EVALUATING EFFECTS OF DISEASE STATUS ON HABITAT SELECTION OF BIGHORN SHEEP

• Sponsoring Institution: National Institute of Food and Agriculture
• Project Status: TERMINATED
• Funding Source: MCINTIRE-STENNIS
• Reporting Frequency: Annual
• Accession No.: 1017110
• Project No.: SD00M661-19
• Project Start Date: Oct 1, 2018
• Project End Date: Jan 21, 2021

Project Director
Jenks, J, .

Recipient Organization
SOUTH DAKOTA STATE UNIVERSITY
PO BOX 2275A
BROOKINGS,SD 57007

Performing Department
Natural Resource Management

Non Technical Summary
Bighorn sheep are suffering from disease within what is termed the pneumonia complex. This disease involves a number of bacteria and parasites that can, and currently are, negatively impacting bighorn sheep resulting in population declines, limited recruitment, and reduced harvest and viewing opportunities. Determining habitat conditions that support healthy bighorn sheep herds could help to minimize the impact of this disease. Appropriate habitat conditions could provide nutrients to support healthy bighorn sheep immune systems, provide relief from stress-related predator escape, and provide an environment that maintains females within their thermoneutral zone, which reduces energy expenditures and thus, allows focus on response and elimination of disease threat. Methods used to evaluate the relationships between habitat quality and animal health are currently in use by wildlife and forestry professionals who assess forage availability and cover characteristics of habitats. If optimal bighorn sheep habitat conditions can be identified, the benefits would include healthy herds with improved recruitment, which in turn would increase public opportunities for wildlife viewing and hunting.

Animal Health Component

0%

Research Effort Categories

Basic

0%

Applied

100%

Developmental

0%

Classification

Knowledge Area (KA)	Subject of Investigation (SOI)	Field of Science (FOS)	Percent
136	0830	1070	20%
135	0860	1010	40%
134	0899	3100	10%
123	0610	1070	30%

Knowledge Area
135 - Aquatic and Terrestrial Wildlife; 136 - Conservation of Biological Diversity; 134 - Outdoor Recreation; 123 - Management and Sustainability of Forest Resources;

Subject Of Investigation
0610 - Conifer forests of the North; 0830 - Wild animals; 0899 - Wildlife and natural fisheries, general/other; 0860 - Endangered species;

Field Of Science
1070 - Ecology; 1010 - Nutrition and metabolism; 3100 - Management;

Keywords

bighorn sheep

habitat selection

disease resistance

nutritional condition

forage availability

recruitment

Goals / Objectives
Objective 1: Determine disease status of female bighorn sheep in the Pine Ridge and Wildcat Hills regions of Nebraska.Objective 2: Describe lambing habitat of bighorn sheep in the Pine Ridge and Wildcat Hills regions of Nebraska.Objective 3: Characterize foraging habitats of female bighorn sheep in the Pine Ridge and Wildcat Hills regions of Nebraska.

Project Methods
Objective 1: Determine disease status of female bighorn sheep in the Pine Ridge and Wildcat Hills regions of Nebraska. Ewe bighorn sheep will be captured via helicopter via dart rifle (Dan-Inject, Børkop, Denmark, EU). Pregnancy status of ewes will be evaluated via ultrasonography (Universal Ultrasound, Bedford Hills, NY, USA) at the time of capture. The nasals of ewes will be swabbed to determine presence of Mycoplasma ovipneumonia via PCR (Besser et al. 2012). Pregnant ewes will be fitted with vaginal implant transmitters with a redesigned wing system and antenna length of 6 cm (Bishop et al. 2011). Ewes that are not pregnant or not checked for pregnancy at the time of capture will not fitted with VITs. Methods of VIT deployment will follow Bishop et al. (2011) and Smith et al (2014). All ewes will be fitted with GPS collars (ATS) that are uniquely marked to facilitate individual identification.Objective 2: Describe lambing habitat of bighorn sheep in the Pine Ridge and Wildcat Hills regions of Nebraska.Prior to the lambing season, radiocollared ewes will be monitored 1-3 times per week from the ground using hand-held directional antennas (Telonics, Inc., Mesa, AZ). We will listen for possible VIT expulsion each time we locate ewes. When we detect an expelled VIT prior to the lambing season, we will retrieved it using ground telemetry, ascertain if the ewe had aborted the fetus on-site, and estimate date of expulsion as the mean date between the first mortality signal and the last active signal received.During the lambing season in May and June, ewes with VITs will be checked once daily to determine if the VIT has been expelled. If the radio signal indicates a VIT had been expelled and terrain permits, personnel will use telemetry to locate the expelled VIT on foot and retrieve it. If the VIT is located at a birth site and the lamb is present, we will attempt to hand-capture it and fit it with an expandable radio collar. Abandoned lambs will be transported to the Wildlife and Fisheries Captive Animal Facility at South Dakota State University. All capture methods have been approved (Approval No. 18-034A) by the Institutional Animal Care and Use Committee at South Dakota State University. The amount of visual obstruction present at each lambing site will be determined using a 1-m2 visual obstruction cloth (Kennedy 1992). Cloth design is a black and white checkerboard layout divided into 100, 10-cm squares. The cloth will be separated into 2 sections, the bottom 50 squares (0.0 - 0.5 m) will be considered representative of visual obstruction available to a bedded ewe, and the top 50 squares, (0.5 - 1.0 m) will be considered representative of visual obstruction available to a standing ewe (Bowyer 1986). The cloth will be held perpendicular to the ground and four readings, one from each of the 4 cardinal directions, will be made from a distance of 10 m from plot center and 1 m above ground. If a square is ≥ 50% covered it will be considered concealed; if a square is < 50% covered it will be considered open. Number of squares concealed in each of the 2 sections will represent the amount of visual obstruction available to a standing and bedded ewe, respectively. Additionally, the distance at which the visual obstruction cloth is 90% concealed will be estimated. For analytical purposes the 4 visual obstruction percentages and distances will be averaged for each location.Objective 3: Characterize foraging habitats of female bighorn sheep in the Pine Ridge and Wildcat Hills regions of Nebraska. We will estimate stand age by standing at locations and bed sites and identifying a sample of trees using a Jim-Gem Cruz-All (Forestry Suppliers, Inc., Jackson, MS, USA) with a basal area factor of 10. We will record mean diameter at breast height (DBH) for all trees in the sample. We will categorize each site into 3 classes based on USDA Forest Service criteria: 1) mature or old growth (DBH >22.9 cm), 2) young (DBH = 12.7-22.9 cm), and 3) shrub/sapling (DBH <12.7 cm). We will estimate percent canopy cover using a GRS densiometer (Forestry Suppliers, Inc., Jackson, MS, USA) in the 4 cardinal directions from the bed site. Additionally, we will evaluate escape terrain by estimating slope at locations and bed sites as well as 4 additional slope measurements at 10-m from locations and bed sites arranged in the 4 cardinal directions. This measurement will provide a rough estimate of the overall slope of the area at that site. These procedures will be repeated at a random locations within 150 m of locations and birth/bed sites. Habitat data will be compared to disease status of female bighorn sheep using Analysis of Variance procedures. Vegetative characteristics will be collected along 100-m transects centered at observed foraging sites of adult female bighorn sheep; transects will be oriented along topographical contours. Overstory canopy cover will be recorded at 1-m intervals along transects using a GRS densitometer (n=100) (Stumpf 1993). Percent understory cover of total herbaceous cover, grass, forbs, and shrubs will be estimated in 0.1 m² quadrats (Daubenmire 1959) at 3-m intervals along transects (n=30). Aspect will be recorded via a Silva Ranger CL15 compass; percent slope will be estimated along this same gradient with a Silva Ranger CL15 clinometer. Distance (m) to nearest escape cover (slope ≥40 degrees) will be measured using a Nikon Prostaff 7 range finder. Downed woody debris (kg/ha) will be interpolated using a pictorial guide (Simmons 1982) provided by the Black Hills National Forest Service. Standing herbage will be clipped to ground level within 0.25 m² circular plots centered at stations and located 40 and 80 m from foraging sites (n=4). Vegetation will be sorted to species, oven dried at 60º C for 48 hours, and weighed to nearest 0.1 g. Species will be analyzed for digestibility (neutral detergent fiber) and fiber (acid detergent fiber) (Van Soest 1982). Data will be analyzed using Analysis of Variance procedures. Results will allow the concepts of nutritional condition, disease status, habitat suitability to be integrated to answer questions related to how female bighorn sheep are able to escape disease exposure using the habitat matrix and forage resources to enhance individual quality and support reproduction.

Progress 10/01/18 to 01/21/21

Outputs
Target Audience:Target audience is wildlife managers, recreationalists, disease ecologists. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?Emily Moberg, M.S. student. Wildlife and Fisheries Sciences. (100% time spent on project) Student gained experience capturing bighorn sheep, sampling bighorn sheep, drafting annual reports, giving presentations, and writing grants. Katelin Frerichs, M.S. student. Wildlife and Fisheries Sciences. (20% time spent on project) Student gained experience developing protocols for laboratory procedures, working with captive bighorn sheep, immobilizing bighorn sheep, and sampling bighorn sheep. How have the results been disseminated to communities of interest?Results were presented to professional audiences at the Midwest Fish and Wildlife Conference. What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? Objective 1: Determine disease status of female bighorn sheep in the Pine Ridge and Wildcat Hills regions of Nebraska. (100% Accomplished) Female bighorn sheep (n = 40) were captured via helicopter net gun in the Pine Ridge and Wildcat Hills regions of Nebraska. Captured bighorn sheep were sampled for exposure to Mycoplasma via nasal and tonsil swabs and blood serum. Samples were sent to the Washington Disease and Diagnostic Lab for analysis. Females with consistent histories of shedding Mycoplasma ovipneumoniae (n = 7) were removed from the Pine Ridge Region and transported to South Dakota State University for further monitoring to confirm shedding status using the same procedures as for captured bighorn sheep. Shedding status was further confirmed via nasal swabs. Of the female bighorn sheep sampled in the Wildcat Hills, none were documented as positive for Mycoplasma. Removal of females with consistent histories of shedding Mycoplasma improved lamb survival; of 35 radio collared lambs, 5 survived (14 percent), which was an improvement over previous lambing periods. Objective 2: Describe lambing habitat of bighorn sheep in the Pine Ridge and Wildcat Hills regions of Nebraska. (100% Accomplished) Global Positioning System (GPS) data from radio collared bighorn sheep have been acquired for the Pine Ridge and Wildcat Hills region of Nebraska from Nebraska Game and Parks Commission. Those data include age class, habitat type (e.g., shrub grasland, rocky outcrop, forest), distance from escape terrain, distance from water, activity (e.g., run), ambient temperature, and time of day. Data was formatted for use in a Geographical Information System (GIS). Data was used to describe lambing habitat using techniques of Smith et al. (Smith, J. B., T. W. Grovenburg, and J. A. Jenks. 2015). Parturition and bed site selection of bighorn sheep at local and landscape scales. Journal of Wildlife Management 79:393-401). Results indicated that when bighorn sheep herds contained disease positive females, grassland use declined from 53% of observations to 20%, whereas use of cropland and rocky outcrop habitats increased from 5 and 24% to 11 and 64%, respectively. In contrast, use of light tree cover habitat declined from 15% to 2%. Bighorn sheep ewes with disease may be more susceptible to predation by occupying more open and anthropogenically altered habitats than disease free herds. Objective 3: Characterize foraging habitats of female bighorn sheep in the Pine Ridge and Wildcat Hills regions of Nebraska. (100% Accomplished) Global Positioning System (GPS) data from radio collared bighorn sheep have been acquired for the Pine Ridge and Wildcat Hills region of Nebraska from Nebraska Game and Parks Commission. Those data include age class, habitat type (e.g., shrub grassland, rocky outcrop, forest), distance from escape terrain, distance from water, activity (e.g., run), ambient temperature, time. Data was formatted for use in a Geographical Information System (GIS) and was used to characterize foraging habitats based on observed activity (foraging) as described within the database. Foraging habitats of female bighorn sheep herds containing diseased individuals changed from 71% grassland, 6% cropland, 12% rocky outcrop, and 10% light tree cover, to 42% grassland, 26% cropland, 23% rocky outcrop, and 5% light tree cover. Bighorn sheep herds with disease utilized more cropland than disease free herds.

Publications

• Type: Conference Papers and Presentations Status: Published Year Published: 2021 Citation: Frerichs, K.E., D.P. Walsh, E.F. Cassirer, T.E. Besser, J.A. Jenks. 2021. The efficacy of mobile PCR to detect Mycoplasma ovipneumoniae in bighorn sheep. Midwest Fish and Wildlife Conference. Minneapolis, MN. Feb. 1-4.

Progress 10/01/18 to 09/30/19

Outputs
Target Audience:Target audience is wildlife managers, recreationalists, disease ecologists. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?Emily Moberg, M.S. student. Wildlife and Fisheries Sciences. (100% time spent on project) Student gained experience capturing bighorn sheep, sampling bighorn sheep, drafting annual reports, giving presentations, and writing grants. Katelin Frerichs, M.S. student. Wildlife and Fisheries Sciences. (20% time spent on project) Student gained experience developing protocols for laboratory procedures, working with captive bighorn sheep, immobilizing bighorn sheep, and sampling bighorn sheep. How have the results been disseminated to communities of interest? Nothing Reported What do you plan to do during the next reporting period to accomplish the goals?Objective 1: Determine disease status of female bighorn sheep in the Pine Ridge and Wildcat Hills regions of Nebraska. We will capture female bighorn sheep (n = 80) from the two regions of Nebraska in February 2020 to continue to assess disease status. Objective 2: Describe lambing habitat of bighorn sheep in the Pine Ridge and Wildcat Hills regions of Nebraska. We will complete analysis of data acquired from Nebraska Game and Parks Commission focusing on lambing habitat characteristics. Objective 3: Characterize foraging habitats of female bighorn sheep in the Pine Ridge and Wildcat Hills regions of Nebraska. We will complete analysis of data acquired from Nebraska Game and Parks Commission focusing on foraging habitats for bighorn sheep in the Wildcat Hills and Pine Ridge Regions of the State.

Impacts
What was accomplished under these goals? Objective 1: Determine disease status of female bighorn sheep in the Pine Ridge and Wildcat Hills regions of Nebraska. (50% Accomplished) Female bighorn sheep (n = 40) were captured via helicopter net gun in the Pine Ridge and Wildcat Hills regions of Nebraska. Captured bighorn sheep were sampled for exposure to Mycoplasma via nasal and tonsil swabs and blood serum. Samples were sent to the Washington Disease and Diagnostic Lab for analysis. Females with consistent histories of shedding Mycoplasma ovipneumoniae (n = 7) were removed from the Pine Ridge Region and transported to South Dakota State University for further monitoring to confirm shedding status using the same procedures as for captured bighorn sheep. Shedding status was further confirmed via nasal swabs. Of the female bighorn sheep sampled in the Wildcat Hills, none were documented as positive for Mycoplasma. Objective 2: Describe lambing habitat of bighorn sheep in the Pine Ridge and Wildcat Hills regions of Nebraska. (25% Accomplished) Global Positioning System (GPS) data from radio collared bighorn sheep have been acquired for the Pine Ridge and Wildcat Hills region of Nebraska from Nebraska Game and Parks Commission. Those data include age class, habitat type (e.g., shrub grasland, rocky outcrop, forest), distance from escape terrain, distance from water, activity (e.g., run), ambient temperature, and time of day. Data will be formatted for use in a Geographical Information System (GIS). Data will be used to describe lambing habitat using techniques of Smith et al. (Smith, J. B., T. W. Grovenburg, and J. A. Jenks. 2015. Parturition and bed site selection of bighorn sheep at local and landscape scales. Journal of Wildlife Management 79:393-401.) Objective 3: Characterize foraging habitats of female bighorn sheep in the Pine Ridge and Wildcat Hills regions of Nebraska. (25% Accomplished) Global Positioning System (GPS) data from radio collared bighorn sheep have been acquired for the Pine Ridge and Wildcat Hills region of Nebraska from Nebraska Game and Parks Commission. Those data include age class, habitat type (e.g., shrub grassland, rocky outcrop, forest), distance from escape terrain, distance from water, activity (e.g., run), ambient temperature, time. Data will be formatted for use in a Geographical Information System (GIS). Those data will be used to characterize foraging habitats based on observed activity (foraging) as described within the database.

Publications