Determinants of dispersal distance in free-ranging juvenile lizards

Dispersal of offspring from their natal site has a critical influence on individual fitness. Although the consequences of dispersal have received much theoretical attention, the determinants of dispersal remain poorly understood for many animals. To address this issue, we marked and released size-manipulated hatchling lizards (Amphibolurus muricatus; Agamidae) over a 3-mo period in the field to evaluate the effects of body size and the time of hatching on dispersal distance. Our mark-recapture data indicated that body size and offspring sex had little effect on distances travelled by individuals. However, the timing of hatching had a strong impact; individuals that hatched early in the season dispersed further than did those hatching late. This pattern may allow early-hatched juveniles to disperse and secure high-quality habitats before the arrival of later-hatched conspecific competitors.