Lizard movement tracks: variation in path re-use behaviour is consistent with a scent-marking function
Abstract
Individual movement influences the spatial and social structuring of a population.
Animals regularly use the same paths to move efficiently to familiar places, or to
patrol and mark home ranges. We found that Australian sleepy lizards (Tiliqua
rugosa), a monogamous species with stable pair-bonds, repeatedly used the same
paths within their home ranges and investigated whether path re-use functions as a
scent-marking behaviour, or whether it is influenced by site familiarity. Lizards can
leave scent trails on the substrate when moving through the environment and
have a well-developed vomeronasal system to detect and respond to those scents.
Path re-use would allow sleepy lizards to concentrate scent marks along these
well-used trails, advertising their presence. Hypotheses of mate attraction and
mating competition predict that sleepy lizard males, which experience greater intrasexual
competition, mark more strongly. Consistent with those hypotheses, males
re-used their paths more than females, and lizards that showed pairing behaviour
with individuals of the opposite sex re-used paths more than unpaired lizards,
particularly among females. Hinterland marking is most economic when home
ranges are large and mobility is low, as is the case in the sleepy lizard. Consistent with
this strategy, re-used paths were predominantly located in the inner 50% home
range areas. Together, our detailed movement analyses suggest that path re-use is a
scent marking behaviour in the sleepy lizard. We also investigated but found less
support for alternative explanations of path re-use behaviour, such as site familiarity
and spatial knowledge. Lizards established the same number of paths, and used them
as often, whether they had occupied their home ranges for one or for more years.
We discuss our findings in relation to maintenance of the monogamous mating
system of this species, and the spatial and social structuring of the population.
Description
Distributed under Creative Commons CC-BY 4.0. https://creativecommons.org/licenses/by/4.0/.