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Hunting
Terms modified by Hunting Selected AbstractsSynergistic Effects of Subsistence Hunting and Habitat Fragmentation on Amazonian Forest VertebratesCONSERVATION BIOLOGY, Issue 6 2001Carlos A. Peres These effects are likely to be considerably aggravated by forest fragmentation because fragments are more accessible to hunters, allow no (or very low rates of ,) recolonization from nonharvested source populations, and may provide a lower-quality resource base for the frugivore-granivore vertebrate fauna. I examined the likelihood of midsized to large-bodied bird and mammal populations persisting in Amazonian forest fragments of variable sizes whenever they continue to be harvested by subsistence hunters in the aftermath of isolation. I used data from a comprehensive compilation of game-harvest studies throughout Neotropical forests to estimate the degree to which different species and populations have been overharvested and then calculated the range of minimum forest areas required to maintain a sustainable harvest. The size distribution of 5564 Amazonian forest fragments,estimated from Landsat images of six regions of southern and eastern Brazilian Amazonia,clearly shows that these are predominantly small and rarely exceed 10 ha, suggesting that persistent overhunting is likely to drive most midsized to large vertebrate populations to local extinction in fragmented forest landscapes. Although experimental studies on this negative synergism remain largely unavailable, the prospect that increasingly fragmented Neotropical forest regions can retain their full assemblages of avian and mammalian species is unlikely. Resumen: La cacería de subsistencia tiene efectos negativos profundos sobre la diversidad de especies, la biomasa y estructura de las comunidades de vertebrados en bosques de la Amazonía que de otra forma están poco perturbadas. Estos efectos se agravan considerablemente por la fragmentación del bosque porque los fragmentos son más accesibles a los cazadores, no permiten la recolonización por poblaciones no cazadas o disminuyen las tasas de recolonizacíon y pueden proporcionar una base de recursos de menor calidad para la fauna de vertebrados frugívoro-granívoros. Examiné la posibilidad de persistencia de poblaciones de aves y mamíferos medianos a grandes en fragmentos de bosque de tamaño variable si continúan sujetos a la cacería de subsistencia como una consecuencia del aislamiento. Utilicé datos de una compilación extensiva de estudios de cacería en bosques neotropicales para estimar el grado en que diferentes especies y poblaciones han sido sobre explotadas y calculé el área de bosque minima requerida para mantener una cosecha sostensible. La distribucíon de tamaños de 5564 fragmentos de bosque amazónica, estimado a partir de imágues de Landsat de seis regiones del sur y del esté de la Amazonía brasileña indica claramente que estos fragmentós son principalmente pegueños y que rara vez exceden las lolta, lo que sugiere que la sobre cacería persistente probablemente lleve a la extincíon local de poblaciones de vertebrados de tamaño mediano a grande en paisajes boscosos fragmentados. Aunque estudios experimentales de este sinergismo negativo no están disponibles, la perspectiva de que las regiones neotropicales cada vez más fragmentadas, puedan retener las comunidades completas de aves y mamíferos poco es probable. [source] Signals and Signal Choices made by the Araneophagic Jumping Spider Portia fimbriata while Hunting the Orb-Weaving Web spiders Zygiella x-notata and Zosis geniculatusETHOLOGY, Issue 7 2000Michael Tarsitano Portia fimbriata is a web-invading araneophagic jumping spider (Salticidae). The use of signal-generating behaviours is characteristic of how P. fimbriata captures its prey, with three basic categories of signal-generating behaviours being prevalent when the prey spider is in an orb web. The predatory behaviour of P. fimbriata has been referred to as aggressive mimicry, but no previous studies have provided details concerning the characteristics of P. fimbriata's signals. We attempt to determine the model signals for P. fimbriata's ,aggressive mimicry' signals. Using laser Doppler vibrometer and the orb webs of Zygiella x-notata and Zosis geniculatus, P. fimbriata's signals are compared with signals from other sources. Each of P. fimbriata's three categories of behaviour makes a signal that resembles one of three signals from other sources: prey of the web spider (insects) ensnared in the capture zone of the web, prey making faint contact with the periphery of the web and large-scale disturbance of the web (jarring the spider's cage). Experimental evidence from testing P. fimbriata with two sizes of lure made from Zosis (dead, mounted in a lifelike posture in standard-size orb web) clarifies P. fimbriata's signal-use strategy: (1) when the resident spider is small, begin by simulating signals from an insect ensnared in the capture zone (attempt to lure in the resident spider); (2) when the resident spider is large, start by simulating signals from an insect brushing against the periphery of the web (keep the resident spider out in the web, but avoid provoking from it a full-scale predatory attack); (3) when walking in the resident spider's web, regardless of the resident spider's size, step toward the spider while making a signal that simulates a large-scale disturbance of the web (mask footsteps with a self-made vibratory smokescreen). [source] ,Pig-Sticking Princes': Royal Hunting, Moral Outrage, and the Republican Opposition to Animal Abuse in Nineteenth-and Early Twentieth-Century BritainHISTORY, Issue 293 2004Antony Taylor This article locates monarchy in the debates arising out of the anti-animal abuse campaigns of the nineteenth and early twentieth centuries. Through a close examination of urban republican criticisms of monarchy, it seeks to question the role of royalty as the custodian of shared national values concerning animal welfare. It demonstrates that hostility to monarchy based on its role in encouraging and patronizing hunting belongs to a long tradition. Much hostility to royalty crystallized around the royal patronage of fox-hunting and of pheasant-shooting. The nineteenth-century precedents for recent concerns about the visible presence of royal figures on the hunting-field articulated many of the component elements of a republican position. For many urban radicals the connection of reigning monarchs with the hunt demonstrated the dysfunctional nature of royal existence, the limitations of royalty's attainments, and the perceived need by monarchs to satisfy the baser, more carnal urges arising from a life devoted to indolence and pleasure. This article shows that hunting, as a marker of a robust masculinity and of the opulence of royalty, brought the reform community into collision with supporters of the monarchy, and provided an example of royal ritual that failed to work in the interests of the throne. The article concludes by revealing the connections between the land debate, criticisms of the royal house, and animal welfare politics in the late nineteenth and early twentieth centuries. [source] Hunting, disturbance and roost persistence of bats in caves at Ankarana, northern MadagascarAFRICAN JOURNAL OF ECOLOGY, Issue 4 2009Scott G. Cardiff Abstract Surveys and monitoring of 37 caves in and around the Ankarana Special Reserve, northern Madagascar, yielded evidence of hunting of bats and potential disturbance of bats by miners and tourists, and colony counts for several bat species of potential conservation concern. Colony size decreased by 95% and 14% for a colony of Hipposideros commersoni and a colony of Eidolon dupreanum, respectively, when recent evidence of hunting occurred at those colonies and those declines are probably attributable to hunting. Evidence of hunting occurred commonly at the roosts of those species and most commonly at the roosts of Rousettus madagascariensis. Hunting of pteropodids was associated with high vulnerability of roosts to hunters, little forest buffer between the cave and open savannah and the absence of tombs in the cave. Roost sites of the hunted species persisted for at least several years and this regularity may facilitate hunting. This work supports the ranking of E. dupreanum, R. madagascariensis and H. commersoni as species of conservation concern. Managers should consider the impact of tourist visits on bats and of increasing access to caves for tourism. Conservation efforts for the hunted species should also seek to protect vulnerable and unprotected cave roosts. Résumé Des études et un suivi continu de 37 grottes dans la Réserve Spéciale d'Ankarana et dans les environs, dans le nord de Madagascar, ont permis de récolter des preuves de la chasse aux chauves-souris et de l'éventuel dérangement des chauves-souris par des mineurs et des touristes; et des comptes de colonies pour plusieurs espèces dont le statut de conservation pourrait être inquiétant. La taille des colonies avait baissé de 95% et de 14% respectivement pour Hipposideros commersoni et pour Eidolon dupreanum, lorsque des preuves récentes de chasse sont apparues dans ces colonies; ces déclins sont probablement dus à la chasse. Des preuves de chasse étaient réguliérement présentes aux dortoirs de ces espèces, et plus communes encore aux dortoirs de Rousettus madagascariensis. La chasse des ptéropodidés était associée à une grande vulnérabilité des dortoirs face aux chasseurs, à une petite zone forestière tampon entre la grotte et la savane ouverte, et à l'absence de tombes dans la grotte. Les sites de repos des espèces chassées existaient depuis plusieurs années au moins, et cette persistance pourrait faciliter la chasse. Ce travail soutient le classement de E. dupreanum, R. madagascariensis et H. commersoni parmi les espèces dont le statut de conservation est inquiétant. Les gestionnaires devraient considérer l'impact des visites de touristes sur les chauves-souris et de l'augmentation de l'accès aux grottes pour le tourisme. Les efforts de conservation des espèces chassées devraient aussi viser à protéger les dortoirs dans des grottes vulnérables et non protégées. [source] High prevalence of anti-hepatitis E virus antibodies in blood donors from South West FranceJOURNAL OF MEDICAL VIROLOGY, Issue 2 2008Jean Michel Mansuy Abstract Cases of autochthonous acute hepatitis E occur in most industrialized countries and are frequent in the South West of France. The prevalence of anti-hepatitis E virus (HEV) IgG antibodies in blood donors in this area was determined. A total of 529 samples from rural and urban blood donors were tested. The overall prevalence was 16.6%, 19.1% of rural donors and 14.2% of urban donors had anti-HEV antibodies (P,=,0.13). The antibodies were widely distributed among all age groups and the sex ratio of the anti-HEV positive blood donors was 1.12 (P,=,0.57). Hunting was the only pastime or profession associated with a high prevalence of anti-HEV antibodies (P,=,0.038). The frequency of anti-HEV antibodies in blood donors could reflect active autochthonous transmission in this area of France. As the risk factors for HEV infection in industrialized countries are still unknown, further studies are needed to clarify the epidemiology of HEV infection in the Midi-Pyrénées region. J. Med. Virol. 80:289,293, 2008. © 2007 Wiley-Liss, Inc. [source] Poison Arrows: North American Indian Hunting and Warfare by David E. JonesAMERICAN ANTHROPOLOGIST, Issue 1 2008THOMAS S. ABLER No abstract is available for this article. [source] Deferred Harvests: The Transition from Hunting to Animal HusbandryAMERICAN ANTHROPOLOGIST, Issue 2 2001Michael S. Alvard We define animal husbandry as prey conservation. Conservation is rare among extant hunters and only likely to occur when prey are highly valued, private goods. The long-term discounted deferred returns from husbandry must also be greater than the short-term returns from hunting. We compare the returns from hunting and husbanding strategies as a function of prey body size. Returns from husbanding are estimated using a maximum sustainable yield (MSY) model. Following Charnov (1993), allometric analyses show that the MSY is nearly independent of prey body size. The opportunity costs of husbanding are measured as prey standing biomass times the discount rate. Since standing biomass scales positively with body size, the opportunity costs of husbanding are greater for larger animals. An evolutionary discount rate is estimated following Rogers (1994) to be between 2.4% and 6%. Using these values, the prey body size for which hunting and meat-only husbanding provide the same return is approximately 40kg. Animals greater than 40kg are predicted to be hunted, [animal husbandry, evolutionary ecology, allometry, hunting, Neolithic transition] [source] Effects of hunting on the behaviour and spatial distribution of farmland birds: importance of hunting-free refuges in agricultural areasANIMAL CONSERVATION, Issue 4 2009F. Casas Abstract Hunting is one of the human activities that directly affect wildlife and has received increasing attention given its socioeconomic dimensions. Most studies have been conducted on coastal and wetland areas and showed that hunting activity can greatly affect bird behaviour and distribution. Hunting-free reserves for game species are zones where birds find an area of reduced disturbance. We evaluated the effect of hunting activities on the behaviour and use of hunting-free areas of lapwings Vanellus vanellus, golden plovers Pluvialis apricaria and little bustards Tetrax tetrax in agricultural areas. We compared the habitat use and behaviour of birds on days before, during and after hunting took place. All three studied species showed strong behavioural responses to hunting activities. Hunting activity increased flight probability and time spent vigilant (higher on hunting days than just before and after a hunting day), to the detriment of resting. We also found distributional (use of hunting-free reserve) responses to hunting activities, with hunting-free reserves being used more frequently during hunting days. Thus, reserves can mitigate the disturbance caused by hunting activities, benefiting threatened species in agricultural areas. Increasing the size or number of hunting-free areas might be an important management and conservation tool to reduce the impacts of hunting activities. [source] The Impact of Hunting on the Mammalian Fauna of Tropical Asian ForestsBIOTROPICA, Issue 3 2007Richard T. Corlett ABSTRACT People have hunted mammals in tropical Asian forests for at least 40,000 yr. This period has seen one confirmed global extinction (the giant pangolin, Manis palaeojavanica) and range restrictions for several large mammals, but there is no strong evidence for unsustainable hunting pressure until the last 2000,3000 yr, when elephants, rhinoceroses, and several other species were progressively eliminated from the large parts of their ranges. Regional declines in most species have occurred largely within the last 50 yr. Recent subsistence hunting has typically focused on pigs and deer (hunted with dogs and spears or with snares), monkeys and other arboreal mammals (often caught with blowpipes), and porcupines and other rodents (smoked or dug out of burrows). Over the last 50 yr, the importance of hunting for subsistence has been increasingly outweighed by hunting for the market. The hunted biomass is dominated by the same species as before, sold mostly for local consumption, but numerous additional species are targeted for the colossal regional trade in wild animals and their parts for food, medicines, raw materials, and pets. Many populations of mammalian dispersers of large seeds and understory browsers have been depleted or eliminated, while seed predators have had a more variable fate. Most of this hunting is now illegal, but the law enforcement is generally weak. However, examples of successful enforcement show that hunting impacts can be greatly reduced where there is sufficient political will. Ending the trade in wild animals and their parts should have the highest regional conservation priority. [source] Demand for Wildlife Hunting in British ColumbiaCANADIAN JOURNAL OF AGRICULTURAL ECONOMICS, Issue 1 2005Lili Sun We present estimates of the demand for hunting licenses by residents and nonresidents in British Columbia for the period 1971,2000. We obtain estimates of both short-run and long-run price elasticities and discuss their revenue implications for future fee increases. We find the demand by nonresidents to be strongly correlated with U.S. income variation over the business cycle, but find no such role for cyclical income variation for resident hunters. The ability of the government to increase revenues from resident hunters turns out to be limited, particularly in the long run, while greater opportunities exist for raising revenues from U.S. hunters as short- and long-run price elasticities of demand are quite inelastic. We argue that conservation surcharges on foreign hunters are one way of capturing more of the resource rent. Nous analysons la demande de permis de chasse par les résidants et les non-résidants de Colombie-Britannique pour la période 1971,2000. Nous présentons des élasticités de court terme et de long terme que nous utilisons ensuite pour évaluer l'effet d'augmenter le coût des permis sur les revenus générés par la vente de ces permis. La demande des non-résidants est fortement corrélée aux fluctuations des revenus américains, mais les variations cycliques du revenu n'ont pas la même incidence sur la demande des chasseurs locaux. La capacité du gouvernement d'augmenter ses revenus en augmentant les coûts des permis des chasseurs locaux est restreinte, surtout à long terme. Ce constat ne s'applique pas aux chasseurs américains puisque leur demande de permis est inélastique, à court terme comme à long terme. Des frais supplémentaires de conservation imposés aux chasseurs étrangers permettraient au gouvernement de s'accaparer une part plus importante de la rente associée à la ressource. [source] Duck Hunting and Wetland Conservation: Compromise or Synergy?CANADIAN JOURNAL OF AGRICULTURAL ECONOMICS, Issue 2 2003Jeff Bennett Duck hunting is an issue , often controversial , that generates both benefits and costs to society. Hunters enjoy benefits from engaging in their sport, while those who have ethical concerns regarding the shooting of ducks endure costs. Some in the community fear that duck hunting puts pressure on the continued ecological viability of the hunted species, while others argue that the demand for hunting provides sufficient economic incentive for wetland conservation. Whether society as a whole should permit or restrict duck hunting is to some extent an empirical question: Are the costs to society of allowing duck hunting greater or less than the benefits it generates? Evidence presented in this paper addresses this question. The benefits enjoyed by people who hunt ducks in the upper south east of South Australia are estimated using the travel cost method. The ethical costs borne by the general community because of duck hunting are estimated using the choice modeling technique. Finally a threshold value analysis is used to assess the activities of Wetlands and Wildlife, a not-for-profit organization that manages wetlands in part for hunting. La chasse au canard est un sujet qui prête souvent à controverse et qui est une source de coûts et d'avantages pour la société. Les chasseurs profitent des avantages que leur procure leur sport, tandis que ceux qui ont des préoccupations d'ordre moral touchant à la chasse subissent des coûts. Certaines personnes dans la communauté craignent que la chasse au canard ne fasse pression sur la viabilitéécologique des espèces chassées. Est-ce que la société dans son ensemble devrait permettre ou limiter la chasse au canard est dans une certaine mesure une question empirique: est-ce que les coûts pour la société de permettre la chasse excèdent ou non les avantages qu'elle procure? Les données présentées dans cet article répondent à cette question. Les avantages reçus par ceux qui chassent le canard dans le haut du sud-est de l'Australie du Sud sont estimés en utilisant la méthode du coût de transport. Les coûts d'ordre moral subis par la communauté dans son ensemble à cause de la chasse au canard sont estimés en utilisant la technique de modélisation des choix. Enfin, une analyse de valeur seuil est utilisée pour évaluer les activités de Zones Aquifères et Nature, un organisme bénévole qui gère les zones aquifères en partie pour la chasse. [source] A Review of Feral Cat Eradication on IslandsCONSERVATION BIOLOGY, Issue 2 2004MANUEL NOGALES efecto de depredación; erradicación; Felis catus; gato asilvestrado; islas Abstract:,Feral cats are directly responsible for a large percentage of global extinctions, particularly on islands. We reviewed feral cat eradication programs with the intent of providing information for future island conservation actions. Most insular cat introductions date from the nineteenth and twentieth centuries, whereas successful eradication programs have been carried out in the last 30 years, most in the last decade. Globally, feral cats have been removed from at least 48 islands: 16 in Baja California (Mexico), 10 in New Zealand, 5 in Australia, 4 in the Pacific Ocean, 4 in Seychelles, 3 in the sub-Antarctic, 3 in Macaronesia (Atlantic Ocean), 2 in Mauritius, and 1 in the Caribbean. The majority of these islands (75%; n= 36) are small (,5 km2). The largest successful eradication campaign took place on Marion Island (290 km2), but cats have been successfully removed from only 10 islands (21%) of ,10 km2. On Cousine Island (Seychelles) cat density reached 243 cats/km2, but on most islands densities did not exceed 79.2 cats/km2 (n= 22; 81%). The most common methods in successful eradication programs were trapping and hunting (often with dogs; 91% from a total of 43 islands). Frequently, these methods were used together. Other methods included poisoning (1080; monofluoracetate in fish baits; n= 13; 31%), secondary poisoning from poisoned rats (n= 4; 10%), and introduction of viral disease (feline panleucopaenia; n= 2; 5%). Impacts from cat predation and, more recently, the benefits of cat eradications have been increasingly documented. These impacts and benefits, combined with the continued success of eradication campaigns on larger islands, show the value and role of feral cat eradications in biodiversity conservation. However, new and more efficient techniques used in combination with current techniques will likely be needed for success on larger islands. Resumen:,Los gatos asilvestrados han sido responsables directos de un gran número de extinciones, particularmente en islas. En este estudio, se revisan los programas de erradicación de este felino con el fin de ofrecer información de utilidad en futuras acciones de conservación en islas. La mayor parte de las introducciones datan de los siglos diecinueve y veinte, mientras que las erradicaciones han sido realizadas básicamente durante los últimos 30 años, y sobre todo en la última década. Los gatos asilvestrados han sido erradicados de al menos 48 islas: 16 de ellas en Baja California (México), 10 en Nueva Zelanda, 5 en Australia, 4 en el Océano Pacífico, 4 en Seychelles, 3 en la Región Subantártica, 3 en Macaronesia (Océano Atlántico), 2 en Mauricio, y una en el Caribe. La mayoría de éstas (75%; n= 36) son de reducidas dimensiones (,5 km2), mientras que la más extensa es Marion Island (290 km2). En tan sólo 10 islas (21%) , 10 km2 se ha podido erradicar este depredador. En Cousine Island (Seychelles) la densidad de gatos alcanzó 243 individuos/km2; sin embargo, en la mayoría de las islas, las densidades no excedieron los 79,2 individuos/km2 (n= 22; 81%). Los métodos más comúnmente empleados fueron el trampeo y la caza, a menudo con perros (91% de un total de 43 islas). Con frecuencia dichas prácticas fueron empleadas conjuntamente. Otros métodos incluyeron venenos (1080, monofluoracetato de sodio en cebos de pescado: n= 13; 31%), envenenamiento secundario con ratas envenenadas (n= 4; 10%) y el virus de la leucemia felina (n= 2; 5%). La información sobre el efecto negativo de los gatos en islas y, más recientemente, el beneficio de su erradicación, se ha ido dando a conocer paulatinamente, poniendo de manifiesto su importancia en la conservación de la biodiversidad insular. No obstante, la combinación de técnicas nuevas y más eficientes junto con las habituales, será necesaria para el éxito de la erradicación de los gatos en islas de grandes dimensiones. [source] Demography of the California Condor: Implications for ReestablishmentCONSERVATION BIOLOGY, Issue 4 2000Vicky J. Meretsky The most prominent mortality factor was lead poisoning resulting from ingestion of bullet fragments in carcasses. Successful captive breeding has allowed many birds to be released to the wild since 1992, based originally on an assumption that exposure to lead could be prevented by food subsidy. The mortality of released birds, however, has generally exceeded levels needed for population stability calculated from simple population models. Collision with overhead wires was the most frequent cause of death in releases before 1994. Lead poisoning again surfaced as a problem starting in 1997 as older birds began feeding on carcasses outside the subsidy program. Although poisonings have been treated successfully by chelation therapy in recaptured birds, food subsidy is proving an ineffective solution to lead exposure. The best long-term solution appears to be either the creation of large reserves where hunting is prohibited or the restriction of hunting to nontoxic ammunition in release areas. Until sources of lead contamination are effectively countered, releases cannot be expected to result in viable populations. In addition, problems involving human-oriented behavior have resulted in the permanent removal of many released birds from the wild. The most promising reduction in human-oriented behavior has been achieved in one release of aversively conditioned, parent-reared birds. Rigorous evaluation of the factors reducing attraction to humans and human structures has been hampered by confounding of techniques in releases. Behavioral problems could be more quickly overcome by adoption of a comprehensive experimental approach. Resumen: Las poblaciones silvestres remanentes del cóndor de California (Gymnogyps californianus) de los anõs 80 exhibieron una disminución poblacional rápida debido a altas tasas de mortalidad de individuos adultos e inmaduros. El factor de mortalidad más prominente fue el envenenamiento por plomo ocasionado por la ingestión de fragmentos de municiones en cadáveres. La reproducción exitosa en cautiverio ha permitido muchas liberaciones en ambientes silvestres desde 1992, bajo el argumento de que la exposición al plomo puede ser prevenida mediante el subsidio de alimento. Sin embargo, la mortalidad de aves liberadas ha excedido generalmente los niveles necesarios para alcanzar una estabilidad poblacional calculada a partir de modelos poblacionales simples. Las colisiones con alambres en lo alto fueron la causa más frecuente de las muertes en liberaciones anteriores a 1994. A partir de 1997, el envenenamiento con plomo surgió una vez más como un problema, puesto que las aves de edad avanzada comenzaron a alimentarse de cadáveres fuera del programa de subsidio. A pesar de que el envenenamiento ha sido tratado exitosamente mediante terapia de quelación de las aves recapturadas, el subsidio de alimento ha probado ser una solución ineficaz contra la exposición al plomo. Las mejores soluciones de largo plazo aparentan ser la creación de reservas grandes donde la caza sea prohibida o se restrinja la caza a municiones no tóxicas en las áreas de liberación. Solo una vez que la contaminación por plomo sea contrarrestada efectivamente, no se podrá esperar que las liberaciones resulten en poblaciones viables. Además, los problemas de conductas orientadas hacia humanos ha resultado en la remoción permanente de muchas aves liberadas de zonas silvestres. La reducción más prometedora de conductas orientadas hacia humanos ha sido obtenida en una liberación de aves criadas por sus padres y condicionadas adversamente. La evaluación rigurosa de los factores que reducen la atracción hacia humanos y estructuras de humanos ha sido obstaculizada por la confusión de técnicas en las liberaciones. Los problemas de conducta podrían ser superados más rápidamente mediante la adopción de una estrategia experimental comprensiva. [source] Nutritional consequences of a change in diet from native to agricultural fruits for the Samoan fruit batECOGRAPHY, Issue 4 2000Suzanne L. Nelson The Samoan fruit bat Pteropus samoensis Peak, an endemic flying fox that inhabits the Samoan archipelago, prefers to forage on native fruit species. This species has recently been subjected to extreme population threats including hunting and severe storms, as well as large-scale habitat degradation. If habitat destruction continues at its present rate, P. samoensis may be forced to forage more within an agricultural matrix. In this study, we analyzed sixteen species of native fruits and four species of agricultural fruits for five organic components and eight minerals to test whether native fruits provided a higher quality diet or more varied diet than agricultural fruits. Within native fruits, we also focused on four species of figs, because these fruits are often considered an important food item for tropical frugivores. Overall, native fruits provided more variation and had higher average values for several nutrients than agricultural fruits. Native fruits were especially high in biologically important minerals (calcium, iron, and sodium), and provided up to 5 times more calcium, 10.5 times more iron, and 8 times more sodium than agricultural fruits. Figs were found to be an especially rich source of many nutrients, particularly for calcium. Thus. P. samoensis. a sequential specialist, may be better able to adjust its diet to obtain higher levels of minerals when consuming a variety of native fruits than when restricted to the consumption of only agricultural fruits. These findings suggest a need to preserve native habitat and to create parks to sustain the long term health and viability of P. samoensis. [source] A perturbation analysis of harmonic generation from saturated elements in power systemsELECTRICAL ENGINEERING IN JAPAN, Issue 4 2010Teruhisa Kumano Abstract Nonlinear phenomena such as saturation of magnetic flux have considerable effects in power systems analysis. It is reported that a failure in a real 500-kV system triggered islanding operation, where resultant even harmonics caused malfunctions in protective relays. It is also reported that the major origin of this wave distortion is nothing but unidirectional magnetization of the transformer iron core. Time simulation is widely used today to analyze phenomena of this type, but it has basically two shortcomings. One is that the time simulation takes too much computing time in the vicinity of inflection points in the saturation characteristic curve because certain iterative procedures such as N-R (Newton,Raphson) must be used and such methods tend to be caught in an ill-conditioned numerical hunting. The other is that such simulation methods sometimes do not aid an intuitive understanding of the studied phenomenon because all of the nonlinear equations are treated in matrix form and are not properly divided into understandable parts, as is done in linear systems. This paper proposes a new computation scheme that is based on the so-called perturbation method. Magnetic saturation of iron cores in a generator and a transformer are taken into account. The proposed method has a special feature to deal with the first shortcoming of the N-R-based time simulation method stated above. The proposed method does not use an iterative process to reduce the equation residue, but uses perturbation series, so that it is free of the ill-conditioning problem. The user need only calculate the perturbation terms one by one until the necessary accuracy is attained. In a numerical example treated in the present paper, first-order perturbation can achieve reasonably high accuracy, which means very fast computing time. In a numerical study, three nonlinear elements are considered. The calculation results are almost identical to the conventional N-R-based time simulation, which shows the validity of the method. The proposed method can be effectively used in screening where many case studies are needed. © 2009 Wiley Periodicals, Inc. Electr Eng Jpn, 170(4): 35,42, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.20895 [source] Early hominid hunting and scavenging: A zooarcheological reviewEVOLUTIONARY ANTHROPOLOGY, Issue 6 2003Manuel Domínguez-Rodrigo Abstract Before the early 1980s, the prevailing orthodoxy in paleoanthropology considered Early Stone Age archeological sites in East Africa to represent a primitive form of hominid campsites. The faunal evidence preserved in these sites was viewed as the refuse of carcass meals provided by hominid males in a social system presumptively characterized by sexual division of labor. This interpretation of early hominid life ways, commonly known as the "Home Base" or "Food Sharing" model, was developed most fully by Glynn Isaac.1,4 As Bunn and Stanford5 emphasized, this model was greatly influenced by a paradigm that coalesced between 1966 and 1968, referred to as "Man the Hunter."6 [source] Relevance of the genes for bone mass variation to susceptibility to osteoporotic fractures and its implications to gene search for complex human diseasesGENETIC EPIDEMIOLOGY, Issue 1 2002Hong-Wen Deng Abstract We investigate the relevance of the genetic determination of bone mineral density (BMD) variation to that of differential risk to osteoporotic fractures (OF). The high heritability (h2) of BMD and the significant phenotypic correlations between high BMD and low risk to OF are well known. Little is reported on h2 for OF. Extensive molecular genetic studies aimed at uncovering genes for differential risks to OF have focussed on BMD as a surrogate phenotype. However, the relevance of the genetic determination of BMD to that of OF is unknown. This relevance can be characterized by genetic correlation between BMD and OF. For 50 Caucasian pedigrees, we estimated that h2 at the hip is 0.65 (P < 0.0001) for BMD and 0.53 (P < 0.05) for OF; however, the genetic correlation between BMD and OF is nonsignificant (P > 0.45) and less than 1% of additive genetic variance is shared between them. Hence, most genes found important for BMD may not be relevant to OF at the hip. The phenotypic correlation between high BMD and low risk to OF at the hip (approximately ,0.30) is largely due to an environmental correlation (,E = ,0.73, P < 0.0001). The search for genes for OF should start with a significant h2 for OF and should include risk factors (besides BMD) that are genetically correlated with OF. All genes found important for various risk factors must be tested for their relevance to OF. Ideally, employing OF per se as a direct phenotype for gene hunting and testing can ensure the importance and direct relevance of the genes found for the risk of OF. This study may have significant implications for the common practice of gene search for complex diseases through underlying risk factors (usually quantitative traits). Genet. Epidemiol. 22:12,25, 2002. © 2002 Wiley-Liss, Inc. [source] Conservation Geographies in Sub-Saharan Africa: The Politics of National Parks, Community Conservation and Peace ParksGEOGRAPHY COMPASS (ELECTRONIC), Issue 1 2010Brian King Sub-Saharan Africa has been the location of intense conservation planning since the colonial era. Under the auspices of wilderness protection, colonial authorities established national parks largely for the purpose of hunting and tourism while forcibly evicting indigenous populations. Concerns about the ethical and economic impacts of protected areas have generated interest in community conservation initiatives that attempt to include local participation in natural resource management. In recent years, the anticipated loss of biodiversity, coupled with the integration of ecological concepts into planning processes, has generated interest in larger-scale initiatives that maximize protected habitat. Central to this shift are transboundary conservation areas, or Peace Parks, that involve protected territory that supersedes national political borders. This study provides a review of national parks, community conservation, and Peace Parks, in order to understand the development politics and governance challenges of global conservation. Although these approaches are not mutually exclusive, the study asserts that they represent major trajectories to conservation planning in Sub-Saharan Africa and other parts of the developing world. In considering the histories of these models in Sub-Saharan Africa, I argue that conservation planners often prioritize economic and ecological factors over the political circumstances that influence the effectiveness of these approaches. The study concludes by suggesting that an analysis of these three models provides a lens to examine ongoing debates regarding the employ of conservation as an economic development strategy and the challenges to environmental governance in the 21st century. [source] ,Pig-Sticking Princes': Royal Hunting, Moral Outrage, and the Republican Opposition to Animal Abuse in Nineteenth-and Early Twentieth-Century BritainHISTORY, Issue 293 2004Antony Taylor This article locates monarchy in the debates arising out of the anti-animal abuse campaigns of the nineteenth and early twentieth centuries. Through a close examination of urban republican criticisms of monarchy, it seeks to question the role of royalty as the custodian of shared national values concerning animal welfare. It demonstrates that hostility to monarchy based on its role in encouraging and patronizing hunting belongs to a long tradition. Much hostility to royalty crystallized around the royal patronage of fox-hunting and of pheasant-shooting. The nineteenth-century precedents for recent concerns about the visible presence of royal figures on the hunting-field articulated many of the component elements of a republican position. For many urban radicals the connection of reigning monarchs with the hunt demonstrated the dysfunctional nature of royal existence, the limitations of royalty's attainments, and the perceived need by monarchs to satisfy the baser, more carnal urges arising from a life devoted to indolence and pleasure. This article shows that hunting, as a marker of a robust masculinity and of the opulence of royalty, brought the reform community into collision with supporters of the monarchy, and provided an example of royal ritual that failed to work in the interests of the throne. The article concludes by revealing the connections between the land debate, criticisms of the royal house, and animal welfare politics in the late nineteenth and early twentieth centuries. [source] Internet job hunting: A field study of applicant experiences with on-line recruitingHUMAN RESOURCE MANAGEMENT, Issue 2 2002Daniel C. Feldman This field study examines the experiences of managers and professionals searching for jobs via the Internet. Results suggest that facility with Internet navigation is significantly associated with the amount of general job searching, particularly for those who want to explore job options initially in private without fear of retribution from supervisors. The data also suggest that managers and professionals are more likely to use the Internet for job hunting when the geographical scope of the job hunt is wide, when a major salary increase is desired, and when both small and large firms are being considered as potential employers. Use of the Internet is perceived as a somewhat less effective job search strategy than personal networking, but far superior to searching for jobs through newspaper ads and "cold calling." Major issues found to impede the effectiveness of on-line recruiting are the degree and speed of follow-up on-line applications, lack of specific and relevant job descriptions on a company's Web site, concerns about the security of personal information, and difficulty in customizing, formatting, and downloading resumes to companies' specifications. The article concludes with recommendations for improving the effectiveness of on-line recruiting. © 2002 Wiley Periodicals, Inc. [source] Diet and food preferences of the endangered Bearded Vulture Gypaetus barbatus: a basis for their conservationIBIS, Issue 2 2009ANTONI MARGALIDA The Bearded Vulture Gypaetus barbatus population in the Pyrenees is managed using feeding stations to increase breeding success and reduce mortality in the pre-adult population. Nevertheless, very little quantitative and qualitative information has been published on such basic aspects of the species' ecology as feeding habits and dietary preferences. This study investigated both aspects through direct and unbiased observation of breeding Bearded Vultures during the chick-rearing period. Bearded Vulture diet comprises mammals (93%), birds (6%) and reptiles (1%), with medium-sized ungulates (mainly sheep/goats) the most important species in the diet (61%, n = 677). Prey items were not selected in proportion to their availability, with the remains of larger species (cows and horses) being avoided, probably due to the variable cost/benefit ratios in handling efficiency, ingestion process and transport. There is no relationship between the proportion of sheep limbs in the diet and the proximity of feeding stations, suggesting that these sites are probably less important for breeding adults than for the pre-adult population. On the other hand, diet specificity seems related to productivity, with territories with greater trophic breadth being those with higher fecundity. Bearded Vultures prefer to eat limbs, although meat remains (provided principally by small mammals) can play an important role in guaranteeing breeding success during the first few weeks after hatching. The management of carrion provided by animals that die naturally in extensive livestock practices and the remains of wild ungulates which have died naturally or by human hunting, are important conservation tools for the Bearded Vulture and other carrion-eating species. [source] Invertebrate diet of the Houbara Bustard Chlamydotis [undulata] macqueenii in Abu Dhabi from calibrated faecal analysisIBIS, Issue 3 2000BARBARA J. TIGAR The ecology of the Houbara Bustard Chlamydotis [undulata] macqueenii is poorly known and populations are declining due to hunting and habitat loss. As wintering populations in Abu Dhabi may be limited by habitat and food, we studied the diet using calibrated faecal analysis. Prey were categorized into 16 groups and fed to captive birds under controlled conditions. We calculated the recovery rates of prey following digestion and identified consistent fragments for each group. Wild Houbara Bustard faeces were collected and examined for key fragments, and initial prey intake was calibrated. Plant remains were identified and their contribution was estimated. Fewer than 28% faeces contained >50% plant material by volume and only 12% contained 95% or more. Numerically, the most important prey were: ants (64%), large nocturnal tenebrionids (14.5%), small climbing tenebrionids (12%) and diurnal tenebrionids. However, the Tenebrionidae contributed 97% of the animal biomass. The relative proportions of prey in the diet were similar to relative abundance as assessed by pitfall trapping. Estimates of the energetic value of the prey suggested that on average Houbara Bustards must consume around 670 desert invertebrates/day to meet energy needs. The effort required to catch these prey may vary at least ten-fold seasonally. On average plants could provide a further 6.4,14% energy but more work is needed on this. Whether Houbara Bustards wintering in Abu Dhabi are prey-limited depends on prey densities and renewal rates which remain unknown. [source] Skeletal remains of dogs unearthed from the Van-Yoncatepe necropolisesINTERNATIONAL JOURNAL OF OSTEOARCHAEOLOGY, Issue 5 2002Vedat Onar Abstract A total of 15 dog skulls and a number of bones have been discovered in two burial chambers dating from 1,000 BC in the necropolises of the Van-Yoncatepe Castle in eastern Turkey. The finds were a dog skeleton in burial chamber M5 and 14 dog skulls and plenty of bones in burial chamber M6. It was determined on examination that the skeleton found in burial chamber M5 was an 11,12-year female dog, and that the skulls unearthed from burial chamber M6 belonged to dogs with an age range of seven to eight months to 12,13 years. In the latter chamber, however, except for one skull whose sex could not be determined, one was ascertained to belong to a female dog and the rest to males. Calculations of 20 different indices and ratios were made on the skulls. This showed that these skulls were of the dolichocephalic type. It was observed that there were signs of a widespread periodontal disease and alveolar recession. Enamel hypoplasia and abscess chambers detected on the teeth, and deformations observed in the hard palate were evidence enough to suggest that these were undernourished dogs. There were also some facial fractures, which were noticed to have occurred before death. On the other hand, examination carried out on the bones revealed that the dogs were of medium size, and that they were likely to have had a withers height of 50,55 cm. The data obtained from both the burial chambers brought to light the fact that these dogs were more of the hunting or working types. Copyright © 2002 John Wiley & Sons, Ltd. [source] Estimating age and season of death of pronghorn antelope (Antilocapra americana Ord) by means of tooth eruption and wearINTERNATIONAL JOURNAL OF OSTEOARCHAEOLOGY, Issue 3 2001Patrick M. Lubinski Abstract Age and season of death information for prey animals at archaeological sites can address issues such as season of site occupation and prey hunting or harvesting strategies. Unfortunately, adequate reference information for estimating age and season is lacking for many wild species, including pronghorn antelope. To address this problem, new methods of scoring tooth eruption and wear have been developed and have been applied to a sample of over 500 pronghorn mandibles to obtain improved eruption and wear schedules. One implication of this study is that ,age class discreteness' is an unreliable method for demonstrating mass mortality of prey. This study provides a much larger comparative sample than previously available, although larger known-age mandible samples are still needed for pronghorn and many other wild species. Copyright © 2001 John Wiley & Sons, Ltd. [source] Functional anatomy of the forelimb in Promegantereon* ogygia (Felidae, Machairodontinae, Smilodontini) from the Late Miocene of Spain and the origins of the sabre-toothed felid modelJOURNAL OF ANATOMY, Issue 3 2010Manuel J. Salesa Abstract We examine the functional anatomy of the forelimb in the primitive sabre-toothed cat Promegantereon ogygia in comparison with that of the extant pantherins, other felids and canids. The study reveals that this early machairodontine had already developed strong forelimbs and a short and robust thumb, a combination that probably allowed P. ogygia to exert relatively greater forces than extant pantherins. These features can be clearly related to the evolution of the sabre-toothed cat hunting method, in which the rapid killing of prey was achieved with a precise canine shear-bite to the throat. In this early sabre-toothed cat from the Late Miocene, the strong forelimbs and thumb were adapted to achieve the rapid immobilization of prey, thus decreasing the risk of injury and minimizing energy expenditure. We suggest that these were the major evolutionary pressures that led to the appearance of the sabre-toothed cat model from the primitive forms of the Middle Miocene, rather than the hunting of very large prey, although these adaptations reached their highest development in the more advanced sabre-toothed cats of the Plio-Pleistocene, such as Smilodon and Homotherium. Although having very different body proportions, these later animals developed such extremely powerful forelimbs that they were probably able to capture relatively larger prey than extant pantherins. [source] Hunting for large carnivore conservationJOURNAL OF APPLIED ECOLOGY, Issue 6 2009Adrian Treves Summary 1. Carnivores are difficult to conserve because of direct and indirect competition with people. Public hunts are increasingly proposed to support carnivore conservation. This article reviews scientific evidence for the effectiveness of public hunts of large carnivores in attaining three common policy goals: stable carnivore populations, preventing conflict with carnivores (property damage and competition over game) and building public support for carnivore conservation. 2. Sustainable exploitation of stable wildlife populations has a solid, scientific foundation but the theory and its predictions must be adapted to complex patterns of carnivore behavioural ecology and population dynamics that demand years of landscape-level monitoring to understand fully. 3. A review of the evidence that hunting prevents property damage or reduces competition for game reveals large gaps in our understanding. Reducing the number of large carnivores to protect hunters' quarry species seems straightforward but we still know little about behavioural and ecological responses of the contested prey and sympatric meso-predators. For reducing property damage, the direct effect , numerical reduction in problematic individual carnivores , presents numerous obstacles, whereas the indirect effect , behavioural avoidance of humans by hunted carnivores , holds more promise. 4. Scientific measures of public support for carnivore-hunting policies are almost completely lacking, particularly measures of attitudes among hunters before and after controversial wildlife is designated as legal game species. Moreover, illegal killing of carnivores does not appear to diminish if they are designated as game. 5.Synthesis and applications. Sustainable hunting to maintain stable populations is well understood in theory but complex life histories of carnivores, and behavioural changes of hunters and the carnivores they stalk may result in unsustainable mortality for carnivores. The direct impact of hunting on carnivore damage to property is unclear and even doubtful given the inability or unwillingness of hunters to remove specific individuals selectively. However, hunters may indirectly deter carnivores from people and their property. The assumption that hunters will steward carnivores simply because they have in the past helped conserve other game species requires more study as preliminary results suggest it is incorrect. Policy-makers may achieve support for policy if they mesh utilitarian and preservationist values held by the general public. A number of opposed hypotheses should be disentangled before researchers confidently inform policy on sustainable hunting to prevent conflicts and build public support for carnivore conservation. [source] Modelling the long-term sustainability of indigenous hunting in Manu National Park, Peru: landscape-scale management implications for AmazoniaJOURNAL OF APPLIED ECOLOGY, Issue 4 2009Taal Levi Summary 1. ,Widespread hunting throughout Amazonia threatens the persistence of large primates and other vertebrates. Most studies have used models of limited validity and restricted spatial and temporal scales to assess the sustainability. 2. ,We use human-demographic, game-harvest and game-census data to parameterize a spatially explicit hunting model. We explore how population growth and spread, hunting technology and effort, and source,sink dynamics impact the density of black spider monkeys Ateles chamek over time and space in the rainforests of south-eastern Peru. 3. ,In all scenarios, spider monkey populations, which are vulnerable to hunting, persist in high numbers in much of Manu National Park over the next 50 years. Nonetheless, shotguns cause much more depletion than traditional bow hunting by Matsigenka (Machiguenga) indigenous people. 4. ,Maintenance of the current indigenous lifestyle (dispersed settlements, bow hunting) is unlikely to deplete spider monkeys and, by extension, other fauna, despite rapid human population growth. This helps explain why large, pre-Colombian human populations did not drive large primates to extinction. When guns are used, however, spider monkeys quickly become depleted around even small settlements, with depletion eventually reversing the short-term harvest advantage provided by shotgun hunting. Thus, our models show that when guns are used, limits on settlement numbers can reduce total depletion. 5. ,Synthesis and applications. Our framework lets us visualize the future effects of hunting, population growth, hunting technology and settlement spread in tropical forests. In Manu Park, the continued prohibition of firearms is important for ensuring long-term hunting sustainability. A complementary policy is to negotiate limits on new settlements in return for development aid in existing settlements. The advantage of the latter approach is that settlement numbers are more easily monitored than is hunting effort or technology. Similar policies could help to reduce landscape-scale depletion of prey species in human-occupied reserves and protected areas throughout the Amazon. [source] Host culling as an adaptive management tool for chronic wasting disease in white-tailed deer: a modelling studyJOURNAL OF APPLIED ECOLOGY, Issue 2 2009Gideon Wasserberg Summary 1Emerging wildlife diseases pose a significant threat to natural and human systems. Because of real or perceived risks of delayed actions, disease management strategies such as culling are often implemented before thorough scientific knowledge of disease dynamics is available. Adaptive management is a valuable approach in addressing the uncertainty and complexity associated with wildlife disease problems and can be facilitated by using a formal model. 2We developed a multi-state computer simulation model using age, sex, infection-stage, and seasonality as a tool for scientific learning and managing chronic wasting disease (CWD) in white-tailed deer Odocoileus virginianus. Our matrix model used disease transmission parameters based on data collected through disease management activities. We used this model to evaluate management issues on density- (DD) and frequency-dependent (FD) transmission, time since disease introduction, and deer culling on the demographics, epizootiology, and management of CWD. 3Both DD and FD models fit the Wisconsin data for a harvested white-tailed deer population, but FD was slightly better. Time since disease introduction was estimated as 36 (95% CI, 24,50) and 188 (41,>200) years for DD and FD transmission, respectively. Deer harvest using intermediate to high non-selective rates can be used to reduce uncertainty between DD and FD transmission and improve our prediction of long-term epidemic patterns and host population impacts. A higher harvest rate allows earlier detection of these differences, but substantially reduces deer abundance. 4Results showed that CWD has spread slowly within Wisconsin deer populations, and therefore, epidemics and disease management are expected to last for decades. Non-hunted deer populations can develop and sustain a high level of infection, generating a substantial risk of disease spread. In contrast, CWD prevalence remains lower in hunted deer populations, but at a higher prevalence the disease competes with recreational hunting to reduce deer abundance. 5Synthesis and applications. Uncertainty about density- or frequency-dependent transmission hinders predictions about the long-term impacts of chronic wasting disease on cervid populations and the development of appropriate management strategies. An adaptive management strategy using computer modelling coupled with experimental management and monitoring can be used to test model predictions, identify the likely mode of disease transmission, and evaluate the risks of alternative management responses. [source] Niche overlap between marsupial and eutherian carnivores: does competition threaten the endangered spotted-tailed quoll?JOURNAL OF APPLIED ECOLOGY, Issue 2 2008A. S. Glen Summary 1The significance of top-down regulation by carnivores is receiving increasing global recognition. As a consequence, key objectives in many programmes that seek to maintain ecosystem function now include conserving carnivores and understanding their interactions. This study examined overlap in resource use (space and diet) of introduced eutherian carnivores and an endangered marsupial carnivore, the spotted-tailed quoll Dasyurus maculatus, in eastern Australia. We also investigated mechanisms of niche partitioning and evidence for interspecific aggression. 2Dietary overlap between quolls, red foxes Vulpes vulpes and wild dogs Canis lupus ssp. was assessed by analysis of scats. Trapping, radio-tracking and direct observations were used to quantify spatial overlap between quolls, foxes, wild dogs and feral cats Felis catus. 3Dietary overlap among the carnivores was extensive. Medium-sized mammals were the most important prey for all three predators, indicating potential for exploitative interactions. However, hunting of different size classes of secondary prey and consumption by quolls of more arboreal prey than their counterparts may assist coexistence. Remains of quoll were found in two dog scats, and cat hair in another, possibly indicating intraguild predation. 4We observed extensive spatial overlap between quolls and eutherian carnivores. However, we inferred from dietary data that quolls foraged primarily in forested habitat, while canids foraged mainly in cleared habitat. 5Synthesis and applications. Our results indicate strong potential for competition between spotted-tailed quolls and eutherian carnivores, and thus a situation where control of introduced predators may be desirable, not only for the conservation of prey species but also for the protection of native carnivores. Concern over potential non-target mortality of quolls has hindered efforts to control foxes in eastern Australia using poison baits. We contend that, rather than harming quoll populations, baiting for foxes should aid the conservation of quolls and should be implemented in areas of sympatry where fox numbers are high. [source] Quantifying the grazing impacts associated with different herbivores on rangelandsJOURNAL OF APPLIED ECOLOGY, Issue 6 2007S. D. ALBON Summary 1Rangelands, produced by grazing herbivores, are important for a variety of agricultural, hunting, recreation and conservation objectives world-wide. Typically, there is little quantitative evidence regarding the magnitude of the grazing impact of different herbivores on rangeland habitats to inform their management. 2We quantified the grazing and trampling impact of sheep, cattle, red deer Cervus elaphus, rabbits Oryctolagus cuniculus, mountain hares Lepus timidus and red grouse Lagopus lagopus on open-hill habitats in 11 areas of upland Scotland. The degradation of heather in upland Scotland Calluna vulgaris -dominated habitats, of conservation significance at a European scale, has been attributed, anecdotally, to increasing sheep and red deer populations. 3Field indicators of habitat condition were used to generate a five-point scale of impact in vegetation polygons of seven habitats. The presence of each herbivore species was attributed on the basis of ,signs' of occupancy. A Bayesian regression model was used to analyse the association of herbivore species with grazing impact on plant communities, controlling for environmental attributes. 4Overall the presence of sheep was associated with the largest increase (7/11 areas) in grazing and trampling impact of all herbivores. Cattle had the second largest impact but generally this was restricted to fewer areas and habitats than sheep. In contrast, impacts associated with wild herbivores tended to be small and only significant locally. 5Although red deer presence was associated with a significantly lower impact than sheep, this impact increased with increasing deer density at both land-ownership and regional scales. For sheep there was little or no evidence of density dependence. 6Synthesis and applications. The higher impact associated with sheep presence probably reflects their greater aggregation because of their limited ranging behaviour, exacerbated by sheep being herded in places convenient for land managers. Consequently, future reductions in sheep numbers as a result of reform of European Union farming policies may limit the extent of their impact, but not necessarily the local magnitude. However, reductions in sheep stocks may lead to increases in deer densities, with greater impact, particularly in heather-dominated habitats. Where habitat conservation is a priority this may well require a reduction in deer numbers. [source] | |||||||||||||||||||||||||||||||||||||||||||