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Predicting intensity of white-tailed deer herbivory in the Central Appalachian Mountains

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Journal of Forestry Research 2018年第3期29卷 830-839页

作者： Andrew B.Kniowski W.Mark Ford department of fish and wildlife conservation Virginia Tech U.S. Geological Survey Virginia Cooperative Fish and Wildlife Research Unit Virginia Tech

In eastern North America, white-tailed deer(Odocoileus virginianus) can have profound influences on forest biodiversity and forest successional *** to high deer populations in the central Appalachians have resulted in lower forest *** effects in some areas persist even following deer population reductions or declines. This has prompted managers to consider deer population management goals in light of policies designed to support conservation of biodiversity and forest regeneration while continuing to support ample recreational hunting opportunities. However,despite known relationships between herbivory intensity and biodiversity impact, little information exists on the predictability of herbivory intensity across the varied and spatially diverse habitat conditions of the central Appalachians. We examined the predictability of browsing rates across central Appalachian landscapes at four environmental scales: vegetative community characteristics, physical environment, habitat configuration, and local human and deer population demographics. In an information-theoretic approach, we found that a model fitting the number of stems browsed relative to local vegetation characteristics received most(62%) of the overall support of all tested models assessing herbivory impact. Our data suggest that deer herbivory responded most predictably to differences in vegetation quantity and type. No other spatial factors or demographic factors consistently affected browsing intensity. Because herbivory, vegetation communities, and productivity vary spatially, we suggest that effective broad-scale herbivory impact assessment should include spatially-balanced vegetation monitoring that accounts for regional differences in deer forage *** monitoring is necessary to avoid biodiversity impacts and deleterious changes in vegetation community composition that are difficult to reverse and/or may not be detected using traditional deer-density based

关键词： Biodiversity Central Appalachian Mountains Herbivory Odocoileus virginianus Predicting browsing intensity White-tailed deer

Density and carrying capacity in the forgotten tigerland:Tigers in the understudied Nepalese Churia

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Integrative Zoology 2017年第3期12卷 211-227页

作者： Kanchan THAPA Marcella J.KELLY department of fish and wildlife conservation Virginia TechBlacksburgVirginiaUSA conservation Science Unit WWF NepalBaluwatarKathmanduNepal

While there are numerous wildlife ecology studies in lowland areas of Nepal,there are no in-depth studies of the hilly Churia habitat even though it comprises 7642 km2 of potential wildlife habitat across the Terai *** investigated tiger,leopard and prey densities across this understudied *** camera trapping survey covered 536 km2 of Churia and surrounding areas within Chitwan National Park(CNP).We used 161 trapping locations and accumulated 2097 trap-nights in a 60-day survey period during the winter season of *** addition,we walked 136 km over 81 different line transects using distance sampling to estimate prey *** photographed 31 individual tigers,28 individual leopards and 25 other mammalian *** capture-recapture methods resulted in lower density estimates for tigers,ranging from 2.3 to 2.9 tigers per 100 km2,than for leopards,which ranged from 3.3 to 5.1 leopards per 100 *** addition,leopard densities were higher in the core of the Churia compared to surrounding *** estimated 62.7 prey animals per 100 km2 with forest ungulate prey(sambar,chital,barking deer and wild pig),accounting for 47%of the *** on prey availability,Churia habitat within CNP could potentially support 5.86 tigers per 100 km2 but our density estimates were lower,perhaps indicating that the tiger population is below carrying *** results demonstrate that Churia habitat should not be ignored in conservation initiatives,but rather management efforts should focus on reducing human disturbance to support higher predator numbers.

关键词： camera trapping carrying capacity churia habitat Panthera tigris tigris spatially explicit capture recapture

Estimating time-based instantaneous total mortality rate based on the age-structured abundance index

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Chinese Journal of Oceanology and Limnology 2015年第3期33卷 559-576页

作者：王迎宾 JIAO Yan fishery College Zhejiang Ocean University department of fish and wildlife conservation Virginia Polytechnic Institute and State University

The instantaneous total mortality rate(Z) of a fish population is one of the important parameters in fisheries stock assessment. The estimation of Z is crucial to fish population dynamics analysis,abundance and catch forecast,and fisheries management. A catch curve-based method for estimating time-based Z and its change trend from catch per unit effort(CPUE) data of multiple cohorts is developed. Unlike the traditional catch-curve method,the method developed here does not need the assumption of constant Z throughout the time,but the Z values in n continuous years are assumed constant,and then the Z values in different n continuous years are estimated using the age-based CPUE data within these years. The results of the simulation analyses show that the trends of the estimated time-based Z are consistent with the trends of the true Z,and the estimated rates of change from this approach are close to the true change rates(the relative differences between the change rates of the estimated Z and the true Z are smaller than 10%). Variations of both Z and recruitment can affect the estimates of Z value and the trend of Z. The most appropriate value of n can be different given the effects of different factors. Therefore,the appropriate value of n for different fisheries should be determined through a simulation analysis as we demonstrated in this study. Further analyses suggested that selectivity and age estimation are also two factors that can affect the estimated Z values if there is error in either of them,but the estimated change rates of Z are still close to the true change rates. We also applied this approach to the Atlantic cod(G adus morhua) fishery of eastern Newfoundland and Labrador from 1983 to 1997,and obtained reasonable estimates of time-based Z.

关键词： instantaneous total mortality rate (Z) catch per unit effort (CPUE) time-based change trend simulation selectivity incorrect age estimation

Antipredator deception in terrestrial vertebrates

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Current Zoology 2014年第1期60卷 16-25页

作者： Tim CARO department of wildlife Fish and Conservation Biology and Center of Population Biology University of California Davis CA95616 USA

Abstract Deceptive antipredator defense mechanisms fall into three categories： depriving predators of knowledge of prey＇s presence, providing cues that deceive predators about prey handling, and dishonest signaling. Deceptive defenses in terrestrial vertebrates include aspects of crypsis such as background matching and countershading, visual and acoustic Batesian mimicry, active defenses that make animals seem more difficult to handle such as increase in apparent size and threats, feigning injury and death, distractive behaviours, and aspects of flight. After reviewing these defenses, I attempt a preliminary evaluation of which aspects of antipredator deception are most widespread in amphibians, reptiles, mammals and birds

关键词： Amphibians Birds Defenses Dishonesty Mammals Prey Reptiles

Fuel and vegetation changes in southwestern, unburned portions of Great Smoky Mountains National Park, USA, 2003-2019

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Journal of Forestry Research 2022年第5期33卷 1459-1470页

作者： T.Adam Coates W.Mark Ford department of Forest Resources and Environmental conservation Virginia Polytechnic Institute and State UniversityBlacksburgVA 24061USA U.S.Geological Survey Virginia Cooperative Fish and Wildlife Research UnitDepartment of Fisheries and Wildlife ConservationVirginia Polytechnic Institute and State UniversityBlacksburgVA 24061USA

Overstory basal area,ericaceous shrub cover(Kalmia latifolia *** Rhododendron maximum L.),and fuels(i.e.,woody fuel loads and depths and O Horizon thickness) were assessed within Great Smoky Mountains National Park,USA,in *** to recent wildfire activity within the southern Appalachian Mountain region(including Great Smoky Mountains National Park),the potential spread and expansion of ericaceous shrubs,and the impacts of the hemlock woolly adelgid(Adelges tsugae Annand) on eastern hemlock(Tsuga canadensis(L.) Carrière),these same ecosystem components were again assessed in *** and moisture regime(xeric,intermediate,and mesic) were included in this assessment as potential influential *** evaluation of repeated measurements from 40 plots suggested that O Horizon thickness did not change significantly over the 16-year period,but increased as elevation increased,and moisture regime(xeric O Horizon thickness> mesic O Horizon thickness) was a significant,related *** sum of 1-,10-,and 100-h fuel loads(fuels less 7.6 cm diameter),total woody fuel loads,ericaceous shrub cover,total basal area,or live *** basal area were *** *** basal area decreased with increasing ***,standing *** basal area increased from 2003-2019,and that increase was most pronounced as elevation increased on xeric and intermediate ***,we found that:*** increases in total woody fuel loads and ericaceous shrub cover were not present;and *** and moisture regime were most related to observed changes in vegetation and fuel condition.

关键词： Eastern hemlock Hemlock woolly adelgid Mountain laurel Rhododendron

Personalities in a crowd： What shapes the behaviour of Eurasian perch and other shoaling fishes？

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Current Zoology 2012年第1期58卷 35-44页

作者： Carin MAGNHAGEN department of wildlife Fish and Environmental Studies Swedish University of Agricultural Sciences

Lately, there has been an increasing interest in intraspeciflc variation in behaviour, and numerous studies on persona- lity have been performed in a variety of animals, including several fish species. Individuals have been divided into coping style categories or arranged along a behaviour gradient, such as the bold/shy continuum. However, many fish species live in groups, and the social environment can influence the behaviour of an animal in different ways. There may be conflicts within groups due to competition for resources, and dominance hierarchies are commonly found. On the other hand, there are many benefits of con- sensus decision-making within the group. Conformity of behaviour is probably adaptive, due to the benefit of public information on, for example, food resources and predation risk. Accordingly, studies of fish shoals have found evidence of consensus deci- sion-making. Furthermore, factors in the environment, such as predation risk would also influence the behaviour expressed. To be able to understand behaviour patterns in a group of fish, it is necessary to consider the variation of individual characteristics, and how the group, as well as other environmental factors, affects the behaviour of individuals. Here, I will review studies on different aspects of personality within a social context in fish, with a special emphasis on the Eurasian perch Percafluviatilis [Current Zo- ology 58 （1）： 35-44, 2012].

关键词： Percafluviatilis Boldness Group influence Behavioural syndromes Consensus Predation risk

Effects of historic wildfire and prescribed fire on site occupancy of bats in Shenandoah National Park,Virginia,USA

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Journal of Forestry Research 2020年第4期31卷 1255-1270页

作者： Lauren V.Austin Alexander Silvis W.Mark Ford Karen E.Powers department of fish and wildlife conservation Virginia TechBlacksburgVA 24061USA Resource Environmental Solutions WarrentonVA 20187USA U.S.Geological Survey Virginia Cooperative Fish and Wildlife Research UnitBlacksburgVA 24061USA Biology department Radford UniversityRadfordVA 24141USA

Given the likelihood of regional extirpation of several once-common bat species in eastern North America from white-nose syndrome,it is critical that the impacts of forest management activities,such as prescribed fire,are known in order to minimize potentially additive negative effects on bat *** wildfires may offer a suitable surrogate to assess long-term burn impacts on bats for planning,implementing and assessing burn *** examine the effects of historic fire on bats,we sampled bat activities at 24 transect locations in burned and unburned forest stands in the central Appalachian Mountains of Shenandoah National Park(SNP),Virginia,*** was limited evidence of positive fire effects over time on hoary bats(Lasiurus cinereus Beauvois)and big brown bats(Eptesicus fuscus Beauvois)***,there were few or mostly equivocal relationships of bat occupancy relative to burn conditions or time since fire in SNP across species using a false-positive occupancy *** results suggest that fire does not strongly affect bat site occupancy short-or long-term in the central Appalachians.

关键词： Appalachian mountains Bats False-positive occupancy Prescribed fire Wildfire

Ecological correlates of invasion impact for Burmese pythons in Florida

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Integrative Zoology 2012年第3期7卷 254-270页

作者： Robert N.REED John D.WILLSON Gordon H.RODDA Michael E.DORCAS US Geological Survey Fort Collins Science CenterFort CollinsColorado department of fish and wildlife conservation Virginia TechBlacksburgVirginia department of Biology Davidson CollegeDavidsonNorth CarolinaUSA

An invasive population of Burmese pythons(Python molurus bivittatus)is established across several thousand square kilometers of southern Florida and appears to have caused precipitous population declines among several species of native *** has this giant snake had such great success as an invasive species when many established reptiles have failed to spread?We scored the Burmese python for each of 15 literature-based attributes relative to predefined comparison groups from a diverse range of taxa and provide a review of the natural history and ecology of Burmese pythons relevant to each *** focused on attributes linked to spread and magnitude of impacts rather than establishment *** results suggest that attributes related to body size and generalism appeared to be particularly applicable to the Burmese python’s success in *** attributes with the highest scores were:high reproductive potential,low vulnerability to predation,large adult body size,large offspring size and high dietary ***,attributes of ectotherms in general and pythons in particular(including predatory mode,energetic efficiency and social interactions)might have also contributed to invasion *** establishment risk assessments are an important initial step in prevention of new establishments,evaluating species in terms of their potential for spreading widely and negatively impacting ecosystems might become part of the means by which resource managers prioritize control efforts in environments with large numbers of introduced species.

关键词： body size Burmese python Florida invasive species Python molurus

Anti-bat tiger moth sounds:Form and function

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Current Zoology 2010年第3期56卷 358-369页

作者： Aaron J.CORCORAN William E.CONNER Jesse R.BARBER department of Biology Wake Forest University department of fish Wildlife and Conservation BiologyColorado State University

The night sky is the venue of an ancient acoustic battle between echolocating bats and their insect prey. Many tiger moths （Lepidoptera： Arctiidae） answer the attack calls of bats with a barrage of high frequency clicks. Some moth species use these clicks for acoustic aposematism and mimicry, and others for sonar jamming, however, most of the work on these defensive functions has been done on individual moth species. We here analyze the diversity of structure in tiger moth sounds liom 26 spe- cies collected at three locations in North and South America. A principal components analysis of the anti-bat tiger moth sounds reveals that they vary markedly along three axes：（1） frequency, （2） duty cycle （sound production per unit time） and frequency modulation, and （3） modulation cycle （clicks produced during flexion and relaxation of the sound producing tymbal） structure. Tiger moth species appear to cluster into two distinct groups： one with low duty cycle and few clicks per modulation cycle that supports an acoustic aposematism function, and a second with high duty cycle and many clicks per modulation cycle that is con- sistent with a sonar jamming function. This is the first evidence from a community-level analysis to support multiple functions for tiger moth sounds. We also provide evidence supporting an evolutionary history for the development of these strategies. Further- more, cross-correlation and spectrogram correlation measurements failed to support a ＂phantom echo＂ mechanism underlying sonar jamming, and instead point towards echo interference [Current Zoology 56 （3）： 358-369, 2010].

关键词： Acoustic aposematism Sonar jamming Arctiidae Cross-correlation Autocorrelation