Behavioural responses to human‐induced environmental change

Abstract

The initial response of individuals to human-induced environmental change is often behavioural. This can improve the performance of individuals under sudden, large-scale perturbations and maintain viable populations. The response can also give additional time for genetic changes to arise and, hence, facilitate adaptation to new conditions. On the other hand, maladaptive responses, which reduce individual fitness, may occur when individuals encounter conditions that the population has not experienced during its evolutionary history, which can decrease population viability. A growing number of studies find human disturbances to induce behavioural responses, both directly and by altering factors that influence fitness. Common causes of behavioural responses are changes in the transmission of information, the concentration of endocrine disrupters, the availability of resources, the possibility of dispersal, and the abundance of interacting species. Frequent responses are alterations in habitat choice, movements, foraging, social behaviour and reproductive behaviour. Behavioural responses depend on the genetically determined reaction norm of the individuals, which evolves over generations. Populations first respond with individual behavioural plasticity, whereafter changes may arise through innovations and the social transmission of behavioural patterns within and across generations, and, finally, by evolution of the behavioural response over generations. Only a restricted number of species show behavioural adaptations that make them thrive in severely disturbed environments. Hence, rapid human-induced disturbances often decrease the diversity of native species, while facilitating the spread of invasive species with highly plastic behaviours. Consequently, behavioural responses to human-induced environmental change can have profound effects on the distribution, adaptation, speciation and extinction of populations and, hence, on biodiversity. A better understanding of the mechanisms of behavioural responses and their causes and consequences could improve our ability to predict the effects of human-induced environmental change on individual species and on biodiversity.

Fitness-associated consequences of an omnivorous diet for the mangrove tree crab Aratus pisonii

“…However, a mechanistic understanding of how diet influences these metrics is key in predicting how species and populations may respond to environmental changes. Organisms frequently respond to human-induced rapid environmental changes with behavioral modifications, including altered foraging, and this can lead to changes in population dynamics (Tuomainen & Candolin 2011). For instance, blue crabs Callinectes sapidus in a contaminated estuary had reduced success capturing active prey items and consumed more algae, sediment, and detritus than those from an uncontaminated reference site (Reichmuth et al 2009).…”

Animal cognition in a human-dominated world

“…Large-scale land clearing to increase grazing opportunities for cattle, coupled with installation of permanent water holes, has created ideal ecological conditions for large grazing marsupials, such as the Australian eastern grey kangaroo (Macropus eugenii), whose Queensland populations exploded from 11 to 23 mio in just four years prior to the instigation of commercial harvesting in 2004 (Australian Government 2013). These and many other examples (Candolin and Wong 2012;Sol et al 2013;Tuomainen and Candolin 2011;Wong and Candolin 2015) make it clear that for those animals with cognitive systems capable of handling these novel opportunities, HIREC offers opportunities that are not only extraordinarily abundant, but also fast increasing as a consequence of human population expansion.…”

Natural and anthropogenic drivers of cub recruitment in a large carnivore

“…If a female cheetah with cubs cannot forage effectively, then this could have an indirect impact on her offspring (Frid & Dill, 2002; Laurenson, 1994) . Human disturbance can also cause changes in behavior (Elowe & Dodge, 1989) and increase stress levels (Creel et al., 2002; Hayward & Hayward, 2009) which in turn could influence fitness (Tuomainen & Candolin, 2011). For example, juvenile hoatzins ( Opisthocomus hoazin ) were found to be susceptible to tourist‐induced stress which was negatively correlated to their survival (Müllner, Linsenmair, & Wikelski, 2004).…”