Category: Natural History Observations Page 22 of 34

Having four legs is overrated

A year ago, I reported on the surprisingly high incidence of limb loss in brown anoles from Staniel Cay, Bahamas. By the end of that trip, we found five lizards missing a part of their limb, usually the forelimb (see pictures in the previous post) out of 500 we examined (1%). We attributed this limb devastation to predators, but didn’t know what the cause was.

This year in Abaco, we’ve examined close to 400 lizards now, and have only found one case of leg loss. However, it’s an interesting one: most of a hindleg is gone. Yet, the lizard lives–the wound is healed over, so this lizard seems to be doing just fine.

Photo from http://static.flickr.com/75/183141170_b188735c85.jpg

Vega-Castillo and Puente-Rolón in the December, 2011 issue of Herpetological Review report fruit consumption by A. gundlachi, A. stratulus and, most notably, the grass-bush A. krugi. This adds to recent reports of frugivory in three other Puerto Rican species, A. cuvieri, A. evermanni and A. monensis.

As I discussed in Lizards in an Evolutionary Tree, frugivory is quite common in anoles, but there are interesting ecological and biogeographical aspects:

“Many anole species are known to eat fruits at least occasionally, and in some species at some localities, frugivory is quite common (Herrel et al., 2004). Species known to be frugivorous are larger than those not known to eat fruits, and West Indian species are frugivorous more than mainland species (30% versus 0% in Herrel et al.’s [2004] survey). Among West Indian anoles, no grass-bush anoles and all crown-giants have been reported to be frugivorous; data for other ecomorphs is mixed. My hunch is that when more species are studied, almost all but the smallest species will be found to occasionally take fruit. For example, the fact that an A. evermanni, not definitively known to eat fruit, once jumped on my shoulder, ran down my arm, perched on my thumb, and bit at the red knob of the stop watch I was holding suggests to me that this trunk-crown anole will eat red berries, just like many other anoles. Seeds (Reagan, 1996) and “seeds or fruit” (Lister, 1981) have been reported in the diet of this species, so my prediction that it is frugivorous is not very daring.

Seed eating is also reported for a number of species (e.g., Wolcott, 1923; Reagan, 1996). In some cases, these seeds may have been ingested incidentally, but in other instances, seeds, which are digested more slowly than pulp, may be the last remaining trace of a fruity meal in the digestive tract of an anole.

Nectarivory has been reported in a number of West Indian trunk-crown anoles (Liner, 1996; Perry and Lazell, 1997; Campbell and Bleazy, 2000; Echternacht and Gerber, 2000; Okochi et al., 2006; Valido, 2006), a grass-bush anole (Perry and Lazell, 2006), and two Lesser Antillean species (Timmermann et al., 2008). The greater occurrence of frugivory and nectarivory among island species compared to those on the mainland agrees with a trend seen for lizards in general (Olesen and Valido, 2003).

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        Two male Anole lizards pose and posture in a mock fight display. One individual is distinguished by the regrowth of his tail lost in some previous incident. In this incident, no physical contact seemed to have occurred, but biting and locking of jaws in actual combat has been observed between males of this species. These still photos do not convey the rapid change of posture, circling and feinting of attacks. Finally in the last photo the lizard with the regrown tail is seen alone in a victory pose with legs fully extended and tail held straight off the ground. It should also be noted that while I photographed at no time did I observe either male display its dewlap. This may have occurred in a prelude to their face-off on this urban sidewalk arena.

Read all about it here.

Fighting carolinensis. Photo from https://twitter.com/#!/tsansmerci/status/183640654881095681/photo/1

Wowie zowie! Check that out. The top carolinensis is holding the other one in mid-air by its jaws. No wonder they have such big heads (female carolinensis heads are much smaller) and such powerful toepads.

Otocryptis wiegmanni. Photo by Akila De Silva from http://lazy-lizard-tales.blogspot.com/2012/01/year-of-dragon-amazing-agamids.html

A while back we had a post discussing the many times lizards have evolved dewlaps, and more recently our mystery lizard was a most anole-like agamid lizard, Sitana ponceriana. Above is a close relative of Sitana, Otocryptis wiegmanni, doing its best anole imitation. Really, someone needs to do a comparative anatomical study of all these dewlaps to see how similar they are in construction–I’m guessing pretty similar!

The photo comes from a cool website, The Lazy Lizard’s Tales, and this particular post is chockful of cool looking agamids