SDE Feature Class
Tags
mule deer, Odocoileus hemionus, GPS, Brownian bridge movement model, migration mapper, stopover, winter range, telemetry, connectivity, Verdi, Truckee, Reno, California, Sierra Nevada, Nevada
Migration corridor, stopover, and winter range locations for mule deer (Odocoileus hemionus) developed by the California Department of Fish and Wildlife (CDFW) for the Verdi-Truckee herd, which migrate between Nevada and California. Corridors, stopovers, and winter ranges were developed in Migration Mapper with Brownian Bridge Movement Models using GPS locations from collared deer. Migration corridors represent movement routes used by deer between winter and summer range habitats. Moderate use corridors were used by greater than or equal to 10% of the animals sampled, and high use corridors were used by greater than or equal to 20% of the animals sampled. Migration stopovers and winter range polygons also represent high use areas.
The project leads for the collection of this data were Sara Holm with California Department of Fish and Wildlife and Mike Cox with Nevada Department of Wildlife. Carl Lackey and Cody Schroeder of the Nevada Department of Wildlife and Julie Garcia of California Department of Fish and Wildlife also contributed to the completion of the mapping and project. The Verdi-Truckee mule deer herd primarily winters south of Interstate 80 in the Carson Range along the California-Nevada border, although a portion of this herd also winters north and east of Verdi, Nevada on Peavine Mountain. Migration routes to summer range follow I-80 southwest along both sides of the Truckee River toward Martis Valley and Truckee, California. The summer range for this small herd (approximately 500 animals estimated in 2019) is located east the town of Truckee, California and includes portions of Juniper Flat, Martis Creek, and south of the Truckee River to the confluence of Gray Creek. Migration behavior and timing of migration is highly dependent on seasonal weather conditions and the depth of snow during late fall and early winter periods. Significant challenges to this deer herd include barriers to movement, such as Interstate 80 and associated vehicle collisions, as well as increased housing development on winter range in the Garson Road area and surrounding Verdi neighborhoods. Twenty-five adult female mule deer were captured and fitted with store-on-board GPS collars from 2009 to 2010, and additional deer were collared sporadically between 2012-2017. Between 2 and 22 location fixes were recorded per day. To improve the quality of the data set as per Bjrneraas et al. (2010), the GPS data were filtered prior to analysis to remove locations which were: i) further from either the previous point or subsequent point than an individual deer is able to travel in the elapsed time, ii) forming spikes in the movement trajectory based on outgoing and incoming speeds and turning angles sharper than a predefined threshold , or iii) fixed in 2D space and visually assessed as a bad fix by the analyst.
The methodology used for this migration analysis allowed for the mapping of winter ranges and the identification and prioritization of migration corridors in a single deer population. Brownian Bridge Movement Models (BBMMs; Sawyer et al. 2009) were constructed with GPS collar data, including location, date, time, and average location error as inputs in Migration Mapper. Thirty-one deer contributing 91 migration sequences were used in the modeling analysis. Corridors and stopovers were prioritized based on the number of animals moving through a particular area. BBMMs 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 31 individual deer and 74 wintering sequences using a fixed motion variance of 1000. Winter range designations for this herd would likely expand with a larger sample, filling in some of the gaps between winter range polygons in the map. Large water bodies were clipped from the final outputs.
Corridors are visualized based on deer use per cell, with greater than or equal to 1 deer, greater than or equal to 3 deer (10% of the sample), and greater than or equal to 6 deer (20% of the sample) from the Loyalton dataset 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 m 2 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 50 th percentile contour of the winter range utilization distribution.
Migration Mapper: https://migrationinitiative.org/content/migration-mapper Bjrneraas, K., Van Moorter, B., Rolandsen, C. M., and Herfindal, I. (2010). Screening global positioning system location data for errors using animal movement characteristics. The Journal of Wildlife Management, 74(6), 1361-1366. Sawyer, H., Kauffman, M. J., Nielson, R. M., and Horne, J. S. (2009). Identifying and prioritizing ungulate migration routes for landscapelevel conservation. Ecological Applications, 19(8), 2016-2025.
The user accepts sole responsibility for the correct interpretation of this report and the correct use of its accompanying dataset. Prior to using this dataset, please contact Cody Schroeder or Julie Garcia to ensure correct interpretation of the data. The data is best interpreted at a scale of 1:100,000 or larger. Given the small sample size used to construct winter range utilization distributions and migration corridors from this herd, winter range for mule deer likely extends beyond the borders of what is considered winter range in our analysis, and may not represent the true extent of the winter range for this population. Moreover, our sample only represents a small fraction of the true population of migrating mule deer in this herd; therefore, many corridors may have gone undetected in our analysis. This analysis represents migration corridors, stopovers, and winter range from one deer herd, one study, and is one of a suite of datasets being developed for Californias ungulate herds by CDFW.
CDFW makes no warranty of any kind regarding these data, express or implied. By downloading these datasets, the user understands that these data are subject to change at any time as new information becomes available. The user will not seek to hold the State or the Department liable under any circumstances for any damages with respect to any claim by the user or any third party on account of or arising from the use of data or maps. CDFW reserves the right to modify or replace these datasets without notification. No statement or dataset shall by itself be considered an official response from a state agency regarding impacts to wildlife resulting from a management action subject to the California Environmental Quality Act (CEQA).
License: This work is licensed under Creative Commons Attribution 4.0 International License ( https://creativecommons.org/licenses/by/4.0/ ). Using the citation standards recommended for BIOS datasets ( https://www.wildlife.ca.gov/Data/BIOS/Citing-BIOS ) satisfies the attribution requirements of this license.
Disclaimer: The State makes no claims, promises, or guarantees about the accuracy, completeness, reliability, or adequacy of these data and expressly disclaims liability for errors and omissions in these data. No warranty of any kind, implied, expressed, or statutory, including but not limited to the warranties of non-infringement of third party rights, title, merchantability, fitness for a particular purpose, and freedom from computer virus, is given with respect to these data.
Extent
West | -120.299724 | East | -119.862547 |
North | 39.584094 | South | 39.320724 |
Maximum (zoomed in) | 1:5,000 |
Minimum (zoomed out) | 1:150,000,000 |
The user accepts sole responsibility for the correct interpretation of this report and the correct use of its accompanying dataset. Prior to using this dataset, please contact Cody Schroeder or Julie Garcia to ensure correct interpretation of the data. The data is best interpreted at a scale of 1:100,000 or larger. Given the small sample size used to construct winter range utilization distributions and migration corridors from this herd, winter range for mule deer likely extends beyond the borders of what is considered winter range in our analysis, and may not represent the true extent of the winter range for this population. Moreover, our sample only represents a small fraction of the true population of migrating mule deer in this herd; therefore, many corridors may have gone undetected in our analysis. This analysis represents migration corridors, stopovers, and winter range from one deer herd, one study, and is one of a suite of datasets being developed for Californias ungulate herds by CDFW.
CDFW makes no warranty of any kind regarding these data, express or implied. By downloading these datasets, the user understands that these data are subject to change at any time as new information becomes available. The user will not seek to hold the State or the Department liable under any circumstances for any damages with respect to any claim by the user or any third party on account of or arising from the use of data or maps. CDFW reserves the right to modify or replace these datasets without notification. No statement or dataset shall by itself be considered an official response from a state agency regarding impacts to wildlife resulting from a management action subject to the California Environmental Quality Act (CEQA).
License: This work is licensed under Creative Commons Attribution 4.0 International License ( https://creativecommons.org/licenses/by/4.0/ ). Using the citation standards recommended for BIOS datasets ( https://www.wildlife.ca.gov/Data/BIOS/Citing-BIOS ) satisfies the attribution requirements of this license.
Disclaimer: The State makes no claims, promises, or guarantees about the accuracy, completeness, reliability, or adequacy of these data and expressly disclaims liability for errors and omissions in these data. No warranty of any kind, implied, expressed, or statutory, including but not limited to the warranties of non-infringement of third party rights, title, merchantability, fitness for a particular purpose, and freedom from computer virus, is given with respect to these data.