Seasonal and predator-prey effects on circadian activity of free-ranging mammals revealed by camera traps

Abstract

Endogenous circadian and seasonal activity patterns are adapted to facilitate effective utilisation of environmental resources. Activity patterns are shaped by physiological constraints, evolutionary history, circadian and seasonal changes and may be influenced by other factors, including ecological competition and interspecific interactions. Remote-sensing camera traps allow the collection of species presence data throughout the 24 h period and for almost indefinite lengths of time. Here, we collate data from 10 separate camera trap surveys in order to describe circadian and seasonal activity patterns of 10 mammal species, and, in particular, to evaluate interspecific (dis)associations of five predator-prey pairs. We recorded 8,761 independent detections throughout Northern Ireland. Badgers, foxes, pine martens and wood mice were nocturnal; European and Irish hares and European rabbits were crepuscular; fallow deer and grey and red squirrels were diurnal. All species exhibited significant seasonal variation in activity relative to the timing of sunrise/sunset. Foxes in particular were more crepuscular from spring to autumn and hares more diurnal. Lagged regression analyses of predator-prey activity patterns between foxes and prey (hares, rabbits and wood mice), and pine marten and prey (squirrel and wood mice) revealed significant annual and seasonal cross-correlations. We found synchronised activity patterns between foxes and hares, rabbits and wood mice and pine marten and wood mice, and asynchrony between squirrels and pine martens. Here, we provide fundamental ecological data on endemic, invasive, pest and commercially valuable species in Ireland, as well as those of conservation importance and those that could harbour diseases of economic and/or zoonotic relevance. Our data will be valuable in informing the development of appropriate species-specific methodologies and processes and associated policies.

Environmental DNA (eDNA) metabarcoding of pond water as a tool to survey conservation and management priority mammals

“…mice, voles, shrews. Importantly, the deployment period, height, and positioning of camera traps may have influenced small mammal detection by this method (Caravaggi et al, 2018). Ishige et al (2017) achieved comparable mammal detection at salt licks with eDNA metabarcoding and camera trapping, but species presence was inconsistent between salt licks surveyed.…”

“…Many mammals are nocturnal and elusive thus monitoring requires non-invasive, observational methods, e.g. camera traps and field signs (Caravaggi et al, 2018; Harris & Yalden, 2004; Sadlier, Webbon, Baker, & Harris, 2004). Camera trapping is cost-efficient, standardised, reproducible, and produces data suited to site occupancy modelling, but only surveys a fraction of large, heterogeneous landscapes.…”

“…Camera trapping is cost-efficient, standardised, reproducible, and produces data suited to site occupancy modelling, but only surveys a fraction of large, heterogeneous landscapes. Trap placement can substantially influence species detection probabilities, and traps often miss small species (Burton et al, 2015; Caravaggi et al, 2018; Ishige et al, 2017; Stat et al, 2019). Field sign surveys are inexpensive, but resource-intensive for broad geographic coverage (Sadlier et al, 2004).…”

Interspecific visitation of cattle and badgers to fomites: A transmission risk for bovine tuberculosis?

“…Camera trapping is a useful method in quantifying species-specific space-use when conducted at focal sites of interest (Caravaggi et al, 2018), in this case, likely bTB fomites. Operating 24 hr a day for 7 days, remote cameras provide continuous survey effort at each location and generate large volumes of footage to process (Swann, Kawanishi, & Palmer, 2011).…”

Quantifying group size in the red fox: impacts of definition, season and intrusion by non‐residents

“…Data were managed in Camera Base v. 1.6 (Tobler, 2013). Since foxes are primarily crepuscular/nocturnal (Saunders et al, 1993;Caravaggi et al, 2018), 'days' started and ended at noon to ensure independent sampling.…”