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1.
J Environ Manage ; 319: 115676, 2022 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-35839648

RESUMO

Providing sufficient benefits to local people can be an important component of effective and equitable conservation, especially where local communities face substantial opportunity costs or disbenefits from conservation. However, the distribution of benefits to local people is often inadequate or inequitable. In this study we investigated the heterogeneity in the extent to which people living near Hwange National Park (HNP), Zimbabwe, perceive benefit from the presence of the park. Specifically, we examined the relationships between a diverse set of candidate predictor variables and perceived benefit from HNP. Our candidate predictor variables broadly relate to personal assets, social capital, value orientation, fear of lions, and belief and participation in human-wildlife conflict mitigation schemes. One third of respondents reported that their household experienced at least some benefits from HNP. Of all respondents, 6% perceived their household to benefit strongly from HNP and 2% very strongly. Livestock loss to wildlife was the most important factor for predicting perceived benefit, with those suffering more loss less likely to perceive benefit. Multiple demographic factors predicted perceived benefit with, for instance, older people and those with less education perceiving less benefit. Employment in conservation-related work positively affected perceived benefit, whereas fear of lions had a negative impact. Social capital appeared to have a positive influence on perceived benefit from HNP. The relationship between social capital and perceived benefit was positive and plateauing, which suggests that social capital is especially impactful on the benefit perceived by individuals reporting the least social capital. We also found a positive association between belief in compensation schemes and perceived benefit from HNP. We posit hypotheses for this association but are unable to determine the underlying drivers of this relationship. Finally, participation in the community guardians programme, a human-lion conflict mitigation programme, was positively related to perceived benefit from HNP. Thus, our findings emphasise the value of considering a diverse array of factors when investigating park-people relationships and yield insights for improving the equitability of conservation in and around HNP and similar systems.


Assuntos
Gado , Capital Social , Idoso , Animais , Animais Selvagens , Conservação dos Recursos Naturais , Medo , Humanos
2.
Oecologia ; 195(1): 51-63, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33507398

RESUMO

Apex predators play important roles in ecosystem functioning and, where they coexist, intraguild interactions can have profound effects on trophic relationships. Interactions between predators range from intraguild predation and competition to facilitation through scavenging opportunities. Despite the increased availability of fine-scale GPS data, the determinants and outcomes of encounters between apex predators remain understudied. We used simultaneous GPS data from collared spotted hyaenas (Crocuta crocuta) and African lions (Panthera leo) in Hwange National Park, Zimbabwe, to determine the environmental conditions of the encounters between the two species, which species provoked the encounter, and which species dominated the encounter. Our results show that encounters between hyaenas and lions are mostly resource-related (over a carcass or around waterholes). In the wet season, encounters mainly occur at a carcass, with lions being dominant over its access. In the dry season, encounters mainly occur in the absence of a carcass and near waterholes. Movements of hyaenas and lions before, during, and after these dry-season encounters suggest two interference scenarios: a passive interference scenario whereby both predators would be attracted to waterholes but lions would leave a waterhole used by hyaenas because of prey disturbance, and an active interference scenario whereby hyaenas would actively chase lions from waterhole areas, which are prime hunting grounds. This study highlights the seasonal dynamics of predator interactions and illustrates how the relative importance of negative interactions (interference competition during the dry season) and positive interactions (scavenging opportunities during the wet season) shifts over the course of the year.


Assuntos
Ecossistema , Leões , Animais , Comportamento Predatório , Estações do Ano
3.
Conserv Biol ; 31(3): 513-523, 2017 06.
Artigo em Inglês | MEDLINE | ID: mdl-27783450

RESUMO

In a world of shrinking habitats and increasing competition for natural resources, potentially dangerous predators bring the challenges of coexisting with wildlife sharply into focus. Through interdisciplinary collaboration among authors trained in the humanities, social sciences, and natural sciences, we reviewed current approaches to mitigating adverse human-predator encounters and devised a vision for future approaches to understanding and mitigating such encounters. Limitations to current approaches to mitigation include too much focus on negative impacts; oversimplified equating of levels of damage with levels of conflict; and unsuccessful technical fixes resulting from failure to engage locals, address hidden costs, or understand cultural (nonscientific) explanations of the causality of attacks. An emerging interdisciplinary literature suggests that to better frame and successfully mitigate negative human-predator relations conservation professionals need to consider dispensing with conflict as the dominant framework for thinking about human-predator encounters; work out what conflicts are really about (they may be human-human conflicts); unravel the historical contexts of particular conflicts; and explore different cultural ways of thinking about animals. The idea of cosmopolitan natures may help conservation professionals think more clearly about human-predator relations in both local and global context. These new perspectives for future research practice include a recommendation for focused interdisciplinary research and the use of new approaches, including human-animal geography, multispecies ethnography, and approaches from the environmental humanities notably environmental history. Managers should think carefully about how they engage with local cultural beliefs about wildlife, work with all parties to agree on what constitutes good evidence, develop processes and methods to mitigate conflicts, and decide how to monitor and evaluate these. Demand for immediate solutions that benefit both conservation and development favors dispute resolution and technical fixes, which obscures important underlying drivers of conflicts. If these drivers are not considered, well-intentioned efforts focused on human-wildlife conflicts will fail.


Assuntos
Animais Selvagens , Conservação dos Recursos Naturais , Ecossistema , Animais , Características Culturais , Humanos , Comportamento Predatório
4.
Ecol Lett ; 16(11): 1414, e4, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23962143

RESUMO

Creel et al. argue against the conservation effectiveness of fencing based on a population measure that ignores the importance of top predators to ecosystem processes. Their statistical analyses consider, first, only a subset of fenced reserves and, second, an incomplete examination of 'costs per lion.' Our original conclusions remain unaltered.


Assuntos
Carnívoros , Conservação dos Recursos Naturais/métodos , Leões , Densidade Demográfica , Animais , Humanos
5.
Ecol Lett ; 16(5): 635-41, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23461543

RESUMO

Conservationists often advocate for landscape approaches to wildlife management while others argue for physical separation between protected species and human communities, but direct empirical comparisons of these alternatives are scarce. We relate African lion population densities and population trends to contrasting management practices across 42 sites in 11 countries. Lion populations in fenced reserves are significantly closer to their estimated carrying capacities than unfenced populations. Whereas fenced reserves can maintain lions at 80% of their potential densities on annual management budgets of $500 km(-2) , unfenced populations require budgets in excess of $2000 km(-2) to attain half their potential densities. Lions in fenced reserves are primarily limited by density dependence, but lions in unfenced reserves are highly sensitive to human population densities in surrounding communities, and unfenced populations are frequently subjected to density-independent factors. Nearly half the unfenced lion populations may decline to near extinction over the next 20-40 years.


Assuntos
Carnívoros , Conservação dos Recursos Naturais/métodos , Leões , Densidade Demográfica , Animais , Conservação dos Recursos Naturais/economia , Gana , Humanos , Namíbia , Dinâmica Populacional , Setor Privado , África do Sul
6.
Ecology ; 90(1): 23-30, 2009 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-19294909

RESUMO

Predators may influence their prey populations not only through direct lethal effects, but also through indirect behavioral changes. Here, we combined spatiotemporal fine-scale data from GPS radio collars on lions with habitat use information on 11 African herbivores in Hwange National Park (Zimbabwe) to test whether the risk of predation by lions influenced the distribution of herbivores in the landscape. Effects of long-term risk of predation (likelihood of lion presence calculated over four months) and short-term risk of predation (actual presence of lions in the vicinity in the preceding 24 hours) were contrasted. The long-term risk of predation by lions appeared to influence the distributions of all browsers across the landscape, but not of grazers. This result strongly suggests that browsers and grazers, which face different ecological constraints, are influenced at different spatial and temporal scales in the variation of the risk of predation by lions. The results also show that all herbivores tend to use more open habitats preferentially when lions are in their vicinity, probably an effective anti-predator behavior against such an ambush predator. Behaviorally induced effects of lions may therefore contribute significantly to structuring African herbivore communities, and hence possibly their effects on savanna ecosystems.


Assuntos
Ecossistema , Equidae/fisiologia , Leões/fisiologia , Comportamento Predatório/fisiologia , Ruminantes/fisiologia , África , Animais , Demografia , Feminino , Masculino
7.
J S Afr Vet Assoc ; 76(4): 187-92, 2005 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-16642713

RESUMO

The combination of medetomidine-zolazepam-tiletamine with subsequent antagonism by atipamezole was evaluated for reversible anaesthesia of free-ranging lions (Panthera leo). Twenty-one anaesthetic events of 17 free-ranging lions (5 males and 12 females, body weight 105-211 kg) were studied in Zimbabwe. Medetomidine at 0.027-0.055 mg/kg (total dose 4-11 mg) and zolazepam-tiletamine at 0.38-1.32 mg/kg (total dose 50-275 mg) were administered i.m. by dart injection. The doses were gradually decreased to improve recovery. Respiratory and heart rates, rectal temperature and relative haemoglobin oxygen saturation (SpO2) were recorded every 15 min. Arterial blood samples were collected from 5 lions for analysis of blood gases and acid-base status. For anaesthetic reversal, atipamezole was administered i.m. at 2.5 or 5 times the medetomidine dose. Induction was smooth and all lions were anaesthetised with good muscle relaxation within 3.4-9.5 min after darting. The predictable working time was a minimum of 1 h and no additional drug doses were needed. Respiratory and heart rates and SpO2 were stable throughout anaesthesia, whereas rectal temperature changed significantly over time. Atipamezole at 2.5 times the medetomidine dose was sufficient for reversal and recoveries were smooth and calm in all lions independent of the atipamezole dose. First sign of recovery was observed 3-27 min after reversal. The animals were up walking 8-26 min after reversal when zolazepam-tiletamine doses < 1 mg/kg were used. In practice, a total dose of 6 mg medetomidine and 80 mg zolazepam-tiletamine and reversal with 15 mg atipamezole can be used for either sex of an adult or subadult lion. The drugs and doses used in this study provided a reliable, safe and reversible anaesthesia protocol for free-ranging lions.


Assuntos
Antagonistas Adrenérgicos alfa/administração & dosagem , Anestesia/veterinária , Anestésicos Combinados/administração & dosagem , Hipnóticos e Sedativos/administração & dosagem , Leões/fisiologia , Anestesia/métodos , Anestésicos Dissociativos/administração & dosagem , Animais , Animais Selvagens , Pressão Sanguínea/efeitos dos fármacos , Temperatura Corporal/efeitos dos fármacos , Relação Dose-Resposta a Droga , Feminino , Frequência Cardíaca/efeitos dos fármacos , Imidazóis/administração & dosagem , Injeções Intramusculares/veterinária , Masculino , Medetomidina/administração & dosagem , Respiração/efeitos dos fármacos , Tiletamina/administração & dosagem , Fatores de Tempo , Zimbábue , Zolazepam/administração & dosagem
9.
Bull Environ Contam Toxicol ; 79(3): 315-8, 2007 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-17639331

RESUMO

Seven adult green frogs (Rana clamitans) were collected from three sites adjacent to intensive agriculture in the lower Fraser River valley, BC Canada. The highest mean concentrations of chemicals were pp'DDE at 0.313 microg/g lipid wt. and Aroclor 1,254/1,260 at 2.12 microg/g lipid wt. On a lipid weight basis, both pp'DDE and PCB concentrations varied by almost an order of magnitude among sites. Only ortho-substituted PCB congeners were detected. The concentrations of organochlorine pesticides and PCBs measured in these frogs from British Columbia are unlikely to elicit negative effects in frogs.


Assuntos
Poluentes Ambientais/metabolismo , Hidrocarbonetos Clorados/metabolismo , Praguicidas/metabolismo , Ranidae/metabolismo , Animais , Colúmbia Britânica , Monitoramento Ambiental
10.
Br Poult Sci ; 37(1): 73-85, 1996 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-8833529

RESUMO

1. The ostrich industry in South Africa (and elsewhere) experiences a high rate of embryo mortality during artificial incubation of eggs. Most of this mortality takes place in the last l0-l4 d of incubation. 2. We carried out post-mortem examinations on 111 embryos that died within this period to assess the causes of this mortality. 3. Malpositioning and severe oedema were the predominant symptoms of dead-in shell embryos with 55% being malpositioned and 41% showing severe oedema. Of these, 22 embryos (24%) showed both symptoms. Malpositioning generally results from incorrect setting of the eggs or inadequate turning and oedema was significantly correlated with the amount of water lost from the eggs which in turn was correlated with egg size. 4. Myopathy, gross lesions of internal organs, haemorrhage, bacterial infections and congenital deformities were found in less than 10% of chicks examined for these symptoms.


Assuntos
Embrião não Mamífero/patologia , Aves Domésticas , Animais , Bactérias/isolamento & purificação , Água Corporal , Edema , Casca de Ovo , Embrião não Mamífero/anormalidades , Embrião não Mamífero/fisiologia , Análise de Regressão , Fatores de Tempo
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