no significant difference in any other objective or subjective parameter. Following administration of atipamezole at five times the dose of medetomidine given, there was a significant difference between the two combinations in recovery time; M-K jackals were standing within 3:42 +/- 2:17 min and M-M jackals within 8:47 +/- 4:32 min. Neither of the combinations caused rough or prolonged recovery. Subjectively, the M-M group had smoother and less ataxic recovery.


Asunto(s)
Anestésicos Combinados/administración & dosificación , Imidazoles/administración & dosificación , Inmovilización/veterinaria , Chacales/fisiología , Antagonistas Adrenérgicos alfa/administración & dosificación , Periodo de Recuperación de la Anestesia , Anestésicos Disociativos/administración & dosificación , Animales , Animales Salvajes/fisiología , Presión Sanguínea/fisiología , Temperatura Corporal/efectos de los fármacos , Temperatura Corporal/fisiología , Femenino , Frecuencia Cardíaca/efectos de los fármacos , Frecuencia Cardíaca/fisiología , Hipnóticos y Sedantes/administración & dosificación , Inmovilización/métodos , Ketamina/administración & dosificación , Masculino , Medetomidina/administración & dosificación , Midazolam/administración & dosificación , Consumo de Oxígeno/fisiología , Respiración/efectos de los fármacos , Factores de Tiempo
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