bluuebunny/crossref_metadata_2025 huggingface dataset:
Human‐Carnivore Conflict and Perspectives on Carnivore Management Worldwide
Authors: TREVES ADRIAN , KARANTH K. ULLAS
Published: December 2003

Abstract:  Carnivore conservation depends on the sociopolitical landscape as much as the biological landscape. Changing political attitudes and views of nature have shifted the goals of carnivore management from those based on fear and narrow economic interests to those based on a better understanding of ecosystem function and adaptive management. In parallel, aesthetic and scientific arguments against lethal control techniques are encouraging the development of nonlethal approaches to carnivore management. We anticipate greater success in modifying the manner and frequency with which the activities of humans and domestic animals intersect with those of carnivores. Success should permit carnivore populations to persist for decades despite human population growth and modification of habitat.
Paying for Tolerance: Rural Citizens' Attitudes toward Wolf Depredation and Compensation
Authors: NAUGHTON‐TREVES LISA , GROSSBERG REBECCA , TREVES ADRIAN
Published: December 2003

Abstract:  As wolf (Canis lupus) populations recover in Wisconsin (U.S.A.), their depredations on livestock, pets, and hunting dogs have increased. We used a mail‐back survey to assess the tolerance of 535 rural citizens of wolves and their preferences regarding the management of “problem” wolves. Specifically, we tested whether people who had lost domestic animals to wolves or other predators were less tolerant of wolves than neighboring residents who had not and whether compensation payments improved tolerance of wolves. We assessed tolerance via proxy measures related to an individual's preferred wolf population size for Wisconsin and the likelihood she or he would shoot a wolf. We also measured individuals' approval of lethal control and other wolf‐management tactics under five conflict scenarios. Multivariate analysis revealed that the strongest predictor of tolerance was social group. Bear (Ursus americanus) hunters were concerned about losing valuable hounds to wolves and were more likely to approve of lethal control and reducing the wolf population than were livestock producers, who were more concerned than general residents. To a lesser degree, education level, experience of loss, and gender were also significant. Livestock producers and bear hunters who had been compensated for their losses to wolves were not more tolerant than their counterparts who alleged a loss but received no compensation. Yet all respondents approved of compensation payments as a management strategy. Our results indicate that deep‐rooted social identity and occupation are more powerful predictors of tolerance of wolves than individual encounters with these large carnivores.
Limiting Depredation by African Carnivores: the Role of Livestock Husbandry
Authors: OGADA MORDECAI O. , WOODROFFE ROSIE , OGUGE NICHOLAS O. , FRANK LAURENCE G.
Published: December 2003

Abstract:  Most large carnivore species are in global decline. Conflict with local people, particularly over depredation on livestock, is a major cause of this decline, affecting both nominally protected populations and those outside protected areas. For this reason, techniques that can resolve conflicts between large carnivores and livestock farmers may make important contributions to conservation. We monitored rates of livestock depredation by lions ( Panthera leo), leopards (Panthera pardus), cheetahs (Acinonyx jubatus), and spotted hyenas (Crocuta crocuta), and retributive killing of these species by farmers in livestock‐producing areas of Laikipia District, Kenya. Farmers killed more lions, leopards, and spotted hyenas where these predators killed more livestock. Livestock husbandry had a clear effect on rates of depredation and hence on the numbers of predators killed. Cattle, sheep, and goats experienced the lowest predation rates when attentively herded by day and enclosed in traditional corrals (bomas) by night. Construction of the boma, the presence of watchdogs, and high levels of human activity around the boma were all associated with lower losses to predators. Although most of this work was carried out on commercial ranches, local Maasai and Samburu pastoralists have practiced nearly identical forms of husbandry for generations. Our study shows that traditional, low‐tech husbandry approaches can make an important contribution to the conservation of large carnivores.
Nonlethal Techniques for Managing Predation: Primary and Secondary Repellents
Authors: SHIVIK JOHN A. , TREVES ADRIAN , CALLAHAN PEGGY
Published: December 2003

Abstract:  Conservation biology requires the development of practical tools and techniques to minimize conflicts arising from human modification of ecosystems. We applied behavioral theory of primary and secondary repellents to predator management by using aversive stimulus devices (electronic training collars) and disruptive stimulus devices (behavior‐contingent audio and visual repellents) in a multipredator (Canis lupus, Haliaeetus leucocephalus, Ursus spp.) study in the United States. We examined fladry and a newly developed disruptive stimulus device contingent upon behavior on six wolf territories in Wisconsin, (U.S.A.) and determined that the disruptive stimulus device gave the greatest degree of protection from predation. We also compared the efficacy of a primary repellent (disruptive stimulus device) versus a secondary repellent (electronic training collars) to keep captive wolves from consuming a food source. Disruptive stimulus devices effectively prevented captive wolves from consuming the food resource, but did not produce an aversion to that food resource. With training collars, logistical and behavioral variability limited our ability to condition wolves. Our studies highlight the complexity of application of nonlethal techniques in real‐world situations.
Wolf Depredation Trends and the Use of Fladry Barriers to Protect Livestock in Western North America
Authors: MUSIANI MARCO , MAMO CHARLES , BOITANI LUIGI , CALLAGHAN CAROLYN , GATES C. CORMACK , MATTEI LIVIA , VISALBERGHI ELISABETTA , BRECK STEWART , VOLPI GIULIA
Published: December 2003

Abstract:  In Alberta, Canada (1982–2001), and in Idaho, Montana, and Wyoming, United States (1987–2001), wolves (Canis lupus) killed various domestic animals, among which the major prey were sheep in the United States (68%,n =494) and cattle in Canada (95%;n =1633). Under recovery programs, the wolf population increased in the United States, and depredation events increased proportionately. In both countries, the number of domestic animals killed each year was correlated with the number of wolves killed by government authorities for depredation management. We tested the ability of antiwolf barriers made of flags hanging from ropes to impede wolf access to food and livestock. In 18 experiments, barriers prevented captive wolves(n =9)from accessing food for up to 28 hours and allowed daily separation of wolves to administer contraceptive pills to a female wolf. Barriers prevented access by wild wolves to 100‐m2 baited sites during two 60‐day tests. We also set barriers around three cattle pastures. In Alberta during two 60‐day trials on 25‐ha pastures, wolves approached barriers on 23 occasions but did not cross them, and no cattle were killed. Wolves killed cattle on neighboring ranches during the trials and before and after the trials on the tested ranches. In Idaho four radiocollared wolves crossed barriers and killed cattle in a 400‐ha ranch after 61 days of barrier exposure. Our results suggest that antiwolf barriers are effective in deterring captive and wild wolves for >1 and ≥60 days, respectively, and that wild wolves switch to alternative livestock when excluded from one herd of livestock. Our depredation data indicate that protecting livestock from wolves reduces the necessity for killing wolves. Barriers could play a role among the limited set of preventive measures available and offer a cost‐effective mitigation tool for the problem of livestock depredation on a local scale.
The Role of Incentive Programs in Conserving the Snow Leopard
Authors: MISHRA CHARUDUTT , ALLEN PRISCILLA , McCARTHY TOM , MADHUSUDAN M. D. , BAYARJARGAL AGVAANTSERENGIIN , PRINS HERBERT H. T.
Published: December 2003

Abstract:  Pastoralists and their livestock share much of the habitat of the snow leopard (Uncia uncia) across south and central Asia. The levels of livestock predation by the snow leopard and other carnivores are high, and retaliatory killing by the herders is a direct threat to carnivore populations. Depletion of wild prey by poaching and competition from livestock also poses an indirect threat to the region's carnivores. Conservationists working in these underdeveloped areas that face serious economic damage from livestock losses have turned to incentive programs to motivate local communities to protect carnivores. We describe a pilot incentive program in India that aims to offset losses due to livestock predation and to enhance wild prey density by creating livestock‐free areas on common land. We also describe how income generation from handicrafts in Mongolia is helping curtail poaching and retaliatory killing of snow leopards. However, initiatives to offset the costs of living with carnivores and to make conservation beneficial to affected people have thus far been small, isolated, and heavily subsidized. Making these initiatives more comprehensive, expanding their coverage, and internalizing their costs are future challenges for the conservation of large carnivores such as the snow leopard.
The Oil Industry as an Underlying Factor in the Bushmeat Crisis in Central Africa
Authors: THIBAULT MARC , BLANEY SONIA
Published: December 2003

Abstract:  Although deforestation and habitat loss are considered the main causes of wildlife depletion, the bushmeat trade is one of the foremost threats to biodiversity conservation in central Africa. In 1997 and 1998, we set up a bushmeat trade monitoring program in the town of Gamba to assess the pressure exerted on wildlife by the human population attracted by the oil industry in the Gamba Protected Areas Complex. During 279 days of observations, we recorded 19 mammal species, 4 bird species, and 7 reptile taxa, for a total of 2845 animal carcasses with an estimated weight of 189,728 kg. Even though the bushmeat trade is illegal in protected areas, calculation of annual production levels and hunting yields showed that this trade is not sustainable for some species. We calculated the ratio of bushmeat found in the markets of Gamba to the human population. Compared with other Gabonese towns, Gamba had the highest ratio in the country. We suggest that the oil industry is another contributor to the bushmeat crisis in central Africa. It is important to recognize the role of oil companies in the current crisis in order to heighten the awareness of the public and of oil companies and to seek ways of lessening the impact of the oil industry on the bushmeat trade in central Africa.
Predicting Future Threats to the Native Vegetation of Robinson Crusoe Island, Juan Fernandez Archipelago, Chile
Authors: DIRNBÖCK THOMAS , GREIMLER JOSEF , LOPEZ S. PATRICIO , STUESSY TOD F.
Published: December 2003

Abstract:  The Juan Fernandez Archipelago, a Chilean national park and biosphere reserve, is 700 km west of continental Chile. Invasive plant species pose major threats to the native, highly endemic vegetation, especially on Robinson Crusoe Island (Mas a Tierra), where there is a permanent settlement. We used historical and recent vegetation map data as well as recent vegetational point data to reconstruct vegetational changes on the island since the early twentieth century. In addition, we used logistic regression models with environmental variables or their surrogates (elevation, solar radiation, topographic similarity index, slope position) to estimate the potential distributions of the worst invaders. Native vegetation has been affected most severely by Acaena argentea, Aristotelia chilensis, Rubus ulmifolius, and Ugni molinae, leading to a significant decrease of endemic plants in the montane forests and native shrublands. The native forest has decreased by approximately one‐third. The area affected by Aristotelia chilensis increased from 6.5% to 14% of the total island area. Ugni molinae, once rare, is now abundant (4.6%), as is Acaena (11.9%). Rubus ulmifolius, not present 80 years ago, now covers about 7% of the island's surface. The distributions of all studied species except Rubus ulmifolius are significantly (p < 0.05) controlled by the environmental factors we examined. Inferring from potential distributions of Aristotelia chilensis and Ugni molinae, 50% of the native montane forest could be invaded or replaced (with a probability of >60%) by these plants. Based on the invasion speed of the past 80 years, this would take another 80 years if conservation measures do not succeed.
Using Age Structure to Detect Impacts on Threatened Populations: a Case Study with Steller Sea Lions
Authors: HOLMES E. E. , YORK A. E.
Published: December 2003

Abstract: A delayed response to change is often a characteristic of long‐lived species and presents a major challenge to monitoring their status. However, rapid shifts in age structure can occur even while population size remains relatively static. We used time‐varying matrix models to study age‐structure information as a tool for improving detection of survivorship and fecundity change and status. We applied the methods to Steller sea lions ( Eumetopias jubatus), a long‐lived endangered marine mammal found throughout the North Pacific Rim. Population and newborn counts were supplemented with information on the fraction of the population that was juvenile, obtained by measuring animals in aerial photographs taken during range‐wide censuses. By fitting the model to 1976–1998 data, we obtained maximum‐likelihood estimates and 95% confidence intervals for juvenile survivorship, adult survivorship, and adult fecundity in the mid‐1980s, late 1980s, and 1990s. We used a series of nested models to test whether the data were best fit by a model with one, two, or three temporal changes in demographic rates, and we fit the models to different lengths of data to test the number of years of data needed to detect a demographic change. The declines in the early 1980s were associated with severely low juvenile survivorship, whereas declines in the 1990s were associated with disproportionately low fecundity. We repeated these analyses, fitting only to the count data without the juvenile‐fraction information, to determine whether the age‐structure information changed the conclusions and/or changed the certainty and speed with which demographic‐rate changes could be detected. The juvenile‐fraction data substantially improved the degree to which estimates from the model were consistent with field data and significantly improved the speed and certainty with which changes in demographic rates were detected.
Differing Effects of Cattle Grazing on Native and Alien Plants
Authors: KIMBALL SARAH , SCHIFFMAN PAULA M.
Published: December 2003

Abstract:  Habitat managers use cattle grazing to reduce alien plant cover and promote native species in California grasslands and elsewhere in the western United States. We tested the effectiveness of grazing as a restoration method by examining the effects of herbivory on native and alien plants. At Carrizo Plain National Monument, California, we surveyed native and alien species cover in adjacent grazed and ungrazed areas. We also established experimental plots in which plants were clipped or mulch (dead biomass) was removed. In addition, we clipped plants grown in pots and plants in the field that grew with and without competitors. Native species were negatively affected by clipping in 1999, 2000, and 2001, whereas alien species were unaffected. In the experimental field plots, the European annual forb Erodium cicutarium compensated in growth and reproduction following simulated herbivory. In contrast, growth and reproduction of the native perennial bunchgrass Poa secunda were reduced 1 year after clipping. In pots, E. cicutarium overcompensated and grasses undercompensated. In the field, European grasses were unaffected by the removal of competitors. It is unclear by what mechanism E. cicutarium was able to compensate, but the ability may be related to its basal rosette growth form and indeterminately growing inflorescences. The native California grassland community assembled in the absence of grazing herds, whereas invasive European species have been exposed to grazing for centuries. It may be that these invaders have adaptations that better enable them to recover from grazing. In the grassland we studied, the strategy of livestock grazing for restoration is counterproductive. It harms native species and promotes alien plant growth.
Limb Deformities as an Emerging Parasitic Disease in Amphibians: Evidence from Museum Specimens and Resurvey Data
Authors: JOHNSON PIETER T. J. , LUNDE KEVIN B. , ZELMER DEREK A. , WERNER J. KIRWIN
Published: December 2003

Abstract:  Widespread reports of malformed amphibians are of growing conservation concern. Although accounts of mass malformations (>5%) in North American amphibian populations date back to the 1940s, they are often poorly documented and are rarely explained. We reviewed available information for nine historical accounts from California, Colorado, Idaho, Mississippi, Montana, Ohio, and Texas reported between 1946 and 1988. We then asked the following questions: (1) Which of these cases were associated with Ribeiroia (Trematoda: Digenea) infection? (2) Are malformations still occurring at these sites? And (3) if so, have the frequency or types of abnormalities changed? Each site was resurveyed between 1999 and 2002, and original voucher specimens were redescribed and examined for trematode infection. Direct identification and classification by discriminant function analysis indicated that historical malformations at six of eight sites were associated with infection by Ribeiroia, dating back as far as 1946. Malformations recorded historically at these sites were consistent with the documented effects of Ribeiroia infection, including extra limbs, cutaneous fusion, and bony triangles. Of the six sites that still supported amphibians upon resurvey, three continued to support severe limb malformations at frequencies of 7–50% in one or more species. Although no pesticides were detected, amphibians from each of these sites were infected with Ribeiroia metacercariae. Taken together, these results suggest that Ribeiroia infection has historically been an important cause of mass malformations in amphibians. We conclude that although parasite‐induced malformations are not a new phenomenon, there is qualitative evidence suggesting that their prevalence has increased recently, and we highlight the need for long‐term research to evaluate the impacts of malformations on amphibian population viability.
Effects of Historic Livestock Grazing on Vegetation at Chaco Culture National Historic Park, New Mexico
Authors: FLOYD M. LISA , FLEISCHNER THOMAS L. , HANNA DAVID , WHITEFIELD PAUL
Published: December 2003

Abstract:  Livestock grazing is the most ubiquitous land use in western North America, yet it rarely has been studied in a controlled manner because of the lack of large areas free of grazing. We compared the ecological effects of three grazing treatments—long‐term protection, short‐term protection, and currently grazed—at Chaco Culture National Historic Park in northern New Mexico. Chaco has a long history of human habitation and is now one of the largest grazing exclosures in the American West. We studied the effects of livestock grazing on the cover of plants, soil crusts, and plant species richness at six sites with different potential natural vegetation. Species richness was higher under long‐term protection than under current grazing at all six sites. Trends in shrub and grass response varied significantly across the six sites. Shrub cover increased with long‐term protection at four upland sites, and grass cover increased with protection at four sites. The response of Chaco vegetation to release from grazing varied significantly according to each site's ecological potential, determined in part by edaphic and topographic characteristics. These nuances in vegetation response represent natural ecological variation and contrast with the notions of widespread shrub “invasion” often inferred in the past.
Potential Effects of Passenger Pigeon Flocks on the Structure and Composition of Presettlement Forests of Eastern North America
Authors: ELLSWORTH JOSHUA W. , McCOMB BRENDA C.
Published: December 2003

Abstract: We considered the possible effects Passenger Pigeon (Ectopistes migratorius) flocks may have had on the disturbance regime and species composition of presettlement forests in eastern North America. We suggest that the activities of roosting and nesting Passenger Pigeons caused widespread, frequent disturbances in presettlement eastern forests through tree limb and stem breakage and nutrient deposition from pigeon excrement. We suspect that the deposition of fine fuels resulting from such disturbances may have influenced fire intensity and frequency in presettlement forests. Further, we propose that consumption of vast quantities of acorns by pigeons during the spring breeding season may partially explain the dominance of white oak (Quercus alba) throughout much of the presettlement north‐central hardwoods region. Consequently, the pigeon's extinction may have facilitated the increase and expansion of northern red oak (Quercus rubra) during the twentieth century. Although it is difficult to accurately quantify how physical and chemical disturbances and mast consumption by Passenger Pigeon flocks affected forest ecology, we suspect they shaped landscape structure and species composition in eastern forests prior to the twentieth century. We believe their impact should be accounted for in estimates of the range of natural variability of conditions in eastern hardwood forests.
Avoiding Pitfalls of Using Species Distribution Models in Conservation Planning
Authors: LOISELLE BETTE A. , HOWELL CHRISTINE A. , GRAHAM CATHERINE H. , GOERCK JAQUELINE M. , BROOKS THOMAS , SMITH KIMBERLY G. , WILLIAMS PAUL H.
Published: December 2003

Abstract:  Museum records have great potential to provide valuable insights into the vulnerability, historic distribution, and conservation of species, especially when coupled with species‐distribution models used to predict species' ranges. Yet, the increasing dependence on species‐distribution models in identifying conservation priorities calls for a more critical evaluation of model robustness. We used 11 bird species of conservation concern in Brazil's highly fragmented Atlantic Forest and data on environmental conditions in the region to predict species distributions. These predictions were repeated for five different model types for each of the 11 bird species. We then combined these species distributions for each model separately and applied a reserve‐selection algorithm to identify priority sites. We compared the potential outcomes from the reserve selection among the models. Although similarity in identification of conservation reserve networks occurred among models, models differed markedly in geographic scope and flexibility of reserve networks. It is essential for planners to evaluate the conservation implications of false‐positive and false‐negative errors for their specific management scenario before beginning the modeling process. Reserve networks selected by models that minimized false‐positive errors provided a better match with priority areas identified by specialists. Thus, we urge caution in the use of models that overestimate species' occurrences because they may misdirect conservation action. Our approach further demonstrates the great potential value of museum records to biodiversity studies and the utility of species‐distribution models to conservation decision‐making. Our results also demonstrate, however, that these models must be applied critically and cautiously.
Targeting Conservation Action through Assessment of Protection and Exurban Threats
Authors: THEOBALD DAVID M.
Published: December 2003

Abstract:  Landscape‐level assessments of biodiversity strive to guide land‐use planning and conservation activities by providing information about areas of high biodiversity value and low protection status. I developed a methodology to assess the level of threat to conservation of biodiversity to help guide conservation action. This method incorporates socioeconomic indicators of risk, including developed and roaded areas, and measures the proportion of conservation lands affected by developed areas. In addition, I developed a metric called conservation potential to measure the degree of fragmentation of patches caused by development. As an illustration I applied this methodology to Colorado (U.S.A.). Protection levels were determined by examining land ownership, resulting in protected lands (status levels 1 and 2) and unprotected lands (status levels 3 and 4). Areas were considered threatened (at risk) if a land‐cover patch had >20% roaded area, >15% developed area, or was highly fragmented. Although 24 of 43 natural land‐cover types were unprotected (49% of the state), 9 additional types were threatened. Combining conservation‐status protection levels with patterns of threat targets the geographic area where conservation action is needed, provides a way to determine where so‐called protected areas are at risk, and allows conservation strategies to be better refined.
Landowners' Responses to an Endangered Species Act Listing and Implications for Encouraging Conservation
Authors: BROOK AMARA , ZINT MICHAELA , DE YOUNG RAYMOND
Published: December 2003

Abstract: Private landowners manage many rare species' habitats, yet research on their responses to species conservation legislation is scarce. To address this need, we examined private landowners' responses to the listing of the Preble's meadow jumping mouse (Zapus hudsonius preblei) as threatened under the U.S. Endangered Species Act (ESA). We mailed a questionnaire designed to measure these responses to a sample of landowners. The adjusted response rate was 46% (n =379). The questionnaire asked landowners whether they had managed their land to improve the Preble's habitat and to minimize the chance of the Preble's living on it. We also asked whether landowners had or would allow a survey for the Preble's on their property. We hypothesized that landowners would respond to these questions based on their aesthetic preferences, economic concerns, information sources, parcel size, personal values, recreation activities, residence status, social influences, and other factors. Listing the Preble's under the ESA does not appear to have enhanced its survival prospects on private land. In terms of hectares owned, for example, the efforts of landowners who reported they had sought to help the Preble's (25%) were canceled out by the efforts of those who sought to harm it (26%). Moreover, the majority of respondents had not or would not allow a biological survey (56%), thus preventing the collection of data for conserving the species. All eight hypothesized determinants significantly predicted responses to the listing when they were considered individually. When considered simultaneously, however, only one economic consideration (dependence on agriculture), recreation activity (consumptive), and social factor (distrusting government), and select information sources (conservation and social), and personal values (valuing nature, valuing local control, and denying landowner responsibility) remained direct determinants. To promote the conservation of rare species by private landowners, we recommend communicating information through social networks, alleviating landowners' economic concerns, increasing use of collaborative processes, and institutionalizing assurances that landowners will not be harmed by managing their land to help rare species.
Cattle Grazing Impacts on Annual Forbs and Vegetation Composition of Mesic Grasslands in California
Authors: HAYES GREY F. , HOLL KAREN D.
Published: December 2003

Abstract:  Livestock grazing represents a major human alteration of natural disturbance regimes in grasslands throughout the world, and its impacts on plant communities have been highly debated. We investigated the impact of cattle grazing on the California coastal prairie plant community with a focus on native annual forbs, a number of which are of conservation concern. In spring 2000 and 2001, we surveyed the vegetation community composition, vegetation structure, and soil chemical parameters at 25 paired grazed and ungrazed sites over a 670‐km range of the ecosystem. Native annual forb species richness and cover were higher in grazed sites, and this effect was concomitant with decreased vegetation height and litter depth. Soil properties explained less of the variation. Exotic annual grass and forb cover were higher in grazed sites. Native grass cover and species richness did not differ in grazed and ungrazed sites, but cover and species richness of native perennial forbs were higher in ungrazed sites. Our results suggest that cattle grazing may be a valuable management tool with which to conserve native annual forbs in the ecosystem we studied but that grazing differentially affects the various life‐history guilds. Therefore, land managers must focus on creating a matrix of disturbance regimes to maintain the suite of species native to these mesic grasslands. The results of this and other studies highlight the importance of considering the adaptation of vegetation communities to disturbance in making recommendations for grazing management.
Countryside Biogeography of Neotropical Mammals: Conservation Opportunities in Agricultural Landscapes of Costa Rica
Authors: DAILY GRETCHEN C. , CEBALLOS GERARDO , PACHECO JESÚS , SUZÁN GERARDO , SÁNCHEZ‐AZOFEIFA ARTURO
Published: December 2003

Abstract: The future of mammalian diversity in the tropics depends largely on the conservation value of human‐dominated lands. We investigated the distribution of non‐flying mammals in five habitats of southern Costa Rica: relatively extensive forest (227 ha), coffee plantation, pasture, coffee with adjacent forest remnant (<35 ha), and pasture with adjacent forest remnant (<35 ha). Of the 26 native species recorded in our study plots, 9 (35%) were restricted to forest habitat, 14 (54%) occurred in both forest and agricultural habitats, and 3 (11%) were found only in agricultural habitats. Species richness and composition varied significantly with habitat type but not with distance from the extensive forest. Interestingly, small forest remnants (<35 ha) contiguous with coffee plantations did not differ from more extensive forest in species richness and were richer than other agricultural habitat types. Small remnants contiguous with pasture were species‐poor. When clearing started, the study region likely supported about 60 species. Since then, at least 6 species (10%), one family (4%), and one order (11%) have gone extinct locally. The species that disappeared were the largest in their families and included carnivorous (e.g., jaguar[Panthera onca]),herbivorous (e.g., Baird's tapir, [Tapirus bairdii]),and arboreal (e.g., mantled howler monkey[Alouatta palliata])species. Although there is no substitute for native forest habitat, the majority of native, nonflying mammal species use countryside habitats. The populations of many persist even >5 km from relatively extensive forest, at least over the 40 years since forest clearance. Moreover, if hunting ceased, we expect that at least one of the locally extinct species could be reestablished in the existing landscape. Thus, there is an important opportunity to maintain and restore the diversity, abundance, and ecosystem roles of mammals in at least some human‐dominated regions of the Neotropics.
Designing Effective Marine Protected Areas in Seaflower Biosphere Reserve, Colombia, Based on Biological and Sociological Information
Authors: FRIEDLANDER A. , NOWLIS J. SLADEK , SANCHEZ J. A. , APPELDOORN R. , USSEGLIO P. , McCORMICK C. , BEJARANO S. , MITCHELL‐CHUI A.
Published: December 2003

Abstract:  Ecologists have paid increasing attention to the design of marine protected areas (MPAs), and their design advice consistently recommends representing all habitat types within MPAs or MPA networks as a means to provide protection to all parts of the natural ocean system. Recent developments of new habitat‐mapping techniques make this advice more achievable, but the success of such an approach depends largely on our ability to define habitat types in a way that is ecologically relevant. We devised and tested the ecological relevance of a set of habitat‐type definitions through our participation in a stakeholder‐driven process to design a network of MPAs, focusing on no‐take marine reserves in the Seaflower Biosphere Reserve, San Andrés Archipelago, Colombia. A priori definitions of habitat types were ecologically relevant, in that our habitat‐type definitions corresponded to identifiable and unique characteristics in the ecological communities found there. The identification of ecological pathways and connectivity among habitats also helped in designing ecologically relevant reserve boundaries. Our findings contributed to the overall design process, along with our summary of other general principles of marine reserve design. Extensive stakeholder input provided information concerning the resources and their patterns of use. These inputs also contributed to the reserve design process. We anticipate success for the Seaflower Biosphere Reserve at achieving conservation and social goals because its zoning process includes detailed yet flexible scientific advice and the participation of stakeholders at every step.
Assessing the Potential Impact of Cane Toads on Australian Snakes
Authors: PHILLIPS BEN L. , BROWN GREGORY P. , SHINE RICHARD
Published: December 2003

Abstract:  Cane toads (Bufo marinus) are large, highly toxic anurans that were introduced into Australia in 1937. Anecdotal reports suggest that the invasion of toads into an area is followed by dramatic declines in the abundance of terrestrial native frog‐eating predators, but quantitative studies have been restricted to nonpredator taxa or aquatic predators and have generally reported minimal impacts. Will toads substantially affect Australian snakes? Based on geographic distributions and dietary composition, we identified 49 snake taxa as potentially at risk from toads. The impact of these feral prey also depends on the snakes' ability to survive after ingesting toad toxins. Based on decrements in locomotor (swimming) performance after ingesting toxin, we estimate the LD50 of toad toxins for 10 of the at‐risk snake species. Most species exhibited a similar low ability to tolerate toad toxins. Based on head widths relative to sizes of toads, we calculate that 7 of the 10 taxa could easily ingest a fatal dose of toxin in a single meal. The exceptions were two colubrid taxa (keelbacks [ Tropidonophis mairii] and slatey‐grey snakes [ Stegonotus cucullatus]) with much higher resistance to toad toxins (up to 85‐fold) and one elapid (swamp snakes [ Hemiaspis signata]) with low resistance but a small relative head size and thus low maximum prey size. Overall, our analysis suggests that cane toads threaten populations of approximately 30% of terrestrial Australian snake species.
Amplifying Nuclear and Mitochondrial DNA from African Elephant Ivory: a Tool for Monitoring the Ivory Trade
Authors: COMSTOCK KENINE E. , OSTRANDER ELAINE A. , WASSER SAMUEL K.
Published: December 2003

Abstract:  The ability to extract DNA from ivory provides the basis for genetically tracking the origin of poached ivory and thus has important implications for elephant conservation and management. We describe a method to isolate and amplify both genomic and mitochondrial DNA from African elephant ivory that requires very small amounts of ivory taken from any location on the tusk. We pulverized ivory and isolated DNA with a modified QIAamp kit. Ivory as old as 10 to 20 years, stored at ambient conditions, was amenable to DNA isolation with this method. The isolated DNA was robustly amplified at 16 elephant microsatellite loci and two mitochondrial DNA loci. This method has important applications for the forensic analysis of poached African elephant ivory. It enables determination of where stronger antipoaching efforts are needed and provides the basis for monitoring the extent of the trade as well as the consequences of future international trade decisions.
Improving the Quality of Distribution Models for Conservation by Addressing Shortcomings in the Field Collection of Training Data
Authors: VAUGHAN I. P. , ORMEROD S. J.
Published: December 2003

Abstract: Conservation biology can benefit greatly from models that relate species' distributions to their environments. The foundation of successful modeling is a high‐quality set of field data, and distribution models have specialized data requirements. The role of a distribution model may be primarily predictive or, alternatively, may emphasize relationships between an organism and its habitat. For the latter application, the environmental variables recorded should have direct, biological relationships with the organism. Interacting species may be valuable predictors and can improve understanding of distribution patterns. Sampling should cover the full range of environmental conditions within the study region, with samples stratified across major environmental gradients to ensure thorough coverage. Failure to sample correctly can lead to erroneous organism‐environment relationships, affecting predictive ability and interpretation. Sampling ideally should examine a series of spatial scales, increasing the understanding of organism‐environment relationships, identifying the most effective scales for predictive modeling and complementing the spatial hierarchies often used in conservation planning. Consideration of statistical issues could benefit most studies. The ratio of sample sites to environmental variables considered should ideally exceed a ratio of 10:1 to improve the analytical power and reliability of subsequent modeling. Presence and/or absence models may suffer bias if training data detect the study organism at an atypical proportion of sites. We considered different strategies for spatial autocorrelation and recommend it be included wherever possible for the benefits in biological realism, predictive accuracy, and model versatility. Finally, we stress the importance of collecting independent evaluation data and suggest that, as with the training data, a systematic approach be used to ensure broad environmental coverage, rather than relying on a random selection of test sites.
Bird Extinctions in Atlantic Forest Fragments of the Viçosa Region, Southeastern Brazil
Authors: RIBON RÔMULO , SIMON JOSÉ EDUARDO , THEODORO DE MATTOS GERALDO
Published: December 2003

Abstract: We studied the conservation status of Atlantic forest birds in 43 forest fragments ranging in size from 1 to 384 ha in the Viçosa region of southeastern Brazil. We compared data from 15 years of field work with historical records from the region, mainly originating from specimens collected by João Moojen during the 1930s. We used published studies associated with museum data and current field work to assess the decline of forest birds during the last 70 years and to relate their disappearance to forest fragmentation and destruction. At least 28 bird species have become locally extinct, 43 are critically endangered, and 25 are vulnerable, representing 60.7% of the original forest bird community known to exist in the region. Vulnerability to fragmentation differed among guilds, forest strata, and endemicity status. Birds that feed on fruit and seeds, and those that feed on insects, were more threatened than omnivores and carnivores. Nectarivorous species were less threatened than other guilds. Moreover, terrestrial and understory birds or birds using only one forest stratum also were more likely to have been threatened. Finally, Atlantic forest endemics were more likely to have become extinct than nonendemic species. In general, sensitivity to environmental disturbance at the local level was similar to the predicted vulnerability to regional disturbance derived from the literature. Our results indicate that a serious decline of Atlantic forest birds is underway and that many other species of birds, not previously recognized as threatened, are of conservation concern.
Effects of Aquarium Collectors on Coral Reef Fishes in Kona, Hawaii
Authors: TISSOT BRIAN N. , HALLACHER LEON E.
Published: December 2003

Abstract:  No previous studies have conclusively documented the magnitude of the effect of aquarium collecting on natural populations. In Hawaii concern over the effects on reef fish populations of collecting for the aquarium trade began in the early 1970s, primarily in response to multiple‐use conflicts between aquarium‐fish collectors and recreational dive‐tour operators. In 1997–1998 we used a paired control‐impact design to estimate the effect of aquarium collectors. We compared differences in fish abundance along visual belt transects between collection sites, where collecting was known to occur, and control sites, where collecting was prohibited. To test the assumptions of our observational design, we surveyed a combination of species captured by aquarium collectors and those not captured. The extent of bleaching, broken coral, and coral cover was also surveyed. Seven of the 10 aquarium species surveyed were significantly reduced by collecting. The abundance of aquarium fish at collection sites ranged from 38% lower (Chaetodon multicinctus) to 75% lower (C. quadrimaculatus) than that at control sites. In contrast, only two of the nonaquarium species displayed a significant collection effect. There were no significant differences in damaged coral between control and collection sites to indicate the presence of destructive fishing practices. In addition, there were no increases in the abundance of macroalgae where the abundance of herbivores was reduced by aquarium collecting. Although our results suggest that aquarium collectors have a significant effect on the abundance of targeted aquarium fishes, better knowledge of the intensity and location of collecting activities is required to make a rigorous assessment of the effects of collecting on nearshore fish populations. Several lines of evidence suggest that the current system of catch reporting underestimates actual removals.
Simple Spatial Modeling Tool for Prioritizing Prescribed Burning Activities at the Landscape Scale
Authors: HIERS J. KEVIN , LAINE STEPHEN C. , BACHANT J. J. , FURMAN JAMES H. , GREENE WELDON W. , COMPTON VERNON
Published: December 2003

Abstract: Resources for prescribed fire are frequently insufficient to manage public lands for all conservation and resource management objectives, necessitating prioritization of the application of fire across the landscape within any given year. Defining tradeoffs when applying prescribed fire to large landscapes is problematic not only because of the complexity of weighing competing management objectives at the landscape scale, but also because of the difficult nature of independently applying need‐to‐burn criteria to large areas. We present a case study of a simple modeling process implemented at Eglin Air Force Base in the Florida Panhandle (U.S.A.) to prioritize the application of prescribed fire. In a workshop setting, managers and biologists identified key conservation criteria and landscape management objectives that drive the application of prescribed fire. Remote sensing and other spatial data were developed to directly or indirectly represent all these criteria. Using geographic information system software, managers and biologists weighted each criterion according to its relative contribution to overall burn prioritization, and individual values for the criterion were scored according to how they influence the need to burn. Subsequently, this process has been validated and modified through ecological monitoring. This modeling process has also been applied to the 77,400‐ha Blackwater River State Forest, public land adjacent to Eglin Air Force Base, demonstrating its applicability to lands with varying management priorities. The advantages of this model‐based approach for prioritizing prescribed fire include the reliance on accessible, inexpensive software, the development of spatially explicit management objectives, the ease of transferability, and clearly stated assumptions about management that may be tested and reviewed through monitoring and public comment.
Predictors of Species Richness in Northwest Florida Longleaf Pine Sandhills
Authors: LOUIS PROVENCHER  , LITT ANDREA R. , GORDON DORIA R.
Published: December 2003

Abstract:  Soil characteristics, disturbance histories, and species richness among distinct groups of plants and animals may be useful predictors of important conservation areas when data are limited. We used multivariate analysis of covariance to test the hypothesis that the species richness of plants, arthropods, herpetofauna, and breeding birds are correlated and increase with soil fertility (silt and clay content in sandy soils), soil variability, and hardwood midstory reduction in subxeric, nutrient‐poor longleaf pine sandhills at Eglin Air Force Base in northwest Florida. During 1994–1995 and 1998–1999, we sampled 30 81‐ha plots with varying fire‐exclusion histories and at two spatial scales of resolution (10 × 40 m and 81 ha). The relationship between the number of plant species and percent silt and clay and its coefficient of variation was significant and positive at the plot level (81 ha) but not at the subplot level (10 × 40 m). Herpetofaunal species richness was the only faunal variable that increased with silt and clay content, but the coefficient of variation did not. Multivariate effects of hardwood reduction were significant in 1998–1999 but not in 1994–1995, which suggests that the reintroduction of fire increased species richness across taxa. Univariate effects of hardwood reduction were marginally significant for plant species richness at the subplot level and not significant for herpetofaunal species richness at either scale. Plant and arthropod species richness were not correlated. Herpetofaunal species richness was not correlated with that of other taxa (plant and animal). The species richness of plants and arthropods were each significantly positively correlated with the richness of breeding bird species at the subplot level during 1994–1995, whereas only arthropod species richness was positively correlated with bird species richness at the plot level in either year. Our results suggest that the restoration of fire regime may be the most effective tool with which to increase diversity in pyrogenic areas considered for conservation protection.