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15
2007a. Response of overwintering caribou to burned habitat in northwest Alaska. Arctic 60
"... ABSTRACT. Caribou (Rangifer tarandus granti) use lichens, when available, as primary forage on their winter range. In boreal forest habitats, wildland fires effectively destroy lichens, and overwintering caribou are known to avoid burned areas for decades while lichen communities regenerate. However ..."
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ABSTRACT. Caribou (Rangifer tarandus granti) use lichens, when available, as primary forage on their winter range. In boreal forest habitats, wildland fires effectively destroy lichens, and overwintering caribou are known to avoid burned areas for decades while lichen communities regenerate. However, little has been published about caribou response to burned habitat in tundra ecosystems. To assess the relationship between winter caribou distribution and burned areas, we instrumented Western Arctic Herd caribou with satellite telemetry collars and evaluated their locations in relation to recent burns of known age ( ≤ 55 years old) across northwestern Alaska. We analyzed caribou distribution for different habitat types (tundra and boreal forest), age categories of burns, and possible edge effects. We also reanalyzed the data, limiting available habitat to a uniform traveling distance (5658 m) from daily satellite locations. Using selection indices that compared caribou use of burns and buffers to their availability, we found that caribou strongly selected against burned areas within the tundra ecosystem. Recent burns were selected against at both large (range-wide) and intermediate (5658 m) spatial scales. Caribou particularly selected against 26- to 55-year-old burns and the interior (core) portions of all burns. We found that caribou were more likely to select burned areas in the late fall and early spring than midwinter. Increased fires in northwestern Alaska could decrease the availability and quality of winter habitat available to the herd over the short term (up to 55 years), potentially influencing herd population dynamics and reducing sustainable harvest levels. We recommend that fire managers consider caribou midwinter range condition and extent: however, management that achieves a mosaic pattern of fire history may benefit a wide array of species, including caribou. A better understanding of the
Upland habitat use by Pyrenean grey partridges Perdix perdix hispaniensis during the breeding season
"... grey partridges Perdix perdix hispaniensis during the breeding season.- Wildl. ..."
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grey partridges Perdix perdix hispaniensis during the breeding season.- Wildl.
Habitat Use by Brood-Rearing Waterfowl in Subarctic Québec
, 1995
"... ABSTRACT. Aerial surveys of waterfowl were conducted in subarctic Québec in 1989 and 1990 on randomly selected 100 km2 plots. We used logistic regression for modelling relationships between the presence of waterfowl broods and habitat characteristics. For each species, models of habitat use were gen ..."
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ABSTRACT. Aerial surveys of waterfowl were conducted in subarctic Québec in 1989 and 1990 on randomly selected 100 km2 plots. We used logistic regression for modelling relationships between the presence of waterfowl broods and habitat characteristics. For each species, models of habitat use were generated with one data set and tested with two others. We also compared the frequency distributions of broods of each species in different habitat types. Correct-classification rates of models varied between 0.53 and 0.77. Sensitivity of models generally increased when applied to validation data sets. Models showed that green-winged teals (Anas crecca) avoided lakes> 501 ha and used vegetated lakes, ponds and fens or bogs more than predicted by their availability. Black scoters (Melanitta nigra) and surf scoters (M. perspicillata) were found mostly on small lakes (< 10 ha) and medium lakes (10 –100 ha). Black scoters were associated with the presence of ponds and lakes with sedge and grass, whereas surf scoters were not. The presence of scaup (Aythia spp.) broods was associated with the presence of vegetation. Green-winged teals were observed more often on bogs than were either scoters or scaups. Black scoters were observed more often on ponds and less often on medium-sized lakes than surf scoters and scaups. The latter differed in their use of lakes < 10 ha: surf scoters, like black scoters, mostly used unvegetated lakes, while scaups and green-winged teals mostly used vegetated lakes. The accuracy and precision of logistic models may be enhanced by additional habitat variables, careful selection of sample-cell size and further investigation of the breeding biology of the surveyed species. Key words: habitat, model, logistic regression, northern Québec, black scoter, surf scoter, green-winged teal, scaup, brood
Central Oregon Cascades.
"... A total of 14 adult female black bears were radio- tracked from June 1993 to December 1995 to determine home range characteristics and analyze habitat selection at both the home range and landscape scale. Locations were obtained from the ground and classified to one of six habitats based on stand st ..."
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A total of 14 adult female black bears were radio- tracked from June 1993 to December 1995 to determine home range characteristics and analyze habitat selection at both the home range and landscape scale. Locations were obtained from the ground and classified to one of six habitats based on stand structure, and digitally overlaid onto a habitat map produced from a LANDSAT Thematic Mapper scene of the study area. Home range sizes were calculated using the 95% adaptive kernel and 95 % minimum convex polygon methods. To analyze habitat associations, a total of 1,073 locations were entered into a geographic information system alongwith habitat attribute data obtained from digital coverages. Logistic regression and other statistical techniques were used to determine variables significantly associated with bear locations, including habitat class, patch size, slope, elevation, aspect, edge type, and distance to roads, streams, and edges. Female black bear home ranges averaged 32 km2 (95 % adaptive kernel method) and 30 km2 (95 % minimum convex polygon method). Home range size was significantly affected by individual variation among bears, most likely due to differences in food availability within each bear's home range. Female bears inhabited geographically stable home ranges from year to year and tolerated home range overlap with other female bears. Habitat use within home ranges shifted
Ó Wildlife Biology, NKV
"... of plant phenology and vertical height on accuracy of radiotelemetry locations ..."
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of plant phenology and vertical height on accuracy of radiotelemetry locations
Journal of Animal Ecology 2006
"... Validation of a randomization procedure to assess animal ..."
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ASPECTS OF THE ECOLOGY OF FERAL PIGS (SUS SCROFA) IN THE MURCHISON AREA, NEW ZEALAND*
"... Summary: Seven feral pigs (Sus scrofa), radio-tracked in relatively undisturbed rough pasture and forest near Murchison, New Zealand, for periods of 18-186 days, occupied home ranges of 28-209 ha. The immature pigs were significantly more active and had significantly larger home ranges than the adul ..."
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Summary: Seven feral pigs (Sus scrofa), radio-tracked in relatively undisturbed rough pasture and forest near Murchison, New Zealand, for periods of 18-186 days, occupied home ranges of 28-209 ha. The immature pigs were significantly more active and had significantly larger home ranges than the adults, particularly adult females. The pigs were mainly nocturnal but they varied individually. The frequency of grazing and the rooting up of pasture and bracken (Pteridium esculentum) varied seasonally. Some of the pigs preferred pasture and bracken in their home ranges while others preferred mixed beech (Nothofagus spp.) forest. The number of pigs and their use of habitat were probably related to the seasonal availability and quality of food and shelter. Farrowing occurs throughout the year but peaks during spring. Litter sizes ranged from 1-9. Density was roughly 12-43 pigs per km 2 compared with 3-8 per km 2 in a nearby, more heavily hunted area.
Research Article Analysing telemetry data with a GIs-based vector structure
, 1992
"... Abstract. This paper proposes a unique method for plotting field bearing locations, of the kind typically taken by wildlife biologists on free ranging species, directly on a computer-compatible habitat map. We show how to use a GIS data base to identify differential habitat use directly from the pol ..."
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Abstract. This paper proposes a unique method for plotting field bearing locations, of the kind typically taken by wildlife biologists on free ranging species, directly on a computer-compatible habitat map. We show how to use a GIS data base to identify differential habitat use directly from the polygon formed by each set of bearings. A geometric algorithm is developed to interpret the bearings accurately. The technique avoids the most difficult errors associated with using point locations, namely those due to animal movement, and distance from receiver to transmitter, and is especially useful for habitat preference studies 1.
Approved by:
, 2006
"... Roads have direct and indirect consequences for wildlife. Vehicle collisions are a direct cost of roads on wildlife. Indirectly, roads may increase mortality of game species by increasing hunting pressure along these roads. Adult male black bears (Ursus americanus) are the most desirable age and sex ..."
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Roads have direct and indirect consequences for wildlife. Vehicle collisions are a direct cost of roads on wildlife. Indirectly, roads may increase mortality of game species by increasing hunting pressure along these roads. Adult male black bears (Ursus americanus) are the most desirable age and sex class to many hunters, which may lead to overharvest of this sex and age class. Road closures (permanently closing or seasonally restricting roads) are used to mitigate impacts of roads on wildlife, including bears. Little is known about how roads affect harvest vulnerability of black bears. I hypothesized that adult male black bears will avoid roads during hunting seasons compared to summer; so road use, and therefore hunting vulnerability, should decrease during hunting times. I used samples of six and ten adult male black bears and evaluated the amount to which these bears avoided roads between seasons. I used ANCOVA to find the effects of season, diel period, and factor interactions on the proportion of
