Shown below is the number of white-tailed deer captured and collared during 2018 (n = 190) and 2019 (n = 97) within Little Girls Point (LGP), Lake Gogebic (LKG), West Iron County (WIC), East Middle Branch (EMB) deer wintering complexes and Dickinson County chronic wasting disease core area (DNC), western Upper Peninsula of Michigan, USA.
Shown below are movements of collared white-tailed deer (n = 287; 4 January 2018–15 December 2020) captured in Little Girls Point (green), Lake Gogebic (red), West Iron County (blue), and East Middle Branch (yellow) deer wintering complexes and Dickinson County (magenta) chronic wasting disease (CWD) core area. Also shown are movements of adult female deer collared for the Michigan Predator-Prey study in East Middle Branch (yellow; n = 131; 4 January 2017–15 December 2020), western Upper Peninsula of Michigan, USA. Boundaries include deer management units (orange lines), county borders (black lines), CWD core area (dark red polygon), and deer wintering complexes or study areas (blue shaded polygons). Map inset shows the location of study areas within the Great Lakes region of the USA.
Shown below are the paths of the deer with the furthest movements out of Little Girls Point (53.1 km [32.9 mi], green), Lake Gogebic (32.8 km [20.4 mi], red), West Iron County (26.3 km [16.3 mi], blue), East Middle Branch (87.0 km [54.1 mi], yellow), and Dickinson County (21.8 km [13.5 mi], magenta) in relation to chronic wasting disease (CWD) positive deer (both free-ranging [pink squares with white deer symbol] and captive deer at cervid facilities [orange square with white deer symbol]) in Wisconsin and Michigan, western Upper Peninsula of Michigan, USA, 4 January 2018-15 December 2020. Boundaries include deer management units (orange lines), county borders (black lines), CWD core area (dark red polygon), and deer wintering complexes or study area (blue shaded polygons) of interest for the deer movement study. Map inset shows the location of study areas within the Great Lakes region of the USA.
We determined migratory behavior of collared white-tailed deer during 2017-2020 using model driven classification of animal movement based on net squared displacement (package migrateR for R). Of those individuals classified as migratory (n = 114), we observed peak fall migration occurring between 7th December and 28th December of each year (1st and 3rd quartiles: 21 November and 9 January, respectively). We observed peak spring migration occurring between 14th April and 24th April of each year (1st and 3rd quartiles: 2 April and 2 May, respectively). Mean residency on the winter range (107 days) was shorter than on the summer range (139 days). Western Upper Peninsula of Michigan, USA.
Below is a GIF showing the movements of collared white-tailed deer during February-June 2017, 2018, and 2019 that were captured in Little Girls Point, Lake Gogebic, West Iron County, and East Middle Branch deer wintering complexes and the chronic wasting disease core area in southern Dickinson County. The observed expansion by deer during March-May shows typical spring migration back to their summer range and the annual variation associated with the timing of migration as it relates to snowmelt. Mean distance between summer and winter ranges for migratory and mixed migratory white-tailed deer increased across deer wintering complexes with respect to greater snowfall (1.0 km [DNC], 6.9 km [WIC], 12.5 km [LGP], 23.8 km [LKG], and 32.4 km [EMB]). Western Upper Peninsula of Michigan, USA.
Below is the number of cause-specific mortalities by month for 2018-2020 combined. Human-caused mortalities were attributed to legal deer harvest (n = 50) during September-December, vehicle collisions (n = 6), and one deer that ran into an electric fence. Predations were attributed to wolves (n = 19), coyotes (n = 9), unknown canid (n = 3), unknown predators (n = 3), and bobcats (n = 2). We observed 20 mortalities due to starvation or exposure and one due to an infection. We designated 12 mortalities as unknowns where we were unable to determine the cause of mortality due to a lack of evidence at the site. Western Upper Peninsula of Michigan, USA.
Below are Kaplan-Meier survival estimates for collared adult (> 1-year-old) white-tailed deer during 1 June 2018-31 May 2019 (red) and 1 June 2019-31 May 2020 (blue). Survival estimates include all collared adult (> 1-year-old) individuals from the UP Deer Movement Study and the Michigan Predator-Prey Project. Two pronounced declines in survival occur during the biological year for deer surrounding deer hunting season and late winter, where the amount of mortality is dependent on hunting pressure and winter severity, respectively. Western Upper Peninsula of Michigan, USA.
Below are Kaplan-Meier survival estimates for all male (M) and female (F) adult (> 1-year-old) white-tailed deer collared on the UP Deer Movement Study and Michigan Predator-Prey Project during 1 June 2018–31 May 2019 (18) and 1 June 2019–31 May 2020 (19). Survival probability is significantly less for adult males as compared to adult females with most adult male mortality occurring over a short period of time during the fall hunting season. Western Upper Peninsula of Michigan, USA.
Shown below are locations of 296 remote cameras set by U.P. Deer Movement Study (red asterisks), Michigan Predator-Prey Project (blue asterisks), or Michigan Department of Natural Resources Wildlife Division (green asterisks). Cameras were set along secondary roads or trails (black lines) to collect images of deer during July–October. Also shown are county boundaries (gray lines), hydrology (blue lines/polygons), and deer management units (orange lines with orange highlighted text). Inset showing the location within the upper Great Lakes region of the USA. Western Upper Peninsula of Michigan, USA, 2018-2020.
Shown below are preliminary white-tailed deer density estimates for 2018 and 2019 camera surveys during 1 August-5 September. Color gradient represents snowfall zones (low = green, mid = yellow, high = orange) for Dickinson County (DNC), West Iron County (WIC), Deer Foot Lodge (DFL), Little Girls Point (LGP), Lake Gogebic (LKG), and East Middle Branch (EMB) populations. *Densities in 2018 for LKG were estimated with a shorter interval (i.e., 1–15 August) due to lesser detection probability in the second half of the survey. Western Upper Peninsula of Michigan, USA.
Deployed remote cameras captured 823,660 images during 2018, 2019, and 2020 surveys. Images of deer were cataloged into 3 categories; fawn, adult male, and adult female for analysis. In addition to the detection of deer, we will also use the detection of carnivores at sites as a covariate to see if their presence influences deer detection and ultimately abundance. The number of images obtained for select species during 2019 surveys is listed below from each camera array deployed by the U.P. Deer Movement Study (Dickinson County, Lake Gogebic, Little Girls Point, West Iron County), Michigan Predator-Prey Project (East Middle Branch; not all species were indexed), or the Michigan Department of Natural Resources Wildlife Division (Deer Foot Lodge) during July–October. Western Upper Peninsula of Michigan, USA.