Predators in a mining landscape: Threats to a behaviourally unique, endangered lizard

Abstract

Patchy resource distribution can cluster predator activity around areas of the highest productivity in ecosystems. For the endangered Western Spiny-tailed Skink (Egernia stokesii badia) in Western Australia, the log piles that they permanently inhabit in an otherwise patchy, arid landscape, represent a potentially reliable, high abundance food source for predators. Not only are encounter rates by potential predators of E. s. badia likely to be influenced by vegetation structure at the microhabitat scale but also E. s. badia occurs in a region where mine sites and associated infrastructure, such as landfill sites, likely concentrate generalist predators (e.g. Feral Cats and corvids). We assessed the influence of the presence of coarse woody debris (CWD) and distance to the landfill on predator behaviour towards E. s. badia through plasticine model experiments, unbounded point count bird surveys and camera trapping. We found that CWD inhabited by E. s. badia attracted a greater relative activity of corvids compared with uninhabited CWD, or control sites without CWD. The relative activity of corvids and predatory birds combined increased with decreasing distance from the landfill. Preferential hunting by corvids at CWD inhabited by E. s. badia compared to both uninhabited CWD and open sites suggests that inhabited CWD may be targeted by generalist predators in the region, and that adaptive management may be required for species conservation around active mining areas.

Movement ecology of an endangered mesopredator in a mining landscape

“…Another potential explanation for the observed avoidance of mining habitats in breeding season may be due to risk avoidance, or the landscape of fear [ 153 , 154 ]. Like natural landscapes where quolls avoid predators that thrive in spinifex grassland [ 53 , 155 ], mining habitats often present comparable or greater threats from feral cats and dingoes [ 43 , 54 , 55 , 156 ]. Built infrastructure, such as roads and waste dumps, can attract predators and increase predation risk [ 101 , 157 , 158 ].…”

“…Mine sites are expected to be similarly unattractive to northern quolls as spinifex grassland, given the similar predator risk [ 54 , 55 ], and presumed lack of denning resources compared to rocky habitat [ 48 ]. While there are some known instances of northern quolls interacting with human features such as rail infrastructure [ 56 , 57 ] and rehabilitated habitats [ 47 ], our understanding of their movement and energy requirements in active mining landscapes remains poor [ 50 ].…”

Hyperpredation of Freshwater Turtles and Tortoises by Subsidized Corvids

“…(Table 2) discussed in this review. The management of Corvus is directly advised for the conservation of several vulnerable turtles in the United States (Boarman 2002, 2003; Kristan and Boarman 2003; Leary et al 2008), South Africa (Loehr and Keswick 2022), and Australia (Burbridge et al 2010; Bower and Hodges 2014), as well as several lizard (Oversby et al 2018; Bradley et al 2022) and bird species (Liebezeit and George 2002; Peery and Henry 2010; Coates et al 2016; Ekanayake et al 2016). Corvids can be subject to unjust vilification, and therefore it is important that assessments of their impact on biodiversity and decisions regarding population management be rooted in sound science (Luginbuhl et al 2001; Liebezeit and George 2002; Boarman 2003).…”

Ecological Considerations When Designing Mitigation Translocations: An Australian Reptile Case Study

“…The influence of the presence of log piles on predator behaviour towards E. s. badia was assessed through plasticine model experiments, unbounded point count bird surveys and camera trapping [ 52 ]. An equal number of sites with and without log piles were selected, and replica plasticine models of E. s. badia were placed at each site type to assess predation pressure in relation to log piles.…”