title: Repeatability and correlation of physiological traits: Do ectotherms have a "thermal type"?
abstract: Across a range of taxa, individuals within a species differ in suites of correlated traits. These trait complexes, known as syndromes, can have dramatic evolutionary consequences as they do not evolve independently but rather as a unit. Current research focuses primarily on syndromes relating to aspects of behavior and life history. What is less clear is whether physiological traits also form a syndrome. We measured 10 thermal traits in the delicate skink,Lampropholis delicata, to test this idea. Repeatability was calculated and their across-context correlations evaluated. Our results were in alignment with our predictions in that individual thermal traits varied consistently and were structured into a physiological syndrome, which we are referring to as the thermal behavior syndrome (TBS). Within this syndrome, lizards exhibited a "thermal type" with each being ranked along a cold-hot continuum. Hot types had faster sprint speeds and higher preferred body temperatures, whereas the opposite was true for cold types. We conclude that physiological traits may evolve as a single unit driven by the need to maintain optimal temperatures that enable fitness-related behaviors to be maximized.
authors.affiliation: School of Biological Sciences Monash University Clayton Vic. Australia.
authors.forename: Celine T
authors.initials: CT
authors.lastname: Goulet
authors.affiliation: School of Biological Sciences University of Sydney Sydney NSW Australia.
authors.forename: Michael B
authors.initials: MB
authors.lastname: Thompson
authors.affiliation: School of Biological Sciences Monash University Clayton Vic. Australia.
authors.forename: David G
authors.initials: DG
authors.lastname: Chapple
keywords: individual variation; locomotor performance; selected body temperature; syndrome; thermal physiology