Birds

Here is a Chesnut-mandibled Toucan that I spotted high in the canopy at La Selva. Chesnut-mandibled are the largest Toucans in Costa Rica and seeing such a beautiful bird up close is always exciting. Notice the really blue feet!

Another vividly colored bird (and a cousin of the Toucan) that inhabits the canopy is the Collared Aracari. I spotted this one in a tree near the Arenal Volcano…

Bichos

Being by far the most ubiquitous of any creature in Costa Rica, I thought I would share some of the more interesting insects that I encountered…

Here is an absolutely fantastic grasshopper that was crawling on the wall outside my room at Monteverde.

Here is a collection of some other amazing insects and arachnids I saw..

Above right is the caterpillar of a sphinx moth, which has a pair of brightly colored spots on its oversized head that closely resemble the eyes of some larger and less edible creature. Bottom right is a scorpion who decided that my shower curtain was a good place to hang out… I disagreed.

Top left is a very unique green spider I spotted at Palo Verde. Top right is an enormous wolf spider I found on a night walk at La Selva. Bottom left is giant swallow-tailed butterfly and Bottom right is easily the largest butterfly I have ever seen, with a 1 foot wingspan.

“Frogs”

Of all the many creatures that can be found in Costa Rica, the frogs are definitely my favorite. The diversity of color, size, shape, and sound that the frogs of Costa Rica exhibit is unparalleled, and I spent lots of time trying to find and photograph as many as I could.

Here are some of the best….

Here is an amazing red-eyed stream frog (Duellmanohyla uranochroa) on a pane of glass that I photographed at a frog garden in Monteverde.

Here is the same species in the wild, found near a stream in Monteverde…

La Selva Biological Station in the lowlands of Costa Rica is something of a frog haven, especially after a large rainfall. La Selva is one of the best places to find the iconic Red-eyed Leaf  Frog (Agalychnis callidryas), and one night at the swamp I came across this one posing for me on a stem…

Here is another La Selva resident Hyla Loquax…

Another unique tree frog found in Costa Rica is the glass frog. Many species of glass frog such as this one have almost transparent skin which is thought to aid in camouflage. Glass frogs are quite rare and this one was in a frog garden in Monteverde.

Monkeys

I also had many memorable encounters with monkeys during my stay in Costa Rica. The howler (above) and spider monkeys were always interesting and entertaining to watch, but perhaps the most feisty are the Capuchins. These are relatively little monkeys, but they can be quite aggressive, and they are certainly not afraid of humans.

Here is a rather upset male that was trying to lead his family group through the grounds of our hotel at Manuel Antonio beach. He was clearly perturbed by our presence and actually ended up punching my Mum in the back! (She was fine)…

After making a quick retreat, the male capuchin’s family soon followed, and it became clear why he was so protective…

Serpientes

Anyone who has read this blog before will know about my encounters with the eyelash viper. It is the most vividly colored of all the creatures I saw in my travels, and being able to get so close to one and watch it capture an anole lizard is something I will never forget…

Costa Rica is home to many tree snakes, including this Blunt-headed Vine snake which I found slithering around the understory at La Selva.

This is one of my favorite finds that I made during the trip. It is an intertwined mating pair of Mangrove Boas that were sitting in a tree literally on the beach at Manuel Antonio. Limited mostly to certain coastal regions, Mangrove Boas are rare and to catch a glimpse of one up close is lucky. To find a mating pair like this is extremely lucky.

ANTS

I want to end this post with the most common of all creatures in Costa Rica, and the entire world for that matter… Ants!

Perhaps the most well known ant that can be found throughout almost of all of Costa Rica is the leaf-cutter. These tenacious harvesters live in colonies of millions and can completely de-leaf a tree in no time at all. Extraordinarily, these ants don’t eat the leaves that they harvest and instead feed it to a fungus that grows within their colony. It is this fungus that the ants consume.

Below, a lone worker carries her leaf back to the colony. Notice the small ant sitting on the leaf. This is a member of a different caste from the leaf cutter colony called minima. The exact purpose of these smaller freeloaders is unknown, but it is thought they help to defend the larger ant from parasitic flies.

Although small as individuals, ants find great strength in numbers. It is amazing to see what a colony of thousands or millions can achieve by working together as one unit. Army ants are an excellent example of just how powerful ants can be.

Living in large, mobile colonies, army ants leave their nest every morning and spread across the forest floor in waves of hundreds of thousands, swarming and capturing anything that gets in their way. Using their stingers and powerful mandibles the ants will then dismember their prey and bring it back to the nest. Few forest floor dwellers are safe from the army ants, and they have been known to capture frogs, snakes, and even small mammals that can’t escape.

Even powerful scorpions fall victim to the ruthless ants, and here is a poor individual getting swarmed and killed right outside my door at Palo Verde…

Army ants are a force to be reckoned with (especially when you feel their sting), but they are not the most feared in Costa Rica. That title is held by the aptly named bullet ant, which gets its name from the fact that being stung feels like being shot. The pain from a bullet ant sting is excruciating and can last for five hours. Bullet ants are also a full inch long, have huge mandibles, and are fairly aggressive. The first time I saw one I couldn’t believe that an ant could be so large…

Here is a bullet ant at La Selva. Check out the size of its mandibles!

This praying mantis is an excellent example. Not only are the body parts colored and shaped like leaves, the wings also have patterns that mimic the venation of a leaf.

Across the insect world, leaf mimicking is a very prevalent form of camouflage. The quality of some insect’s leaf guises are incredible. Here is a leaf-mimicking katydid quite effectively portraying a dead leaf.

Here, a closer look reveals the extreme level detail that this katydid has evolved… blotches of light and dark color, intricate and accurate venation patterns, and of course, a leaf-like shape.

Yet another excellently camouflaged insect is this grasshopper, shown here blending into the thorny trunk of a tree at La Selva. This is a great hiding spot, and even the most keen-eyed bird would never spot it.

Here is an amazing example of camouflage, a butterfly chrysalis that looks like a dead leaf. The detail is again amazing and to a passing predator, this looks a lot more like an unpalatable leaf than a nutritious meal.

Upon my arrival in Costa Rica, it did not take long for me to realize that there are alot of spiders here, and perhaps more importantly, many are unpleasantly large.  Although most of them are relatively harmless, waking up to see a 4-inch spider on the ceiling above your head is frankly quite upsetting.

Having said all this, spiders are also interesting creatures. Many (such as the orb weavers) are responsible for massive, intricate, webs which catch anything unfortunate enough to fly into them. Other spiders such as the countless massive lycosids, which make me jump out of bed, are nocturnal hunters, waiting patiently for a passing meal.

Here is such a lycosid I found in the Las Cruces Gardens.

Web-weaving spiders are also prevalent. Here is a giant Golden Orb-weaver, which I found at La Selva. If you look closely, you can see the tiny, red, male directly above his massive counterpart.

Of course, these diurnal spiders pale in comparison to the monsters that lurk in the night…

This very large brown tarantula is one of many that can be found at La Selva, and I didn’t realize how big they actually are until I saw one in person.

Perhaps the most interesting spider I have seen so far is the Net-Casting Spider. It has a very unique way of catching insects, whereby it weaves a thick net of web (which you can see suspended below the spider), and then uses it to pounce on insects that pass on the underlying plant, snaring them in the net. In this picture, the spider is in the process of weaving the net, and you can see a trail of silk coming from the abdomen.

Here is a juvenile male howler monkey I met while crossing the bridge at La Selva. He seemed to be having a good time climbing around on the cables and only acknowledged me when I did my best monkey howl…

A few days later I ran into what I think is the same howler and decided to get in a yelling match with him. I took this picture mid-howl…

Monkeys are probably the most charismatic mammals in Costa Rica, but there is another, more enigmatic mammal which frequents the rainforest. Often feared, and poorly understood, I refer to the bat. Costa Rica is home to many types of bat, including fruit bats, frog-eating bats, vampire bats and nectar bats.

I have already had many encounters with bats so far, including one who decided to live in my room for a couple of days. Considering their nocturnal inclinations, it is ironic that my most interesting bat experience occurred in the middle of the day…

While I was walking through the large botanical gardens at Las Cruces Biological Station, I noticed a large palm leaf who’s leaflets were all folded down forming a conical tent. I decided to investigate, and looking up inside the tent from below this is what I saw…

These two fruit bats (Artibeus) where hanging together from the center of the leaf, and seemed as surprised to see me as I was to see them. These, as it turns out are tent-making fruit bats, named as such because they structurally alter the palm leaf to form this tent-structue, which is used as a roost.

The La Selva suspension bridge seems to be a wildlife hotspot, and a few days ago, this three-toed sloth was very slowly making its way from end to another. The greenish tint to it’s fur is actually algae, which happily grows in the absence of grooming.

Mammals are certainly not the only furry creatures in Costa Rica, and one perhaps unexpected example is this rather furry catipillar I found on the underside of a leaf in the Las Cruces gardens…

On another walk through a different swamp at La Selva, I found these frisky Hourglass Tree Frogs (Hyla ebraccata)…

This prevalant, brightly colored little frog is highly territorial, and if threatened by another male, will vigorously gaurd its little patch of forest by wrestling the intrudor. This epic struggle for property and mating rights is quite an entertaining show, even if the subjects are only 2 cm long. After the battle, the victor claims the territory, and the loser must vacate to a new home. My project involves testing to see if males identify each other as competitors using only sound, or if visual cues (color) are involved as well.

Another iconic amphibian which I had the pleasure of seeing a few nights ago is the Red-eyed Leaf Frog (Agalychnis callidryas)…

This is certainly one of the most recognized frogs in the word, and for good reason. The vivid contrast of the red eyes, black pupils, green body, and golden underbelly is stunning.

The Red-eyed Leaf Frog’s appearenence is further enhanced when it closes the protective nicitating membranes over its eyes to reveal an elaborate pattern of golden pigments…

Here is another picture of the Red-eyed Tree Frog and some other interesting frogs I have come across so far…

The Common Tink Frog

Pigmy Rain Frog

Mexican Tree Frog (Smilisca baudinii)

Smokey Jungle Frog (Rana ternero)…This frog was six inches tall while sitting!

With a range throughout most of Central America, this fairly small, arboreal snake is aptly named as it possesses distinct, modified scales or “eyelashes” that adorn it’s exceptional eyes.

This almost mature individual was found on the STR trail at La Selva Biological Station in northern Costa Rica.

A few days after this initial sighting, I spotted what was likely the same individual, perched in a tree, on a different part of the trail…

As fate would have it, while my friends and I debated the snake’s favorite prey item, a fairly large anole lizard climbed within only two feet of the viper. Perhaps it was the sheer willpower of the group, or a slight diversion created by my hand, (which may or may not have ushered the lizard in a certain direction), but what followed was a flash of yellow and one of the most amazing natural scenes I have witnessed…

Here is a Bird-eating Snake (Pseustes poecilonotus), which a slightly over-enthusiastic (or just bored) La Selva guard informed me of by waving dramatically, pointing, and yelling SERPIENTE!!! All while I stood literally 3 feet away.

Here is a picture of another snake that I spotted at La Selve Biological Station: The Cat-eyed Snake (Culebra ojigata). This aptly named nocturnal snake feeds almost entirely on frogs and frog spawn, and favors swamps and marshes.

On another night walk through the La Selva forests, I found this Brown Blunt-headed Vine Snake (Imantodes cenchoa) hunting for large insects and lizards in a small tree…

On the same walk, I spotted a much larger snake high in a tree. Further inspection revealed it as the Annulated Tree Boa (Corallus annulatus). This reclusive constrictor is not widely distributed, and I am lucky to have seen it at all.

The massive amount of biodiversity in Costa Rica makes it a paradise for a budding biologist… Birds, reptiles, mammals and everything else are present in great variation and beauty, making this narrow little strip of land a true wonder of the world. My stay in Costa Rica lasts for a semester, 3 weeks of which have already elapsed. In that time I have already had many incredible experiences, and I am sure there are many to come…

Enjoy!