Mule Deer Migration Corridors - Kern River - 2020-2021 [ds2977]

The project leads for the collection of this data were Julie Garcia and Evan King. Mule deer (32 adult females) from the Kern River herd were captured and equipped with Lotek LiteTrack Iridium collars, transmitting data from 2020-2021. GPS fixes were set for 2-hour intervals. The Kern River herd migrates from winter ranges in Sequoia National Forest north of Johnsondale and east of Slate Mountain northward to the area around Redrocks Meadows and along the Kern Canyon ridgeline to Sequoia National Park. Due to a high percentage of poor fixes, likely due to highly variable topographic terrain, between 2-18 percent of GPS locations per deer were fixed in 2-dimensional space and removed to ensure locational accuracy. The methodology used for this migration analysis allowed for the mapping of winter ranges and the identification of migration corridors and stopovers. Brownian Bridge Movement Models (BBMMs; Sawyer et al. 2009) were constructed with GPS collar data from 27 migrating deer, including 69 migration sequences, location, date, time, and average location error as inputs in Migration Mapper. The average migration time and average migration distance for deer was 15.38 days and 32.13 km, respectively. Corridors and stopovers were prioritized based on the number of animals moving through a particular area. Separate models using Brownian bridge movement models (BMMM) and fixed motion variances of 1000 were produced per migration sequence and compared for the entire dataset, with best models being combined prior to population-level analyses (10 percent of sequences selected with BMMM). Corridors were produced at a spatial resolution of 50 m using a sequential fix interval of less than 27 hours. Winter range analyses were based on data from 27 individual deer and 60 wintering sequences using a fixed motion variance of 1000. Winter range designations for this herd may expand with a larger sample, filling in some of the gaps between winter range polygons in the map. Additional migration routes and winter range areas likely exist beyond what was modeled in our output.Corridors are visualized based on deer use per cell in the BBMMs, with greater than or equal to 1 deer, greater than or equal to 3 deer (10 percent of the sample), and greater than or equal to 6 deer (20 percent of the sample) representing migration corridors, moderate use, and high use corridors, respectively. Stopovers were calculated as the top 10 percent of the population level utilization distribution during migrations and can be interpreted as high use areas. Stopover polygon areas less than 20,000 m2 were removed, but remaining small stopovers may be interpreted as short-term resting sites, likely based on a small concentration of points from an individual animal. Winter range is visualized as the 50th percentile contour of the winter range utilization distribution.

Data and Resources

Field Value
accessLevel public
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identifier 536cee32-97f9-4766-a5f0-8b275383fee6
issued 2022-02-17T20:59:07.000Z
modified 2022-02-17T20:59:20.071Z
publisher California Department of Fish and Wildlife
resource-type Dataset
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source_hash e3c38fa370db7cb919dffd8d29a77bdbf7288066
source_schema_version 1.1
theme {"Natural Resources",Water}
Groups
  • AmeriGEOSS
  • National Provider
  • North America
Tags
  • amerigeo
  • amerigeoss
  • authcdfw
  • brownian-bridge-movement-model
  • california
  • california-department-of-fish-and-wildlife
  • california-natural-resources-agency
  • caopendata
  • cdfw
  • ckan
  • connectivity
  • ds297720220204wm
  • geo
  • geoss
  • gps
  • migration
  • migration-mapper
  • mule-deer
  • national
  • north-america
  • odocoileus-hemionus
  • stopover
  • telemetry
  • tulare
  • united-states
  • winter-range
isopen False
license_id notspecified
license_title License not specified
maintainer BIOS_Admin
maintainer_email bios@wildlife.ca.gov
metadata_created 2025-11-22T22:15:21.417571
metadata_modified 2025-11-22T22:15:21.417575
notes The project leads for the collection of this data were Julie Garcia and Evan King. Mule deer (32 adult females) from the Kern River herd were captured and equipped with Lotek LiteTrack Iridium collars, transmitting data from 2020-2021. GPS fixes were set for 2-hour intervals. The Kern River herd migrates from winter ranges in Sequoia National Forest north of Johnsondale and east of Slate Mountain northward to the area around Redrocks Meadows and along the Kern Canyon ridgeline to Sequoia National Park. Due to a high percentage of poor fixes, likely due to highly variable topographic terrain, between 2-18 percent of GPS locations per deer were fixed in 2-dimensional space and removed to ensure locational accuracy. The methodology used for this migration analysis allowed for the mapping of winter ranges and the identification of migration corridors and stopovers. Brownian Bridge Movement Models (BBMMs; Sawyer et al. 2009) were constructed with GPS collar data from 27 migrating deer, including 69 migration sequences, location, date, time, and average location error as inputs in Migration Mapper. The average migration time and average migration distance for deer was 15.38 days and 32.13 km, respectively. Corridors and stopovers were prioritized based on the number of animals moving through a particular area. Separate models using Brownian bridge movement models (BMMM) and fixed motion variances of 1000 were produced per migration sequence and compared for the entire dataset, with best models being combined prior to population-level analyses (10 percent of sequences selected with BMMM). Corridors were produced at a spatial resolution of 50 m using a sequential fix interval of less than 27 hours. Winter range analyses were based on data from 27 individual deer and 60 wintering sequences using a fixed motion variance of 1000. Winter range designations for this herd may expand with a larger sample, filling in some of the gaps between winter range polygons in the map. Additional migration routes and winter range areas likely exist beyond what was modeled in our output.Corridors are visualized based on deer use per cell in the BBMMs, with greater than or equal to 1 deer, greater than or equal to 3 deer (10 percent of the sample), and greater than or equal to 6 deer (20 percent of the sample) representing migration corridors, moderate use, and high use corridors, respectively. Stopovers were calculated as the top 10 percent of the population level utilization distribution during migrations and can be interpreted as high use areas. Stopover polygon areas less than 20,000 m2 were removed, but remaining small stopovers may be interpreted as short-term resting sites, likely based on a small concentration of points from an individual animal. Winter range is visualized as the 50th percentile contour of the winter range utilization distribution.
num_resources 6
num_tags 26
title Mule Deer Migration Corridors - Kern River - 2020-2021 [ds2977]