Today is the United Nations’ World Wildlife Day, a time to especially raise awareness about and celebrate the earth’s plants and animals. The holiday was instituted in 2013 to be commemorated on 3 March, the day of the year on which the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) was signed. The theme for World Wildlife Day 2020 is “Sustaining all life on Earth”, which includes all wild animal and plant species as key components of the world’s biodiversity.
To honor this international day of commemoration (and hopefully awareness-raising and action), I’d like to share some of the reptiles that I’ve seen in Costa Rica. But first, let me show you one North Carolina turtle that I saw yesterday and that I don’t think I had seen before. It’s a large turtle called a Florida cooter (Pseudemys floridana), which has a nice pattern with yellow accents on the carapace.
In Costa Rica, we came across one turtle at which we got a good look — a black wood turtle, also called a river turtle (Rhinoclemmys funerea). This is the largest turtle among the reptiles in its genus; individuals can grow to 14 in (35 cm).
We came across several snakes during our trip in 2019, but a few of them were dead on the road and I decided not to show those. One feisty individual was the cloudy snail-eating snake (Sibon nebulatus); when our guide neared it, the snake reared up in self-defense. Of course, it’s good to remember that most snakes will not strike if they do not feel threatened, as we are reminded by the North Carolina Carolinas Reptile Rescue & Education Center.
A snake that I found particularly beautiful was spotted during the 2018 trip in which I participated; our guide spotted it after we had stopped at the side of a road. The neotropical bird snake (Phrynonax poecilonotus), also known as the puffing snake, eats small vertebrates such as small mammals, frogs, lizards and insects, but it is known to have a preference for birds and bird eggs.
These are non-venomous snakes, but they will bite hard when feeling threatened. They also will inflate their neck area in a way reminiscent of a cobra in order to appear dangerous.
The presence of caimans was advertised in various places we visited in Costa Rica but I didn’t see one until a spectacled caiman (Caiman crocodilus) was spotted as we were driving down a highway one day.
This brings me to the various types of lizards I saw. Anoles (Anolis) were in all the areas we visited, Although I couldn’t identify the specific species for several, I enjoyed seeing the differences between them.
While searching for birds in a heavily shadowed marshy area, we caught sight of what I thought was a slender anole — obviously a male given its prominent inflated neck flap. However, it turns out that slender anoles have white dewlaps with a small orange blotch so this was a different species.
I do believe that this anole was a ground anole (Norops humilis) but would welcome correction if I’m wrong. Their diet includes various insects such as termites, beetles, crickets, termites and flies.
A somewhat larger reptile than the anoles was the – in my opinion – quite attractive Central American whiptail (Holcosus festivus occidentalis). Like the other lizards that you will see below, they have exceptionally long tails.
Juvenile whiptails have blue tails; their skin patterns are quite lovely, which may account for part of their species name – festivus which means merry or joyous in Latin.
Not much information is available online about these lizards, despite their apparent wide distribution. Some studies have been done about another whiptail genus seen elsewhere that aroused scientific interest because reproduction is by parthogenesis. This has not been reported for this species.
The iguanas are the very large reptiles seen in Costa Rica. Despite their size, they appear to be quite agile; it was not unusual to see the large black spiny-tail iguanas (Ctenosaura similis) high up in trees.
The male black spiny-tails can grow as large as 4 ft 3 in (1.3 m), while females are a foot or more shorter. During breeding season, the males develop blue- and peach-colored hues on their jowls, as can be seen in the portrait below, captured by fellow traveler Janet Kurz in 2018.
They have been said to be the fastest lizard species, reaching a speed of 21.5 mph (34.6 km/h) in a sprint. Running away is a strategy to avoid predators but they can also bite and lash with their tails if cornered. They are mostly herbivorous, although they will also consume small animals and insects. Unfortunately, they are eaten by humans, some of whom think they can cure impotence.
The green iguanas (Iguana iguana) are somewhat smaller than the spiny-tails but they are also large, growing to 4.9 ft (1.5 m) or more. We were lucky to see a juvenile green iguana meander along a smaller tree, posing for quite some time. There might have been others nearby but we didn’t see them. It turns out that these iguanas are quite social – juveniles form pods of about four animals and then spend time grooming one another and sleeping together.
Their coloring is quite bright but can be other hues such as reddish brown, black, lavender and blue. These iguanas are good climbers, often staying high in trees; reportedly, they can fall as far down as 50 ft (15 m) and still land unhurt.
The green iguanas are often found near water and they swim well, being able to stay submerged as long as 30 minutes at a time. Like the spiny-tails, they can use their tails in defense. They can also drop their tails when caught and grow new ones.
The basilisks are among the “showiest” reptiles even though they are smaller than the iguanas (e.g., growing up to about 2.5 feet/76 cm in length). They gained the name Jesus Christ lizard because they can “walk” across water when rapidly moving (up to 15 mph/ 24.1 km/h) to escape predators. They have special webbing between the toes on their hind legs and cross the water “standing up” on those legs.
The male common basilisks (Basiliscus basiliscus) have a distinctive fin-like crest on their backs. Both sexes range in color from olive to brown; they are distinguished by a light-colored stripe along their upper lip.
The common basilisks also have a stripe along their body, although this fades as they grow older. The females and juveniles look somewhat similar. The females do not care for the young, leaving the eggs once laid. The hatchlings instinctively know how to care for themselves.
The green basilisk (Basiliscus plumifrons) is also known as the plumed basilisk. Males have three crests (on the head, back and tail), while females (shown in the photos here) only have a head crest. The juveniles have no crests.
Like the other basilisks, these lizards can dive under water after running along the surface for a time. They can stay submerged up to an hour but often do not do this as they could fall prey to aquatic predators.
Like the common basilisks, the green basilisk females leave their eggs and the newly hatched babies are able to run, climb and swim right after birth.
Among the brown basilisks (Basilicus vittatus), also called striped basilisks, the juveniles (shown below) can often run further across water than the adults.
The crests are similar to those in other species. These basilisks have dark bars across their backs and quite yellow stripes.
Like the other basilisks, these lizards often eat insects but also eat berries and other fruit, making them omnivores.
The last type of lizard in this reptile review is another iguana known by a couple popular names: the casque-headed lizard or the smooth helmeted iguana (Corytophanes cristatus).They have several distinct features that make them quite unique.
They are characterized by very long toes, a long tail like the other lizards and highly variable coloration, ranging from olive, grey, black, brown to reddish-brown, often with irregular blotches of other color.
They are also able to change their color rapidly as a form of camouflage. Unlike the other lizards, they tend to freeze in place when predators approach (a strategy called catalyptic freezing). If this and trying to appear larger by erecting their crest and expanding their gular pouch do not scare off predators, they will bite and attack.
They differ from the other iguanas and basilisks in that they often do not actively seek out prey. Rather, they sit and wait for worms, other lizards, insects and spiders to wander by and then pounce on them.
One final noteworthy and unexpected fact: because these lizards sit still for very long periods of time, both a fungus and a plant have been found growing on their skin!
Happy World Wildlife Day!