Deer In Minnesota Research Articles

The role of behavior accessibility and individual risk perceptions in chronic wasting disease risk mitigation behaviors among Minnesota deer hunters

ABSTRACT Human activities, including the movement of harvested cervids, pose significant risks for spreading chronic wasting disease (CWD) to new locations. This study used hierarchical agglomerative clustering to compare Minnesota, USA hunters’ carcass disposal habits and likelihood of CWD testing as a function of individual differences in risk perceptions and hunting area. We utilized a survey of Minnesota hunters conducted during Spring 2020 that included a random sample of individuals that hunt statewide and in a local disease management zone (N = 5,000, response rate = 33%). We did not detect a significant difference in disposal behaviors as a function of CWD risk perceptions, but rather because of increased accessibility of low-risk disposal methods. Conversely, we found perceived likelihood of conducting CWD testing was positively associated with perceptions of risk. These findings have implications for vector tracing for future CWD outbreaks and highlight the benefit of understanding constituent habits and regulation compliance in disease management.

Institutional trust, beliefs, and evaluation of regulations, and management of chronic wasting disease (CWD)

ABSTRACT Institutional trust and perceptions of regulatory efficacy can affect support for management. This study examined how institutional trust, specific trust related to information/management, and support for/perceived efficacy of current regulations related to deer hunters’ attitudes about chronic wasting disease (CWD) management. Results are from a survey of southeastern Minnesota deer hunters from the 2018 season, and suggest acceptance of agency management by a majority of hunters. However, a substantial minority of hunters who perceived the management approach was “too aggressive” believed all CWD regulations were ineffective and opposed regulations other than mandatory disease testing and carcass movement restrictions. Results suggest that a lack of shared values, along with greater trust in agency CWD information and technical competence, correlated with perceiving the management approach as “too aggressive.” Future research is needed to understand the contextual nature of trust and how different elements of trust relate to acceptability of management actions.

Bovine Tuberculosis Management in Northwest Minnesota and Implications of the Risk Information Seeking and Processing (RISP) Model for Wildlife Disease Management.

Bovine tuberculosis (bTB) is an infectious, zoonotic disease caused by Mycobacterium bovis that can spread between domestic and wild animals, as well as to humans. The disease is characterized by the progressive development of lesions that compromise the victim's lungs and lymph system. The disease was first identified in northwest Minnesota in both cattle and white-tailed deer (Odocoileus virginianus) in 2005. Due to its risks to human and animal health, bTB has numerous implications related to population management, policy outcomes, stakeholder relations, and economic impacts. When dealing with complicated risks, like bTB, individuals often seek out and process information as a method to learn about, and cope, with the risk. We developed a questionnaire that adapted components of the Risk Information Seeking and Processing (RISP) model and surveyed northwest Minnesota deer hunters. Our objectives were to better understand how stakeholders perceive and act on information regarding disease management in wildlife and to understand the utility of the RISP model for such management contexts. We drew a random proportional sample of licensed deer hunters (n = 2100) from the area affected by bTB and conducted a multi-contact mail survey. We found that 43% of the variability in the information-seeking behaviors of respondents was explained by demographics, hunting importance, personal risk perceptions, attitudes, and subjective norms. However, these results are largely attributable to the factors in the RISP model encompassed by components of the Theory of Planned Behavior (i.e., attitudes, subjective norms, perceived behavioral control, and behavioral intentions). This information can help managers contextualize individuals' perceived risks to better frame communication efforts to address stakeholder concerns and develop best practices for disease communication. While the state of Minnesota is currently considered free of bTB, future outbreaks remain possible in Minnesota and elsewhere. Understanding the key factors in the processes through which deer hunters seek out information pertaining to the disease can help managers collect the data necessary to aid decisions about desired future management outcomes. In addition, testing RISP model performance in applied research improves its future use across a broad spectrum of topics throughout veterinary disease management.

Evaluation of pathogen-specific biomarkers for the diagnosis of tuberculosis in white-tailed deer (Odocoileus virginianus)

OBJECTIVE To develop a noninvasive biomarker-based detection system specific for Mycobacterium bovis for monitoring infection in wild animals. SAMPLE Serum samples from 8 experimentally infected yearling white-tailed deer (Odocoileus virginianus) and 3 age-matched control deer and from 393 Minnesota Department of Natural Resources hunter-harvested white-tailed deer in northwest Minnesota. PROCEDURES 8 yearling deer were inoculated with 2 × 108 CFUs of virulent M bovis strain 1315 (day 0), and sera were obtained on days 0, 19, 48, and 60; sera were obtained from 3 uninoculated control deer on those same days. Sera from these deer and 9 M bovis-positive hunter-harvested deer were tested for 3 Mycobacterium-specific biomarkers (MB1895c, MB2515c, and polyketide synthase 5) by use of an indirect ELISA. That same ELISA was used to test sera obtained from 384 exposed noninfected deer in northwest Minnesota from 2007 through 2010, concurrent with an outbreak of tuberculosis involving cattle and deer in that region. RESULTS ELISA results revealed that tuberculosis infection could be detected as early as 48 days after inoculation in experimentally infected deer. Results for 384 deer sera revealed that prevalence of tuberculosis decreased over the 4-year period. CONCLUSIONS AND CLINICAL RELEVANCE Results suggested that the prevalence of tuberculosis in Minnesota deer decreased after 2009 but tuberculosis may have persisted (as subclinical disease) at extremely low levels, as indicated by the presence of low concentrations of circulating biomarkers. Biomarker-based diagnostic tests may offer a specific approach for early identification of M bovis infection.

Epidemiology of toxoplasmosis in white tailed deer (Odocoileus virginianus): Occurrence, congenital transmission, correlates of infection, isolation, and genetic characterization of Toxoplasma gondii

The prevalence of Toxoplasma gondii in white tailed deer (WTD) in the USA is high but little is known of the epidemiology of toxoplasmosis in this host. In the present study, we compared T. gondii seroprevalence from 749 WTD collected in 2012 and 2013 from a Metropolitan Park in Ohio and 487 WTD deer shot in Minnesota during 2008, 2009, and 2010. Serum samples were tested for antibodies to T. gondii by the modified agglutination test (cut-off titer, 25). Additionally myocardial samples from 123 seropositive WTD from Ohio were digested in pepsin and the digests were bioassayed for the isolation of T. gondii. Furthermore, to estimate transplacental rate of transmission, brains from 155 fetuses (included twins) from 148 deer from Minnesota were bioassayed in mice for the isolation of viable T. gondii. Seroprevalence of T. gondii varied with the year of collection, geography, and the age of deer. Of the Ohio deer sampled in 2012 and 2013 seroprevalences for the two years were similar (73.4% and 75.7%, respectively); remarkably 150 (66.1%) of 227 deer of <1 year of age were seropositive. Of the Minnesota deer, seroprevalence was lowest for the year 2008 (14.8%, 26/175) versus 2009 (27.7%, 59/213), and 2010 (25.2%, 25/99), thought to be related to environmental temperatures. Viable T. gondii was isolated in mice from the myocardium of four WTD from Ohio, and brain of one WTD fetus from Minnesota. Tachyzoites from infected mouse tissues were further propagated in cell culture. The DNA isolated from culture-derived tachyzoites of these five T. gondii isolates was characterized using 11 PCR-RFLP markers (SAG1, 5′- and 3′-SAG2, alt.SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1 and Apico). Four genotypes were found, including ToxoDB genotype no. 1 (Type II), no. 2 (Type III), no. 3 (Type II variant) and no. 146. Results indicate fluctuating seroprevalence, probably related to weather and warrant further epidemiological studies.

Preventing the establishment of a wildlife disease reservoir: a case study of bovine tuberculosis in wild deer in Minnesota, USA.

Bovine tuberculosis (bTB) has been found in 12 cattle operations and 27 free-ranging white-tailed deer (Odocoileus virginianus) in northwestern Minnesota, following the state's most recent outbreak of the disease in 2005 in the northwest part of the state. Both deer and cattle have the same strain of bTB. The Minnesota Board of Animal Health has been leading efforts to eradicate the disease in Minnesota's cattle, which have included the depopulation of all infected herds, a cattle buy-out program, and mandatory fencing of stored feeds. The Minnesota Department of Natural Resources began surveillance efforts in free-ranging white-tailed deer in fall 2005. All bTB-infected deer have been found within a 16 km2 area in direct association with infected cattle farms. Aggressive efforts to reduce deer densities through liberalized hunting and sharpshooting have resulted in a 55% decline in deer densities. Also, recreational feeding of wild deer has been banned. Disease prevalence in deer has decreased from 1.2% in 2005 to an undetectable level in 2010.

Winter Use of Senescent Herbaceous Plants by White-Tailed Deer in Minnesota

During winter in northern North America, white-tailed deer (Odocoileus virginianus) have been reported to consume non-woody browse items such as dried leaves (of woody plants), lichens, and evergreen herbaceous plants. We report use of five species of senescent (dead) herbaceous perennial plants in winter by a high density white-tailed deer herd in south-central Minnesota during a winter of average snow depths and below average temperatures. While low in digestible energy, senescent herbaceous material may present deer with a forage item higher in digestible protein than larger diameter woody twigs during periods of nutritional stress.

Isolation and Propagation of the Ap-Variant 1 Strain of Anaplasma phagocytophilum in a Tick Cell Line

The first tissue culture isolates of the unique Anaplasma phagocytophilum strain, Ap-Variant 1, were obtained in the Ixodes scapularis tick-derived cell line ISE6. Two isolates were from goat blood samples: one from a goat infected with I. scapularis ticks from Rhode Island and a second from a goat infected by serial passage of blood from the first infected goat. Eight isolates were made directly from I. scapularis ticks collected from white-tailed deer in Minnesota and represent the first isolations of an Anaplasma species directly from ticks. Each of the 10 isolates had a 16S rRNA gene sequence identical to that previously described for Ap-Variant 1, but differences within the ank gene were found that suggest natural variation. Prevalence of Anaplasma in the Minnesota ticks was 63.9%; 23 of 36 ticks tested by PCR were positive. Six of the tick-derived isolates were obtained from a set of 18 PCR-positive ticks, for a 33.3% isolation success rate. The conservation of host tropism among the Rhode Island and Minnesota isolates of Ap-Variant 1 was examined by use of experimental infections of mice and a goat. A Minnesota tick-derived isolate (MN-61-2) was used to inoculate naïve animals, and this isolate was able to infect a goat but unable to infect each of five mice, confirming that the Minnesota isolates have the same host tropism as Ap-Variant 1 from the northeastern United States. Light and electron microscopy of the Ap-Variant 1 isolate MN-61-2 in ISE6 cells showed cytoplasmic inclusions characteristic of A. phagocytophilum with pleomorphic bacteria in membrane-bound vacuoles and both electron-dense and electron-lucent forms.

Prevalence of antibody titers to Leptospira spp. in Minnesota white-tailed deer.

Serum samples (n = 204) from 124 white-tailed deer (Odocoileus virginianus) in northeastern Minnesota (USA) were collected from 1984 through 1989 and tested for antibodies to six serovars of Leptospira interrogans (bratislava, canicola, grippotyphosa, hardjo, icterohemorrhagiae, and pomona) using a microtiter agglutination test. Eighty-eight (43%) sera were positive at greater than or equal to 1:100 for antibodies against serovars pomona and/or bratislava; none was positive for any of the other four serovars. None of the 31 sera collected in 1984-85 was positive, whereas all 54 sera collected from 1986 through 1988 had titers of greater than or equal to 1:100. During 1989, only 34 (29%) of 119 sera had titers of greater than or equal to 1:100. Based on these results, we believe there to be wide variability in exposure of Minnesota deer to Leptospira interrogans.

Seasonal patterns of weight, hematology, and serum characteristics of free-ranging female white-tailed deer in Minnesota

Weights, hematology, and serum profiles of white-tailed does in the central Superior National Forest of northeastern Minnesota were examined year-around to determine seasonal patterns of nutritional condition and metabolism. Deer were initially captured by Clover trap or rocket net. Between 15 February 1989 and 23 January 1990, we recaptured 12 adult (&gt; 1.5 years) female deer 1–9 times each (a total of 59 recaptures) using a radio-controlled capture collar. Monthly weights of deer exhibited a cyclic seasonal pattern. Mean weight declined 22% from February to an annual minimum during May, then steadily increased 45% to a maximum in October. Seasonal patterns were most evident for hemoglobin concentration, red blood cells, packed cell volume, serum total protein, urea nitrogen, creatinine, the urea N to creatinine ratio, triiodothyronine, cortisol, and potassium. Wide seasonal variations of these characteristics were indicative of shifts in the deer's metabolic physiology. Although seasonal metabolic shifts are partially attributable to an endogenous rhythm, the intensity of their expression was most likely affected by nutritional changes and concomitant alterations of body condition. Annual changes in seasonal trends of blood characteristics may be useful in investigating nutritional effects of specific environmental and demographic factors. We compare our findings with those reported for deer on ranges farther south.

Habitat Use and Seasonal Range Size of White-Tailed Deer in Northcentral Minnesota

Seventeen radio-collared female white-tailed deer (Odocoileus virginianus) were monitored during 1968-74 in northcentral Minnesota to determine their use of plant communities. During January-October, the Balsam Fir (Abies balsamea)-Trembling Aspen (Populus tremuloides)-Paper Birch (Betula papyrifera) Community was used by deer more than expected. It probably provided the best winter cover and was a floristically rich community that provided high quality food. Home-range size was largest in April-May (f ? SE = 75 ? 42 ha) and smallest in January (30 ? 14 ha). J. WILDL. MANAGE. 51(3):644-648 Numbers of white-tailed deer in Minnesota increased rapidly in the 1930's and 1940's after logging and fires from 1900 to the early 1930's created large areas of early successional stages of forest vegetation (Erickson et al. 1961). Changes in forest structure and composition now occur almost entirely by logging or direct wildlife habitat improvement. Currently, the supply of wood in Minnesota is about twice the demand (Spencer and Ostrom 1979, Jakes and Raile 1980). In some areas forest succession is advancing faster than it is being set back and has been responsible, in part, for a major decline in deer numbers (Mech and Karns 1977). To optimize forest management practices for enhancement of deer populations in Minnesota, detailed habitat and movement studies are required. Such studies have been conducted in northeast Minnesota (Irwin 1974; Wetzel et al. 1975; Nelson 1979; Nelson and Mech 1981, 1984), where forests have a strong boreal component (Ohmann and Ream 1971). Fewer studies are available from the more widespread aspen-balsam fir dominated forests where the majority of deer are impacted by forest manipulations. This paper reports on seasonal habitat use and range size of white-tailed deer in a portion of northcentral Minnesota. Included are data from Kohn and Mooty (1971), Waddell (1973), and Pierce (1975), as well as additional unpublished data. The objective of the study was to identify the major forest types most utilized by deer so that high quality deer habitat could be created and maintained. We thank E. W. Wroe, J. G. Wetzel, the late J. B. Moyle, and the staff and boys of the Thistledew Youth Corrections Camp for their assistance. D. M. Heisey and C. A. Macken assisted with the statistical analysis, and R. L. Glazer with the soils analysis. R. E. Lake provided valuable comments on earlier drafts of this paper.

Occurrence of antibodies to the etiologic agents of infectious bovine rhinotracheitis, parainfluenza 3, leptospirosis, and brucellosis in white-tailed deer in Minnesota.

A serologic survey was conducted on 628 white-tailed deer (Odocoileus virginianus) in 1976 and 1979-1980. Tests for antibodies to the etiologic agents of infectious bovine rhinotrancheitis (IBR), parainfluenza 3 (PI3), leptospirosis, and brucellosis produced positive results of 15%, 20%, 3% and 0%, respectively. Adult deer had significantly higher prevalence of antibodies to IBR virus and PI3 virus than fawns. These data provide a basis for monitoring these disease agents in Minnesota's white-tailed deer.

Metabolic Indicators of Habitat Differences in Four Minnesota Deer Populations

Metabolic Indicators of Habitat Differences in Four Minnesota Deer Populations

Summer Foods of Deer in Northern Wisconsin

Summer foods of white-tailed deer (Odocoileus virginianus) were studied using rumina from 76 road-killed deer collected between 15 April and 15 November. Aspen (Populus spp.) leaves and grasses were found to comprise more food volume than any other plants. Barren strawberry (Waldsteinia sp.), bush-honeysuckle (Diervilla sp.), lilies (Liliaceae), and acorns (Quercus spp.) were seasonally important contributors to the rumina. Woody browse comprised only 3 percent of the aggregate volume. Most foods eaten were shade-intolerant species which suggested most feeding occurred in open forest types. Forest and habitat management to favor aspen, oaks (Quercus spp.), upland brush, and sodded openings will favor deer forage production. J. WILDL. MANAGE. 38(2):215-219 Most deer habitat and forage research in the Lakes States has focused on the obvious limitations of winter range. Aldous and Smith's (1938) report on late fall and winter food habits of Minnesota deer constitutes the only major food habits study based on rumen analysis for the area. More recently, limitations in summer deer ranges have become increasingly evident as essentially even-aged forests mature and convert to more tolerant types (McCaffery and Creed 1969:6). Also, increasing concern has been expressed for total nutrition and year-round habitat. We studied the summer food habits of deer in northern Wisconsin to better understand their seasonal dependence on specific foods and forest types. Since deer are selective feeders when a variety of forage is available (Klein 1970), we felt foods eaten by deer would reflect both forage and habitat preferences. We wish to acknowledge F. W. Stearns, at the University of Wisconsin-Milwaukee, for supervising the laboratory portion of this study. A note of thanks also goes to those who assisted with the sometimes unpleasant task of extracting samples. METHODS Rumen samples were collected from roadkilled deer between 15 April and 15 November in 1969 and 1970. Four subseasons were used to determine changes in utilization or availability: spring (April-May), early summer (June-July), late summer (August-September), and fall (OctoberNovember). Approximately equal numbers of deer were desired in each subseason. Deer were sampled as they became available in the subseason of interest. Samples were taken in quart (0.946 liter) jars and preserved with 10 percent formalin.

Movements and Habitat Use of White-Tailed Deer in Minnesota

Radio transmitters were placed on six white-tailed deer (Odocoileus virginianus) in the winter of 1963-64 and eight deer in the winter of 1964-65 and their movements followed with an automatic tracking system. Winter home ranges were between 400 and 1,200 acres. Monthly home ranges were between 422 and 576 acres for the months January through March, 1964 and between 83 and 576 acres for the same months in 1965. Home ranges decreased with increased snow depth. The mean percentage of time associated with a cedar swamp changed from 74 percent during the day in January, 1964 to 17 percent during the night in March, 1964, while it changed from 73 to 88 percent during the same periods in 1965. Migration of seven radio-tagged deer occurred shortly after snow melted in fields in midApril, 1965, but was between late April and early May for three deer in 1964 when snow was mostly gone in March. Does and juveniles moved with practically no meandering from their winter to summer range while adult bucks seemed more inclined to wander. This paper reports on winter home ranges, gross analysis of vegetation types within these home ranges, and spring migration of white-tailed deer in east-central Minnesota. Data were obtained by placing radio transmitters on the deer and following them with the automatic tracking system located at the Cedar Creek Natural History Area (CCNHA) (Cochran et al. 1965). Six deer were radio-tagged during the winter, 196364 and eight during the winter of 1964-65. In addition, three deer were ear-tagged in February, 1965. Much of our data is relevant to the phenomenon of during the winter. However, our objectives were to determine gross movements and gross habitat usage of deer in the area, and the study was not designed to determine how and why deer yard. Ozoga (1968) has reviewed the relevant literature on yarding and reported on microclimatic differences that exist among 1 Supported by the U. S. Atomic Energy Commission, COO-1332-43, and by PHS Training Grant No. 5 to 1 GM01779-01 from the National Institute of General Medical Sciences. Computer time was provided by the University of Minnesota Numerical Analysis Center. 2 Present address: Department of Wildlife Ecology, University of Wisconsin, Madison, 53706. 366 various food and cover components of a conifer swamp deeryard. Although radio transmitters would be a valuable aid in a deer-yarding study and in relating deer behavior with microclimatic conditions, locations based on triangulation (Heezen and Tester 1967:126) would in most cases not be accurate enough for microclimate interpretation. Portable receivers would be needed to determine exact locations (whether the deer was under a tree or beside it). Because getting exact locations usually disturbs the animal, and because we tried to keep human influence on our study area to a minimum, we settled for gross determinations. Habitat within the study area has been described in detail by Pierce (1954), Bray et al. (1959), and others. For purposes of interpreting use of the available habitat by deer in winter, the types of communities in the 16 square miles containing and surrounding CCNHA were subjectively categorized as follows: 64 percent upland (23 percent woods, 41 percent fields); 32 percent lowland (18 percent marsh, 14 percent wooded swamp); and 4 percent open water. White cedar (Thuja occidentalis) of varying density occurs in about one-fourth (350 acres) of the wooded swamp; the remainder MOVEMENTS OF DEER IN MINNESOTA Rongstad and Tester 367 is characterized mainly by alder (Alnus rugosa) and tamarack (Larix laricina). About half of the fields in the area were cultivated while the others had been retired from cultivation for various periods of time. The main crops were corn (Zea mays), soybeans (Glycine max), alfalfa (Medicago sativa), and rye (Secale cereale). Corn was usually all picked by December 1, but enough waste corn remained to provide food for deer. Deer were present on CCNHA throughout the year, but the number increased during the winter when animals moved into the area. We suspect that this movement is related to the cedar swamp which is the only conifer swamp cover for many miles around. Ozoga (1968) found that mature swamp conifers offered deer the best protection from cold and the least hazardous snow conditions of six habitat types studied. We are grateful to K. L. Heezen and J. C. Moulton who captured and marked the deer as part of their thesis research, and to the many personnel of the Radio Tracking Project who assisted them in both field and laboratory aspects. W. H. Marshall and A. Peterson of CCNHA provided facilities and field assistance. D. B. Siniff generously assisted with computer processing of the data.

Pneumostrongylus tenuis in Deer in Minnesota and Implications for Moose

Pneumostrongylus tenuis in Deer in Minnesota and Implications for Moose