Homeward bound: factors affecting homing ability in a polymorphic lizard.

Colour polymorphism is a widespread phenomenon among reptiles and is often associated with alternative physiological and behavioural strategies, including dispersal and movement patterns. To test the homing ability of Podarcis muralis and look for morph-specific responses, we conducted a translocation experiment in two areas of Northern Italy during 2009 and 2010. The first study area was a wall surrounding a city park with a linear and simplified habitat structure; the second one was an archaeological park in a natural area, including stone walls remains, grasses and woods. Lizards of both sexes (203 and 288 for site, respectively) were translocated at 50-200 m distances using cloth bags to block lizard sight. Podarcis muralis were able to return home as 56.7% of translocated individuals in the first site and 35.1% of translocated individuals in the second site successfully returned to their home range. The homing ability decreased with increasing distances, whereas body size positively affected homing behaviour, probably depending on the territoriality of adult lizards. More interestingly, homing performance differed among colour morphs, as yellow lizards of both sexes had significantly better homing skill than other morphs. [ABSTRACT FROM AUTHOR]