Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 9 de 9
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Conserv Biol ; 36(5): e13974, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-35796039

RESUMO

Fear-induced generalization of threats to noninimical stimuli is a behavioral tendency of humans to minimize exposure to potential threats. In human-carnivore conflict zones, people often generalize their fear of predation by obligate carnivores to nonobligate carnivores despite differences in species' predation rates. We investigated the effect of a perceived threat of large obligate carnivores to livestock on tolerance and perception of striped hyena (Hyaena hyaena) in an area of high human-carnivore conflict. We surveyed 197 households through asemistructured questionnaire to determine people's perception and tolerance of striped hyenas in Sathyamangalam and Mudumalai Tiger Reserves after identification of the current distribution range of hyena determined through camera trap and sign surveys. Through the random forest algorithm, we modeled the level of tolerance of striped hyena as a function of loss of livestock to predation and from disease, the perceived threat of predation by hyena, and other socioeconomic attributes. Animal husbandry was a major source of income but was severely affected by livestock loss due to predation and disease. Sixty-nine percent of people were uncertain about predatory behavior of hyena; out of that, 23% reported a negative conservation attitude. Only 6 instances of hyena depredation on livestock and 2 on dogs were reported. Our model confirmed that economic instability associated with increased loss to predation and disease, livestock dependency, and a decrease in family annual income negatively affected people's tolerance of hyena. Perceptual uncertainty related to predatory behavior of hyena also negatively affected people's tolerance. In our study area, economic instability and perceptual uncertainty led to generalization of fear of large carnivores to a nonobligate predator. Such generalization may affect the attitude of people toward many other species. Understanding the role of economic instability and perceptual uncertainty should facilitate conservation of species, such as the hyena, that are vulnerable to false generalization.


Generalización de las Amenazas Atribuidas a los Grandes Carnívoros en las Áreas con un Elevado Conflicto Humano-Fauna Resumen La generalización de las amenazas inducidas por el miedo a los estímulos no desfavorables es una tendencia del comportamiento humano para minimizar la exposición ante las amenazas potenciales. En las zonas de conflicto humano-carnívoros, las personas transfieren con frecuencia su miedo a los carnívoros obligados hacia los no obligados a pesar de las diferencias en las tasas de depredación de las espcies. Investigamos el efecto de la amenaza percibida que representan los grandes carnívoros obligados para el ganado sobre la tolerancia a y la percepción de la hiena rayada (Hyaena hyaena) en un área con un conflicto elevado entre humanos y carnívoros. Encuestamos a 197 hogares con un cuestionario semiestructurado para determinar la percepción y tolerancia que tienen las personas hacia la hiena rayada en las reservas de tigres de Satayamangalam y Mudumalai después de identificar la distribución actual de la hiena mediante cámaras trampa y censos de indicios. Modelamos el nivel de tolerancia a la hiena rayada con el algoritmo de bosque aleatorio como función de la pérdida de ganado por depredación o enfermedad, la amenaza percibida de la hiena como depredador y otros atributos socioeconómicos. La crianza de animales fue una gran fuente de ingresos aunque con severas afectaciones por la pérdida de ganado por depredación o enfermedad. El 69% de las personas tenían incertidumbre acerca del comportamiento de depredación de la hiena; de ese porcentaje, el 23% reportó una actitud negativa de conservación. En cuanto a las hienas, sólo se reportaron seis instancias de depredación de ganado y dos de perros. Nuestro modelo confirmó que la inestabilidad económica asociada con el incremento en las pérdidas por depredación y enfermedad, la dependencia por el ganado y una reducción en el ingreso anual familiar afectó negativamente la tolerancia que tienen las personas hacia las hienas. La incertidumbre percibida relacionada con el comportamiento de depredación de las hienas también afectó negativamente la tolerancia de las personas. La inestabilidad económica y la incertidumbre percibida derivaron en una transferencia del miedo a los grandes carnívoros hacia los depredadores no obligados en nuestra área de estudio. Dicha transferencia puede afectar la actitud de las personas hacia muchas otras especies. El conocimiento sobre el papel que tiene la inestabilidad económica y la incertidumbre percibida debería facilitar la conservación de especies que son vulnerables a las falsas generalizaciones, como es el caso de la hiena.


Assuntos
Carnívoros , Hyaenidae , Animais , Animais Selvagens , Conservação dos Recursos Naturais , Cães , Humanos , Gado , Comportamento Predatório
2.
J Environ Manage ; 316: 115315, 2022 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-35598453

RESUMO

The global effort to protect megaherbivore populations is largely dependent on how human-wildlife conflict is identified, prioritized, and remedied. We examined the socio-ecological and landscape-scale factors determining spatial patterns of human-megaherbivore (Asian elephant Elephas maximus and gaur Bos gaurus) interactions across sixteen Forest Divisions in Tamil Nadu, India. Using a systematic grid-based design, we conducted questionnaire-based surveys of 1460 households at the human-wildlife interface adjacent to Protected Areas, Reserve Forest and Fringe Areas. We specifically collected information on elephant and gaur conflict incidents (e.g., human death/injuries, property damage, and crop-raiding), cropland type, extent of crop area and area lost to crop-raiding, from each household. We found that human-elephant conflict increased with percentage of crop cover, diversity of major and minor crops grown, proximity to water source, flat terrain, and lower rates of precipitation. Human-gaur conflict was greatest with a high diversity of major crops, proximity to water source, moderate precipitation, and more undulating terrain. We identified ca. 7900 km2 hotspot area of contiguous high-intensity elephant conflict. For gaur, we identified high-frequency conflict hotspot areas covering ca. 625 km2, which were patchily distributed, highly localised, and attributed mostly to the recent changing land-use patterns. Our findings will help policymakers and park managers in developing landscape-scale human-wildlife conflict mitigation plans in the identified conflict hotspots.


Assuntos
Conservação dos Recursos Naturais , Elefantes , Animais , Animais Selvagens , Bovinos , Produtos Agrícolas , Humanos , Índia , Água
3.
Sci Total Environ ; 822: 153268, 2022 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-35074387

RESUMO

The outbreak of the COVID-19 pandemic brought unprecedented changes in human activity via extensive lockdowns worldwide. Large-scale shifts in human activities bestowed both positive and negative impacts on wildlife. Unforeseen reduction in the activities of people allowed wildlife to venture outside of forested areas to exploit newfound habitats and increase their diurnal activities. While on a negative note, a reduction in forest-related law enforcement led to substantial increase in illegal activities such as poaching. We conducted mammal surveys in forested and nearby farmland of a fragmented landscape under two distinct scenarios: pre-lockdown and lockdown. An increase in poaching activities observed during the lockdown period in our study area provided us an opportunity to investigate the impact of the lockdown on wildlife. Camera trapping data of four highly poached mammalian species, namely black-naped hare Lepus nigricollis, wild pig Sus scrofa, four-horned antelope Tetracerus quadricornis and leopard Panthera pardus were considered to investigate activity patterns and habitat use, to understand the effect of lockdown. The pre-lockdown period was used as a baseline to compare any changes in trends of activity patterns, habitat use and detection probabilities of targeted species. Species-specific changes in activity patterns of study species were observed, with an increment in daytime activity during lockdown. The results showed species-specific increase in the habitat use of study species during lockdown. Reduction in the detection probability of all study species was witnessed. This is the first study to highlight the effect of the COVID-19 lockdown on the responses of wildlife by considering the changes in their temporal and spatial use before and during lockdown. The knowledge gained on wildlife during reduced human mobility because of the pandemic aid in understanding the effect of human disturbances and developing future conservation strategies in the shared space, to manage both wildlife and humans.


Assuntos
Animais Selvagens , COVID-19 , Animais , Animais Selvagens/fisiologia , COVID-19/epidemiologia , Controle de Doenças Transmissíveis , Ecossistema , Humanos , Índia/epidemiologia , Mamíferos , Pandemias
5.
Ambio ; 50(10): 1866-1878, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-33677809

RESUMO

Urbanisation is rapidly transforming natural landscapes with consequences for biodiversity. Little is documented on the response of African wildlife to urbanisation. We reviewed case studies of vertebrate species' responses to urbanisation in KwaZulu-Natal, South Africa to determine trends. Connected habitat mosaics of natural and anthropogenic green spaces are critical for urban wildlife persistence. We present a novel modification to the final of three phases of the framework described by Evans et al. (2010), which documents this sequence for vertebrate species persistence, based on the perspective of our research. Species in suburbia exhibit an initial phase where behavioural and ecological flexibility, life-history traits and phenotypic plasticity either contribute to their success, or they stay at low numbers. Where successful, the next phase is a rapid increase in populations and distribution; anthropogenic food resources and alternate breeding sites are effectively exploited. The modified third phase either continues to spread, plateau or decline.


Assuntos
Biodiversidade , Ecossistema , Animais , Conservação dos Recursos Naturais , África do Sul , Urbanização , Vertebrados
6.
Glob Chang Biol ; 24(1): e27-e39, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-28799245

RESUMO

Globally, long-term research is critical to monitor the responses of tropical species to climate and land cover change at the range scale. Citizen science surveys can reveal the long-term persistence of poorly known nomadic tropical birds occupying fragmented forest patches. We applied dynamic occupancy models to 13 years (2002-2014) of citizen science-driven presence/absence data on Cape parrot (Poicephalus robustus), a food nomadic bird endemic to South Africa. We modeled its underlying range dynamics as a function of resource distribution, and change in climate and land cover through the estimation of colonization and extinction patterns. The range occupancy of Cape parrot changed little over time (ψ = 0.75-0.83) because extinction was balanced by recolonization. Yet, there was considerable regional variability in occupancy and detection probability increased over the years. Colonizations increased with warmer temperature and area of orchards, thus explaining their range shifts southeastwards in recent years. Although colonizations were higher in the presence of nests and yellowwood trees (Afrocarpus and Podocarpus spp.), the extinctions in small forest patches (≤227 ha) and during low precipitation (≤41 mm) are attributed to resource constraints and unsuitable climatic conditions. Loss of indigenous forest cover and artificial lake/water bodies increased extinction probabilities of Cape parrot. The land use matrix (fruit farms, gardens, and cultivations) surrounding forest patches provides alternative food sources, thereby facilitating spatiotemporal colonization and extinction in the human-modified matrix. Our models show that Cape parrots are vulnerable to extreme climatic conditions such as drought which is predicted to increase under climate change. Therefore, management of optimum sized high-quality forest patches is essential for long-term survival of Cape parrot populations. Our novel application of dynamic occupancy models to long-term citizen science monitoring data unfolds the complex relationships between the environmental dynamics and range fluctuations of this food nomadic species.


Assuntos
Migração Animal , Aves/fisiologia , Mudança Climática , Florestas , Animais , África do Sul
7.
Ecol Evol ; 7(6): 1964-1973, 2017 03.
Artigo em Inglês | MEDLINE | ID: mdl-28331603

RESUMO

Identifying the primary causes affecting population densities and distribution of flagship species are necessary in developing sustainable management strategies for large carnivore conservation. We modeled drivers of spatial density of the common leopard (Panthera pardus) using a spatially explicit capture-recapture-Bayesian approach to understand their population dynamics in the Maputaland Conservation Unit, South Africa. We camera-trapped leopards in four protected areas (PAs) of varying sizes and disturbance levels covering 198 camera stations. Ours is the first study to explore the effects of poaching level, abundance of prey species (small, medium, and large), competitors (lion Panthera leo and spotted hyenas Crocuta crocuta), and habitat on the spatial distribution of common leopard density. Twenty-six male and 41 female leopards were individually identified and estimated leopard density ranged from 1.6 ± 0.62/100 km2 (smallest PA-Ndumo) to 8.4 ± 1.03/100 km2 (largest PA-western shores). Although dry forest thickets and plantation habitats largely represented the western shores, the plantation areas had extremely low leopard density compared to native forest. We found that leopard density increased in areas when low poaching levels/no poaching was recorded in dry forest thickets and with high abundance of medium-sized prey, but decreased with increasing abundance of lion. Because local leopard populations are vulnerable to extinction, particularly in smaller PAs, the long-term sustainability of leopard populations depend on developing appropriate management strategies that consider a combination of multiple factors to maintain their optimal habitats.

8.
Ecol Evol ; 7(6): 1974-1983, 2017 03.
Artigo em Inglês | MEDLINE | ID: mdl-28331604

RESUMO

Distributions of avian mutualists are affected by changes in biotic interactions and environmental conditions driven directly/indirectly by human actions. The range contraction of red-billed oxpeckers (Buphagus erythrorhynchus) in South Africa is partly a result of the widespread use of acaracides (i.e., mainly cattle dips), toxic to both ticks and oxpeckers. We predicted the habitat suitability of red-billed oxpeckers in South Africa using ensemble models to assist the ongoing reintroduction efforts and to identify new reintroduction sites for population recovery. The distribution of red-billed oxpeckers was influenced by moderate to high tree cover, woodland habitats, and starling density (a proxy for cavity-nesting birds) with regard to nest-site characteristics. Consumable resources (host and tick density), bioclimate, surface water body density, and proximity to protected areas were other influential predictors. Our models estimated 42,576.88-98,506.98 km2 of highly suitable habitat (0.5-1) covering the majority of Limpopo, Mpumalanga, North West, a substantial portion of northern KwaZulu-Natal (KZN) and the Gauteng Province. Niche models reliably predicted suitable habitat in 40%-61% of the reintroduction sites where breeding is currently successful. Ensemble, boosted regression trees and generalized additive models predicted few suitable areas in the Eastern Cape and south of KZN that are part of the historic range. A few southern areas in the Northern Cape, outside the historic range, also had suitable sites predicted. Our models are a promising decision support tool for guiding reintroduction programs at macroscales. Apart from active reintroductions, conservation programs should encourage farmers and/or landowners to use oxpecker-compatible agrochemicals and set up adequate nest boxes to facilitate the population recovery of the red-billed oxpecker, particularly in human-modified landscapes. To ensure long-term conservation success, we suggest that the effect of anthropogenic threats on habitat distributions should be investigated prior to embarking on a reintroduction program, as the habitat in the historical range may no longer be viable for current bird populations.

9.
PLoS One ; 8(11): e79295, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24244470

RESUMO

Due to their secretive habits, predicting the pattern of spatial distribution of small carnivores has been typically challenging, yet for conservation management it is essential to understand the association between this group of animals and environmental factors. We applied maximum entropy modeling (MaxEnt) to build distribution models and identify environmental predictors including bioclimatic variables, forest and land cover type, topography, vegetation index and anthropogenic variables for six small carnivore species in Mudumalai Tiger Reserve. Species occurrence records were collated from camera-traps and vehicle transects during the years 2010 and 2011. We used the average training gain from forty model runs for each species to select the best set of predictors. The area under the curve (AUC) of the receiver operating characteristic plot (ROC) ranged from 0.81 to 0.93 for the training data and 0.72 to 0.87 for the test data. In habitat models for F. chaus, P. hermaphroditus, and H. smithii "distance to village" and precipitation of the warmest quarter emerged as some of the most important variables. "Distance to village" and aspect were important for V. indica while "distance to village" and precipitation of the coldest quarter were significant for H. vitticollis. "Distance to village", precipitation of the warmest quarter and land cover were influential variables in the distribution of H. edwardsii. The map of predicted probabilities of occurrence showed potentially suitable habitats accounting for 46 km(2) of the reserve for F. chaus, 62 km(2) for V. indica, 30 km(2) for P. hermaphroditus, 63 km(2) for H. vitticollis, 45 km(2) for H. smithii and 28 km(2) for H. edwardsii. Habitat heterogeneity driven by the east-west climatic gradient was correlated with the spatial distribution of small carnivores. This study exemplifies the usefulness of modeling small carnivore distribution to prioritize and direct conservation planning for habitat specialists in southern India.


Assuntos
Ecossistema , Vertebrados , Animais , Meio Ambiente , Geografia , Índia , Modelos Teóricos , Dinâmica Populacional
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...