Predator responses to fire: a global systematic review and meta-analysis

1. Knowledge of how disturbances such as fire shape habitat structure and
composition, and affect animal interactions, is fundamental to ecology and
ecosystem management. Predators also exert strong effects on ecological
communities, through top-down regulation of prey and competitors, which
can result in trophic cascades. Despite their ubiquity, ecological
importance and potential to interact with fire, our general understanding
of how predators respond to fire remains poor, hampering ecosystem
management. 2. To address this important knowledge gap, we conducted a
systematic review and meta-analysis of the effects of fire on terrestrial,
vertebrate predators worldwide. We found 160 studies spanning 1978–2018.
There were 36 studies with sufficient information for meta-analysis, from
which we extracted 96 effect sizes (Hedge’s g) for 67 predator species
relating to changes in abundance indices, occupancy or resource selection
in burned and unburned areas, or before and after fire. 3. Studies spanned
geographic locations, taxonomic families, and study designs, but most were
located in North America and Oceania (59% and 24%, respectively), and
largely focussed on felids (24%) and canids (25%). Half (50%) of the
studies reported responses to wildfire, and nearly one third concerned
prescribed fires. 4. There were no clear, general responses of predators
to fire, nor relationships with geographic area, biome or life history
traits (e.g. body mass and diet). Responses varied considerably between
species. Analysis of species for which at least three effect sizes had
been reported in the literature revealed that red foxes (Vulpes vulpes)
mostly responded positively to fire (e.g. higher abundance in burned
compared to unburned areas) and eastern racers (Coluber constrictor)
negatively, with variances overlapping zero only slightly for both
species. 5. Our systematic review and meta-analysis revealed strong
variation in predator responses to fire, and geographic and taxonomic
knowledge gaps. Varied responses of predator species to fire likely depend
on ecosystem context. Consistent reporting of ongoing monitoring and
management experiments is required to improve understanding of the
mechanisms driving predator responses to fire, and any broader effects
(e.g. trophic interactions). The divergent responses of species in our
study suggest that adaptive, context-specific management of predator-fire
relationships is required.