We have so far become acquainted briefly with French Guiana and part of its flora but the fauna cannot be ignored as animals and plant life are interwoven and one cannot stroll on a local path more than a few meters before meeting one or several animals. Let us see what is hiding there.
A true forest jewel (picture Johann Tascon)
The insects will most likely be the first animal you will encounter on your way so we will start with them. Why would they be so widespread? Well, they do represent more than 80% of the species living on earth and although only a small part has been seriously documented this makes about 1 million species while many scientists seriously think that total amount would be of several tens millions!
Just for French Guiana, a tiny part of South America, there are some 100,000 known insect species and an estimated total of 400,000 to 1 million...If we turn to species known by everybody such as the ants; there are some 12,000 species worldwide out of which only 400 for Europe. A single tree in Guiana can harbor more than 40 different species, some at ground level, some in the bark, some in decaying wood, and some within a nest on the trunk. The most common ones in Guiana are the Atta which are known locally as ‘fourmi manioc' (cassava ants) and can be seen carrying chunks of cut leaves which they can take from high up in trees and bring down to the nest where they will be used to grow mushrooms on which those insects will feed. Those ants can completely defoliate a large tree and are a gardener's nightmare (a well-established colony with a queen and one million worker will need as much vegetal material as one cow!). They are amazingly organized with large ants climbing trees and cutting large pieces of leaves which will fall to the ground to be cut to smaller size by smaller ants, carried back to the nest where they will be cut even more finely and taken by very small ‘gardeners'. Very tiny individuals can be seen clinging to leaves parts carried by a strong worker, those tiny ants do not actually take part in the work process but they act as bodyguards, protecting the large worker against minute wasps that try to lay parasitic eggs on larger preys.
A more aggressive ant is the ‘marabunta' or legionary ants, they do not set a fixed nest but travels through the forest, forming huge colonies between 100,000 and several million ants, looking for whatever is edible, I once witnessed what looked like a small river several meters large moving on the floor of the forest which was a marabunta gang on the hunt. Azteca ants (some 40 species, all endemic to South America) have specialized for some of them at least in associating with plants; Aztecaalfari and Azteca ovaticeps both live exclusively in the hollow trunks of the ‘bois-canon' Cecropia obtusa. They will dig a hole in the stem and use the plant as shelter and also as food provider because it produces carbohydrates, sugars and lipids which the ants harvest. In exchange whenever a menacing insect or animal brushes past the plant myriads of ferocious ants come out and bite in the trouble-maker (I experimented it while climbing a large Ficus tree with some bois-canon growing at its base...).
Cecropia obtusa and its numerous body-guards!
Collective web made by Anelosimus eximius
From the tiny guys to bigger hairy monsters we cannot neglect spiders...I already see a few readers shivering! Let me stipulate here that spiders are not insects as they have eight legs while insects only have six. Spiders belong to the Arachnids together with scorpions and 42,000 species are recorded in the world. Of course many live in Guiana: on the ground, in the trees, in bushes, in houses.
The most impressive one, Aviculariaavicularia known as ‘matoutou' can be 12cm across, covered with black hairs, the tips of the legs are orange. It is often found in houses where people protect them because they hunt and eat roaches. Anelosimus eximius is a social spider which although being of a rather small size (5mm) is able to build webs up to 100 square meters, compensating its modest individual size by a collective work. We could enumerate mosquitoes, wasps, beetles, fleas, termites, ladybirds and so on for hours but I will end with butterflies. The most sought-after and incredible blue morpho (Morpho didius) can be 10 to 12cm large with an incredible metallic blue color catching sunlight in amazing flashes at the forest edge or over rivers. Alas many end in hunter's nest and then nailed in wooden boxes to be sold to tourists, a sad end partaken by many other local insects like the ‘matoutou', large scorpions and various bugs.
A rather impressive 'matoutou'
Podocnemis expansa, a river turtle we rescued from a poacher...
After the insects, let's have a look at some vertebrate animals which are very representative of local fauna: amphibians and reptilians. Amphibians are divided in three groups amongst which the best known and far more important is the Anurans represented by frogs, toads and tree frogs with up to 139 documented species for French Guiana! (Out of the 47 Anurans families worldwide there are 23 in South America and 13 in French Guiana). This is not too surprising if one considers that those animals are pledged to water hence quite comfortable in equatorial forests where humidity is very high and rains can be a daily feature.
All of them are predators which feed on insects and small invertebrates but are also themselves prey to snakes and other vertebrates so they usually are quite prolific in order to survive and have developed various protective strategies. The cane toad (Bufo marinus) protects its eggs with toxins strong enough to kill a man if one were hungry enough to eat them while another toad (Bufo guttatus) is able to project venom three feet away! Tree frogs such as the genus Dendrobates and Phyllomedusa bear very bright colors as warning, they indeed produce very toxic compounds, Phyllomedusa terribilis can intoxicate a person just by touching it and absorbing poison through the skin, while Dendrobates tinctorius will be a problem only if it comes in contact with mucous membranes or an open wound.
Some species make a small basin in the mud close to a river, water will then slowly fill it but fishes will not come in the basin to eat the eggs. Others like the Phyllomedusa build a genuine net by gluing several large leaves together a few feet above water so when the eggs open the larvae will directly fall in the water underneath. And there are of course tree frogs which never set paw on the ground! Trachycephalus resinifictrix and T. hadroceps will never be seen in the forest unless you are able to climb up to a hole in a fork, large branch or any other natural pool where they spend their entire life. On the other hand they can be spotted easily as they have powerful songs which can be heard several hundreds meters away, those species were captured and described in 1995 by Philippe Gaucher, a herpetologist who is also a tree climber.
Dendropsophus leucophyllatus (picture J. Tascon)
We'll stay amongst related animals with reptilians. Again, tropical areas are favorable to such animals, there are some 166 documented species of reptilians in French Guiana. In comparison, there are 37 in France although it is eight time larger in size than Guiana... They are represented by caimans, lizards, tortoises and turtles, amphisbaenas (strange legless burrowing lizards) and snakes. There are four different Caimans species which are now protected as they have been so much hunted for skin and food that they were on the edge of disappearing. Snakes number 98 species so you are very unlikely to roam Guiana for a few days and not encounter one; if nothing else, squashed by a passing car on the road and more likely on a trail. Those animals are predators which feed on a large number of smaller animals; from snails and slugs to frogs, lizards, other snakes, birds, bird's eggs or mammals and even large ones such as a hind when it comes to very large snake species like Eunectes murinus the famous anaconda. This is a giant snake, non-poisonous but a constrictor which means that it will kill its prey by squashing it, as this species lives mostly in rivers and swamps it usually grabs its victim using its powerful jaws and large teeth in order to take its prey underwater and suffocate it. It will eat anything available from fish, tortoises, chicken, dogs, cervidas, even caimans and jaguars but although it has a bad reputation amongst white people (it is revered as a deity by most Indian people) stories of human victims are mostly tales. Of course it can become very impressive, males can grow to 4m and 6m (12 to 18 feet) long and females between 6m and 8m (18 to 24 feet) long with a weight of 200 kg, nothing you want to play with!
Other constrictors of Guiana are the seven species of boas out of which two are tree species; Corallus hortulanus and the beautiful C.caninus or emerald boa. Smaller but not nicer, coral snakes bear characteristic series of red, black, white and yellow rings and those will inject a venom that is neurotoxic and will block respiratory muscles. The larger one is Micrurus surinamensis, found in rivers and swamps and can be 1.5m (5 feet) long. Vine snakes are also common, those have a slender body (the thickness of a man's finger), narrow head and pointed snout; they are between 0.75 and 1.5m (2.5 and 5 feet) and are venomous. As the name states they do look like vines and one may get very close to them before being able to spot one, usually only if it moves away.
The most beautiful Corallus caninus (picture J. Tascon)
Amazing 'vine snake'
Although we are still very far from having met all the insects, spiders, amphibians and reptilians of French Guiana we also have to pay a visit to mammals and birds which will be for our next tour, I hope you will nevertheless sleep sound and not check twenty times under your pillow or your bed to look for a sneaky monster!
A healthy cane toad specimen...
About Jean-Jacques Segalen
I am a Parisian born professional horticulturist specialized in tropical seeds producing, living on Reunion island (just between Mauritius and Madagascar) since 20 years . I spend a lot of time gathering seeds in the wild, the ones I do not grow that is. Also a dedicated Tai-Chi practitioner and fully certified arborist-tree surgeon
Just released my first book on tropical plants and fruits, check it at http://www.barbadine.com/pages/livrejjGB.html