Out on a limb: female chameleons (Bradypodion pumilum) position themselves to minimise detection, whereas males maximise mating opportunity

Abstract

ABSTRACT Although reproductive strategies are poorly documented in chameleons, sperm storage has been confirmed among some species for which male reproductive success may be maximised by increasing the number of females inseminated and/or preventing subsequent female copulation with rival males. Behaviour, such as mate searching, may enable males to maximise the number of mating opportunities with different partners and mate guarding may increase the likelihood that a male will sire offspring with a particular female. In this study, we investigated behavioural differences in movement (distance travelled) and perch choice between sexes of the Cape Dwarf Chameleon, Bradypodion pumilum, to offer data for a better understanding of mate searching and mate guarding behaviours. Wild chameleons were radio-tracked in 2010 (n = 8) and 2014 (n = 5) for approximately two weeks. The geographic location and perch height above ground were recorded multiple times per day to capture both the scale of movement and their perch use. Linear mixed effect models were used to assess differences between sexes. Our results indicated that females perched lower than males and moved shorter distances, offering support of a mate searching strategy in males. Ad hoc field observations revealed behaviours consistent with mate guarding by some males, and mate avoidance by some unreceptive females. Our results could indicate that males increase their reproductive fitness by using higher perches in both a mate guarding and mate searching context and moving further distances in search of receptive females.