Category: Natural History Observations Page 14 of 34

Female Knight anole digging nest at the base of an oak. April 2013

On my way to teach biology lab the other day, I ran into this female knight anole (actually, my buddy Zack is the one who spotted it).  She was obviously spooked by us and after snapping a few photos I backed off to see if she would continue nesting.  After a few seconds she returned to her task.  I don’t know why I imagined anoles would dig with their hind legs, but for some reason I did. However, she continued to excavate with alternating strokes of her front feet.  Unfortunately I had to run to a meeting, but when I returned a few hours later her hole was still there.  Zack had stayed behind to watch her progress and reported that she had aborted the endeavor when a bicyclist whizzed past a bit too close. The hole was about 4 centimeters deep and 5 wide into the mineral soil when she left.

Female Knight anole observed digging nest at the base of a large fig tree. Note the soil under her front claws and on her snout. Observed July 2012.

This is the second time I’ve seen nesting knight anoles in Miami.  The first was last summer when I found a very healthy looking female at the base of a fig tree.  There was dirt on her snout and a small hole where she had been.  In both cases, the nesting females were within 1 meter of a tree, and both were excavating with their front feet and possibly their snout.  Also, the dates of each observation show that there is a protracted nesting season in South Florida that includes April 10^th to July 20^th.  Such a long season explains the variable size of first year knight anoles that I find during the spring.

Here’s something you don’t see every day. More on these guys soon.

No flies on you guys–this remarkably obscure anole was quickly identified. So, what’s its claim to fame?

Well,  we have to backtrack to Anolis onca for a minute. Faithful AA readers will recall that A. onca is the only anole lacking a subdigital toepad. For this reason, at one point it was placed in its own genus, Tropidodactylus. However, in 1974 Ernest Williams described a new species in Breviora based on a single specimen found in a jar of A. onca in the Field Museum in Chicago. At that time, Anolis was characterized by having expanded scales under phalanxes ii and iii of the toe, whereas Tropidodactylus, of course, had none (phalanxes are the bones in a toe–humans have three per finger, for example). What was remarkable was that the new specimen had expanded scales under phalanx ii, the Anolis condition, but only keeled scales under phalanx iii–it was intermediate between the two, hence the specific name annectens. Here’s an image from Williams’ paper and a photograph of an annectens toe.

From Williams (1974).

Anolis annectens foot. Note the lamellae under only one toe bone. Photo by J. Losos.

The term “retrograde” comes from Williams’ paper and refers to the idea that A. annectens and A. onca illustrate a morphocline in toepad reduction–halfway gone, then all the way gone. Incidentally, recent molecular studies confirm that the two species are sister taxa.

Amazingly enough, A. annectens occurs in the same general region as A. onca, near Lake Maracaibo in Venezuela. In 2007, Tito Barros and colleagues reported in Tropical Zoology on the collection of an additional 22 specimens of A. annectens, confirming that the one individual wasn’t a freak. They also provided information on coloration, geographic distribution (it still hasn’t been found in sympatry with A. onca) and some data on ecology.

Since we were in the area any way, we decided to go and look for them after collecting data on A. onca. By “we,” I mean Tito Barros, Gilson Rivas, several students of theirs, and Rosario Castañeda. Anthony Herrel was busy back at the field lab conducting performance trials (sprint speed, bite force), and I was on assignment finding discarded cardboard boxes to make a proper racetrack.

The weather was beastly hot, about 110 degrees Fahrenheit, with no wind. Here’s what Rosario had to say:

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Rob Heathcote posted this photo as a comment on Sean Giery’s post on bird predation on anoles, but the photo is so spectacular that we need to make sure everyone sees it.

Twin embryos of A. apletophallus dissected from a single egg that failed to hatch.

During my research project on A. apletophallus I dissected many eggs that failed to hatch  but I was very surprised to discover two embryos in this egg.  The female had mated in the wild and laid many normal single embryo eggs before and after this one. Twin embryos have been observed in other lizards (e.g Agama agama (Herptelogica 1967,23:57), leopard geckos and bearded dragons) but I did not find any previous report in anoles. Thought it my interest the AA readers. Anyone else seen this?

Anolis tigrinus. Photo by Anthony Herrel

The last leg of our Little Known Mainland Anole Tour took us to the mountains above Caracas, in quest of Anolis tigrinus. A “mystery anole” photo of that species was put up on AA in December, and savvy readers quickly pegged it as a mainland species, noting it’s twig anole-like appearance. Moreover, the only publication on the natural history of this species, by Ugueto, Rivas, Barros, and Smith, suggested it was a twig anole as well. Given our previous work that had identified the twig anolishness of A. proboscis in Ecuador and A. (Phenacosaurus) heterodermus in Colombia (earlier in this trip), we’re beginning to see a trend: twig anoles seem to be the one kind of West Indian ecomorph that has evolved many times on the mainland (the A. pentaprion clade is another candidate).

Colonia Tovar

So, fresh from the beaches of Maracaibo, we headed to the mountains in quest of the tiger anole. A last minute change in plan led us to the little town of Colonia Tovar at about 7000 feet in elevation. We didn’t know what to expect from TC, but Wikipedia describes it as “Germany in the Caribbean.” Established by settlers from Baden (now part of Germany) in the 1850’s, the town gradually declined for a century, before reinventing itself as a kitschy tourist trap in the 1960s, and now it’s booming. And it was delightful. All of the buildings seemed straight out of Bavaria, there were brewhauses and wienerschnitzel (see photo at bottom of post), the waitresses wearing their fraulein get-ups.

The friendly locals in Colonia Tovar

We stayed at a delightful little hotel, Cabañas Heidelberg. And for no extra charge, we were able to go lizard hunting in the little patch of woods out back.

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Two Anolis marmoratus males fighting on Basse Terre, Guadeloupe

When it comes to territorial behavior male anoles tend to get all the attention. I suppose it makes sense – nothing catches the eye like a brightly colored male doing a few dewlap extensions or engaging in a dramatic battle. It would be a bit of an understatement to say that we like to talk about male-male territoriality and aggressive encounters on this blog (1, 2, 3, 4, 5, 6, and the list goes on!). In fact, we’ve even had photo contests to document the best fights, which tend to feature large, colorful males.

Perhaps it’s no surprise, but females can be just as aggressive as males. At SICB this past January, I learned about Jessica Edward’s research on aggressive encounters between Anolis carolinensis and A. sagrei. It turns out that the victor of female-female staged encounters was nearly always A. sagrei. There are plenty of interesting papers on the topic, for those that are interested (1, 2, among others).

Figure 1. The author waiting for the sun (and the lizards) to come out.

Regardless, I was completely caught off guard during my field expedition last summer to the Dominican Republic when a female A. armouri engaged in a territorial display against a male intruder. Along with Ellee Cook, an undergraduate at Trinity, I was catching A. armouri near Loma de Toro high in the Sierra de Baoruco, the mountain chain that runs between Haiti and the Dominican Republic in the southwest of the island. It’s frequently rainy and overcast at these high elevations and we spent most of our time languishing in the drizzle and waiting for the lizards emerge, as evidenced in Figure 1 and Figure 2.

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Within the framework of my PhD, I examine what determines dewlap diversity in Anolis sagrei and aim to improve understanding of the morphological, performance and behavioural variation within this species on diverse Caribbean islands. Last month I was sampling a few brown anole populations on the Cayman Islands and I encountered some interesting curly tail – brown anole interactions, which might be worth mentioning on Anole Annals. Previous observations have shown that curly tails (Leiocephalus carinatus) do eat a lot of anoles, including A. sagrei; see previous posts (<1>, <2>, <3>, <4>)

Curly-tailed together with plasticine anole model on Cayman Brac

Our sample site at Cayman Brac consisted of a very dense brown anole and curly-tailed population living together. To make an estimation of the relative predation pressure, I generally place 120 plasticine anole models per sampling site and recollect them after 48 hours to score for predation marks. Because of the high abundance of curly tails on our site in Cayman Brac, I expected to recollect many attacked plasticine models, but instead… (see pictures). The curly-tailed does not intend to attack the model, but is trying to copulate with it! A rather unexpected observation from my point of view. Of course, the models are not moving and the chemical cues are completely absent, but still… Furthermore, I made lots of  behavioural observations on A. sagrei individuals and had the impression that they didn’t care at all about the presence of curly tails close by. The brown anoles were often perching within less than 1.5m  of a curly-tailed and still very relaxed; and vice versa, the curly tails didn’t really care about the brown anoles sitting near. In contrast, when a red-legged thrush (Turdus plumbeus) was approaching, all anoles in the close surroundings escaped very fast.

Conclusion: it seems that curly tails on Cayman Brac ‘love’ their prey…

httpv://www.youtube.com/watch?v=3ni3QbKgesI

Last year Martha Muńoz posted on AA about odd behaviors of captive anoles.

Following recent posts about the production of “slugs” or infertile eggs, I thought the readers of AA might be interested in this short (low quality) video of  an A. apletophallus female eating her infertile egg. I think this was a very rare event (only observed once – out of many females) and probably an artifact of being in captivity. Possibly the egg rolled off a leaf or branch and the female grabbed it thinking it was an insect. In the wild the infertile eggs would be consumed very quickly by any number of things – like ants or fungus.

Like others breeding anoles, I have thought a lot about the production of infertile eggs. Female A. apletophallus are egg factories; in the absence of sperm they will produce infertile eggs continuously. I have always thought this was strange – it seems like a waste of resources – why don’t they reabsorb or eat their infertile eggs. The female “knows” the egg is infertile – it is deposited with little or no shell and she does not bury it like a fertile egg.  I presume hormones play an important role in governing this bury or do not bury behaviour. In the case of apleotphallus, all mature females have sperm and when they are relocated into captivity will produce fertile eggs. So I think it is fair to say that in nature they are never lacking sperm, so they will not produce infertile eggs often. Hence under normal circumstances there is no cost to producing these “slugs.”