Barrier interactions
To understand hyena behavior around fences and determine the locations
of weak or robust fences on the protected area boundaries, we used the
Barrier Behavior Analysis (BaBA) methodology developed by Xu et al.
(2020). BaBA examines whether, where, and how often animal movements
were altered by linear barriers such as fences by classifying movement
trajectories within set buffers around target barriers into normal
movement (quick cross , average movement), altered movement
(bounce , trace , or back and forth ), and trapped
movement. To assess the appropriate sensitivity for the BaBA results, we
used BaBA with 50m, 100m, and 150m fence buffer distances within which
GPS locations were classified as fence encounters (Xu et al. 2020).
Finally, to supplement our understanding of hyena interactions with and
crossing of the boundary fences, we used images of spotted hyenas from
camera traps placed on sixteen key crossing points at the LNNP fence
from June 2018 - November 2019 (see Wilkinson et al. 2021b for
detailed methodology). Spotted hyenas in camera trap images were
individually identified using spot patterns and compared to individuals
previously listed in both the LNNP and Soysambu Conservancy hyena ID
books (see Supporting Information). Hyenas appearing at the fence were
first compared to the clan with a range closest to the camera trap site
but then expanded to all others in the book if not identified. The hyena
was labeled as unknown if we could not definitively identify the
individual. These unknown individuals were later added to the Lake
Nakuru or Soysambu Conservancy ID Books under a new ID code and used for
further identification of images. We assessed the frequency of fence
approaches at each site and by specific individuals, as well as the
number of different fence crossing sites visited by each individual.