Behavioral syndromes: an ecological and evolutionary overview

Abstract

Recent studies suggest that populations and species often exhibit behavioral syndromes; that is, suites of correlated behaviors across situations. An example is an aggression syndrome where some individuals are more aggressive, whereas others are less aggressive across a range of situations and contexts. The existence of behavioral syndromes focuses the attention of behavioral ecologists on limited (less than optimal) behavioral plasticity and behavioral carryovers across situations, rather than on optimal plasticity in each isolated situation. Behavioral syndromes can explain behaviors that appear strikingly non-adaptive in an isolated context (e.g. inappropriately high activity when predators are present, or excessive sexual cannibalism). Behavioral syndromes can also help to explain the maintenance of individual variation in behavioral types, a phenomenon that is ubiquitous, but often ignored. Recent studies suggest that the behavioral type of an individual, population or species can have important ecological and evolutionary implications, including major effects on species distributions, on the relative tendencies of species to be invasive or to respond well to environmental change, and on speciation rates. Although most studies of behavioral syndromes to date have focused on a few organisms, mainly in the laboratory, further work on other species, particularly in the field, should yield numerous new insights.Humans show consistent individual differences in personality [1]. For example, some people are generally more bold, whereas others are generally more shy. In statistical terms, the tendency for individuals to differ consistently in behavior (e.g. in boldness) across SITUATIONS (see Glossary) is quantified as a BEHAVIORAL CORRELATION ACROSS SITUATIONS. The analog of personality has been studied in considerable detail in a few primates, domesticated animals and laboratory rodents [2,3], with much of the focus being on the genetic and neuroendocrine bases of variation in BEHAVIORAL TYPE. However, recent studies by ethologists and behavioral ecologists have documented 'animal personalities' in a broad range of 'non-model organisms', including several mammals, birds, lizards, amphibians, fish, mollusks and arthropods [3]. Evolutionary ecologists refer to suites of correlated traits as syndromes; for example, life-history or dispersal syndromes [4,5]. We therefore refer to suites of correlated behaviors as BEHA-VIORAL SYNDROMES. A population or species can exhibit a behavioral syndrome with each individual showing a behavioral type (e.g. more bold or more shy). Alternatively, a group of species can exhibit a syndrome with each species having a behavioral type (e.g. species that are more bold versus those that are more shy).The idea of studying correlated suites of behaviors across situations represents an important shift in how behavioral ecologists typically address behavior [6]. In essence, when traits are correlated, they should be studied together, as a package, rather than as isolated units. Here, we des...

Non-random gene flow: an underappreciated force in evolution and ecology

“…Source 2: personality variation Many studies document consistent behavioral differences among individuals (sometimes termed behavioral types, personalities, or behavioral syndromes [25]), which can be correlated with dispersal (reviewed in [26] aggression, and boldness dispersed further in the wild [27]. In the fruit fly Drosophila melanogaster, individuals showed heritable variation in whether they settled on food patches that had no, few, or many conspecifics, resulting in a correlation between genetically determined sociality and social environment [28].…”

Associations between glucocorticoids and sociality across a continuum of vertebrate social behavior

“…For example, exploration and boldness, both of which are measures of proactivity, are linked to group shoaling tendency in fish (Cote, Fogarty, Weinersmith, Brodin, & Sih, 2010; Muraco, Aspbury, & Gabor, 2014; Smith & Blumstein, 2010), social communication in social rodents (Crino, Larkin, & Phelps, 2010), social information use (Marchetti & Drent, 2000), and overall cooperativeness in some highly social birds (Scheid & Noe, 2010) and mammals (English et al., 2010). However, proactivity can also be linked to territorial aggression (Sih, Bell, & Johnson, 2004; Sih, Bell, Johnson, & Ziemba, 2004; Yewers, Pryke, & Stuart‐Fox, 2016; see also Hall, Parson, Riebel, & Mulder, 2016; Taylor & Lattanzio, 2016) and thus the association between GCs and social proactivity may depend on species sociality (e.g., whether a species exhibits territory defense, tolerance or cooperative territory defense).…”

“…Contemporary research on this topic focuses on whether individuals consistently differ in their behavior across contexts (animal personality: Réale, Reader, Sol, McDougall, & Dingemanse, 2007) and whether multiple behaviors co‐vary within individuals (behavioral syndromes: Sih, Bell, & Johnson, 2004; Sih, Bell, Johnson, & Ziemba, 2004). Much of the recent research focuses on the ultimate causes of animal personality traits and behavioral syndromes as well as their possible evolutionary consequences (e.g., Dingemanse & Wolf, 2010; Réale, Dingemanse, Kazem, & Wright, 2010; Wolf, Van Doorn, & Weissing, 2008).…”

Animal cognition in a human-dominated world

“…Coping style (Koolhaas et al 2010) and personality (Réale et al 2007;Sih et al 2004) are facets of animal behaviour that are not generally considered cognitive per se, but are thought to influence or be influenced by, cognitive processing mechanisms (Carere and Maestripieri 2013;Griffin et al 2015;Sih and Del Giudice 2012), justifying the inclusion of this topic in the present special issue. There is mixed evidence as to whether urban areas reliably contain more real and/or perceived threats than natural environments (Gering and Blair 1999;López-Flores et al 2009;Odewald and Earns 2011).…”