DOI: 10.5061/dryad.6m905qg4q
title: Data from: Long term monitoring reveals the importance of large, long unburnt areas and smaller fires in moderating mammal declines in fire-prone savanna of northern Australia

description: Biodiversity loss is often attributable to multiple interacting pressures
 that are moderated across environmental gradients. These
 processes contribute to complex
 responses that are challenging
 to interpret and understand. Well-designed and
 well-implemented monitoring can play a vital role
 in this but is rarely undertaken. Mounting evidence
 suggests that current fire regimes across savanna ecosystems have
 contributed to the decline of a range of biota. Hence, contemporary fire
 regimes are at odds with conservation goals. Using an extensive
 spatio-temporal monitoring dataset from three large National Parks in
 northern Australia, we applied generalised linear mixed models to examine:
 1) trends in mammal richness and abundance through time and how these vary
 across environmental gradients such as productivity or landscape
 position (e.g., terrain ruggedness); and 2)
 how fire, a potential
 driver, is moderated by environmental
 gradients. Across 24-years, major declines in
 mammal richness and
 abundance were observed with greater reductions
 in less rugged and less
 mesic habitats. Patterns of decline
 were related to multiple aspects of fire regimes, but
 not changes in vegetation structure and
 composition, or the arrival
 of Cane Toads Rhinella marina and
 concomitant poisoning
 of predatory animals during consumption. More
 pronounced declines occurred in sites that were exposed
 to larger fires, had less long unburnt (5
 years without fire) vegetation,
 and were more distant from large, long unburnt
 patches. Relationships between mammal persistence and fire varied among
 vegetation communities, with the strongest fire effects observed in
 lowland woodland – relatively drier with few barriers to fire spread –
 where the availability of long unburnt areas moderated declines more than
 in other vegetation communities. Synthesis and applications. Current fire
 regimes are contributing to mammal declines in northern Australian
 savanna. Collectively, our results highlight: 1) the value of long term
 monitoring, and importance of considering landscape position when
 assessing faunal responses to landscape-level perturbations like fire; 2)
 that significant improvements in fire regimes are required to ameliorate
 mammal declines; and 3) the need to shift management focus from retaining
 small, short-lived unburnt patches towards preserving relatively large
 contiguous areas of long unburnt habitat, particularly in less rugged
 lowland and sandstone woodlands.
description: We monitored the mammal community using standardised trapping and
 nocturnal searches. During the 1995 – 2015 monitoring
 period, sites accessible by vehicle were sampled for 72 hrs, and sites
 accessible only by helicopter were sampled for 48 hrs. Sampling occurred
 from April to November, with each site visited in the same month and
 sampled with the same effort between sessions. For the 48 hr surveys, 30
 Elliott traps (33 x 10 x 9 cm) were placed equidistantly around the
 perimeter of a 50 x 50 m trapping quadrat, six cage traps (56 x 20 x 20
 cm) were placed at each corner and mid-way along the perimeter, and three
 20 L pitfall traps (with 10 m of drift-line fence) were placed within the
 quadrat. For the 72 hr surveys, the same number of trap nights were
 achieved using 20 Elliott traps, four cage traps, and two pitfall traps.
 Between 2016 and 2019 sampling occurred from May – August, and the
 trapping period was increased to 96 hours, using 16 Elliott traps, eight
 cage traps, and three pitfall traps. Prior to analysis, the 96 hr sampling
 data was truncated to either 48 or 72 hrs by omitting captures from the
 third and/or fourth night to match the previous sampling effort for each
 site. Cage and Elliott traps were open at night and baited with a mixture
 of peanut butter, honey, and oats. All traps were checked within 1 h of
 dawn on each sampling day. All captured mammals were identified to species
 level and released at the point of capture without being marked.
 Additionally, spotlight searches were performed on each night of sampling
 within a 1 ha square overlaying the trapping quadrat. All mammals seen
 during a 10-minute meander search of the site were recorded.
 This study focused on small to medium sized
 native non-flying mammals (&lt;5 kg body mass, herein referred to as
 mammals), the group for which marked declines have previously been
 reported (Woinarski et al., 2010): i.e., we did not consider bats, the
 dingo <em>Canis familiaris</em> and a small set of macropod
 species. An abundance value for each mammal species was tallied as the sum
 of all captures and all individuals recorded during spotlight searches
 (herein referred to as captures) at each site in each sampling
 session.
description: Microsoft Excel