Striped Anole, Displaying

July 14th, 2012 - 10:22 PM | Filed under Featured Photos | No comments

April 23, 2012 | Arikok National Park, Aruba

The Striped Anole, Anolis lineatus, was probably the species of lizard I most encountered in Aruba. I assume the common and scientific names refer to those dark broken lateral stripes, but it’s known locally as Waltaka.

Here’s another one, a female perhaps.

Female? Or a young male?

My earlier post of the lizard on a tree is also one.

After a good bit of googling, I came across a good free resource on the reptiles and amphibians of Aruba, link below.

Reference:

Amphibians and Reptiles of Aruba
by R. Andrew Odum
PDF hosted at WildAruba

Aruban Lizard on Tree

July 5th, 2012 - 9:01 PM | Filed under Featured Photos | 1 Comment

April 23, 2012 | Arikok National Park, Aruba

Aruba could easily be called “Lizard Island”. You can’t take a step without seeing a few scurrying away. I don’t think there’s a square inch of sand that doesn’t have a lizard track in it.

Cobra-cega (Blind Snake)

March 10th, 2012 - 2:47 PM | Filed under Featured Photos | No comments

~12cm | January 8, 2012 | Tupaciguara, Minas Gerais, Brazil

I came across this small blind snake as it slowly wormed its way along a clear patch of ground next to a corn field. I thought it first it might be a worm, but something just looked a little odd about it. I picked it up and through my hand lens I could see it had scales. I also spotted its tongue darting in and out of its tiny mouth.

I didn’t know it then, but I was in the initial stages of chicken pox. All I knew was that I was feeling poorly and wasn’t motivated to take pictures in the field. I stuffed it in a small container for pictures later. The next day I took a few photos as I held it in my hand. I released it later that day in a field much like the one where I found it.

My brother-in-law’s family suggested it was a cobra-de-duas-cabeças (snake with two heads). It does indeed have a rounded off tail, making it difficult to tell which end is which. Some digging this morning though suggests that that name is more properly applied to a different type of reptile which isn’t a snake at all: amphisbaenians or worm lizards. In addition to not being able to easily tell which end is the head, they have the ability to move equally well both forwards and backwards. Probably the more likely common name for the critter I found is cobra-cega (blind snake).

It actually does have eyes, but they’re vestigial. It simply doesn’t need them since it mostly lives underground. Here’s the best closeup I could get of its tiny head. Too bad I didn’t happen to get one with the tongue flicking out.

Head showing vestigial eye

Blind snakes belong to three families in the  infraorder Scolecophidia. Some reading this morning suggests I probably can’t determine which family this one belongs to based on external characters alone.

I suspected at the time and confirmed this morning that they mostly feed on ants and termites.

 

Anole

July 4th, 2011 - 10:04 AM | Filed under Featured Photos | No comments

 

January 21, 2011 | Finca La Isla, Limon Province, Costa Rica

 

Anoles were abundant everywhere I went in Costa Rica. They are difficult to identify though, and I gave up trying to figure out which species this might be.

 

Anole

 

 

Female Yellow-headed Gecko

June 19th, 2011 - 1:21 PM | Filed under Featured Photos | No comments

January 21, 2011 | Finca La Isla, Limon Province, Costa Rica

Compared to the male, this female Gonatodes albigularis is quite drab.

She looks as if she has suffered some unfortunate incident. Not only does she appear to be regrowing the tip of her tail, but one of her hind feet seems a bit mangled.

Bronze-backed Climbing Skink

June 7th, 2011 - 7:35 AM | Filed under Featured Photos | No comments

January 20, 2011 | Armonia Nature Preserve, Limon Province, Costa Rica

I thought it would be difficult to identify this skink, but it turns out there are only three skinks in Costa Rica. Only two of those occur in the area I was in. And only one, Mabuya unimarginata, is bronzed like this one.

Chiefly arboreal, this one was nonetheless basking on a log near the ground.

Showing more of the body

See more images of this species here.

Reference:

A Guide to Amphibians and Reptiles of Costa Rica
by Twan Leenders

Slender Anole

June 5th, 2011 - 8:39 AM | Filed under Featured Photos | No comments

 

January 20, 2011 | Armonia Nature Preserve, Limon Province, Costa Rica

 

I photographed this slender anole, Norops limifrons, not long after sunset. This species is common and abundant in Costa Rica. It ranges from Mexico to Panama.

According to Leenders, observations suggest that this species mates for life, a rare behavior for a lizard. Energy otherwise spent by the male on defending a territory against other males is instead spent on maintaining the relationship with the female. The male and female stick together, usually never more than a few meters apart. If I’d known this at the time, I’d have looked around for this one’s mate.

References:

A Guide to Amphibians and Reptiles of Costa Rica
by Twan Leenders
The Amphibians and Reptiles of Costa Rica:
A Herptofauna between Two Continents, between Two Seas

by Jay Mathers Savage

 

Yellow-headed Gecko

May 3rd, 2011 - 6:53 PM | Filed under Featured Photos | 1 Comment

January 19, 2011 | Armonia Nature Preserve, Limon Province, Costa Rica

This species, Gonatodes albigularis, can usually be found on surfaces two to three meters above the ground. Not surprisingly then, I spotted this male just above eye-level on the side of a tree, shortly after dark.

Male coloration as shown here is distinctive among Costa Rican lizards. Interestingly though, coloration changes after dark. The head darkens a bit and the body lightens somewhat. Both still remain distinct from each other. What you see above then is the night color phase, or perhaps a transitional phase between the two. Males also have that white-tipped tail.

As the round pupils suggest, this is a diurnal lizard.

I didn’t measure this one, but they generally grow to around 9cm.

Reference:

A Guide to Amphibians and Reptiles of Costa Rica
by Twan Leenders

Brown Blunt-headed Vine Snake

May 2nd, 2011 - 6:12 PM | Filed under Featured Photos | 5 Comments

January 19, 2011 | Armonia Nature Preserve, Limon Province, Costa Rica

As dusk arrived, I spotted this small vine snake, Imantodes cenchoa, descending a large tree. This species is chiefly arboreal, so seeing one near the ground was sheer luck.

A small snake, the head shown here is only 5mm wide. Overall I estimated this one to be less than a meter long, although they can grow to a bit more than that.

The head is much wider than the body. Thin as it may be, it can swallow prey ten times the width of its body. Nocturnal, these snakes hunt sleeping lizards, particularly anoles.

Head much wider than body

Also notable in this and related species are the scales along the middle of the back. These scales are many times wider than scales in adjacent rows. There’s a similar species, Imantodes gemmistratus, but its mid-dorsal scales aren’t quite as wide.

Wider mid-dorsal scales

With highly adapted skeletal and muscular structure, they have the ability to extend out up to half of their body. As shown here, they can reach out to nearby perches.

Body held aloft

Though possessing rear fangs with a weak venom, they rely on camouflage for defense. This one froze in place as soon as it became aware of my presence.

Reference:

A Guide to Amphibians and Reptiles of Costa Rica
by Twan Leenders

Eyelash Viper

March 26th, 2011 - 4:39 PM | Filed under Featured Photos | 2 Comments

~30cm | January 18, 2011 | Gandoca-Manzanillo NWR, Limon Province, Costa Rica

This eyelash viper, Bothriechis schlegelii, was on the side of a tree. A recent crypsis challenge asked readers to find it, which turned out to be fairly easy.

In the photo above, you can easily see the two scales above the far eye that give this snake its common name. No other Costa Rican snake has this distinctive feature.

I used my Canon 100mm macro combined with my Tamron 1.4x teleconverter to get some closeup shots, without getting too close myself. A handful of people die in Costa Rica every year from bites by this snake.

They are arboreal, as suggested by this one’s location.

Dorsal view | Note triangular head, much wider than body

I was in the area for a couple of hours, and the whole time it never budged. They are in fact sit-and-wait predators and may wait motionless for days. Prey includes the usual suspects: frogs, lizards, birds and small mammals.

I have to admit I was slightly disappointed that this one wasn’t the flashy yellow color of some other individuals. Color is remarkably variable. A mother may give birth (live, by the way) to a mix of yellow, green, or brown young, as above. This one does appear to be young, based on its size (estimated, obviously).

At the nearby Jaguar Rescue Center, I had the opportunity to see many more snakes of this species up close, safely behind glass. Have you ever heard that young snakes can be more dangerous than mature snakes? At the center, my guide explained why that might be. Venom is a precious resource for a snake. As snakes age, they learn to control how much venom is released during a strike. Adult snakes are more likely to deliver a measured amount of venom. They may even release no venom at all, a dry strike. So even though the venom doesn’t change as a snake matures, young snakes are more likely to release more of it, yielding a more dangerous bite.

In situ

Reference:

A Guide to Amphibians and Reptiles of Costa Rica
by Twan Leenders

Photo Details:

Canon EOS 60D
EF100mm f/2.8 Macro USM + Tamron 1.4x Teleconverter
Manual exposure, 1/250 sec, f/16, ISO 100
Canon MT-24EX Macro Twin Lite Flash

Canon EOS 60D
EF100mm f/2.8 Macro USM + Tamron 1.4x Teleconverter
Manual exposure, 1/250 sec, f/16, ISO 100
Canon MT-24EX Macro Twin Lite Flash

Canon EOS 60D
EF-S18-55mm f/3.5-5.6, Shot at 18 mm
Auto exposure, Shutter priority AE, 1/160 sec, f/5.6, ISO 800
Canon MT-24EX Macro Twin Lite Flash