Data from: Breeding Sternula antillarum (Least Terns) disturbance distances and duration of escape behaviors: pedestrians necessitate larger conservation buffers than do passing vehicles

We tested the behavioral responses of breeding Sternula antillarum(Least
Terns) to pedestrians and off-road vehicles and show that disturbance
source, intra-colony characteristics, and environmental factors all
influenced the distance, at which the birds were disturbed, as well as the
duration of their response. Our goal was to inform wildlife buffer
distances used to protect breeding S. antillarum at Cape Hatteras National
Seashore, North Carolina and beyond. We measured breeding S. antillarum
behavioral responses to pedestrians and vehicles during routine activities
at eight colonies and during experimental activities at three colonies.
Pedestrians caused the highest flush probability when walking directly
towards a nest (Cox proportional hazard models: cumulative risk = 1 at
both 100 m and 50 m) and lowest when walking past a nest (cumulative risk
= 0.14 at 100 m and cumulative risk = 0.54 at 50 m). Passing vehicles had
the lowest probability of causing birds to flush, cumulative risk = 0.02
at all measured distances, up to 25 m from the nest. We also applied
generalized linear models to model the duration of responses and found
that it was affected by the number of nests in a colony, the density of
nests in a colony, nest life stage, nest clustering, date, degree of pivot
of a disturbance source along its route, and nest distance from colony
edge. These results suggest that conservation managers can reduce S.
antillarum buffers in locations where there are less disturbing human
activities or less reactive S. antillarum colonies.