Browsing by Subject "Telemetry"

Now showing 1 - 2 of 2
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    Assessment of techniques to evaluate American woodcock population response to best management practices applied at the demonstration-area scale
    (2014-09) Daly, Kyle O'keefe
    American woodcock (Scolopax minot; hereafter, woodcock) have experienced long-term population declines across their breeding range based on the American woodcock Singing-ground Survey. Wing-collection surveys have also indicated a decline in woodcock recruitment across their range, especially in the Central Management Region. These declines have been widely attributed to loss or alteration of young forest cover types that support woodcock reproduction across their breeding range. In response to these apparent declines in woodcock abundance and recruitment, a system of woodcock habitat demonstration areas is being developed throughout the woodcock breeding range where specific Best Management Practices (BMPs) are applied with the goal to stabilize and ultimately increase populations. Application of BMPs at a demonstration-area scale (~200-800 ha) is designed to positively influence woodcock population growth by improving habitat quality and abundance at a landscape scale. However, how woodcock vital rates are influenced by BMPs applied at a landscape scale is not fully understood, and techniques used to evaluate woodcock populations at the demonstration-area scale have not been assessed. The objectives of our research were to (1) estimate survival of adult females, nests, and juveniles using radio telemetry and assess relationships between survival and vegetation structure resulting from BMPs, life history traits, and weather, (2) directly estimate a measure of woodcock recruitment (juveniles/adult female during late summer) at a landscape scale by using survival estimates in a population model, and use direct estimates of recruitment to evaluate the accuracy and usefulness of indirect estimates of recruitment based on less costly and effort-intensive methods (specifically mist netting and night lighting on summer roosting fields), and (3) test for effects of radio transmitters on juvenile woodcock survival. In 2011 and 2012, we radio-marked and tracked 41 adult female and 73 juvenile woodcock, and monitored 51 broods and 48 nests. Breeding season cumulative survival for adult females was consistent between years, whereas nest and juvenile survival were related to year. Juvenile survival was also positively related to age, minimum temperature, and stem density, and negatively related to precipitation. We found no effects of radio-marking juvenile woodcock. In July of 2011 and 2012, we captured 204 woodcock using mist nets during crepuscular movements from diurnal feeding cover to roosting fields and 69 woodcock via night-lighting on roosting fields. Our recruitment estimates (juveniles/adult female) derived from our demographic model were higher in 2012 than 2011 due to higher nest and juvenile survival rates during that year, suggesting that nest and juvenile survival, and factors related to nest and juvenile survival, may be key to understanding woodcock population ecology. Our assessment of indirect methods to estimate woodcock recruitment at a landscape scale indicated that the indirect methods we considered of estimating woodcock recruitment at a landscape scale are likely not reliable proxies for estimating recruitment directly.
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    Moose movement in Minnesota and the use of known moose movement to evaluate the random encounter model
    (2021-12) Hinojoza-Rood, Valerie
    Abstract. Moose (Alces alces) are cold-adapted ruminants with a relatively low tolerance for warmer temperatures. The movement and activity of free-ranging moose can be recorded simultaneously through GPS locations and activity sensors to analyze the effects of season, temperature, and bout duration on the movement and bedding behavior of moose. Nine adult moose were fitted with GPS collars and dual-axis activity sensors in the Superior National Forest in northern Minnesota. GPS locations were recorded every 20 minutes and synchronized with activity counts. Intervals with activity counts of 0 were considered inactive while intervals with activity counts greater than 0 were considered active. Short 20-minute bouts were the most frequent across all seasons and periods where moose moved less than an average of 0.5 m/minute for an hour were more common in bouts over 2 hours long. Activity and distance moved during each 20-minute interval peaked at the middle of each active bout. This pattern may be caused by the smaller comfort movements that characterize the beginning and end of active bouts or by increasing rumen fill during the latter half of active browsing bouts. The duration of inactive bouts decreased as temperature increased while the duration of active bouts increased until reaching a maximum. The percent of each day spent active varied by season with moose spending more time active from Julian day 100 in spring to Julian day 250 in late summer. The male moose had an additional spike at the beginning of rut lasting from Julian day 215 to Julian day 247. Daily moose movement and activity was crepuscular, peaking about 2 hours after sunrise and sunset. Moose activity also increased slightly 1 to 4 hours before sunset in all seasons except winter. Activity and travel distances during daily maximums were highest during summer when nocturnal activity and movement also increased. The maximum bout duration for female moose occurred at a higher temperature than the maximum for the male. The effect of temperature on distance moved was more pronounced during the warmer months where average travel distance stopped increasing around 12 C during spring and decreased around 18 C in summer. Moose modified their activity and movement during warmer temperatures, suggesting feeding behavior during spring and summer may be affected by higher temperatures brought about by climate change.These frequent recordings of moose locations using GPS telemetry were also used to quantify moose populations. Reliable estimates of animal population densities are vital to many wildlife studies and management recommendations. The random encounter model (REM) uses data from field cameras and concepts from the ideal gas model to estimate population densities with less study effort than traditional mark-recapture studies. REM accuracy and precision was assessed using GPS telemetry from moose recorded at 15-minute and 20-minute intervals since these known movements were more realistic approximations of animal movement than computer simulations. REM estimates of moose density had a 5.1 ± 3.3 percent error on average when using daily velocities calculated from all available moose telemetry data. Estimates of moose density had a 0.95 ± 0.78 percent error when using velocities specific to the times and individual moose used within the camera survey. However, precision was low for both surveys with only about 51.3 ± 32 percent of moose densities calculated using the general velocity and 52.2 ± 33 percent of moose densities calculated using the specific velocities within a 25 percent error of the actual population density. When only cameras from forested habitats were used in the survey, accuracy decreased to a 6.8 ± 4.1 percent error and precision decreased so that only 50 ± 31 percent of calculated densities was within a 25 percent error. For all surveys, accuracy increased with study area size, study duration, and percent of the study area within the camera frame of view of a camera. REM precision was most strongly affected by the percent of a study area covered by a camera view so field studies should either increase the camera coverage within the study area or perform replicate REM surveys to increase the accuracy and precision of calculated population densities.