by Greg Mayer
I’ve previously noted a recent paper about fruit eating lizards that wind up as bird fodder. Fortunately, the cases I’m about to relate here don’t end tragically in an avian maw. The lizards that I study, anoles, are primarily insectivorous, but eat a modest amount of meat and fruit as well. I’ve seen the Jamaican Anolis opalinus eat runny banana (the banana had been sliced and left out to attract birds), Puerto Rican Anolis cristatellus pursue round, red fruits (pursue because the fruit kept rolling away as the lizard tried to grab it), and Virgin Island A. cristatellus defecate purplish feces with small black seeds (perhaps from Turk’s cap cactus, Melocactus).
My colleague Manuel Leal of Duke has posted at Anole Annals a video of Bahamian Anolis sagrei eating fruit. This is a tough-skinned fruit. It was opened by another type of lizard (a curly tail or lion lizard), and the sagrei is nomming the pulp left behind.
The video was taken by Dave Steinberg. For more on anole feeding, see Jon Losos’s book, Lizards in an Evolutionary Tree, noted here previously at WEIT.
That’s the way of the balance of life. If we did not have the multitude of the Lesser White Heron here in South Florida we would be inundated with the lizards.We have one of the lizards on our ninth floor terrace and are thankful it helps keeps the mosquito population under control; so there you go, the laws of survival.
I had a breeding pair of Green Anoles for over 8 years – they should live about 2-3 I was told/read.
They female was a tame little thing and would happily sit on your hand, come when called (honest!) but the male was Mr Timid. He would eat from your hand, but never sit on it. He never came when called – he was probably deaf. 😉
I used to put fruit and veg in the tank to feed the crickets – but I never saw the lizards eat the fruit.
So, you (should_ learn something new every day – this is today’s “learn”.
Cheers,
Norm.
Perhaps they only eat rotting fruit as it is easier to snap up rather than bite with feeble jaws?
Dominic,
you could be correct – but having been bitten by the male a couple of time, there’s nothing feeble about their jaws.
And as for baby pics, sorry, it was many years ago while I still lived in Scotland, and digital cameras were extremely expensive. My film camera didn’t have the proper lens for a decent close up. 🙁
Cheers,
Norm.
PS. My desert phase California kingsnake had to be put down after 15 years. 🙁
No reptiles in the house now. Two hives of bees in the garden though!
PS – did you get babies?? Pictures of cute lizardettes/lizardlings will be appreciated!
NomNomNom – that could well be an island lizard’s mantra when it comes to fruits! In the simplified ecosystems of many isolated islands, where terrestrial mammals and many larger frugivorous birds are absent, ever-present lizards often broaden their diet to include substantial amounts of fruits (and nectar). On some oceanic islands, after the extinctions of the few large-bodied frugivores (flightless birds, giant tortoises), medium-sized lizards are the largest native frugivores left.
Examples of important island lizard frugivores (& thus seed dispersers!) include the skink Leiolopisma telfairii from Mauritius and the Gallotia lizards on the Canary Islands.
Oh, and of course the world’s most amazing island lizard is Gray’s monitor lizard, Varanus olivaceus, from the Philippines. A 2-m arboreal lizard that climbs from fruiting tree to fruiting tree and noms 80% fruits for breakfast, lunch, and dinner.
A good overview is given in a paper by Olesen & Valido, 2003. Lizards as pollinators and seed dispersers: an island phenomenon. Trends in Ecology & Evolution 18:177-181.
Oh, and much more information about the Varanus (“Butaan”) can be found on:
http://www.mampam.com/index.php?option=com_content&task=blogcategory&id=39&Itemid=34
Thanks for the links. It is beautiful. Am I right in thinking that some seeds need to pass through a digestive tract to germinate? I just saw that Balanites wilsoniana tree of east Africa depends on elephants to disperse the seeds which are not eaten otherwise & only germinate where they fall.
Biological Conservation
Volume 134, Issue 1, January 2007, Pages 40-47
doi:10.1016/j.biocon.2006.08.002
Dominic, you are very right about this – but the extent to which gut passage increases or reduces germination rate depends entirely on the seed species and the frugivore species. Some frugivores are relatively ‘benign’, providing an excellent dispersal service to plants, while others crush or otherwise destroy a large proportion of ingested seeds. Frugivore-fruit interactions run all the way from mutualism to antagonism – and the distinction is also context dependent: If you are a fruiting tree in a forest where a large lizard and a pigeon both eat your fruits, you’d probably ‘prefer’ to have the lizard eat the fruits (it passes most seeds unscathed; the pigeon crushes most of them in its gizzard). However, in a forest with only the pigeon around, even a bad disperser is better than none.
I was going to mention the Gray’s monitor. I have a soft spot for reptiles in general, but especially varanids. My icon is a breeding pair of varanus Acanthurus (dwarf monitor lizards)- that was quite a while ago and I no longer have any reptiles, but these guys were so fascinating…it was kinda cute to see them tear up a cricket as a komodo dragon tears up a deer – although I have lost my stomach for such things as I’ve aged.
Do lizards get drunk if they accidentally ingest fermenting fruits? I know mammals and birds do, so it would seem likely, but an “evolutionary history of drunkeness” could be a fun research project (for the Annals of Improbable Research, anyway).
(Also, those hand sanitizer things often use ethanol, so I suspect that at least some effects of booze are very ancient phylogenetically …)