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1.
Ambio ; 52(3): 598-615, 2023 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-36583831

RESUMEN

Conservationists speculated on potential benefits to wildlife of lockdown restrictions because of the COVID-19 pandemic but voiced concern that restrictions impeded nature conservation. We assessed the effects of lockdown restrictions on biodiversity conservation in South Africa, a biodiverse country with economic inequality and reliance on wildlife resources. We solicited expert opinion using the IUCN's Threats Classification Scheme to structure a questionnaire and illustrated responses with individual case studies from government parastatal and non-governmental conservation organisations. The most highly reported threats were biological resource use, residential/commercial developments, invasive species, and human intrusions. The trends reported by 90 survey respondents were supported by case studies using environmental compliance data from parastatal conservation organisations. Lack of tourism revenue and funding were cited as hindrances to conservation. Mechanisms to prevent environmental degradation in the face of global emergencies must be implemented and 'ring-fenced' to ensure conservation is not a casualty during future global crises.


Asunto(s)
COVID-19 , Conservación de los Recursos Naturales , Animales , Humanos , Animales Salvajes , Control de Enfermedades Transmisibles/legislación & jurisprudencia , COVID-19/prevención & control , Sudáfrica , Encuestas y Cuestionarios
2.
J Environ Manage ; 291: 112664, 2021 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-33975269

RESUMEN

Reliable estimates of wildlife mortality due to wildlife-vehicle collisions are key to understanding its impact on wildlife populations and developing strategies to prevent or reduce collisions. Standardised approaches for monitoring roadkill are needed to derive robust and unbiased estimates of mortality that are comparable across different study systems and ecological contexts. When designing surveys, there is a trade-off between survey frequency (and hence logistical effort and financial cost) and carcass detection. In this regard, carcass persistence (the period a carcass remains detectable before being removed by decomposition or scavengers) is important; the longer a carcass persists, the greater the likelihood it will be detected with lower survey effort by conducting more infrequent surveys. Using multi-taxon carcass data collected over a month of repeated driven surveys, combined with five covariates (species functional group, body weight, carcass position on road, carcass condition [either flattened or not after impact], and rainfall prior to each survey), we explored the drivers of carcass persistence with the overall aim of providing information to optimise the design of carcass surveys along linear infrastructure. Our methodological approach included a survival analysis to determine carcass persistence, linear regressions to test the effect of covariates, a subsampling analysis (using field data and a simulation exercise) to assess how the proportion of carcasses detected changes according to survey frequency, and an analysis to compare the costs of surveys based on study duration, transect length and survey frequency. Mean overall carcass persistence was 2.7 days and was significantly correlated with position on road and within-functional group body weight. There was no evidence for a significant effect of rainfall, while the effect of carcass condition was weakly non-significant. The proportion of carcasses detected decreased sharply when survey intervals were longer than three days. However, we showed that survey costs can be reduced by up to 80% by conducting non-daily surveys. Expanding on the call for a standardised methodology for roadkill surveys, we propose that carcass persistence be explicitly considered during survey design. By carefully considering the objectives of the survey and characteristics of the focal taxa, researchers can substantially reduce logistical costs. In addition, we developed an R Shiny web app that can be used by practitioners to compare survey costs across a variety of survey characteristics. This web app will allow practitioners to easily assess the trade-off between carcass detection and logistical effort.


Asunto(s)
Animales Salvajes , Animales , Probabilidad , Encuestas y Cuestionarios
3.
Conserv Biol ; 33(4): 760-768, 2019 08.
Artículo en Inglés | MEDLINE | ID: mdl-31206825

RESUMEN

Compassionate conservation focuses on 4 tenets: first, do no harm; individuals matter; inclusivity of individual animals; and peaceful coexistence between humans and animals. Recently, compassionate conservation has been promoted as an alternative to conventional conservation philosophy. We believe examples presented by compassionate conservationists are deliberately or arbitrarily chosen to focus on mammals; inherently not compassionate; and offer ineffective conservation solutions. Compassionate conservation arbitrarily focuses on charismatic species, notably large predators and megaherbivores. The philosophy is not compassionate when it leaves invasive predators in the environment to cause harm to vastly more individuals of native species or uses the fear of harm by apex predators to terrorize mesopredators. Hindering the control of exotic species (megafauna, predators) in situ will not improve the conservation condition of the majority of biodiversity. The positions taken by so-called compassionate conservationists on particular species and on conservation actions could be extended to hinder other forms of conservation, including translocations, conservation fencing, and fertility control. Animal welfare is incredibly important to conservation, but ironically compassionate conservation does not offer the best welfare outcomes to animals and is often ineffective in achieving conservation goals. Consequently, compassionate conservation may threaten public and governmental support for conservation because of the limited understanding of conservation problems by the general public.


Deconstrucción de la Conservación Compasiva Resumen La conservación compasiva se enfoca en cuatro principios: no causar daño; los individuos importan; la integración de los animales individualmente; y la coexistencia pacífica entre los humanos u los animales. Recientemente, la conservación compasiva ha sido promovida como una alternativa a la filosofía convencional de la conservación. Creemos que los ejemplos presentados por los conservacionistas compasivos han sido elegidos arbitraria o deliberadamente por estar enfocados en los mamíferos; por ser inherentes y no compasivos; y por ofrecer soluciones de conservación poco efectivas. La conservación compasiva se enfoca arbitrariamente en las especies carismáticas, principalmente los grandes depredadores y los megaherbívoros. La filosofía no es compasiva cuando deja que los depredadores invasores dentro del ambiente causen daño a un vasto número de individuos nativos o usa el miedo al daño por superdepredadores para aterrorizar a los mesodepredadores. El entorpecimiento del control de especies exóticas (megafauna, depredadores) in situ no mejorará las condiciones de conservación de la mayoría de la biodiversidad, incluso si los conservacionistas compasivos no dañan a los individuos exóticos. Las posiciones que toman los llamados conservacionistas compasivos sobre especies particulares y sobre las acciones de conservación podrían extenderse para entorpecer otros tipos de conservación, incluyendo las reubicaciones, el encercado para la conservación y el control de la fertilidad. El bienestar animal es increíblemente importante para la conservación e irónicamente, la conservación compasiva no ofrece los mejores resultados de bienestar para los animales y comúnmente es poco efectiva en el logro de los objetivos de conservación. Como consecuencia, la conservación compasiva puede poner en peligro el apoyo público y del gobierno que tiene la conservación debido al entendimiento poco limitado que tiene el público general sobre los problemas de conservación.


Asunto(s)
Biodiversidad , Conservación de los Recursos Naturales , Bienestar del Animal , Animales , Empatía , Humanos
4.
Conserv Biol ; 33(5): 1106-1119, 2019 10.
Artículo en Inglés | MEDLINE | ID: mdl-30767306

RESUMEN

As landscapes continue to fall under human influence through habitat loss and fragmentation, fencing is increasingly being used to mitigate anthropogenic threats and enhance the commercial value of wildlife. Subsequent intensification of management potentially erodes wildness by disembodying populations from landscape-level processes, thereby disconnecting species from natural selection. Tools are needed to measure the degree to which populations of large vertebrate species in formally protected and privately owned wildlife areas are self-sustaining and free to adapt. We devised a framework to measure such wildness based on 6 attributes relating to the evolutionary and ecological dynamics of vertebrates (space, disease and parasite resistance, exposure to predation, exposure to limitations and fluctuations of food and water supply, and reproduction). For each attribute, we set empirical, species-specific thresholds between 5 wildness states based on quantifiable management interventions. We analysed data from 205 private wildlife properties with management objectives spanning ecotourism to consumptive utilization to test the framework on 6 herbivore species representing a range of conservation statuses and commercial values. Wildness scores among species differed significantly, and the proportion of populations identified as wild ranged from 12% to 84%, which indicates the tool detected site-scale differences both among populations of different species and populations of the same species under different management regimes. By quantifying wildness, this framework provides practitioners with standardized measurement units that link biodiversity with the sustainable use of wildlife. Applications include informing species management plans at local scales; standardizing the inclusion of managed populations in red-list assessments; and providing a platform for certification and regulation of wildlife-based economies. Applying this framework may help embed wildness as a normative value in policy and mitigate the shifting baseline of what it means to truly conserve a species.


Un Marco de Trabajo para Medir el Estado Salvaje de Poblaciones de Vertebrados Mayores bajo Manejo Resumen Conforme los paisajes siguen cayendo bajo la influencia del humano por causa de la pérdida del hábitat y la fragmentación, cada vez se usa más el encercado para mitigar las amenazas antropogénicas o incrementar el valor comercial de la fauna. La intensificación subsecuente del manejo tiene el potencial para erosionar el estado salvaje al desincorporar a las poblaciones de los procesos a nivel de paisaje, desconectando así a las especies del proceso de selección natural. Por lo tanto, se necesitan herramientas para medir el grado al cual las poblaciones de especies de vertebrados mayores dentro de áreas de fauna protegidas y privadas son autosostenibles y libres de adaptarse. Diseñamos un marco de trabajo para medir dicho estado salvaje con base en seis atributos relacionados con las dinámicas evolutivas y ecológicas de los vertebrados (espacio, resistencia a las enfermedades y a los parásitos, exposición a la depredación, exposición a las limitaciones y fluctuaciones en las reservas de agua y alimentos, y reproducción). Para cada atributo, establecimos umbrales empíricos y específicos por especie entre cinco estados salvajes basados en las intervenciones de manejo cuantificables. Usamos datos de 205 propiedades privadas de fauna con objetivos de manejo que abarcan desde el ecoturismo hasta el uso para consumo para probar el marco de trabajo en seis especies de herbívoros con una gama de estados de conservación y valores comerciales. Los puntajes de estado salvaje entre las especies difirieron significativamente y la proporción de poblaciones identificadas como salvajes osciló del 12% al 84%, lo que indica que la herramienta detectó diferencias a escala de sitio entre las poblaciones de diferentes especies y las poblaciones de la misma especie bajo diferentes regímenes de manejo. Si cuantificamos el estado salvaje, este marco de trabajo les proporciona a los practicantes las unidades de medida estandarizadas que vinculan a la biodiversidad con el uso sostenible de la fauna. Las aplicaciones de este marco de trabajo incluyen informar a los planes de manejo de las especies a escalas locales; estandarizar la inclusión de las poblaciones manejadas en las evaluaciones de listas rojas; y proporcionar una plataforma para la certificación y regulación de las economías basadas en la fauna. La aplicación de este marco de trabajo puede ayudar a insertar a la fauna como un valor normativo dentro de la política y a mitigar la línea base cambiante de lo que significa conservar verdaderamente a una especie.


Asunto(s)
Biodiversidad , Conservación de los Recursos Naturales , Animales , Animales Salvajes , Ecosistema , Humanos , Vertebrados
5.
Proc Natl Acad Sci U S A ; 114(3): 528-533, 2017 01 17.
Artículo en Inglés | MEDLINE | ID: mdl-28028225

RESUMEN

Establishing and maintaining protected areas (PAs) are key tools for biodiversity conservation. However, this approach is insufficient for many species, particularly those that are wide-ranging and sparse. The cheetah Acinonyx jubatus exemplifies such a species and faces extreme challenges to its survival. Here, we show that the global population is estimated at ∼7,100 individuals and confined to 9% of its historical distributional range. However, the majority of current range (77%) occurs outside of PAs, where the species faces multiple threats. Scenario modeling shows that, where growth rates are suppressed outside PAs, extinction rates increase rapidly as the proportion of population protected declines. Sensitivity analysis shows that growth rates within PAs have to be high if they are to compensate for declines outside. Susceptibility of cheetah to rapid decline is evidenced by recent rapid contraction in range, supporting an uplisting of the International Union for the Conservation of Nature (IUCN) Red List threat assessment to endangered. Our results are applicable to other protection-reliant species, which may be subject to systematic underestimation of threat when there is insufficient information outside PAs. Ultimately, conserving many of these species necessitates a paradigm shift in conservation toward a holistic approach that incentivizes protection and promotes sustainable human-wildlife coexistence across large multiple-use landscapes.


Asunto(s)
Acinonyx , Conservación de los Recursos Naturales , África , Animales , Asia , Biodiversidad , Simulación por Computador , Extinción Biológica , Modelos Biológicos , Dinámica Poblacional/tendencias , Factores de Riesgo
6.
PLoS One ; 10(3): e0122782, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-25822468

RESUMEN

This study provides a framework to assess the feasibility of reintroducing carnivores into an area, using African wild dogs (Lycaon pictus) as an example. The Great Fish River Nature Reserve in the Eastern Cape Province, South Africa, has been identified as a potential reserve to reintroduce wild dogs, and we applied this framework to provide a threat assessment of the surrounding area to determine potential levels of human-wildlife conflict. Although 56% of neighbouring landowners and local communities were positive about a wild dog reintroduction, data collected from questionnaire surveys revealed that human-wild dog conflict is a potential threat to wild dog survival in the area. Additional potential threats include diseases, snaring, poaching and hunting wild dogs for the use of traditional medicine. A threat index was developed to establish which properties harboured the greatest threats to wild dogs. This index was significantly influenced by the respondent's first language (isiXhosa had more positive indices), education level (poorer education was synonymous with more positive threat indices), land use (wildlife ranching being the most negative) and land tenure (community respondents had more positive indices than private landowners). Although threats are present, they can be effectively mitigated through strategies such as carnivore education programs, vaccination campaigns and anti-snare patrols to promote a successful reintroduction of this endangered canid.


Asunto(s)
Canidae , Conflicto Psicológico , Adulto , Anciano , Animales , Conservación de los Recursos Naturales , Transmisión de Enfermedad Infecciosa , Estudios de Factibilidad , Femenino , Humanos , Masculino , Persona de Mediana Edad , Conducta Predatoria , Encuestas y Cuestionarios , Adulto Joven
7.
Ecol Evol ; 4(15): 3060-71, 2014 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-25247063

RESUMEN

Previous assessments of wildlife road mortality have not used directly comparable methods and, at present, there is no standardized protocol for the collection of such data. Consequently, there are no internationally comparative statistics documenting roadkill rates. In this study, we used a combination of experimental trials and road transects to design a standardized protocol to assess roadkill rates on both paved and unpaved roads. Simulated roadkill were positioned over a 1 km distance, and trials were conducted at eight different speeds (20-100 km·h(-1)). The recommended protocol was then tested on a 100-km transect, driven daily over a 40-day period. This recorded 413 vertebrate roadkill, comprising 106 species. We recommend the protocol be adopted for future road ecology studies to enable robust statistical comparisons between studies.

8.
PLoS One ; 9(6): e99686, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-24918935

RESUMEN

Compared to their main competitors, African wild dogs (Lycaon pictus) have inferior competitive abilities and interspecific competition is a serious fitness-limiting factor. Lions (Panthera leo) are the dominant large carnivore in African savannah ecosystems and wild dogs avoid them both spatially and temporally. Wild dog young are particularly vulnerable and suffer high rates of mortality from lions. Since lions do not utilize all parts of the landscape with an equal intensity, spatial variation in lion densities can be exploited by wild dogs both during their general ranging behaviour, but more specifically when they are confined to a den with vulnerable young. Since patches of rugged terrain are associated with lower lion densities, we hypothesized that these comparatively safe habitats should be selected by wild dogs for denning. We investigated the relationship between the distribution of 100 wild dog den sites and the occurrence of rugged terrain in four wild dog populations located in Tanzania, Zimbabwe and South Africa. A terrain ruggedness index was derived from a 90 m digital elevation model and used to map terrain ruggedness at each site. We compared characteristics of actual and potential (random) den sites to determine how wild dogs select den sites. The distributions of wild dog dens were strongly associated with rugged terrain and wild dogs actively selected terrain that was more rugged than that available on average. The likelihood of encountering lions is reduced in these habitats, minimizing the risk to both adults and pups. Our findings have important implications for the conservation management of the species, especially when assessing habitat suitability for potential reintroductions. The simple technique used to assess terrain ruggedness may be useful to investigate habitat suitability, and even predict highly suitable denning areas, across large landscapes.


Asunto(s)
Conducta Animal/fisiología , Perros/fisiología , Leones/fisiología , Animales , Ecosistema , Pradera , Riesgo , Sudáfrica , Tanzanía , Zimbabwe
9.
J Anim Ecol ; 83(6): 1418-27, 2014 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-24724917

RESUMEN

Top predators can dramatically suppress populations of smaller predators, with cascading effects throughout communities, and this pressure is often unquestioningly accepted as a constraint on mesopredator populations. In this study, we reassess whether African lions suppress populations of cheetahs and African wild dogs and examine possible mechanisms for coexistence between these species. Using long-term records from Serengeti National Park, we tested 30 years of population data for evidence of mesopredator suppression, and we examined six years of concurrent radio-telemetry data for evidence of large-scale spatial displacement. The Serengeti lion population nearly tripled between 1966 and 1998; during this time, wild dogs declined but cheetah numbers remained largely unchanged. Prior to their local extinction, wild dogs primarily occupied low lion density areas and apparently abandoned the long-term study area as the lion population 'saturated' the region. In contrast, cheetahs mostly utilized areas of high lion density, and the stability of the cheetah population indicates that neither high levels of lion-inflicted mortality nor behavioural avoidance inflict sufficient demographic consequences to translate into population-level effects. Population data from fenced reserves in southern Africa revealed a similar contrast between wild dogs and cheetahs in their ability to coexist with lions. These findings demonstrate differential responses of subordinate species within the same guild and challenge a widespread perception that lions undermine cheetah conservation efforts. Paired with several recent studies that document fine-scale lion-avoidance by cheetahs, this study further highlights fine-scale spatial avoidance as a possible mechanism for mitigating mesopredator suppression.


Asunto(s)
Acinonyx/fisiología , Canidae/fisiología , Cadena Alimentaria , Leones/fisiología , Conducta Predatoria , Animales , Ecosistema , Dinámica Poblacional , Sudáfrica , Tanzanía , Telemetría
10.
PLoS One ; 9(1): e86265, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-24465998

RESUMEN

The Kruger National Park is a stronghold for African wild dog Lycaon pictus and cheetah Acinonyx jubatus conservation in South Africa. Tourist photographic surveys have been used to evaluate the minimum number of wild dogs and cheetahs alive over the last two decades. Photographic-based capture-recapture techniques for open populations were used on data collected during a survey done in 2008/9. Models were run for the park as a whole and per region (northern, central, southern). A total of 412 (329-495; SE 41.95) cheetahs and 151 (144-157; SE 3.21) wild dogs occur in the Kruger National Park. Cheetah capture probabilities were affected by time (number of entries) and sex, whereas wild dog capture probabilities were affected by the region of the park. When plotting the number of new individuals identified against the number of entries received, the addition of new wild dogs to the survey reached an asymptote at 210 entries, but cheetahs did not reach an asymptote. The cheetah population of Kruger appears to be acceptable, while the wild dog population size and density are of concern. The effectiveness of tourist-based surveys for estimating population sizes through capture-recapture analyses is shown.


Asunto(s)
Acinonyx , Animales de Zoológico , Canidae , Fotograbar , Animales , Recolección de Datos , Femenino , Masculino , Sudáfrica
11.
PLoS One ; 7(5): e34543, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-22567086

RESUMEN

Belly-size ratings or belly scores are frequently used in carnivore research as a method of rating whether and how much an animal has eaten. This method provides only a rough ordinal measure of fullness and does not quantify the amount of food an animal has consumed. Here we present a method for estimating the amount of meat consumed by individual African wild dogs Lycaon pictus. We fed 0.5 kg pieces of meat to wild dogs being temporarily held in enclosures and measured the corresponding change in belly size using lateral side photographs taken perpendicular to the animal. The ratio of belly depth to body length was positively related to the mass of meat consumed and provided a useful estimate of the consumption. Similar relationships could be calculated to determine amounts consumed by other carnivores, thus providing a useful tool in the study of feeding behaviour.


Asunto(s)
Carnívoros/fisiología , Ingestión de Alimentos , Animales , Perros , Estómago
12.
Biol Conserv ; 150(1): 15-22, 2012 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-32226083

RESUMEN

Infectious diseases impact African wild dogs (Lycaon pictus), but the nature and magnitude of this threat likely varies among populations according to different factors, such as the presence and prevalence of pathogens and land-use characteristics. We systematically evaluated these factors to assist development of locally appropriate strategies to mitigate disease risk. Wild dogs from 16 sites representing five unconnected populations were examined for rabies virus, canine distemper virus (CDV), canine parvovirus, canine coronavirus, and Babesia spp. exposure. Analyses revealed widespread exposure to viral pathogens, but Babesia was never detected. Exposure to CDV was associated with unprotected and protected-unfenced areas where wild dogs likely have a high probability of domestic dog contact and, in the case of protected-unfenced areas, likely reside amongst high wildlife densities. Our findings also suggest that domestic dog contact may increase rabies and coronavirus exposure risk. Therefore, domestic dogs may be a source of CDV, rabies and coronavirus, while wildlife may also play an important role in CDV transmission dynamics. Relatively high parvovirus seroprevalence across land-use types suggests that it might persist in the absence of spillover from domestic dogs. Should intervention be needed to control pathogens in wild dogs, efforts to prevent rabies and coronavirus exposure might be directed at reducing infection in the presumed domestic dog reservoir through vaccination. If prevention of CDV and parvovirus infections were deemed a management necessity, control of disease in domestic dogs may be insufficient to reduce transmission risks, and vaccination of wild dogs themselves may be the optimal strategy.

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