Entries in ants (1)


The Real Jungle Predators

Many animals inspire fear and awe here in the jungle but for me, few can compare to ants. I could watch these guys all day long. For most people, ants are irritating insects that occasionally get into your food.

However, ants are such an important part of any ecosystem, especially here in the tropics where ants are often used in habitat assessment as indicators of healthy forest. In fact, ants are the largest organisms in the tropics if you calculate total biomass. That means that if you combine all organisms in a particular family (mammals, reptiles, butterflies etc), ants have by far the most mass.

Different species of ants have coevolved important symbiotic relationships, become important pollinators on top of being brilliant predators and a food source for numerous other animals. Their social behaviour is fascinating and can be either simple or exceptionarily complex depending on the species.

As a colony, they are highly intelligent yet extremely simple animals that will think nothing of attacking animals which are orders of magnitude larger than themselves. Personally, I don’t fear the usual conspicuous creepy crawlies like spiders or snakes. Oh no! These guys will generally want to avoid you as much as you wish to avoid them.

The ants, however, will think nothing of swarming anyone that is unfortunate enough to accidentally put a hand on their tree! Costa Rica has a number of very interesting ants and you can find them just about anywhere in the jungle.

Here is a little information about a few notable ants and their danger ratings.

Fire Ants

The kitchen is a like a spring break for fire ants. These very small, ginger coloured ants are ubiquitous anywhere humans gather and deliver a nasty sting if they crawl onto you. Their stingers are packed with formic acid and deliver a venom-injecting sting which is surprisingly painful for their tiny size. They also have strong mandibles which they use to bite any unsuspecting human who crosses their path. These aggressive ants can also be seen attacking and killing much larger invertebrates and sometimes small reptiles and amphibians. They’re opportunistic scavengers who will consume large prey - like a dead cane toad - in a matter of hours.

Verdict: Amber

Golden Carpenter Ants

You’ll often come across these large ants with a shiny golden fuzzy body on forest trails. Keep an eye out whilst surveying on Luna Ridge. They can be seen crawling up and down trees as they forage for food. Carpenter ants get their name from their habit of carving out nests in trees. Unlike termites, they don’t get any nutrition from the bark but their strong mandibles allow them to dig out hollow tunnels in the trees. They also use their strong and easily visible mandibles as protection against predators. If that wasn’t enough, a threatened carpenter ant can also move their abdomen over the bite and spray formic acid on the wound. On a nicer note, carpenter ants are also farmers. They tend a “herd” of aphids for their nectar but this is only second to foraging, scavenging and hunting other insects.

Verdict: Amber

Army Ants

Last week we had a visit from an army ant raiding party. Army ants is the general name given to over 200 species of aggressive ants who forage in a pack of up to millions of individuals simultaneously. These ants don’t build nests but rather live in a colony which is constantly in motion during their nomadic phase. When the queen is in her laying stage, the ants forage during the day and build bivouacs at night to keep the babies safe. The bivouac is a “nest” formed of thousands, sometimes millions of ants linked together to protect the queen and eggs on the inside. These ants generally aren’t interested in humans but will attack en masse anything that threatens their queen or young.

Verdict: Amber

Leafcutter Ants

One of my favourite ants are the leafcutter ants. I studied them at university. My dissertation supervisor had a colony that he grew from individuals collected in Columbia. The lab was interested in discovering novel antibiotics. We’re lucky to have a few colonies right here on camp. The leafcutter ants forage the jungle for leaves which they feed to fungi back in the colony. The ants tend the fungi much like people tend domesticated plants in agriculture. The fungi digest the plants and turn the cellulose into digestible sugars exudate for the ants to eat. The fungi are undisturbed by infection from other fungi or bacteria because the leafcutter ants have patches of Streptomyces bacteria on the breasts which produce a range of antibiotics, killing off any unwanted infection. The symbiotic ant-fungi-bacteria symbiosis isn’t fully known and it’s one of the few three-way symbiotic relationships known to science.

Verdict: Green

Bullet Ants

Without doubt the most vicious ants are the bullet ants. Thankfully we haven’t got them on camp but they are present in the Osa Peninsula. Their name is derived from the powerful and potent venomous sting. Apparently, being stung by these ants feels like being shot and is ranked the most painful sting according to the Schmidt sting pain index – a rating above a tarantula hawk wasp. The victim is said to feel waves of burning, throbbing, all-consuming pain that continues unabated for up to 24 hours. The Satere-Mawe people of Brazil use intentional bullet ant stings as part of their initiation rights to becoming a warrior. Young men place their hands in stinger laced gloves and keeps it there for 10 minutes. To fully complete the initiation, the boy must go through the ordeal over 20 times over the course of several months or years. Verdict: RED!!!!

By Melanie Bennet - Costa Rica Wildlife Conservation Intern

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