Early experience influences both habitat choice and locomotor performance in tiger snakes

Through adaptive developmental plasticity, individuals may function most effectively in the type of environment in which they have spent most of their time. Such habitat-specific modifications may favor active selection of that habitat type later in life, further reinforcing developmentally plastic phenotypic modifications. The interaction between these processes may have profound evolutionary implications. In nature, Australian tiger snakes (Notechis scutatus) use a complex mosaic of terrestrial, arboreal, and aquatic habitats. We raised juvenile tiger snakes for the first 11 months of life in enclosures mimicking one of these habitats and then tested their habitat selection when offered a choice of habitat types. Snakes consistently selected the habitat types in which they had been reared, and they were more effective at locomotion in those habitats than in the others. This attachment to a familiar habitat and phenotypically flexible adjustments in order to function effectively in that habitat constitute a positive feedback loop. That is, animals benefit by choosing a familiar habitat because they can fine-tune behaviors in ways that enable them to function better in that habitat, and, by consistently selecting that kind of habitat, they not only reinforce those phenotypically plastic adjustments but also are placed under continuing selection to cope with the challenges (of foraging, predator evasion, etc.) imposed by that habitat type. The end result may be to create ecomorphs, whereby different individuals within a population become specialized for different types of habitats even in the absence of genetic differentiation.