iHerp Australia Issue 9 | Page 14

The Bonaire Island Whiptail Lizard (Cnemidophorus murinus) is the largest known nectivorous lizard. Image by Jan Burletson. durations. The Black Spiny-tailed Iguana (Ctenosaura similis), for example, has been reported to be capable of dispersing seeds up to 500m. The rate of passage through lizards’ digestive tracts is also comparatively long (>4 days), which provides a greater chance for seeds to be deposited at some distance from the parent plant, where competition is reduced. in its jaws, and then turns its head to the side to press the fruit against the ground, using the rocky ground to split it open. Juveniles feed on figs broken open by adults or birds, or by vigorously shaking their head whilst grasping the fig in their jaws, which breaks it into manageable pieces. ‘ Some authors propose reptilian What sort of floral traits appear to be favoured by lizards? Because most lizards are active for longer than insects, and have higher energy requirements, there is some evidence that sauriphily promotes the evolution of plants that secrete a fairly continuous supply of abundant nectar, at high concentrations. Lizards (and birds, which are, phylogenetically speaking, also reptiles), have good colour vision especially in the red range of the electromagnetic spectrum (unlike bees), and so red flowers and nectar do appear to be associated with many plants visited by lizard pollinators. Likewise, fruits that are red in colour seem to have a particular attraction for many lizards. Phylogenetic constraints limit the ability of lizards to chew fruits with tougher skins, and body size has been identified as a key trait influencing frugivory. Larger lizards are increasingly frugivorous; not only do they have greater bite force, but importantly also a greater gape size, allowing them to swallow fruits without chewing. Nevertheless, some lizards can overcome morphological and functional constraints by using behavioural means to consume fruits that their jaws would otherwise preclude them from eating. The cordylid Platysaurus capensis, a relatively small reptile, feeds voraciously on figs when they are temporarily available, despite being unable to chew or engulf these fruits whole. An adult grasps a fig pollination of flowering plants to be an ancient mutualism, PRECEDING even POLLINATION BY BEETLES . ’ Taxonomically, nectivory is dominated by geckos, whereas frugivory is most common among skinks. As can be expected, most lizards that consume nectar are fairly small, averaging 126mm, and ranging from the tiny Puerto Rican Bush Anole (Anolis pulchellus) with an SVL of 35-43mm, to the Bonaire Island Whiptail Lizard (Cnemidophorus murinus), which may reach lengths of up to 500mm, and has been reported to consume Aloe nectar. As outlined above, frugivorous lizards tend to be larger, and the average body size of species included in this review is 213mm. The single frugivorous varanid, Gray’s Monitor (Varanus olivaceus) is also the largest frugivorous lizard, with a total length of up to 180cm, and consumes a great diversity of fruits. However, there are some small- bodied frugivores; the smallest being Duvaucel’s Gecko (Hoplodactylus duvaucelii), with an SVL of as little as 40mm. Interestingly, the largest nectivorous lizard species also consumes fruits, while the smallest frugivorous species also consumes nectar.