DOI: 10.5061/dryad.s77dk4v
title: Data from: Temporal partitioning of activity: rising and falling top-predator abundance triggers community-wide shifts in diel activity

description: Top predators cause avoidance behaviours in competitors and prey, which
 can lead to niche partitioning and facilitate coexistence. We investigate
 changes in partitioning of the temporal niche in a mammalian community in
 response to both the rapid decline in abundance of a top predator and its
 rapid increase, produced by two concurrent natural experiments: 1) the
 severe decline of the Tasmanian devil due to a transmissible cancer, and
 2) the introduction of Tasmanian devils to an island, with subsequent
 population increase. We focus on devils, two mesopredators, and three prey
 species, allowing us to examine niche partitioning in the context of
 intra- and inter-specific competition, and predator-prey interactions. The
 most consistent shift in temporal activity occurred in devils themselves,
 which were active earlier in the night at high densities, presumably
 because of heightened intraspecific competition. When devils were rare,
 their closest competitor, the spotted-tailed quoll, increased activity in
 the early part of the night, resulting in increased overlap with the
 devil’s temporal niche and suggesting release from interference
 competition. The invasive feral cat, another mesopredator, did not shift
 its temporal activity in response to either decreasing or increasing devil
 densities. Shifts in temporal activity of the major prey species of devils
 were stronger in response to rising than to falling devil densities. We
 infer that the costs associated with not avoiding predators when their
 density is rising (i.e., death) are higher than the costs of continuing to
 adopt avoidance behaviours as predator densities fall (i.e., loss of
 foraging opportunity), so rising predator densities may trigger more rapid
 shifts. The rapid changes in devil abundance provide a unique framework to
 test how the non-lethal effects of top predators affect community-wide
 partitioning of temporal niches, revealing that this top-predator has an
 important but varied influence on the diel activity of other species.
description: Temporal overlap:
 top-predator declineCamera data used to
 analyse changes in temporal activity on the Tasmanian mainland in response
 to Tasmanian devil population declines. This data file was used in the
 analysis of circular overlap, and was used to produce the left column of
 Figure 2 from our paper in Ecography. See README for details about
 variables.overlapData_decliningDevil_Ecography.csvTemporal overlap: top-predator introductionCamera data used to analyse changes in temporal activity following the introduction of Tasmanian devils to Maria Island. This data file was used in the analysis of circular overlap, and was used to produce the right column of Figure 2 from our paper in Ecography. See README for details about variables.overlapData_increasingDevil_Ecography.csvChanges in Tasmanian devil temporal activity following population declineChanges in Tasmanian devil temporal activity following severe population declines.Camera data was analysed using a GAM to produce Fig 3A of our paper in Ecography. Tasmanian devil records at each site were binned into the nearest hourly bin i.e. there was a total of 24 bins. We then calculated the proportion of total activity in each hour of the day for each site. See paper for details.devilTemporalActivity_GAM_decliningDevil.csvChanges in spotted-tailed quoll temporal activityChanges in spotted-tailed quoll temporal activity following the decline of Tasmanian devils. This camera data was analysed using a GAM to produce Fig 3B of our paper in Ecography. Spotted-tailed quoll records at each site were binned into the nearest hourly bin i.e. there was a total of 24 bins. We then calculated the proportion of total activity in each hour of the day for each site. See paper for details.quollTemporalActivity_GAM.csvChanges in Tasmanian devil temporal activity following increase in densityChanges in Tasmanian devil temporal activity following the introduction of Tasmanian devils to Maria Island ("MI"), compared to a control site ("C"). This camera data was analysed using a GAM to produce Fig 3C of our paper in Ecography. Devil records at each site were binned into the nearest hourly bin i.e. there was a total of 24 bins. We then calculated the proportion of total activity in each hour of the day for each site. See paper for details.devilTemporalActivity_GAM_increasingDevil.csvChanges in Bennett's wallaby temporal activity following increase in top-predator densityChanges in Bennett's wallaby temporal activity following the introduction of Tasmanian devils to Maria Island ("MI"), compared to a control site ("C"). This camera data was analysed using a GAM to produce Fig 3D of our paper in Ecography. Wallaby records at each site were binned into the nearest hourly bin i.e. there was a total of 24 bins. We then calculated the proportion of total activity in each hour of the day for each site. See paper for details.wallabyTemporalActivity_GAM.csv