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Wildlife viewing within protected areas is an increasingly popular recreational activity. Management agencies are often tasked with providing these opportunities, yet quantitative analyses of factors influencing wildlife sightings are lacking. We analyzed locations of GPS-collared wolves and wolf sightings from 2945 trips in Denali National Park and Preserve, Alaska, USA, to provide a mechanistic understanding of how viewing opportunities are influenced by attributes of wolves and physical, biological, and harvest characteristics. We found that the presence of masking vegetation, den site proximity to the road, pack size, and presence of a wolf harvest closure adjacent to the park affected wolf sightings, and the influence of den proximity on sightings depended on harvest management. Wolf sightings increased with den site proximity to the road in years with a harvest closure adjacent to the park but not in the absence of the closure. The effect of the harvest closure on sightings was similar in magnitude to an increase in pack size by two wolves or a more than a two-fold decrease in masking vegetation. These findings were consistent across a 10-fold change in spatial resolution. Quantitative analysis of the factors influencing wildlife sightings provides valuable insight for agencies tasked with managing viewing opportunities. Key words: Alaska; Canis lupus; gray wolf; Denali National Park; national parks; non-consumptive use; protected areas; spatially explicit; wildlife viewing; wildlife sightings L'observation de la faune dans les aires protegees est un loisir qui prend de plus en plus d'ampleur. Souvent, les organismes de gestion ont le mandat d'offrir de telles activites et pourtant, il n'y a toujours pas d'analyses quantitatives des facteurs qui exercent une influence sur les observations fauniques. Nous avons analyse les emplacements de loups munis de colliers GPS et les observations de loups decoulant de 2 945 deplacements au parc national et a la reserve de Denali, en Alaska, aux Etats-Unis afin d'obtenir une comprehension mecaniste de la maniere dont les activites d'observation sont influencees par les attributs des loups ainsi que par les caracteristiques physiques, biologiques et de recolte. Nous avons remarque que la presence de vegetation masquante, la proximite des tanieres de la route, la taille des meutes et la presence d'une interdiction de recolte de loups dans le secteur adjacent au parc ont eu un effet sur les observations de loups, et que l'influence de la proximite des tanieres par rapport aux observations dependait de la gestion des recoltes. Les observations de loups augmentaient en fonction de la proximite des tanieres par rapport a la route au cours des annees pendant lesquelles il y avait interdiction de recolte de loups dans le secteur adjacent au parc, mais ce n'etait pas le cas en l'absence d'interdiction. L'ampleur de l'effet de l'interdiction de recolte sur les observations etait semblable a une augmentation de la taille de la meute correspondant a deux loups ou plus, ou a la diminution de plus du double de la vegetation masquante. Ces constatations se recoupaient dans un changement correspondant au decuple dans la resolution spatiale. L'analyse quantitative des facteurs influencant les observations fauniques offre une importante perspective aux organismes dont le mandat consiste a gerer les activites d'observation. Mots cles : Alaska; Canis lupus; loup gris; parc national de Denali; parcs nationaux; utilisation sans consommation; aires protegees; spatialement explicite; observation de la faune; observations fauniques Traduit pour la revue Arctic par Nicole Giguere., INTRODUCTION Wildlife viewing is one of the most popular outdoor recreational activities (Higginbottom, 2004). Approximately one in three people over the age of 16 participate in wildlife viewing activities each [...]

SiC vertical MOSFETs are fabricated and characterized with blocking voltages of about 1 kV and a specific on-resistance as low as 8.3 m[omega].[cm.sup.2]. The internal body diode's reverse recovery characteristics have shown injection-limited conduction, which are attributed to the implanted P-anode layers.

The performance of bias stress induced breakdown voltage (BV) slump measurements on DMOSFETs is discussed. Findings reveal that the BV slumped after the DMOSFET was bias stressed at 1200 V for 2 hours at 175 degree Celsius.

Fecal analysis is one way of examining the diet of animals, and stable isotope analysis of bones and hair can also be used to compare diets between individuals and categories and between the past and present. A study of black and brown bears has found that there has been little change in the proportions of plants and meat eaten in the past and by modern bears. Male brown bears were more carinivrous than other groups, while black bears in Alaska were more likely to eat salmon.

We present a method of comparing data on habitat use and availability that allows availability to differ among observations. This method is applicable when habitats change over time and when animals are unable to move throughout a predetermined study area between observations. We used maximum-likelihood techniques to derive an index that estimates the probability that each habitat type would be used if all were equally available. We also demonstrate how these indices can be used to compare relative use of available habitats, assign them ranks, and assess statistical differences between pairs of indices. The set of these indices for all habitats can be compared between groups of animals that represent different seasons, sex or age classes, or experimental treatments. This method allows quantitative comparisons among types and is not affected by arbitrary decisions about which habitats to include in the study. We provide an example by comparing the availability of four categories of sea ice concentration to their use by adult female polar bears (Ursus maritimus), whose movements were monitored by satellite radio tracking in the Bering and Chukchi Seas during 1990. Use of ice categories by bears was nonrandom, and the pattern of use differed between spring and late summer seasons. Key words: Bering Sea; Chukchi Sea; geographic information systems; habitat availability; habitat selection; polar bears; radiotelemetry; remote sensing; resource selection functions; sea ice concentration; Ursus maritimus., INTRODUCTION Studies that quantify habitat use by a species can be used to assess the species' biological requirements, predict effects of habitat changes, justify protection of key areas, or test [...]

Presently, high-power soft-switching resonant pole converters, such as the auxiliary resonant commutated pole (ARCP) converter, that have internal dc link voltages above 1.5 kV, can only use gate turn-off thyristors (GTO's) as main switching devices. For these applications, considerable effort has been spent to design, evaluate, and enhance the dynamic performance of high-voltage MOS-controlled thyristors (HVMCT's). It is expected that in the near future HVMCT's, which require little gate power because of their high gate impedance, will gradually replace high-voltage GTO's. The purpose of this paper is to present and summarize key HVMCT characterization results gathered to date as they relate to their dynamic performance during zero-voltage switching. HVMCT devices capable of turning off 300 A and withstanding 3000 V are presented. The paper concludes with a comparison of the soft-switching performance of HVMCT's and GTO's in an ARCP converter phase leg.

The dispersal of juvenile fishers (Martes pennanti) in a harvested population in Maine was studied. It was found that 73% of males and 100% of females were dispersed by the age of one year, but 32% of males and no females dispersed before the age of nine months. Mean distances between birth and adult ranges were similar for males and females (10.8km and 11.2km respectively). Fisher density may be limited by intrasexual territoriality and food competition. Dispersing young replaced adults removed by fur trapping but the short dispersal distances may limit their ability to recolonize isolated areas.

The reliability of cementum annuli counts to calculate ages of fishers was tested. The findings showed that cementum annuli correctly gauged ages of fishers less than or equal to 3 years old and could be employed to separate reproductive females from juveniles and yearlings. However, given the cost of counting cementum annuli and the probable inaccuracy of the resulting information, the use of other measures such as trapper success rates or the sex ratio of the harvest was recommended.

Most activity of adult fishers (Martes pennanti) occured shortly before sunrise and after sunset, but some activity occurred throughout the day and night. Males and females showed similar amounts of activity, and both were active more frequently in summer than winter. Movements of males were greatest during the spring breeding season; nonreproductive females moved similar distances during all seasons. Eleven maternal dens were in tree cavities; the denning period lasted 8-12 weeks from March through May. The maximum annual parturition rate among females [is less than or equal to]2 years old was 75% (n = 4). This was less than pregnancy rates indicated by corpora lutea, and suggested that some pregnancies were unsuccessful. We hypothesize that delayed implantation allows mating to occur at a favorable time for adults, and births to occur when offspring have the maximum time for development before winter.