Experimental evidence that matching habitat choice drives local adaptation in a wild population

Abstract

Matching habitat choice is a unique, flexible form of habitat choice based on self-assessment of local performance. This mechanism is thought to play an important role in adaptation and population persistence in variable environments. Nevertheless, the operation of matching habitat choice in natural populations remains to be unequivocally demonstrated. We investigated the association between body colour and substrate use by ground-perching grasshoppers ( Sphingonotus azurescens ) in an urban mosaic of dark and pale pavements, and then performed a colour manipulation experiment to test for matching habitat choice based on camouflage through background matching. Naturally, dark and pale grasshoppers occurred mostly on pavements that provided matching backgrounds. Colour-manipulated individuals recapitulated this pattern, such that black-painted and white-painted grasshoppers recaptured after the treatment aggregated together on the dark asphalt and pale pavement, respectively. Our study demonstrates that grasshoppers adjust their movement patterns to choose the substrate that confers an apparent improvement in camouflage given their individual-specific colour. More generally, our study provides unique experimental evidence of matching habitat choice as a driver of phenotype–environment correlations in natural populations and, furthermore, suggests that performance-based habitat choice might act as a mechanism of adaptation to changing environments, including human-modified (urban) landscapes.

Urban specialization reduces habitat connectivity by a highly mobile wading bird

“…Individual specialization in habitat use, and in urban habitats in particular, contributed to low connectivity in our network analysis. Habitat specialization by individuals could arise if it provides fitness benefits [ 33 , 69 ]. For example, urban environments can increase fitness in individuals with reduced antipredator responses [ 70 ] or favorable behavioral traits like boldness [ 13 ].…”

Positive feedback promotes terrestrial emergence behaviour in an amphibious fish

“…Positive feedback moves systems away from equilibrium and as a result this feedback been hypothesized to facilitate major evolutionary transitions (Crespi, 2004; Hendry, 2016) such as the invasion of land. For example, on evolutionary timescales, phenotypic change coupled with matching habitat choice is thought to promote local adaptation and potentially speciation (Camacho et al, 2020; Jacob et al, 2017; Muñoz and Losos, 2018; Nicolaus and Edelaar, 2018). Our results indicate that analogous feedback between plasticity and habitat choice can cause phenotypic divergence within the lifetime of individuals.…”

Habitat choice promotes and constrains phenotypic plasticity

“…This 'matching habitat choice' occurs when individuals sample and compare different environments and settle in those that best match their phenotype [14][15][16][17]. For example, grasshoppers painted black choose darker environments compared to those painted white, presumably to improve camouflage [18].…”

“…This habitat selection effectively homogenizes the temperatures the lizards experience across elevations and thus constrains the evolution of thermal physiology, but the differences in preferred substrate cause evolved skeletal changes to maximize locomotor capabilities in each habitat [6]. In this way, matching habitat choice can promote local adaptation [7,13,18]. If individual phenotypic differences and their resulting habitat choices are heritable, then positive feedback between these processes should strengthen each of them and promote local specialization [13,[25][26][27].…”