FORUM: Ecologists need robust survey designs, sampling and analytical methods

Abstract

Summary1. Research that yields conflicting results rightly causes controversy. Where methodological weaknesses are apparent, there is ready opportunity for discord within the scientific community, which may undermine the entire study. 2. We use the debate about the role of dingoes Canis dingo in conservation in Australia as a case study for a phenomenon that is relevant to all applied ecologists, where conflicting results have been published in high-quality journals and yet the problems with the methods used in these studies have led to significant controversy. 3. To alleviate such controversies, scientists need to use robust methods to ensure that their results are repeatable and defendable. To date, this has not occurred in Australia's dingo debate due to the use of unvalidated indices that rely on unsupported assumptions. 4. We highlight the problems that poor methods have caused in this debate. We also reiterate our recommendations for practitioners, statisticians and researchers to work together to develop long-term, multi-site experimental research programmes using robust methods to understand the impacts of dingoes on mesopredators. 5. Synthesis and applications. Incorporating robust methods and appropriate experimental designs is needed to ensure that conservation actions are appropriately focused and are supported with robust results. Such actions will go a long way towards resolving the debate about the role of dingoes in conservation in Australia, and other, ecological debates.

An oasis in the desert: The potential of water sources as camera trap sites in arid environments for surveying a carnivore guild

“…However, detection probability has been shown to vary with a number of factors including local density, seasonal or behavioural patterns, amount of area surveyed (Bailey et al, 2004), and survey design (Sollmann et al, 2013), meaning the assumption is unlikely to hold true (O'Connell et al 2012), but is rarely accounted for (Kellner and Swihart, 2014). This issue has most recently been highlighted by Hayward et al (2015) as one of the key problems facing the debate regarding the conservation use of dingoes Canis dingo in Australia. Hayward et al (2015) suggest that conflicting results regarding the species' role in mesopredator suppression may be a merely an artefact of sampling methods used and failure to account for detection probability.…”

“…This issue has most recently been highlighted by Hayward et al (2015) as one of the key problems facing the debate regarding the conservation use of dingoes Canis dingo in Australia. Hayward et al (2015) suggest that conflicting results regarding the species' role in mesopredator suppression may be a merely an artefact of sampling methods used and failure to account for detection probability.…”

Settling the browser–grazer debate for African buffalo in grass-limited Eastern Cape thicket, South Africa

“…Even though such weaknesses can undermine science and management (e.g. Hayward et al 2015;Stephens et al 2015), this might still improve our understanding if it encourages additional robust interrogation. For buffalo in thicket, additional testing confirmed what was already known about their diet, which probably limited our ability to develop broader insights because our approaches were motivated by a single hypothesis.…”

“…Hayward et al 2015;Stephens et al 2015). Here we use an example of a diet study of African buffalo Syncerus caffer that had starved to death (De Graaff, Schulz & Van der Walt 1973), and whose findings were anomalous and initially accepted, only to be challenged later (Landman & Kerley 2001;Novellie, Hall-Martin & Joubert 1991).…”

Environmental effects are stronger than human effects on mammalian predator-prey relationships in arid Australian ecosystems

“…Tracking plot surveys were conducted quarterly and at the same time each year, although excessive wind or rain prohibited undertaking some surveys. Sampling fauna in this way allows PTI calculations to be used as a reliable measure of activity or relative abundance when analysed appropriately (Wilson and Delahay, 2001;Engeman, 2005;Allen and Engeman, 2014; but see Hayward and Marlow, 2014and Hayward et al, 2015 for further discussion).…”