MODELING WOLF IMPACTS ON WHITE-TAILED IN WISCONSIN DEER USING GPS TELEMETRY

• Sponsoring Institution: National Institute of Food and Agriculture
• Project Status: COMPLETE
• Funding Source: HATCH
• Reporting Frequency: Annual
• Accession No.: 1009702
• Project Start Date: Sep 1, 2016
• Project End Date: Aug 31, 2019
• Program Code: [(N/A)]- (N/A)

Recipient Organization
UNIV OF WISCONSIN
21 N PARK ST STE 6401
MADISON,WI 53715-1218

Performing Department
Forest and Wildlife Ecology

Non Technical Summary
In the central region, where wolf populations are expected to expand, there are comparatively few depredation events. When coupled with the lack of evidence of wolf predation on white-tailed deer in agricultural regions, it is difficult to predict how expanding wolf populations will affect either livestock depredation or white-tailed deer populations. This research project will integrate with existing research projects to quantify the impacts of wolves on white-tailed deer. We propose to use a combination of GPS telemetry and field investigations to describe the space-time characteristics of wolf kill sites during winter. Using these characteristics we will build statistical models of kill sites based on the movements of collared wolves. We propose to use these methods to quantify the total number of deer killed by wolves throughout the course of the year by fitting these models to observed movement paths and activity clusters. This will be the first attempt to numerically quantify the impacts of wolves on white-tailed deer and will provide a tool to wildlife managers for predicting the impacts of expanding wolf populations on white-tailed deer in Wisconsin and elsewhere in the Great Lakes region. Moreover, understanding predation dynamics will allow for more accurate models of livestock depredation and white-tailed deer population dynamics in agricultural regions.

Animal Health Component

100%

Research Effort Categories

Basic

(N/A)

Applied

100%

Developmental

(N/A)

Classification

Knowledge Area (KA)	Subject of Investigation (SOI)	Field of Science (FOS)	Percent
135	0830	1070	50%
315	0830	1070	50%

Knowledge Area
135 - Aquatic and Terrestrial Wildlife; 315 - Animal Welfare/Well-Being and Protection;

Subject Of Investigation
0830 - Wild animals;

Field Of Science
1070 - Ecology;

Keywords

wolves

white-tailed deer

depredation

agricultural damage

wildlife management

Goals / Objectives
The overall objective of this research project is to better understand wolf predation patterns on both white-tailed deer and its relationship to livestock and plant agriculture. This overall objective will be facilitated through the following specific objectives.Objective 1 - Spatial characteristics of wolf predations on livestockPrevious research in Wisconsin has focused on developing risk maps of livestock depredations (e.g. Treves et al. 2011). This research essentially modeled the landscape and landcover features that separate farms with reported livestock depredations from farms without. This research is useful for predicting broad risk of depredation. However, understanding wolf depredation patterns on livestock and mitigating those risks at the level of individual farms cannot be accomplished without a concomitant finer scale examination of predation patterns on wildlife, as it is the combination of livestock and wild animals that collectively inform foraging strategies that determine the diets of local wolves. By examining wolf kill-sites of wild animals we will develop spatial risk maps of predation for the primary prey species of wolves, white-tailed deer. This will provide a fine-scale companion to livestock predation risk maps that will help to describe better the spatial characteristics of wolf feeding behavior and will provide a model for additional management of community-level impacts of predation.Objective 2 - Quantifying wolf kill ratesEstimating predator impacts on prey population is inherently difficult, but can be facilitated through the use of GPS telemetry technology (e.g. Miller et al. 2013). Using GPS clusters and field investigations we will describe the space-time characteristics of wolf kill sites and then use those estimates to derive annual kill rates based on high resolution GPS data. This will facilitate the numerical estimation of the total amount of white-tailed deer killed by wolves and, by extension, inference on the total amount of biomass consumed.Objective 3 - Spatial distribution of wolf kills of deer relative to agricultureWolf predation on deer can only have cascading effects on agricultural crops if the deer that the wolves are killing are the same deer that are damaging agricultural crops. Using GPS clusters and field investigations we will describe the space-time characteristics of wolf kill sites and then use those data to model the spatial distribution of predation events with respect to local agricultural features, and literature-based drivers of deer foraging during the growing season. This will enable us to infer the degree to which wolves are killing deer that are likely to be causing agricultural damage to common crops in Wisconsin.

Project Methods
We propose to use a combination of field research and statistical modeling to quantify the spatial components of wolf predation and to estimate wolf kill rates. As part of a larger wolf research project directed by Co-PI Crimmins, there are currently five wolves in the Black River State Forest area that are equipped with VECTRONICS® GPS Plus satellite collars (VECTRONICS® Aerospace, Berlin, Germany). These collars are programmed to record a location every two hours and remotely upload locations to a cloud-based storage system that can be accessed at any time through proprietary software provided by VECTRONICS®. From this interface, locations and movement paths can be exported in keyhole markup language (kml) format for visualization in Google Earth, or as .dbf files for use in a GIS. The Wisconsin Department of Natural Resources will be handling the collaring of the wolves, collar maintenance, wolf tracking/monitoring, and kill site location/identification.Locations from GPS collars typically generate location estimates with spatial errors less than about 10m or so depending on signal attenuation (through overstory cover) and satellite geometry (Hebblewhite et al. 2007). Consequently - navigation to and identification of kill site characteristics at location clusters is efficient and straight-forward (i.e. requires less search time relative to standard VHF telemetry techniques). Use of telemetry-derived location clusters to identify predation events enables fine-scale study of predatory behavior with respect to local topography and vegetation, landscape context, and intra-species influences (Bartnick et al. 2013).Previous research has identified the space-time patterns in GPS telemetry data that represent locations with a high probability of being wolf kill sites (DeCesare 2012; Webb et al. 2008). Using these criteria, we will identify GPS clusters with a high probability of being a kill-site for field investigation based on a space-time permutation scan statistic (Kulldorff et al. 2005). We will investigate these clusters in the field within 45 days of occurrence to maximize the probability of identifying the prey species (Webb et al. 2008). We will quantify clusters as kill sites based on evidence of prey remains, blood in the snow, or signs of a chase or struggle (Bartnick et al. 2013).

Progress 09/01/16 to 08/31/19

Outputs
Target Audience:Target audience is wildlife researchers and conservationists with interests in wolf and deer conservation. Changes/Problems:Quantification on wolf kill rates from ongoing telemetry research was not possible because of changes in WI DNR data-sharing that occurred during the project and that were beyond our control. Hence, objective 2 was precluded. What opportunities for training and professional development has the project provided?This project provided support for a graduate student who earned a Master's Degree in Wildlife Ecology. How have the results been disseminated to communities of interest?The completed thesis has been provided to managers and researchers in the Wisconsin DNR, the graduate student has made several presentations at professional meetings and there is a ms under review. What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? We monitored 499 white-tailed deer for cause-specific mortality between 2011-2014 using VHF radio collars. We investigated kill sites of which there were 28 wolves kill sites and 35 coyote kill sites. We analyzed spatial patterns of kill sites using resource selection functions (RSFs) in a model selection framework, incorporating spatially explicit variables including land cover, human activity (agriculture), water availability, and snow depth. Our findings show that increasing snow depth results in increased white-tailed deer mortality risk from coyote and wolf predation, corroborating other research on the negative effect of snow depth white-tailed deer survival. Our results suggest that understanding the effect of snow depth on white-tailed deer survival may require a better understanding of snow depth variation in space and time. As climate change scenarios predict changes in snowfall throughout the Northern Hemisphere, understanding the implications on the outcome of predator-prey spatial dynamics will be important for conservation efforts. Model selection indicated that kill sites were uninfluenced by proximity to agriculture in our study are (objective 3). This finding precluded estimation of a meaningful risk map for livestock or wolves as a function on human activity (objective 1). Quantification on wolf kill rates from ongoing telemetry research was not possible because of changes in WI DNR data-sharing that occurred during the project and that were beyond our control. Hence, objective 2 was precluded.

Publications

• Type: Theses/Dissertations Status: Published Year Published: 2019 Citation: Olson,Lucas. 2019. Physical factors affect the distribution of two Wisconsin ungulates. Theses. University of Wisconsin-Madison.

Progress 10/01/17 to 09/30/18

Outputs
Target Audience:Wildlife Managers Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?The project has provided support for a Master's student in the department of Forest and Wildlife Ecology at the University of Wisconsin-Madison. During the program, the student has had the opportunity to attend five professional conferences. The student has collaborated with professionals throughout federal and state agencies to increase understanding of relevant topics and skills. How have the results been disseminated to communities of interest?The results of the project have been disseminated through presentations at several professional conferences, as well as two local symposia. The presentations were: 1). Using predation risk to inform resource selection for white-tailed deer. USDA Wildlife Services district meeting. Wapaun, WI. December 11, 2018. L. O. Olson, T. R. Van Deelen, D. Storm, and S. Crimmins. 2). Relating wolf and coyote kill sites to resources selection for white-tailed deer in northern Wisconsin. The Wildlife Society 25thAnnual Conference. Cleveland OH. October 11, 2018. L. O. Olson, T. R. Van Deelen, D. Storm, and S. Crimmins. 3). Relating predation risk to white-tailed deer space use. Research Symposium, Kemp Natural Resource Station. Lake Tomahawk, WI. February 10, 2018. L. O. Olson, T. R. Van Deelen, D. Storm, and S. Crimmins. What do you plan to do during the next reporting period to accomplish the goals?Results are currently being written as a thesis chapter with the intent of submitting as a manuscript to a scientific journal.

Impacts
What was accomplished under these goals? Objective 1- We analyzed patterns of deer kill sites relative to livestock density. Kill locations and spatial data on livestock operations proved insufficient for accurate inference. Objective 2- GPS location data not available. Available data insufficient for wolf kill rate analysis. Objective 3- We analyzed spatial patterns of white-tailed deer kill sites. Model variables included agricultural and forested land cover, human activity, proximity to water, and snow depth. Our findings show that increasing snow depth results in increased white-tailed deer mortality risk from coyote and wolf predation. Our results do not support row crop agriculture as having a major impact on predator-prey spatial dynamics.

Publications

Progress 10/01/16 to 09/30/17

Outputs
Target Audience: Nothing Reported Changes/Problems:Wisconsin DNR has decline to provide access to the on-going wolf telemetry data. To mitigate this problem, we are mounting an analysis of archival related data on predation in radio-collared white-tailed deer. What opportunities for training and professional development has the project provided?This project is supporting the training of a graduate student in the department of Forest and Wildlife Ecology at the University of Wisconsin - Madison. How have the results been disseminated to communities of interest?The principle community of interest is Wisconsin's Department of Natural Resoures (DNR). We disseminated knowledge and progress to DNR by inviting a DNR scientist to be part of the research team and to be on the graduate student's advisory committee. What do you plan to do during the next reporting period to accomplish the goals?We will continue to build the spatial databases needed to do the analyis and to begin fitting statistical models that relate patterns of predation risk to deer with patterns of livestock and row-crop agriculture in the study area.

Impacts
What was accomplished under these goals? Objective 1. Nothing to report. Objectives 2. and 3. Wisconsin DNR has declined to share it's GPS data from currently collared wolves, requiring us to find alternate ways of quantifying wolf kill rates and spatial distrubution of wolf killes of deer relative to agriculture. We are using archived telemetry data from 344 deer that were monitored during 2012 - 2014 to estimate temporal and spatial distribution of kill rates. We have obtained this data and are incorporating it into recent spatial models of landcover to support the analysis. This is a preliminary step to the inference that will address objective 1 (spatial charactheristics of wolf predation risk on livestock) as informed by predation risk to deer in the same study area.

Publications

Progress 09/01/16 to 09/30/16

Outputs
Target Audience:Wildlife managers. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?Support for a Master's student in the department of Forest and Wildlife Ecology at the University of Wisconsin-Madison. 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?We will be working with DNR collaborators to begin field work and secure access to data.

Impacts
What was accomplished under these goals? In the first month of the project, we have committed a graduate student to the project and he has begun the literature review and drafted a formal research proposal. Field work has not started.

Publications