Jonathan A. Jenks

MOVEMENT OF FEMALE WHITE-TAILED DEER: EFFECTS OF CLIMATE AND INTENSIVE ROW-CROP AGRICULTURE

Abstract Movements (e.g., migration, dispersal) of white-tailed deer (Odocoileus virginianus) vary greatly over the geographic range of the species. Therefore, region-specific, empirical information is needed to effectively manage deer populations. Movements of white-tailed deer have been well documented in forest dominated habitats; however, little information related to white-tailed deer movements exists in intensively (>80%) cultivated areas. From January 2001 to August 2002, we monitored movements of 77 (61 adult, 16 young) female white-tailed deer in southwest Minnesota. We collected 6,867 locations, calculated 130 home ranges, and documented 149 seasonal movements. Fifteen percent of deer were nonmigratory, whereas 35% were facultative migrators, and 42.5% were obligate migrators. Mean distance between summer and winter home range was 10.1 km. Temperature and snow depth had the greatest influence on initiation of seasonal migration, whereas crop emergence and harvest had minimal effects. Four deer (8%) dispersed a mean distance of 71.3 km with 1 adult female moving a straight-line distance of 205 km. All dispersing deer occupied a temporary staging area for approximately 1 month between previous winter and new summer ranges. Mean home range (95% use area) in winter (5.2 km2) was over twice as large as home range in summer (2.3 km2). Movements exhibited by white-tailed deer in southwest Minnesota were influenced by large annual fluctuations in climate and a highly fragmented landscape dominated by row-crop agriculture. We provide data beneficial to biologists managing northern populations of white-tailed deer in fragmented environments by detailing the relationship between climate, intensive agriculture, and deer movements.

Survival of white-tailed deer in an intensively farmed region of Minnesota

Abstract Survival and cause-specific mortality of white-tailed deer (Odocoileus virginianus) have been well documented in forested habitat, but limited information has been collected in intensively farmed regions. The objectives of this study were to determine survival and cause-specific mortality of neonate, fawn female, and adult female white-tailed deer in an intensively farmed (>80% land cover) region of Minnesota. We captured and radiocollared 77 female deer >8 months old (61 adults, 16 fawns) and 39 neonates (17 male, 22 female). Hunting was the greatest cause of mortality among adult deer, with 43% of mortalities attributed to firearms hunters. Annual survival rate of all adult and fawn (≥8 months) radiocollared deer was 0.77 (n = 58, SE = 0.06). Overall (Jan. 2001-Aug. 2002) adult survival was 0.75 (n = 77, SE = 0.05) and was similar to survival rates reported elsewhere for female white-tailed deer. Natural causes (e.g., disease, predation) of mortality were minor compared to human-related causes (e.g., hunting, vehicle collision). In total, 67% of neonate mortalities were due to predators. Neonate summer survival rate pooled over years was 0.84 (n = 39, SE = 0.06) and was high compared to other studies. High neonate survival was likely associated with a low predator density, quality vegetation structure at neonate bed sites, and high nutritional condition of dams. Deer management in the highly fragmented and intensively farmed regions of Minnesota relies on hunter harvest to maintain deer populations at levels tolerable to landowners.

Facts From Feces: Nitrogen Still Measures Up as a Nutritional Index for Mammalian Herbivores

Abstract Fecal nitrogen (FN) has been applied widely as an index of dietary quality in studies of nutritional ecology of free-ranging and captive vertebrate herbivores, particularly ruminants. Three related articles in the Journal of Wildlife Management (JWM; Leslie and Starkey 1985, 1987; Hobbs 1987) have been cited (n = 150) in 87 publications and 39 peer-reviewed journals. The critique by Hobbs (1987) and the reply by Leslie and Starkey (1987) on limitations and appropriate applications of FN have been used to justify use of FN or negate its value as a nutritional proxy. We undertook a retrospective analysis of FN applications since 1985, largely because we sensed that methodological cautions noted in the 3 JWM publications were not being followed, leading to faulty conclusions and management applications, and that application protocols needed updating. From January 1986 through July 2007, the 107 species-by-continent applications of FN, citing the 3 JWM publications singly or in any combination, were diverse; FN was used in various ways on 5 continents and for 50 wild and domestic species. Cumulative rates of departure from recommended FN applications increased in recent years, largely in studies that compare different species while failing to fully acknowledge that differences likely reflected digestive capabilities rather than differences in some aspect of dietary intake. Post-1985 research on plant secondary compounds (e.g., tannins) has refined limitations to the application of FN, permitting more straightforward protocols than were possible in 1985. Although use does not necessarily reflect value, the number of published applications during the past 22 years indicates that peer reviewers from a variety of scientific disciplines view FN as a suitable proxy for nutritional status, which can be used to contrast study units when carefully defined by the study design. Any index can have shortcomings, and there are still circumstances when application of FN is problematic. Precise prediction of intake with FN under field conditions is still hampered by inherent variability, but contrasts of comparable study units and species can be appropriate. Published protocols for FN, as amended herein, should be adhered to, and conclusions are strengthened by the use of multiple nutritional indices.

Evaluating Ungulate Mortality Associated With Helicopter Net‐Gun Captures in the Northern Great Plains

Abstract Ungulate mortality from capture-related injuries is a recurring concern for researchers and game managers throughout North America and elsewhere. We evaluated effects of 7 variables to determine whether ungulate mortality could be reduced by modifying capture and handling procedures during helicopter net-gunning. During winter 2001–2006, we captured 208 white-tailed deer (Odocoileus virginianus) and 281 pronghorn (Antilocapra americana) by helicopter net-gunning throughout the Northern Great Plains. Of 281 pronghorn, 25 (8.9%) died from capture-related injuries; 12 were from direct injuries during capture, and 13 occurred postrelease. Of 208 deer, 3 (1.4%) died from injuries sustained during helicopter captures, with no mortalities documented postrelease. We used logistic regression to evaluate the probability that ungulates would die of injuries associated with helicopter net-gun captures by analyzing effects of snow depth, transport distance, ambient and rectal temperatures, pursuit and handling times, and whether individuals were transported to processing sites. The probability of capture-related mortality postrelease decreased 58% when transport distance was reduced from 14.5 km to 0 km and by 69% when pursuit time decreased from 9 minutes to <1 minute. Wildlife managers and researchers using helicopter capture services in landscapes of the Midwest should limit pursuit time and eliminate animal transport during pronghorn and white-tailed deer capture operations to minimize mortality rates postrelease.

Causes of Pneumonia Epizootics among Bighorn Sheep, Western United States, 2008–2010

Mycoplasma ovipneumoniae is a primary pathogen.

VARIATION IN GASTROINTESTINAL CHARACTERISTICS OF MALE AND FEMALE WHITE-TAILED DEER: IMPLICATIONS FOR RESOURCE PARTITIONING

We assessed variation in intestinal lengths and gut capacity of white-tailed deer (Odocoileus virginianus). We hypothesized that differences in morphology of males and females could have important implications relative to intersexual variation in patterns of habitat use and forage acquisition. Deer were collected from study areas in McCurtain Co., Oklahoma, and Howard and Pike counties, Arkansas. Populations of white-tailed deer in McCurtain and Howard counties were in poorer nutritional condition than deer in Pike Co. possibly because of competitive interactions with cattle stocked on study areas in McCurtain and Howard counties. Lactating females had longer gastrointestinal tracts and more digesta within their rumens and intestines than did males in summer and winter. Lactating females also had longer intestinal tracts and more digesta in rumens and intestines than did pregnant females during winter. Nonpregnant females in winter were primarily fawns with low body mass, but did not differ from adult females or males relative to gastrointestinal characteristics. Females collected from Pike Co. in winter had less digesta in rumens and intestines than did other populations. Additionally, deer collected from Pike Co. in winter had proportionately less digesta in rumens and more digesta in intestines than other populations. Our findings indicated that sexual segregation of populations of white-tailed deer in summer results from females attempting to maintain maximum volume of digesta in gastrointestinal tracts; winter segregation might be influenced by dietary selection.

Long-distance dispersal by a subadult male cougar from the black hills, south Dakota

Dispersal is the movement of an animal from its natal range upon reaching age of independence (Bekoff 1989). While subadult (i.e., prepubescent individual independent of its mothers care; Logan and Sweanor 2001) female cougars (Puma concolor) tend to be philopatric, subadult male cougars generally disperse greater distances (Anderson et al. 1992, Sweanor et al. 2000). This phenomenon occurs in cougars at 10-33 months of age (Hemker et al. 1984, Maehr 1990, Ross and Jalkotzky 1992, Beier and Barrett 1993, Sweanor et al. 2000) and has been suggested to take place due to competition for resources and avoidance of inbreeding (Logan and Sweanor 2001). Dispersal movements have been documented in most

Seasonal Movements and Home-Range Use by Female Pronghorns in Sagebrush-Steppe Communities of Western South Dakota

Abstract Knowledge of seasonal movements by pronghorns (Antilocapra americana) within the easternmost extension of sagebrush-steppe communities is limited. Current hypotheses regarding movement patterns suggest that pronghorns initiate seasonal movements in response to severe winter weather, snowfall patterns, spatial and temporal variation in forage abundance, and availability of water. From January 2002 to August 2005, we monitored movements of 76 adult (≥1.5 years) female pronghorns on 2 study areas (Harding and Fall River counties) in western South Dakota. We collected 8,750 visual locations, calculated 204 home ranges, and documented 17 seasonal movements. Eighty-four percent (n = 55) of pronghorns were nonmigratory and 10% (n = 6) were conditional migrators. Mean distance between summer and winter range was 23.1 km (SE = 2.8 km, n = 13). Five adult pronghorns (8%) dispersed a mean distance of 37.6 km (SE = 12.4 km); of which 1 female moved a straight-line distance of 75.0 km. Winter and summer home-range size varied (P < 0.0001) between study sites. Mean 95% adaptive kernel winter and summer home-range size of pronghorns was 55.5 and 19.7 km2, respectively, in Harding County and 127.2 and 65.9 km2, respectively, in Fall River County. Nonmigratory behavior exhibited by pronghorns was likely associated with minimal snow cover and moderate temperatures during winter 2002–2004. Variation in size of adult seasonal home ranges between sites was likely associated with differences in forage distribution and availability between regions.

Migrating Mule Deer: Effects of Anthropogenically Altered Landscapes

Background Migration is an adaptive strategy that enables animals to enhance resource availability and reduce risk of predation at a broad geographic scale. Ungulate migrations generally occur along traditional routes, many of which have been disrupted by anthropogenic disturbances. Spring migration in ungulates is of particular importance for conservation planning, because it is closely coupled with timing of parturition. The degree to which oil and gas development affects migratory patterns, and whether ungulate migration is sufficiently plastic to compensate for such changes, warrants additional study to better understand this critical conservation issue. Methodology/Principal Findings We studied timing and synchrony of departure from winter range and arrival to summer range of female mule deer (Odocoileus hemionus) in northwestern Colorado, USA, which has one of the largest natural-gas reserves currently under development in North America. We hypothesized that in addition to local weather, plant phenology, and individual life-history characteristics, patterns of spring migration would be modified by disturbances associated with natural-gas extraction. We captured 205 adult female mule deer, equipped them with GPS collars, and observed patterns of spring migration during 2008–2010. Conclusions/Significance Timing of spring migration was related to winter weather (particularly snow depth) and access to emerging vegetation, which varied among years, but was highly synchronous across study areas within years. Additionally, timing of migration was influenced by the collective effects of anthropogenic disturbance, rate of travel, distance traveled, and body condition of adult females. Rates of travel were more rapid over shorter migration distances in areas of high natural-gas development resulting in the delayed departure, but early arrival for females migrating in areas with high development compared with less-developed areas. Such shifts in behavior could have consequences for timing of arrival on birthing areas, especially where mule deer migrate over longer distances or for greater durations.

Effect of compositing samples on analysis of fecal nitrogen

We compared percent nitrogen of 12 composited fecal samples of white-tailed deer (Odocoileus virginianus) with means of samples that were analyzed individually (n = 191). We hypothesized that composites and means of individual samples would be similar in fecal nitrogen (FN). No significant differences in FN were found between composites and means of individuals (P > 0.70). Comparison of deer populations using composites and individuals yielded similar results (P > 0.10). J. WILDL. MANAGE. 53(1):213-215 Compositing fecal samples is common in studies of wildlife nutrition (Kie and Burton 1984, Leslie and Starkey 1985). Large numbers of samples can be handled in less time when aliquots of individual samples are combined into composites because the number of analyses is reduced. Also, many small mammal species may not produce adequate amounts of fecal material for individual analysis. However, the assumption that composites are similar to means of individual samples has not been tested and some information (e.g., sample variance) is unavailable when composites are used in statistical anal-