Wildlife Management Strategies Research Articles

Molecular profiling of marine fauna: Integration of omics with environmental assessment of the world's oceans

Many species that contribute to the commercial and ecological richness of our marine ecosystems are harbingers of environmental change. The ability of organisms to rapidly detect and respond to changes in the surrounding environment represents the foundation for application of molecular profiling technologies towards marine sentinel species in an attempt to identify signature profiles that may reside within the transcriptome, proteome, or metabolome and that are indicative of a particular environmental exposure event. The current review highlights recent examples of the biological information obtained for marine sentinel teleosts, mammals, and invertebrates. While in its infancy, such basal information can provide a systems biology framework in the detection and evaluation of environmental chemical contaminant effects on marine fauna. Repeated evaluation across different seasons and local marine environs will lead to discrimination between signature profiles representing normal variation within the complex milieu of environmental factors that trigger biological response in a given sentinel species and permit a greater understanding of normal versus anthropogenic-associated modulation of biological pathways, which prove detrimental to marine fauna. It is anticipated that incorporation of contaminant-specific molecular signatures into current risk assessment paradigms will lead to enhanced wildlife management strategies that minimize the impacts of our industrialized society on marine ecosystems.

Differential Annual Movement Patterns in a Migratory Species: Effects of Experience and Sexual Maturation

Some animals migrate long distances to exploit important seasonal food resources in the northern regions of the northern hemisphere, whilst avoiding winter starvation. Changes in the individual's age and navigational skills are likely to affect migration, which in turn influences the geographic distribution of individuals. Processes such as sexual maturation and navigational abilities are affected by age, and age is thus a key factor in understanding migration patterns and differences in distribution ranges. In the present study, we investigated the effects of age on the geographic distribution of a population of Lesser Black-backed Gulls Larus fuscus throughout its annual cycle, by analyzing a dataset of 19,096 records from 10,000 color-ringed gulls. In contrast to previous assumptions, the results showed that gulls were geographically segregated by age throughout the entire annual cycle, rather than showing a geographic age-related cline only in the wintering areas. This asymmetric distribution results from a reduction in the annual range of sexually mature gulls, and the differential distribution of mature and immature individuals (mature birds remained in more northern areas, compared to immature birds, throughout the annual cycle). Furthermore, although immature gulls travelled longer distances than adults, they initiated their fall migration with short movements, in contrast to adults that migrated using longer movements. The effects identified in this study explain the non-homogenous distribution of populations throughout the annual cycle, with wide implications for the development of effective human health policies and/or wildlife management strategies.

No sympathy for the devil

Pathogens are a significant driver of biodiversity loss. We examine two wildlife disease management strategies that have seen growing use, sometimes in combination: (i) trapping-and-culling infectious animals (disease control), and (ii) trapping-and-translocating healthy animals to a reserve, with possible future reintroduction. A reserve can improve conservation when there is no disease. But, when infection exists, we show investing in the reserve may counteract disease control. We find jointly pursuing both strategies is sub-optimal when the reserve is costly to maintain. Numerically, we examine management of Devil Facial Tumor Disease, which has generated extinction risks for Tasmanian Devils. Disease control (though not eradication) is generally part of an optimal strategy, although a reserve is also optimal if it can be maintained costlessly. This implies preserving the original population by addressing in situ conservation risks, rather than translocating animals to a reserve and giving up on the original population, is generally the first-best.

The impacts of herbivory on vegetation in Moremi Game Reserve, Botswana: 1967–2001

Browsing and grazing pressure on vegetation in the Moremi Game Reserve in Botswana was analyzed using remotely sensed imagery comprising CORONA photographs of 1967 and Landsat TM and Landsat ETM imagery of 1989 and 1994 and 2001, respectively. Comparison of temporal variations in the spatial distributions of different vegetation types and changes in the abundance of selected wildlife species demonstrate a persistent decrease in capacity of the environment to support wild animals, due to increasing abundance of poorly preferred browse species and increasing scarcity of favored varieties. Given the long-term direction of change showing continued deterioration of habitat conditions and the limited prospects for reversal of this trend, it is apparent that there is immediate need to realign wildlife management strategies in ways that can enhance the sustainability of wildlife and the supporting environment.

Recent advances in the management of bovine tuberculosis in free-ranging wildlife

Established foci of Mycobacterium bovis (the causative agent of bovine tuberculosis [bTB]) in free-ranging wildlife are currently under various stages of management on three continents (Africa, Europe and North America) and in New Zealand. Other, as yet undiagnosed, foci seem likely to exist elsewhere. The complex roles that these wildlife foci play in the ecology of bTB remain among the greatest challenges facing bTB control globally. Conceptually, management of bTB in free-ranging wildlife can be thought of as progressing from the discovery of an outbreak through frequently overlapping stages of epidemiological characterization, initial control, simulation and forecasting, focused control, and verification of eradication. Surveillance in its various forms remains a critical component of assessment throughout. Since the Fourth International M. bovis Conference in 2005, research on management of bTB in free-ranging wildlife has encompassed such areas as the human dimensions of wildlife management, mitigation of bTB risks from wildlife on cattle farms, vaccine biology, and epidemiology, with a major contribution from simulation modeling. In order to advance the actual field management of bTB, however, research must be sufficiently grounded to aid development of practical, affordable and politically defensible management interventions which stand a reasonable chance of being implemented. The current management of two wildlife reservoirs of bTB, brushtail possums ( Trichosurus vulpecula) in New Zealand, and white-tailed deer ( Odocoileus virginianus) in Michigan, USA, serve as contrasting examples of different wildlife management strategies aimed at achieving a common goal. In New Zealand, the importance of agricultural export markets and the status of the possum as a non-native pest have facilitated direct, aggressive management of the disease reservoir, resulting in considerable progress towards bTB freedom since 1994. In Michigan, the relative importance of the hunting economy and of whitetails as a game animal have made such aggressive culling politically untenable. This has forced reliance upon publicly supported, and implemented, management tools, and so provided impetus to better understand social support for wildlife management policy, its limitations, and ways to employ it in disease control policy development.

Archaeological Protein Residues: New Data for Conservation Science

The utility of zooarchaeological data for addressing wildlife management and conservation research has been increasingly recognized over the past two decades. As the field of ‘applied zooarchaeology’ continues to grow, newfound opportunities for discovery have arisen via collaborative interdisciplinary approaches. The burgeoning field of proteomics, in particular, has provided numerous opportunities for enhancing the degree to which meaningful information can be recovered from the archaeological record. Archaeological protein residues can inform conservation biologists about paleobiogeography and ecological/evolutionary history and thereby provide insight into wildlife management strategies. In addition to pointing out several cases where archaeological protein residues may be of benefit, I justify the use of protein residues in particular and discuss areas for improvement.

Archaeological Protein Residues: New Data for Conservation Science

The utility of zooarchaeological data for addressing wildlife management and conservation research has been increasingly recognized over the past two decades. As the field of ‘applied zooarchaeology’ continues to grow, newfound opportunities for discovery have arisen via collaborative interdisciplinary approaches. The burgeoning field of proteomics, in particular, has provided numerous opportunities for enhancing the degree to which meaningful information can be recovered from the archaeological record. Archaeological protein residues can inform conservation biologists about paleobiogeography and ecological/evolutionary history and thereby provide insight into wildlife management strategies. In addition to pointing out several cases where archaeological protein residues may be of benefit, I justify the use of protein residues in particular and discuss areas for improvement.

Wabusk of the Omushkegouk: Cree-Polar Bear (Ursus maritimus) Interactions in Northern Ontario

In order to understand wabusk (polar bear, Ursus maritimus) behaviours and interactions with people in the Hudson Bay lowlands of northern Ontario we conducted this collaborative study of Cree kiskayndamowin/knowledge. Our findings reveal that Cree knowledge supports previously published information on polar bears, while adding further contextual findings: that male polar bears travel greater distances into the muskeg than previously recorded; that wabusk prey on amisk (beaver, Castor canadensis); that wabusk interact with muskwa (black bears, Ursus americanus); and that human-polar bear interactions occur in this region of northern Canada. Bearing in mind that Cree knowledge has been recognized in wildlife management strategies (i.e., for beaver, caribou and moose) elsewhere in Canada, this particular body of information is timely, especially since polar bears are considered threatened under the Ontario Endangered Species Act, and the province is developing a recovery strategy for the Southern Hudson Bay polar bear population. The federal government is also contemplating listing polar bears in Canada as a “species of special concern” under the Species at Risk Act (SARA). While it is unclear as to how these decisions will impact the Cree-polar interactions, the listing of polar bears by both governments, but especially the provincial government of Ontario, must recognize treaty and Aboriginal rights, acknowledge its duties to consult and properly accommodate Aboriginal people’s views, incorporate Cree kiskayndamowin/knowledge of wabusk, and re-examine the proposed Wabusk Co-Management Agreement draft developed by the Ontario Ministry of Natural Resources (OMNR) and Coastal Cree First Nations of Northern Ontario in 1994. The article provides recommendations that highlight how the Northern Cree First Nations, through the development of the Recovery Strategy for Polar Bear in Ontario, can become engaged in the management of wabusk in Ontario and throughout Canada.

British Columbia's Interior: Fisher Wildlife Habitat Decision Aid

Fishers (Martes pennanti) are forest-dependent carnivores of the weasel family that are considered a Species at Risk under the Identified Wildlife Management Strategy and Species of Special Concern (blue-listed) by British Columbia Conservation Data Centre. Under the Forest and Range Practices Act, forest and range licensees in British Columbia are required to develop Forest Stewardship Plans and manage their operations to maintain limiting habitats of Identified Wildlife within their tenures accordingly. Several aspects of the ecology of fishers make them susceptible to forest-harvest activities, including their use of structural elements found primarily in late-successional forests. This Wildlife Habitat Decision Aid (WHDA) summarizes the latest scientific and experiential information that forestry practitioners, including silviculture planners and operational foresters, need to consider when managing for fisher habitat requirements. This information was obtained through an extensive literature analysis and discussions with experts in fisher ecology in British Columbia. Most information on fisher ecology in this extension note was derived from studies conducted in the Cariboo, Williston, Chilcotin, and South Peace regions.The WHDA format has been used to convey information on factors requiring consideration when managing forests and range in British Columbia for specific wildlife species. This WHDA provides information on habitats used by fishers for birthing and rearing young, resting, and foraging; a provincial fisher distribution map and a list of biogeoclimatic zones where fishers most commonly occur; and forest management considerations when harvesting and conducting silviculture activities within fisher range. Also included is a resource and reference list that contains more detailed information. Most reference material that is not available online can be ordered through libraries.

British Columbia's Southern Interior: Badger Wildlife Habitat Decision Aid

Under the Forest and Range Practices Act, forest and range licensees in British Columbia are required to develop Forest Stewardship Plans and manage their operations to maintain limiting habitats of Identified Wildlife within their tenures. North American badgers (Taxidea taxus) are large members of the weasel family that are a Species At Risk within the Identified Wildlife Management Strategy (IWMS) and are listed as Endangered by COSEWIC. Several aspects of their ecology make them susceptible to forest and range management activities, including their dependence on the grassland, open forest, and modified forested habitat that supports their prey. This Wildlife Habitat Decision Aid (WHDA) summarizes the latest scientific and experiential information that forest and range managers, including silviculture planners, operational foresters, and ranchers, need to consider when managing for badger habitat requirements. This information was obtained through a literature review and discussions with researchers studying badger ecology in British Columbia.The WHDA format has been used to convey information on factors requiring consideration when managing forests and range in British Columbia for specific wildlife species. This WHDA provides information on habitat features needed by badgers for reproductive dens, resting sites, and foraging habitats; biogeoclimatic zones where badgers occur; and considerations when conducting harvesting, silviculture activities, or livestock grazing in badger range. We provide a map of the distribution and list the biogeoclimatic zones in which badgers occur to help users identify where to apply management considerations. Also included is a valuable resource and reference list that contains more detailed information. Most reference material that is not available online can be ordered through libraries.

Land-Use Pattern, Urbanization, and Deer–Vehicle Collisions in Alabama

With the rise in deer-vehicle collisions across the United States, the associated costs also have risen. Increasingly, however, researchers are learning that these collisions are not a random phenomena but follow a systematic pattern. Building on this insight, we explored the role of county characteristics in infl uencing the pattern and incidence of white-tailed deer- (Odocoileus virginianus) related auto collisions. Using county level data from 1994 to 2003 in Alabama, we tested several data models with the above mentioned factors as covariates. Our results showed that county characteristics, such as (1) having a deer population density (≥31/km 2 ), (2) being part of a metropolitan statistical area, (3) having a high proportion of pasture, urban and other land relative to woodland, and (4) having greater vehicle density per road km were more likely to increase the odds of deer-vehicle collisions. In contrast, high proportion of cropland relative to woodland, and wildlife management tools, such as increase in hunting license sales, and high deer bag limits, reduced the frequency of deer-vehicle collisions. These fi ndings suggested that urban planners need to consider the impact of urban development and infrastructure activities on deer habitat and densities, and how wildlife management strategies (e.g., judicious manipulation of bag limits and ways to promote hunting license sales) can be used along with other mitigation techniques to reduce deer-vehicle collisions.

Shifts in macropod home ranges in response to wildlife management interventions

Context. Understanding how the individual movement patterns and dispersion of a population change following wildlife management interventions is crucial for effective population management. Aims. We quantified the impacts of two wildlife management strategies, a lethal intervention and a subsequent barrier intervention, on localised populations of the two most common macropod species in Tasmania, the Tasmanian pademelon (Thylogale billardierii) and the red-necked wallaby (Macropus rufogriseus rufogriseus). This manipulation allowed us to examine two competing hypotheses concerning the distribution of individuals in animal populations – the Ideal Free Distribution (IFD) hypothesis and the Rose Petal (RP) hypothesis. We predicted that the RP would be supported if individuals maintained their previous home ranges following intervention, whereas the IFD would be supported if individuals redistributed following the management interventions. Methods. The movement patterns of T. billardierii and M. r. rufogriseus were tracked using GPS technology before and after the two management interventions. Key results. Following lethal intervention, pademelons and wallabies (1) maintained their home-range area, (2) increased their utilisation of agricultural habitat and (3) shifted their mean centroid locations compared with the pre-intervention period. Following barrier intervention, pademelons and wallabies (1) maintained their home-range area, (2) decreased their utilisation of agricultural habitat and (3) shifted their mean centroid locations compared with the pre-intervention period. Conclusions. On the basis of the individual responses of macropods to the management strategies (1) lethal intervention appeared to induce small shifts in home-range distributions of those remaining individuals in the population with home ranges overlapping the areas of lethal intervention and (2) barrier intervention is likely to induce whole-scale population movements of the animals that survive the lethal intervention in their search of an alternative food source. Both species displayed spatial and temporal shifts in their home-range distributions in response to lethal and barrier interventions that appear to conform broadly to predictions of IFD, at least in the timeframe of the present experiment. Implications. Wildlife management strategies, which are increasingly constrained by ethical, socio-political and financial considerations, should be based on ecological and behavioural data regarding the likely responses of the target population.

Badger Wildlife Habitat Decision Aid

Under the Forest and Range Practices Act, forest and range licensees in British Columbia are required to develop Forest Stewardship Plans and manage their operations to maintain limiting habitats of Identified Wildlife within their tenures. North American badgers (Taxidea taxus) are large members of the weasel family that are a Species At Risk within the Identified Wildlife Management Strategy (IWMS) and are listed as Endangered by COSEWIC. Several aspects of their ecology make them susceptible to forest and range management activities, including their dependence on the grassland, open forest, and modified forested habitat that supports their prey. This Wildlife Habitat Decision Aid (WHDA) summarizes the latest scientific and experiential information that forest and range managers, including silviculture planners, operational foresters, and ranchers, need to consider when managing for badger habitat requirements. This information was obtained through a literature review and discussions with researchers studying badger ecology in British Columbia.The WHDA format has been used to convey information on factors requiring consideration when managing forests and range in British Columbia for specific wildlife species. This WHDA provides information on habitat features needed by badgers for reproductive dens, resting sites, and foraging habitats; biogeoclimatic zones where badgers occur; and considerations when conducting harvesting, silviculture activities, or livestock grazing in badger range. We provide a map of the distribution and list the biogeoclimatic zones in which badgers occur to help users identify where to apply management considerations. Also included is a valuable resource and reference list that contains more detailed information. Most reference material that is not available online can be ordered through libraries.

British Columbia's Interior: Fisher Wildlife Habitat Decision Aid

Fishers (Martes pennanti) are forest-dependent carnivores of the weasel family that are considered a Species at Risk under the Identified Wildlife Management Strategy and Species of Special Concern (blue-listed) by British Columbia Conservation Data Centre. Under the Forest and Range Practices Act, forest and range licensees in British Columbia are required to develop Forest Stewardship Plans and manage their operations to maintain limiting habitats of Identified Wildlife within their tenures accordingly. Several aspects of the ecology of fishers make them susceptible to forest-harvest activities, including their use of structural elements found primarily in late-successional forests. This Wildlife Habitat Decision Aid (WHDA) summarizes the latest scientific and experiential information that forestry practitioners, including silviculture planners and operational foresters, need to consider when managing for fisher habitat requirements. This information was obtained through an extensive literature analysis and discussions with experts in fisher ecology in British Columbia. Most information on fisher ecology in this extension note was derived from studies conducted in the Cariboo, Williston, Chilcotin, and South Peace regions.The WHDA format has been used to convey information on factors requiring consideration when managing forests and range in British Columbia for specific wildlife species. This WHDA provides information on habitats used by fishers for birthing and rearing young, resting, and foraging; a provincial fisher distribution map and a list of biogeoclimatic zones where fishers most commonly occur; and forest management considerations when harvesting and conducting silviculture activities within fisher range. Also included is a resource and reference list that contains more detailed information. Most reference material that is not available online can be ordered through libraries.

Rickettsia massiliaein the Canary Islands

To the Editor: Rickettsia massiliae was recently recognized as a human tick-borne spotted fever group rickettsia (1). We report the finding of R. massiliae in Rhipicephalus pusillus ticks from Gran Canaria, Canary Islands, Spain. Introduction of this pathogen into the Canary Islands is thought to have resulted from translocation of the European wild rabbit Oryctolagus cuniculus (Linnaeus), a preferred host of R. pusillus ticks (www.kolonin.org/16_4.html), from the Iberian Peninsula 600 years ago (2). We collected questing adult ticks in 2008 in Gran Canaria and identified 2 tick species, Hyalomma lusitanicum (n = 82 [46 females]) and R. pusillus (n = 8 [5 females]). Whole ticks were preserved in 70% ethanol and used for DNA extraction by using TriReagent (Sigma, St. Louis, MO, USA) according to the manufacturer’s instructions. We identified rickettsial sequences by using PCR primers that amplify fragments of 16S rRNA, ompB, atpA, dnaA, dnaK, and recA genes (Table). Amplicons were cloned into pGEM-T (Promega, Madison, WI, USA), and 3 independent clones were sequenced from both ends for each gene marker. Sequence similarity search was performed by using BLAST (www.ncbi.nlm.nih.gov). Rickettsial DNA was detected in 2 R. pusillus males only; sequences were identical in both ticks. Fragments of 16S rRNA were 99% identical to the R. massiliae strain Mtu5 ({type:entrez-nucleotide,attrs:{text:CP000683,term_id:157843848}}CP000683) isolated from R. sanguineus ticks in southern France (3), and fragments of ompB, atpA, dnaA, dnaK, and recA genes were 100% identical to the R. massiliae strain Bar29 ({type:entrez-nucleotide,attrs:{text:AF123710,term_id:6969935}}AF123710, {type:entrez-nucleotide,attrs:{text:AY124739,term_id:32345011}}AY124739, {type:entrez-nucleotide,attrs:{text:DQ821798,term_id:110433410}}DQ821798, {type:entrez-nucleotide,attrs:{text:DQ821828,term_id:110433470}}DQ821828, and {type:entrez-nucleotide,attrs:{text:AY124750,term_id:32345033}}AY124750, respectively), previously isolated from R. sanguineus ticks in Catalonia, Spain (4) (Table). Table Rickettsia massiliae PCR conditions and amplicon size, Canary Islands, 2008* R. massiliae was first isolated in 1992 from R. sanguineus ticks collected near Marseille, France (5). Since then, the pathogen has been identified in different Rhipicephalus species in France, Greece, Portugal, Switzerland, Spain, North and Central Africa, Argentina, and the United States (6,7). R. massiliae has been identified in southern Spain (8) but not in the Canary Islands. R. pusillus ticks are commonly found in southern Europe (Portugal, Spain, and France) and northern Africa (Tunisia and Morocco). All stages of these ticks inhabit burrows of wild rabbits and feed on them (www.kolonin.org/16_4.html). Wild rabbits were introduced into the Canary Islands at the end of 14th century during colonization by the kingdom of Castilla. Colonists were asked to bring rabbit couples with them to provide food in the islands (2), a practice continued by new colonists because of their interest in hunting this rabbit species. Introduction of wild rabbits by colonists led to establishment of parasites, such as helminths, coccidia, and viruses in the Canary Islands (9). R. pusillus, a common ectoparasite (tick) that feeds on wild rabbits on the Iberian Peninsula, was also introduced this way. R. massiliae could have been introduced in the islands by infected R. pusillus ticks or by infected wild rabbits if this species serves as a natural reservoir host for the pathogen. To find evidence for this hypothesis, we tested blood and liver samples of 150 wild rabbits from both Canary Islands and Andalucia (southern Spain) by using Rickettsia-specific PCR primers (Table). No R. massiliae DNA was detected in the rabbit samples tested, suggesting that the pathogen probably was introduced in the Canary Islands with infected R. pusillus ticks feeding on rabbits. Alternatively, R. massiliae infection levels in wild rabbits may be below the PCR detection limit and were not detected. The Canary Islands are a popular tourist destination. The presence of R. massiliae in the islands constitutes a risk for human infection and should be considered in hospital diagnostic and wildlife management strategies. As with other Rhipicephalus spp., R. pusillus ticks could feed on humans under certain circumstances (10). Our results emphasize the risks associated with unsupervised animal translocations, a factor that probably plays a role in the introduction of ticks and tick-borne pathogens in different parts of the world.

Status of the long-tailed macaque Macaca fascicularis in Singapore and implications for management

The long-tailed macaque (Macaca fascicularis) population of the island-state of Singapore consists of ca. 1,218–1,454 individuals. About seventy percent of the population (ca. 1,027 individuals) is concentrated in both Bukit Timah and Central Catchment Nature Reserves, a system of reservoirs and forest reserves located in the center of Singapore. This core population resides mainly along perimeter forest areas of the reserve system, which is bordered by residential and recreational areas (e.g., parks and golf courses) and encircled by expressways. Periphery sub-populations (ca. 427 individuals) persist in forest fragments throughout Singapore mainland and on 5 offshore islands. Much of the Singaporean macaque population overlaps with human settlement and these commensal groups are mainly distributed close to roads, parks and residential areas. At least 70% of these groups are habituated to human presence and at least 50% to food provisioning. Moreover, commensal groups have more individuals and have higher infant:adult female ratios than non-commensal groups. The close association of habituated macaque groups living in human environments has led to increasing human-macaque conflict in Singapore. The overlap is also associated with human-induced population loss resulting from road accidents (2.4%); and trapping efforts (14%) aimed at ameliorating conflict issues. Consequently, it is important to better understand how humans are affecting macaque populations. In order to mitigate human-macaque conflict and at the same maintain a sustainable macaque population in Singapore, there is an urgent need for wildlife management strategies aimed at minimizing the extent of human–macaque conflict. Such strategies should include designing appropriate buffers around reserve areas, revised urban development plans, and managing the behavior of people interfacing with macaques.

WEIGHTED DISTRIBUTIONS AND ESTIMATION OF RESOURCE SELECTION PROBABILITY FUNCTIONS

Understanding how organisms selectively use resources is essential for designing wildlife management strategies. The probability that an individual uses a given resource, as characterized by environmental factors, can be quantified in terms of the resource selection probability function (RSPF). The present literature on the topic has claimed that, except when both used and unused sites are known, the RSPF is non-estimable and that only a function proportional to RSPF, namely, the resource selection function (RSF) can be estimated. This paper describes a close connection between the estimation of the RSPF and the estimation of the weight function in the theory of weighted distributions. This connection can be used to obtain fully efficient, maximum likelihood estimators of the resource selection probability function under commonly used survey designs in wildlife management. The method is illustrated using GPS collar data for mountain goats (Oreamnos americanus de Blainville 1816) in northwest British Columbia, Canada.

Wildlife Conservation and Management in Mexico

Mexico's wildlife has been impacted by human land use changes and socioeconomic and political factors since before the Spanish conquest in 1521. Presently, it has been estimated that more than 60% of the land area has been severely degraded. Mexico ranks in the top 3 countries in biodiversity, is a plant and faunal dispersal corridor, and is a crucial element in the conservation and management of North American wildlife. Wildlife management prerogatives and regulatory powers reside in the federal government with states relegated a minimum role. The continuous shifting of federal agencies responsible for wildlife management with the concomitant lack of adequate federal funding has not permitted the establishment of a robust wildlife program. In addition, wildlife conservation has been further impacted by a failure to establish landowner incentives, power struggles over user rights, resistance to change, and lack of trust and experience in protecting and managing Mexico's wildlife. We believe future strategies for wildlife programs must take into account Mexico's highly diversified mosaic of ecosystems, cultures, socioeconomic levels, and land tenure and political systems. The private sector, along with communal properties, in cooperation with federal and municipal governments, nongovernmental organizations, corporations, and international agencies may have the greatest potential of sustainable management of Mexico's wildlife. The present federal wildlife management strategy is an initial positive effort because it promotes participatory wildlife conservation by key stakeholders. We identify the aspects of this strategy that we believe will be needed to establish a sustainable program to manage Mexico's wildlife.

Prion biology relevant to bovine spongiform encephalopathy1

Bovine spongiform encephalopathy (BSE) and chronic wasting disease (CWD) of deer and elk are a threat to agriculture and natural resources, as well as a human health concern. Both diseases are transmissible spongiform encephalopathies (TSE), or prion diseases, caused by autocatalytic conversion of endogenously encoded prion protein (PrP) to an abnormal, neurotoxic conformation designated PrPsc. Most mammalian species are susceptible to TSE, which, despite a range of species-linked names, is caused by a single highly conserved protein, with no apparent normal function. In the simplest sense, TSE transmission can occur because PrPsc is resistant to both endogenous and environmental proteinases, although many details remain unclear. Questions about the transmission of TSE are central to practical issues such as livestock testing, access to international livestock markets, and wildlife management strategies, as well as intangible issues such as consumer confidence in the safety of the meat supply. The majority of BSE cases seem to have been transmitted by feed containing meat and bone meal from infected animals. In the United Kingdom, there was a dramatic decrease in BSE cases after neural tissue and, later, all ruminant tissues were banned from ruminant feed. However, probably because of heightened awareness and widespread testing, there is growing evidence that new variants of BSE are arising "spontaneously," suggesting ongoing surveillance will continue to find infected animals. Interspecies transmission is inefficient and depends on exposure, sequence homology, TSE donor strain, genetic polymorphism of the host, and architecture of the visceral nerves if exposure is by an oral route. Considering the low probability of interspecies transmission, the low efficiency of oral transmission, and the low prion levels in nonnervous tissues, consumption of conventional animal products represents minimal risk. However, detection of rare events is challenging, and TSE literature is characterized by subsequently unsupported claims of species barriers or absolute tissue safety. This review presents an overview of TSE and summarizes recent research on pathogenesis and transmission.

Mapping lichen in a caribou habitat of Northern Quebec, Canada, using an enhancement_classification method and spectral mixture analysis

Studies of caribou herds in northern regions are important to better understand population dynamics and define wildlife management strategies. Lichen is a primary food source for caribou and is a good indicator of caribou herd activity because of its sensitivity to overgrazing and overtrampling, its widespread distribution over northern areas, and its influence on herd demography. In this paper, we used Landsat TM imagery for mapping lichen in the summer range of the George River caribou herd in northern Quebec, Canada. Results from the enhancement_classification method (ECM) and from spectral mixture analysis (SMA) were evaluated for their suitability to characterize lichen landcover and for their potential to be applied over large territories. ECM and SMA are assessed individually, and also for potential synergistic use. ECM is based on guided unsupervised classification of enhanced satellite images. Validation based on 3536 pixels from a relatively smaller number of field sites (20) showed an overall accuracy of 74.5% (kappa=0.70) for 10 classes and good discrimination between lichen and non_lichen classes, though we interpret these results with caution due to spatial autocorrelation and non_random sampling within field sites. However, discrimination amongst different lichen classes using ECM was more problematic. SMA derives the proportion of individual scene components at sub_pixel scales. This method provided good results in characterizing variations in lichen abundance validated against field observations, and provided additional and new information not provided by ECM which is important since the abundance of lichen as a primary food source is a key indicator of migration and demographic patterns essential for effective wildlife management. We concluded that the ECM and SMA methods are appropriate for different aspects of lichen mapping. ECM provided good discrimination between lichen and non_lichen classes whereas SMA provided additional lichen information not available by classification yet critical to the environmental application, which is also appropriate for application over much larger areas and in spatio_temporal studies. A synergistic use of SMA and ECM is therefore recommended for future research.