Human interference with information processing in wild animals
Adaptive behaviour relies upon accurate information use of relevant ecological parameters (Dall et al. 2005). In environments under strong human impact, physical and biotic environmental changes can be of significance to several organisms, but the way these organisms are behaviourally operating may be affected as well. Humans are interfering with information processing and with the use of environmental cues by wild organisms to a much larger extent than is often realized. Think, for example, about sensory pollution like light and noise pollution. With industrialization, noise pollution from machinery and other human activities continues to expand in space and intensity (Barber et al. 2010). Chronic noise exposure is now widespread. The problem is not limited to terrestrial organisms as freshwater and marine species can also be affected by noise either from terrestrial sources or from traffic and other sources on or in the water (Slabbekoorn et al. 2010). Recent work has mainly focused on the impact of noise on intraspecific animal communication (e.g., Slabbekoorn and Ripmeester 2008), but Siemers and Schaub (2011) provided experimental evidence of an impact of traffic noise on foraging efficiency in acoustic predators and hence on predator–prey interactions. Light pollution is another important case (Hölker et al. 2010). Many ecologists have neglected to consider artificial night lighting as a relevant environmental factor, while conservationists have largely neglected to include the nighttime environment in conservation strategies (Longcore and Rich 2004). We are at the very beginning of understanding evolutionary effects of light pollution and how they may in turn feedback on ecological interactions. The case of light pollution illustrates that human-dominated environments do not only alter the presence and quality of habitats, but also the environmental cues organisms use to deal with their environment. For example, artificial lighting has been shown to disrupt the nocturnal movements of sea turtle hatchlings to the ocean, as artificial light will attract them landward rather than seaward (Tuxbury and Salmon 2005).
Interestingly, some minor details or even unnoticed sources of information to the human observer can be essential for habitat selection in other organisms. This observation has received much attention in dairy management practices and with respect to the well-being of farm animals (Grandin and Johnson 2005). In the same vein, we should recognize the importance for wild animals and hence several of their conservation issues. Take the case of polarized light that is used by several insects to locate water surfaces. Several human creations (including glass buildings, asphalt roads and even particular cars) appear to offer similar cues to these insects (Kriska et al. 2006, 2008; Horvath et al. 2009). Hence, they are attracted to wrongly interpret anthropogenic substrates and defend territories and lay eggs. Interestingly, some predators take advantage of such trapped insect prey in urban areas (e.g., Robertson et al. 2010), illustrating potential positive feedbacks for other species and their urban life styles. The polarized light examples bring us to the concept of ecological and evolutionary traps that have attracted much attention in anthropogenic environments (e.g., Schlaepfer et al. 2002; Gilroy and Sutherland 2007). Ecological traps occur when, by various mechanisms, low-quality habitat is more attractive and hence preferred over available good habitat (e.g., Hollander et al. 2011). Patten and Kelly (2010) argue that also the converse problem may occur: the avoidance of high-quality habitat because it is less attractive. They refer to a ‘perceptual trap’ in such a case and showed evidence with a field experiment in the Lesser Prairie-Chicken Tympanuchus pallidicinctus (Patten and Kelly 2010). However, the label ‘perceptual trap’ is somewhat confusing as perception is also much of an issue in the other cases of trapping. Ecological and evolutionary trapping is anyway a significant issue for conservation in anthropogenic landscapes, even if it often remains difficult to show empirically and in an unequivocal way that reduced breeding success in preferred, low-quality habitat is related to population decline.
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