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Arthropod Predators of Anoles

Orange-legged wandering spider (Cupiennius coccineus) consuming house gecko (Hemidactylus frenatus) at Sirena Biological Station, Corcovado, Costa Rica

Red-legged wandering spider (Cupiennius coccineus) consuming a house gecko (Hemidactylus frenatus) at Sirena Biological Station, Corcovado, Costa Rica

When someone first asked me about the major predators of anoles, my first thought was to talk about curly-tailed lizards (Leiocephalus carinatus) in the Caribbean, vine snakes (Oxybelis spp.) in the neotropics [see my previous post on anole predation by O. aeneus at La Selva], and birds. I think that as herpetologists, we tend to fall into the trap of thinking of invertebrates as “lesser” taxa to be preyed upon by small vertebrates like lizards, and in turn for small vertebrates to be eaten by larger vertebrates.

I, too, when thinking about how selective pressures shape morphological variation in mainland and island habitats turned to fellow herps and birds as the primary predation pressure for mainland anoles. However, it wasn’t until I arrived in Costa Rica that I discovered the high prevalence of voracious arthropods, and I realized that our beloved lizards had much more to fear!

Orange wandering spider (Cupiennius getazi) with egg sac at La Selva Biological Station, Costa Rica

Orange wandering spider (Cupiennius getazi) with egg sac at La Selva Biological Station, Costa Rica

Red-legged wandering spider (Cupiennius coccineus) eating a pink katydid (Tettigoniidae: Phaneropterinae) at La Selva Biological Station, Costa Rica

Red-legged wandering spider (Cupiennius coccineus) eating a pink katydid (Tettigoniidae: Phaneropterinae) at La Selva Biological Station, Costa Rica

A large adult female mantis (Phasmomantis championi) at La Selva Biological Station, Costa Rica

A large adult female mantis (Phasmomantis championi) at La Selva Biological Station, Costa Rica

Conehead katydid (Tettigoniidae: Conocephalinae: Vestria sp.) at La Tarde, Osa Peninsula, Costa Rica

Conehead katydid (Tettigoniidae: Conocephalinae: Vestria sp.) at La Tarde, Osa Peninsula, Costa Rica

In a single night at La Selva, I could easily find dozens of large wandering spiders (Ctenidae), and if I pointed my headlamp higher in the trees I could see eyeshine from hundreds of spiders. Given the high density of large ctenids at La Selva, it is not unlikely that anoles and small tree frogs constitute a major portion of their diet. In fact, I wouldn’t be surprised if large arthropods are one of the most common predators of mainland anoles in some regions.

The same might be the case for giant mantids of the genera Macromantis and Phasmomantis, and conocephaline katydids sporting fearsome mandibles (e.g. Copiphora spp.). Since the invasive Chinese mantids (Tenodera sinensis) in North America are well documented to prey on hummingbirds almost equal in size to the mantids [see Nyffeler et al. 2017], surely larger and bulkier species in the neotropics can take lizards much smaller than themselves. Even though wandering spiders and conehead katydids are primarily nocturnal hunters, I have heard many stories of these arthropods being implicated in anole and tree frog predation. Research looking into how ctenids and nocturnal katydids forage would help determine if they can actually detect sleeping anoles or if predation events occur from the arthropods simply running in to the anoles while on the move.

If anyone here on Anole Annals has any anecdotal or photographic records, please comment below.

To throw a twist on this discussion, is it possible for a spider to prey on a lizard two and a half times its size? A new paper about a vertebrate-eating jumping spider (Salticidae) describes just that! Considering arthropods as possible major players in anole predation could shed light on behavioral and ecological studies of mainland anoles.

Figure 1 from Nyfeller et al. 2017, showing female jumping spiders (Phidippus regius) consuming Carolina anoles (Anolis carolinensis) and Cuban tree frogs (Osteopilus septentrionalis)

Figure 1 from Nyfeller et al. 2017, showing female jumping spiders (Phidippus regius) consuming Carolina anoles (Anolis carolinensis) and Cuban tree frogs (Osteopilus septentrionalis)

Here are a few more spider photos to wrap up this blog post.

Jumping spider (Salticidae: Phiale cf. guttata) eating an assassin bug (Reduviidae)

Jumping spider (Salticidae: Phiale cf. guttata) eating an assassin bug (Reduviidae)

Red-legged wandering spider (Cupiennius coccineus) consuming house gecko (Hemidactylus frenatus) at Sirena Biological Station, Corcovado, Costa Rica

Another angle of a red-legged wandering spider (Cupiennius coccineus) consuming a house gecko (Hemidactylus frenatus) at Sirena Biological Station, Corcovado, Costa Rica

Threat display of a Brazilian wandering spider (Phoneutria boliviensis) from Tárcoles, Costa Rica. A ctenid with medically significant venom.

Threat display of a Brazilian wandering spider (Phoneutria boliviensis) from Tárcoles, Costa Rica. A ctenid with medically significant venom.

Help Identify Costa Rican Anoles

I recently saw these four anoles on a trip to Costa Rica. All four were sighted in La Fortuna in the province of Alajuela. They were sighted on July 18th and 19th, all within a few meters of a forested stream. I have some ideas about their ID’s, but am not completely sure. Can anyone help me with their identification?

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This first anole was found on a tree trunk near the stream at night, while the second one was found on a pole in the morning. Both Anolis lionotus?

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This third one was found on a low shrub in the morning. Anolis limifrons?

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The fourth anole was found on a low-growing shrub at night. Anolis lemurinus?

Thank you in advance for your help.

Shades of Bumpus: Polar Vortex-Induced Natural Selection on Cold Tolerance in the Green Anole

Shane Campbell-Staton had fortuitously measured the thermal physiology of a number of populations of the green anole, Anolis carolinensis, the summer before 2014’s Polar Vortex. So, he went back and examined the survivors. And sure enough, in the most southerly populations, those most strongly affected by the cold snap, natural selection had occurred. Shane tells Scientific American all about it in this podcast. The nifty figure above comes from the University of Illinois’ press release.

 

More Information on the Knight Anole Invasion of the Turks and Caicos

We reported recently that knight anoles (Anolis equestris) have shown up in the T&C. Here’s more on the story from B Naqqi Manco, the Terrestrial Ecologist at the Department of Environment and Maritime Affairs, Turks and Caicos Islands Government:

Cuban knight anoles are currently known from two sites on Providenciales: Vicinity of Beaches Resort in The Bight and Amanyara Resort on Northwest Point. Both populations showed up after the importation of large trees for landscaping from Miami. The properties are both irrigated pretty heavily to keep the bigger trees going. The tree imports were brought in before the Department of Agriculture was fully operative, so unfortunately things got in at that time that probably shouldn’t have made it through.

I don’t have confirmation of the knight anoles breeding, but I know The Bight population has been spreading with individuals having been found on adjacent properties and in a nearby residential neighbourhood. I would be very surprised if they’re not breeding on either site. Unfortunately we don’t have the capacity to monitor them well but this is something we want to keep a closer eye on and it would make a worthwhile research project for a student or intern. 

Thus far, they have not been reported from any other island or cay. 

New Paper Says Anoles Are the Reason for Dave Wake’s Career-Long Focus on Salamanders

Dave Wake: the younger years

Dave Wake: the younger years

The paper, by Nancy Staub and Rachel Mueller and just out in Copeia, is a delightful biography of DBW, as he is referred to by his lab and many others. As for the anole bit, you’ll have to read it to find out.

Knight Anoles Introduced to Turks and Caicos

We’ve previously reported on Anolis equestris introduced to the Bahamas and elsewhere, and brown anoles (A. sagrei) introduced to Turks and Caicos. Now the knight anole is in T&C and people are worried about the impact they may have.

Eh? What’s that? Anolis cristatellus Lacking an External Ear. Also, One Getting Eaten by a Knight Anole and a Brown Anole Eaten by a Warbler

Ljustina and StroudRead all about it in the (almost) latest from the October 2016 issue of Herpetological Review.

White and Cove

JMIH 2017: Anole Morphology Round-up: Comparing Gecko and Anole Toepads and Patterns of Embryonic Limb Development in Diverse Lizards

Travis in the Dominican Republic with Anolis fowleri. Photo by Luke Mahler.

Travis in the Dominican Republic with Anolis fowleri. Photo by Luke Mahler.

Two recent talks at JMIH 2017 shed light on key morphological characters in anoles: toe pad shape and limb length. Travis Hagey presented his work which looks to shed light on why lizard toe pads are shaped the way that they are and addresses whether gecko and anole toe pads are convergent structures. Working with a team of undergraduates, Travis used geometric morphometrics to analyze the structure of toepads in a diverse group of geckos and anoles. Travis found that anole and gecko toe pads have a similar range of values for traits such as the placement of pads on the toes and the shape of the toes (skinny or fat) in relation to claws. However, anole toe pads formed a distinct cluster indicating that they occupy a unique area of trait space not used by geckos. This finding suggests that the divergent evolutionary history of anoles and geckos has resulted in independent evolutionary explorations of toe pad shape.

Immediately following Travis’ talk, Robin Andrews presented work investigating the embryological development of morphological characters in diverse lizard species. In anoles, consistent differences in the morphology of divergent species support the existence of different anole ecomorphs.  Previous research by Sanger and colleagues has shown that the differences in limb-length between anoles of different ecomorphs have their origins early in embryonic development. These early differences in limb length continue throughout the development of anoles into hatchlings and adult forms, a pattern known as transpositional allometry.

Robin compared patterns of limb, tail, and head growth in early stage embryos of four different lizard species, including a chameleon, two geckos, and the brown anole (Anolis sagrei). She found that species-specific differences in limb and tail lengths were exhibited as soon as limb and tail buds emerged from the body and were both best characterized by the same pattern, transpositional allometry. Embryonic head growth, however, showed no specific pattern. Robin’s findings suggest that the adaptive evolution of adult morphology in anole ecomorphs as well as other diverse lizard species is underpinned by developmental reprogramming.

Travis Hagey, Jordan Garcia, Oacia Fair, Nikki Cavalieri, and Barb Lundrigan: Variation in Lizard Adhesive Toe Pad Shape
Robin Andrews: Developmental Origin of Limb Size Variation in Lizards

If West Indian Weevils Colonized the Mainland 19 Million Years Ago, Were Norops Anoles Along for the Ride?

Exophthalmus scalaris. Credit: symbiota4.acis.ufl.edu/scan

Exophthalmus scalaris. Credit: symbiota4.acis.ufl.edu/scan

In their 2008 review  “Are islands the end of the colonisation road?” Bellemain and Ricklefs (2008) concluded that oceanic islands could be important sources of colonisation of mainland continental areas and cited anoles of the Norops clade as a notable success. There are more than 5 times as many Norops clade species in Central and northern South America as in the West Indies; the 23 extant Caribbean species in the clade are distributed in Cuba and Jamaica with one species in Grand Cayman (Nicholson et al, 2005). Data in Nicholson et al (2005) gave support to the reverse colonisation hypothesis, but did not offer specific dating for the colonisation.

New analyses of 65 species in the Exophthalmus weevil genus complex (Zhang et al 2017) have turned up results that are of significance in understanding the biogeographic history of Caribbean anole dispersal and diversification. Like anoles of the Norops clade, the weevils show reverse colonization (island-to-continent), with diversification on the mainland and diversification within the islands. The data also give some support for overwater dispersal as the factor best explaining ancient between-island distribution.

Zhang et al’s best fit biogeographic model gives an estimate of 19Ma for a jump dispersal of Exophthalmus, most likely from Hispaniola,  which went on to diversify into more than 40 species in Central America.   So – did the anoles and the weevils make their journeys to the mainland around the same time and under similar conditions? Can this weevil study and the techniques it uses to arrive at its conclusions inform anole evolution and dispersal?

References

Bellemain, E and RE Ricklefs (2008) Are islands the end of the colonisation road? Trends Ecol Evol. 2008 Aug; 23(8):461-8. doi: 0.1016/j.tree.2008.05.001. Epub 2008 Jun 26.   (Correction to citation numbering: Trends Ecol Evol. 2008 Oct; 23(10):536-7).

Nicholson, KE, RE Glor, JJ Kolbe, A Larson, S Blair Hedges, JB Losos (2005) Mainland colonization by island lizards.  Journal of Biogeography 32 (6), 929-938.

Zhang, G, U Basharat, N Matzke, NM Franz (2017) Model selection in statistical historical biogeography of Neotropical insects—The Exophthalmus genus complex (Curculionidae: Entiminae). Molecular Phylogenetics and Evolution, 109, 226-239. DOI: 10.1016/j.ympev.2016.12.039.

Book Review Rebuttal: Are Honduran Anoles Overly Split?

Two years ago, McCranie and Kohler published The Anoles of Honduras: Systematics, Distribution, and Conservation(available on Amazon for under twenty bucks and downloadable for free on the Museum of Comparative Zoology website).

In turn, two mostly favorable reviews were published. However, one of the reviews, by Levi Gray, did question whether a number of anole species recognized from small distributions in Honduras should be recognized as valid species, rather than just as populations of species that are widespread throughout Central America.

Writing in Zootaxa, Randy McCranie has now responded to this point, forcefully arguing that the species should be recognized and challenging his critics to present their own data if they feel otherwise. You’ll have to read Gray’s review and McCranie’s rebuttal yourself to decide what you think. Gray made his skepticism clear, he also did clearly call for more research to address the question.

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