Pronghorn Home Range - California Valley - 2017-2019 [ds3037]

The project lead for the collection of this data was Bob Stafford. Pronghorn (3 adult females, 3 adult males) from the California Valley herd were captured and equipped with Lotek GPS collars (Lotek GlobalstarTrack , Lotek Wireless, Newmarket, Ontario, Canada ), transmitting data from 2017-2019. The study area was within the California Valley, north of the Carrizo Plain and within a patchwork of private and protected lands. Route 58 divides the home range but does not appear to be an impassible barrier to movement. No exchange has been observed between the California Valley herd and the Carrizo Plain herd, possibly due to subdivision development deterring movement. The California Valley herd does not migrate between traditional summer and winter seasonal ranges. Instead, the herd displays a residential pattern, moving through their home range as needed. Therefore, annual home ranges were modeled using year-round data to demarcate high use areas in lieu of modeling the specific winter ranges commonly seen in other ungulate analyses in California. This herd did demonstrate forays into higher elevation areas in the Coastal Range. GPS locations were fixed at 13-hour intervals in the dataset. 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 elk 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 analysis allowed for the mapping of the herds annual range based on a small sample. Brownian Bridge Movement Models (BBMMs; Sawyer et al. 2009) were constructed with GPS collar data from 5 pronghorn in total, including 8 year-long sequences, location, date, time, and average location error as inputs in Migration Mapper to assess annual range. Annual range BBMMs were produced at a spatial resolution of 50 m using a sequential fix interval of less than 27 hours. Population-level annual range designations for this herd may expand with a larger sample, filling in some of the gaps between high-use annual range polygons in the map. Annual range is visualized as the 50 th percentile contour (high use) and the 99 th percentile contour of the year-round utilization distribution.

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 Bob Stafford, Dave Hacker, or Brandon Swanson 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 annual range utilization distributions from this herd, annual range for pronghorn likely extends beyond the borders of what is considered high use annual range in our analysis, and likely does not represent the true extent of the home range for this herd. This analysis represents annual range from one pronghorn population, 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).

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.