DOI: 10.5061/dryad.1g1jwstwq
title: Data from: Megafires attract avian scavenging but carcasses still persist

description: AIM The effects of fires on vertebrate scavengers have not been
 characterised despite the importance of scavenging in shaping food web
 dynamics. We assessed whether the 2019/2020 megafires in Australia shifted
 the species richness, carcass detection, and feeding times of vertebrate
 scavengers, and whether the fire affected carcasses persistence times.
 LOCATION Blue Mountains, south-eastern Australia. METHOD We monitored
 vertebrate scavengers via remote cameras on a total of 60 experimentally
 placed kangaroo carcasses for 30 days in two periods before the megafire
 (January 2018 and 2019) and one period after the megafire (March 2020) in
 both open and closed canopy habitats. We compared vertebrate species
 richness, carcass discovery and scavenging activity before and after the
 fire and between the two habitats. We also assessed carcass persistence
 (time to carcass removal) before and after the fire and between the two
 habitats. RESULTS We collected more than 689,000 images of nine vertebrate
 scavengers including six avian, two mammal, and one reptile species. We
 detected no decline in scavenger species richness following the fire, and
 rates of carcass detection for mammals and reptiles did not differ across
 pre- and post-fire periods. On the other hand, avian scavengers detected
 carcasses faster in the post-fire period and in open compared to closed
 canopy habitats. Overall, scavengers increased their feeding times in the
 post-fire period, especially avian scavengers, but carcasses persisted
 longer in the post-fire period when compared to the second pre-fire
 period. MAIN CONCLUSION Our study identified that a widespread fire could
 influence avian scavenging dynamics, but that other factors affected
 carcass persistence times over the study period. Future monitoring of
 carcasses following fires should focus on the responses by both vertebrate
 and insect scavengers to fully elucidate the effects of these major
 disturbance events on critical ecosystem processes linked to
 decomposition.
description: <strong>Data collection</strong>
 Our study was conducted in the Wolgan Valley in the Blue
 Mountains, south-eastern New South Wales. Carcass monitoring was conducted
 over three 1-month periods in the warm seasons of summer and autumn. The
 first two monitoring periods were conducted before a fire, in January 2018
 and 2019, and the third was conducted in March of 2020. During each
 monitoring period, we distributed 20 adult eastern grey kangaroo carcasses
 in an equal mix of open grassland (hereafter “open canopy”; n=10 sites)
 and forest (hereafter “closed canopy”; n=10 sites) habitat. Open canopy
 sites were at least 50 m from any stands of trees. The closed canopy sites
 had more than 20% canopy cover before the fire, and in the post-fire
 period carcasses were placed in forested locations where there was
 previously canopy cover of more than 20%. Within monitoring periods,
 carcasses were separated by at least 1 km to mitigate scent travel between
 carcasses. Between monitoring periods, however, carcasses were positioned
 at least 100 m from any previous carcass placement. We used dead kangaroos
 sourced from nearby management culls, so no animals were killed for the
 purpose of this study. Any carcass displaying evidence of disease (e.g.
 heavy parasite loads) was not used. All carcasses were placed into the
 field without freezing within 24 hours of collection (i.e. all at the same
 time, with 24 hours being the longest time between the first and last
 carcass placement; January 2018; 9:00 – 23:00, January 2019; 8:00 – 13:00,
 and March 2020; 23:00 – 6:00). Scientific licenses/permits were obtained
 to relocate the kangaroo carcasses (SL 101901) and research was approved
 by the University of Sydney Animal Ethics Committee (Project number:
 2017/1173). To allow for ongoing monitoring and
 detection of scavengers visiting and feeding on each carcass, we used a
 Reconyx PC800 Hyperfire™ camera trap (Professional Reconyx Inc., Holmen,
 WI, USA) attached to a free-standing star picket 3–4 m away from each
 carcass. The cameras were programmed to take continuous photographs when
 triggered by thermal movement around the carcass (rapidfire, no wait
 period). To prevent complete removal of the carcasses from the remote
 camera monitoring frame, we secured carcasses to the ground by wire
 attaching the neck and achilles tendon of the animal to two metal stakes
 spaced ~0.6 m apart. Cameras were used to monitor carcasses for 30 days to
 capture the main period of vertebrate scavenging activity and because the
 majority of carcass biomass (including meat, skin and bones) were removed
 from the environment in this time. <strong>Data
 processing</strong> Camera images were tagged
 according to each new carcass visitation event by a different species, the
 number of individuals of a species present, whether any of the individual
 species fed on the carcass or not, and the date and time that the
 observation was recorded. A visitation event was considered new if it
 occurred ≥ 10 min from the previous visitation event by the same species.
 We defined scavenger species as species that were observed feeding on at
 least one carcass over the three study periods. All other animals captured
 on the remote cameras were excluded from our analyses. Finally, using a
 combination of in-person visual inspection of the carcasses and inspection
 of camera images, we determined the number of days until complete carcass
 consumption. A carcass was defined as completely consumed when less than
 5% meat biomass and only skin, hair and/or bone remained.
description: Each dataset (tab) used for the main statistical analysis in the
 related paper have been uploaded. Some notes are provided in each
 tab.