Naïveté in novel ecological interactions: lessons from theory and experimental evidence

Abstract

The invasion of alien species into areas beyond their native ranges is having profound effects on ecosystems around the world. In particular, novel alien predators are causing rapid extinctions or declines in many native prey species, and these impacts are generally attributed to ecological naïveté or the failure to recognise a novel enemy and respond appropriately due to a lack of experience. Despite a large body of research concerning the recognition of alien predation risk by native prey, the literature lacks an extensive review of naïveté theory that specifically asks how naïveté between novel pairings of alien predators and native prey disrupts our classical understanding of predator-prey ecological theory. Here we critically review both classic and current theory relating to predator-prey interactions between both predators and prey with shared evolutionary histories, and those that are ecologically 'mismatched' through the outcomes of biological invasions. The review is structured around the multiple levels of naïveté framework of Banks & Dickman (2007), and concepts and examples are discussed as they relate to each stage in the process from failure to recognise a novel predator (Level 1 naïveté), through to appropriate (Level 2) and effective (Level 3) antipredator responses. We discuss the relative contributions of recognition, cue types and the implied risk of cues used by novel alien and familiar native predators, to the probability that prey will recognise a novel predator. We then cover the antipredator response types available to prey and the factors that predict whether these responses will be appropriate or effective against novel alien and familiar native predators. In general, the level of naïveté of native prey can be predicted by the degree of novelty (in terms of appearance, behaviour or habitat use) of the alien predator compared to native predators with which prey are experienced. Appearance in this sense includes cue types, spatial distribution and implied risk of cues, whilst behaviour and habitat use include hunting modes and the habitat domain of the predator. Finally, we discuss whether the antipredator response can occur without recognition per se, for example in the case of morphological defences, and then consider a potential extension of the multiple levels of naïveté framework. The review concludes with recommendations for the design and execution of naïveté experiments incorporating the key concepts and issues covered here. This review aims to critique and combine classic ideas about predator-prey interactions with current naïveté theory, to further develop the multiple levels of naïveté framework, and to suggest the most fruitful avenues for future research.

Predation on Fishes in the Sacramento-San Joaquin Delta: Current Knowledge and Future Directions

“…All else being equal, foraging theory predicts that predators will choose prey that maximize their net energy gain (Grossman 2014), although this can be achieved through a variety of methods. It is likely that Delta predators prefer fish prey that are energy-rich (Hartman and Brandt 1995), easily handled and consumed (i.e., small, softrayed and fusiform) and naïve to invasive predators (Kuehne and Olden 2012;Carthey and Banks 2014). Several authors document the importance of behavioral naiveté to predation mortality by demonstrating that invasive Lake Trout and Northern Pike feed disproportionately on salmonids despite the apparently higher abundance of native catostomid prey (Johnson and Martinez 2000;Johnson et al 2002;Lepak et al 2012).…”

Short-term effects of hunting on naïve black-tailed deer (Odocoileus hemionus sitkensis): behavioural response and consequences on vegetation growth

“…The lack of a strong response of marked deer to the huntingfor-fear experiment might also be due to the short duration of the experiment (11 days of hunting spread over 25 days) that prevented predator-naïve deer from learning and adjusting their behaviour (for a review on naïvety see Carthey and Banks 2014). However, the fact that these deer could be easily recaptured and rehandled during both capture sessions questions their ability to alter their behaviour even when exposed to scaring events over time.…”

The ecology and evolution of constructed ecosystems as green infrastructure

“…Like urban ecosystems in general, constructed ecosystems feature high levels of ecological novelty: combinations of species or environmental conditions that have not occurred in the evolutionary history of the organisms or populations involved (Carthey and Banks, 2014;Fridley and Sax, 2014;McGuire et al, 2015). In some cases, engineered features, small size, or isolation result in these novelties.…”