Data for: Behavioral responses of migratory caribou to semi-permeable roads in Arctic Alaska

Migration conveys many benefits to species, ecosystems, and people, but
relies upon connected landscapes. Anthropogenic development can present
barriers for migrants, but many barriers are semi-permeable, allowing
unhindered or delayed passage. We use a modified version of the Barrier
Behavior Analysis (BaBA) to investigate movement responses and
permeability of roads in northwestern Alaska by adult female Western
Arctic Herd caribou (Rangifer tarandus) from 2009–2024. These data include
the BaBA results that we used to reveal behavioral responses to roads by
study caribou. Our analyses revealed movement responses to all five focal
roads. We found that the roads were semi-permeable barriers to movement,
with altered behaviors including bouncing away, moving back-and-forth, and
tracing along roads. Overall, 63.1% of collared animals encountered
(entered a road-specific buffer) at least one focal road. Of these, 61.5%
displayed altered movements. At the scale of individual encounters with
roads, we found altered movement in 27.1% of road encounters. Each row of
the dataset represents one burst, indicating subdivisions of road
encounters that reflect specific behavioral responses. Encounter timing is
also indicated for each record. Most encounters occurred during fall
migration, and caribou with altered behavior spent longer near focal roads
than those with unaltered movement. We confirm prior findings of altered
fall movements near the Red Dog road and demonstrate that movement
behavior is also altered around other roads and in other seasons.
Nonetheless, many collared caribou did not display altered movements in
response to roads, emphasizing the need for further research to understand
the mechanistic drivers of caribou movement responses. Given increasing
pressures for infrastructure development and global challenges facing
migratory species, it is critical to identify mitigation measures and
inform management decisions seeking to balance responsible development
with conservation of natural systems, including migratory species and the
people that rely upon them.