DOI: 10.5061/dryad.qjq2bvqg6
title: Past agricultural land use affects multiple facets of ungulate antipredator behavior

description: Antipredator behavior affects prey fitness, prey demography, and the
 strength of ecological interactions. Although predator-prey interactions
 increasingly occur in habitats that experience multiple forms of
 human-generated disturbance, it is unclear how different forms of
 disturbance might affect antipredator behavior. Fire is a contemporary
 disturbance that has dramatic effects on terrestrial habitats. Such
 habitats may have also experienced past disturbances, like agricultural
 land use, that leave lasting legacies on habitat structure (e.g.,
 overstory and understory composition). It is unclear how these past and
 present disturbances affect the use of different antipredator behaviors,
 like temporal avoidance and vigilance. We examined whether variation in
 disturbance regimes generates differences in ungulate antipredator
 behavior by using cameras to measure white-tailed deer vigilance and
 activity time across 24 longleaf pine woodlands that vary in past land use
 and contemporary fire regime. Regardless of land-use history, woodlands
 with high fire frequencies had 4 times less vegetation cover than low-fire
 woodlands, generating riskier habitats for deer; however, deer responded
 to fire with different antipredator strategies depending on land-use
 history. In nonagricultural woodlands, fire affected deer activity time
 such that activity was nocturnal in low-fire woodlands and crepuscular in
 high-fire woodlands. In post-agricultural woodlands, fire affected
 vigilance and not activity time such that deer were more vigilant in
 high-fire woodlands than in low-fire woodlands. These results suggest that
 ungulate antipredator behavior may vary spatially depending upon past land
 use and contemporary fire regime, and such disturbances may generate
 “landscapes of fear” that persist for decades after agricultural use. --
description: This study was conducted at the Savannah River Site (SRS; Aiken,
 SC). Sites that were farmland in 1951 were classified as
 “post-agricultural woodlands,” and sites that were forested were
 classified as “nonagricultural woodlands.” The number of fires since 1991
 was determined from annual fire records, and sites were characterized as
 low (five or less burns) or high (more than five burns) fire
 frequency. Sites were not burned the year of the study. At each of our 24
 sites, we deployed an unbaited, motion-activated camera trap between June
 8 and July 9 in 2018 for a total trapping period of 33 days. For every
 photo capturing deer activity during an independent foraging bout, the
 observer recorded the date and time, the sex of the individual, whether or
 not it was in a group, group size, and if the individual was foraging (1)
 or being vigilant (0) as a binomial variable. If the individual’s head was
 up in a non-feeding posture, then the photo was classified as vigilant,
 and if the individual’s head was down in a feeding posture, then the photo
 was classified as foraging. We characterized independent foraging bouts as
 any sequence of deer photos of the same sex captured within 30 minutes at
 a site. Vertical vegetation cover was measured by a single observer using
 a density board that estimated percent visibility across 1 x 1 foot
 quadrats. The density board was placed 15-m from the observer standing at
 the camera-trap station. The observer took four measurements (one in each
 cardinal direction from the station) at each site.