Estimating ungulate migration corridors from sparse movement data

Many ungulates migrate between distinct summer and winter ranges, and identifying, mapping, and conserving these migration corridors have become a focus of local, regional, and global conservation efforts. Brownian bridge movement models (BBMMs) are commonly used to empirically identify these seasonal migration corridors; however, they require location data sampled at relatively frequent intervals to obtain a robust estimate of an animal’s movement path. Fitting BBMMs to sparse location data violates the assumption of conditional random movement between successive locations, overestimating the area (and width) of a migration corridor when creating individual and population-level occurrence distributions, and precluding the use of low-frequency, or sparse, data in mapping migration corridors. In an effort to expand the utility of BBMMs to include sparse global positioning system (GPS) data, we propose an alternative approach to model migration corridors from sparse GPS data. We demonstra..., , , # Estimating ungulate migration corridors from sparse movement data

We provide the 2-hour and 12-hour GPS locations for migration sequences (fall and spring) for the Atlantic Rim mule deer (*Odocoileus hemionus*), Clarks Fork mule deer, Dubois mule deer, and Jackson elk (*Cervus canadensis*) herds in Wyoming, USA.

The 2-hour GPS data come from GPS collars deployed opportunistically on mule deer and elk while on their winter ranges, before the start of the spring migration period. GPS collars collected location data at 2-hour intervals. First, we manually identified the spring and fall migratory periods for each individual by selecting migration start and end dates, which coincided with changes in the net squared displacement (NSD) curve of each animal-year using the Migration Mapper application (Bunnefeld et al. 2011, Merkle et al. 2022). This resulted in the 2-hour GPS migration sequences shared here. Second, we subsampled the 2-hour data to one location every 12 hours (hereafter, 1...