Monday, July 25, 2011

Costa Rica - Day 12-13 More frogs

So far we have seen at least 12 species of frogs around our little patch. The latest include Costa Rica’s largest tree frog, the Milk Frog (Phrynohyas venulosa), and one of the tiny, almost transparent glass frogs. Each night we have at least five large male Masked Tree Frogs (Smilisca phaeota) swimming and calling from the kids' inflatable wading pool.

The Gladiator Tree Frog (Hyla rosenbergi)

A tiny Glass Frog Glass frog (Hyalinobatrachium sp). These frogs have an unusual appearance as their large eyes face forward more than most other species.

Glass Frogs as their name suggests are relatively see-through. From beneath the heart and other organs can be clearly seen.

Hourglass Tree Frog (Hyla ebraccata)

Hourglass Tree Frog (Hyla ebraccata)

Hourglass Tree Frog (Hyla ebraccata)

Hourglass Tree Frog (Hyla ebraccata). Another individual with patterns as unique as a fingerprint.

A Masked Tree Frog (Smilisca phaeota). One of the nightly visitors to the toddlers pool.

Red-eyed Tree Frog (Agalychnis callidryas). This is the iconic frog of Costa Rica. Images of this species are used in all manner of promotion materials for eco-tourism. It took us a while to see one, but this little guy turned up in the front yard.

Red-eyed Tree Frog (Agalychnis callidryas)

Milk Frog (Phrynohyas venulosa). This is Costa Rica’s largest tree frog, growing to over 100mm in body length. It is highly variable in colour and pattern, but has distinctive glandular skin on its back .

A tiny tree frog metamorph, which had just left the water. (This one is for you Claire)

Sunday, July 24, 2011

Costa Rica Day 11 – Wandering spiders

Ctenidae is a family of moderate to large spiders which dominate the spider fauna in Costa Rica, much the same way as the Sparassids (huntsmen) do in Australia. Ctenids are known as wandering spiders and have a very distinctive eye arrangement; they basically have a row of six across the top and two below. Viewed from the front they have four large forward facing eyes which make them quite easy to identify.
Cupiennius sp.
A large ground-dwelling Ctenid

Another large ground dweller we have nicknamed the 'Leopard  wandering spider  due to the spots on the legs.
Some species are very much like huntsman in their hunting methods and speed of movement, whilst others hunt on the ground and are more like over-sized wolf spiders. As their common name suggests, they tend to be wanderers, although I have noticed that some species tend to favour a territory and I will see them each night in much the same place. Their hunting technique basically relies upon ambush; pouncing on their prey with speed and power. So far I have witnessed them feeding on moths, katydids, other spiders and frogs.

A Ctenid spider feeding on a katydid

There are a number of large species around the Osa Peninsula, and we have encountered four here where we are staying. One of the most notable is known a Brazilian Wandering Spider (Phoneutria reidyi). It is a very large spider and has extremely potent venom. I have already heard several stories of locals being hospitalised in excruciating pain from the bite of this species. I have found two of these spiders in my boots, and on one occasion I was just about to slip my bare foot in when I spotted it.
Phoneutria reidyi

Another common Ctenid is the Red-thighed wandering spider (Cupiennius sp.) This is the size of a large huntsman, but more unpredictable in its movement and believe it or not, even faster than most huntsmen I have worked with. We used this species in the studio recently, and it was challenging to keep them on the set and off my back.

Cupiennius sp.
One of the surprising aspects to this family is the variation within egg sac form. Some of the species (Phoneutria spp.) produce a domed sac, that is secured to a flat surface. Others (Cupiennius spp.) create a round sac and trail it behind them as Lycosids do, while others carry the sac with their fangs.

Friday, July 15, 2011

Costa Rica - Day 9-10 Salamanders

In the last couple of days we have encountered two species of salamander, a group of amphibians that we do not have in Australia.

These remarkable animals have soft permeable skin like that of frogs, but at a glance can seem lizard-like. We found a Bark-coloured Salamander (Bolitoglossa lignicolor) on a broad green leaf during one of our evening bug expeditions. It is bizarre to watch; the feet are broad and almost lack distinguishable toes, and it walks in slow motion in a very precise manner. These unusual feet securely anchor it to the moist surfaces on which it travels, and it uses its muscular body and tail to assist it lean out slowly and grasp nearby leaves. Once in the leaf litter, this species all but disappears. Just 30 seconds after I released it I thought it had gone, but in fact it had moved only several centimetres and still right in front of me.

The Bark-coloured Salamander (Bolitoglossa lignicolor)

The bumps below the nostrils are nasolabial tubes. These are grooves which connect the nostrils to the upper lip and play an important role in the reception of chemical traces.

The Worm Salamander (Oedipina uniformis) is a small slender species, which has incredibly small limbs. It still seems to utilise these, but also moves in a worm-like manner quite well too. When I first found this one under a rock, it was thrashing and wriggling very fast, and I had to grab it to be sure of its identity. I could have easily dismissed it as a worm. 

The Worm Salamander (Oedipina uniformis)

Thursday, July 14, 2011

Costa Rica Day 7 – 8 Eyelash Vipers!

Over the last two days we have seen more incredible wildlife, culminating in today where we found not one, but two Eyelash Vipers (Bothriechis schleglii). The first was a small lichen coloured individual I spotted on a palm while looking for praying mantids in the afternoon. The second was an incredible yellow-form individual in our backyard within a small tree.

Eyelash Vipers are relatively small snakes growing up to around 800mm, however they have highly toxic venom. They are arboreal, and are well adapted for life in trees, having a prehensile tail and strong body for climbing. They have heat sensitive pits between their eyes and nostrils and feed upon birds, small mammals, lizards and frogs. Like Australian Death Adders (Acanthophis spp.), Eyelash Vipers utilise caudal luring; the tip of the tail is wriggled like a worm or grub to attract their prey.

Eyelash Viper (Bothriechis schleglii). A young individual with lichen colouration.

Although these snakes are quite placid, their cryptic appearance and tendency to hang low down in trees and shrubs at night does result in some human contact. Bites from this species often occur around the head and chest area, and several people die in Costa Rica each year as a result. 

Eyelash Viper (Bothriechis schleglii). A brilliant yellow adult, in a tree in our backyard.

Wednesday, July 13, 2011

Costa Rica - Day 4-5 Terciopelo!

We had been told that they are very common, and true to form it didn’t take long to see one. The Terciopelo or Fer-de-lance (Bothrops asper) is one of the most feared snakes in Latin America. They belong to the Viper family and can grow to almost 2.5 metres long. In comparison to our Australian snakes, the Terciopelo has enormous fangs; they can get to 2.5cm long. They are apparently much more aggressive than most other Vipers (such as rattlesnakes), and often won’t hesitate to bite if startled. Apart from their fang length and potent tissue-destructive venom, the locals fear these snakes due to their habits. During the day they shelter beneath shrubs and bushes and remain motionless, using their camouflage to conceal them. In this region of Costa Rica, care must be taken before reaching into any area within a bushy garden. At night they emerge and sit in a coiled position waiting for food. They will often sit near water or at the edge of tracks and trails, which means caution must be taken when walking along tracks at night, exactly what we need to do!

We hiked across the Rio Tigre (Tigre River) and up the rainforest trails to a small camp known as Bolita. We came across a selection of fascinating invertebrates and some incredible spiders, all new to me. At Bolita we were ushered to a small pond harbouring several species of frogs calling frenetically, complete with a large resident Terciopelo sitting on the bank waiting for an amphibian snack to approach it. The only disappointment was finding that I had left my camera battery behind on the charger! Fortunately another Terciopelo turned up in our front garden soon after which is the one pictured. This specimen, however, was opaque (preparing to shed its skin) and was quite nervous and flighty, so I only managed to get a couple of quick picks before it fled into the undergrowth.

The Terciopelo or Fer-de-lance (Bothrops asper) in our front yard. Note the milky eye indicating the snake is preparing to shed its skin. Snakes usually don’t feed during this phase, and are often at a heightened state of nervousness due to their diminished vision.

Here’s a few other goodies we’ve seen over the past few days.

Cat-eyed Snake (Leptodeira septentrionalis), a frog eating species. This individual had just finished a frog when I found it. It took off down a steep embankment moments later.

A robust weevil feeding on a leaf.

Another species of weevil. The weevils are the most speciose group of beetles in the world.

A young Common Anole (Norops polylepis) about to pounce on a beetle.  These acrobatic lizards are well known for the showy displays put on by rival males; extending and flashing a colourful dewlap (skin area beneath the throat).

There are a number of species of stingless bees around the yard. Apart from being attracted to flowers, they swarm over any fruit left out and constantly insist on landing on us, presumably to lap up the salts in our sweat.

Rain frogs (Eleutherodactylus spp.) are very common around the Osa Peninsula

Tuesday, July 5, 2011

Costa Rica - Day 2-3

While we are still getting set-up and sorting out logistics such as phone and internet, we have been getting out into the field a little more. Here’s a selection of encounters we have made over the last couple of days, all within 500 metres of our house.

While we try to have cameras at the ready all the time, there have been a few significant encounters we haven’t captured. Yesterday we stopped on the rainforest track that leads into town as we could see a Green Iguana sitting in the middle, about twenty metres further on. When I approached, at least 10 of them suddenly began moving from all around the visible one. They were juveniles of various sizes, and one by one disappeared into the undergrowth. It was reminiscent of a scene from Jurassic Park with the tiny Compsognathus dinosaurs moving in groups.

We also had a reasonably sized mammalian predator in the back yard called a Tayra. This is an arboreal weasel-like animal which is about the size of a cat. We both managed to startle each other quite effectively as I was looking for scorpions at the base of a large tree.

Over the next two weeks we will be investigating more and more sites in order to collect the various species of predatory invertebrates required for the TV series we are working on.

A tiny grasshopper with spectacular colours

Early morning breakfast; a rainforest fly feeds upon a fresh bird dropping, sunny side up.

A dead wasp covered in fungus; a common killer of insects in the tropics.

An large katydid about the size of the Australian Segestidea  queenslandica

Harvestmen are very common at night; there are many species and some are quite large.

There are many species of katydids in Costa Rica that mimic leaves. This one has an amazing shape and detail, but we easily spotted sitting on the larger leaf in our torchlight. 

A heavily armoured iridescent beetle, but unfortunately it was already dead.

A large gecko around 170mm long.

A leaf-hopper sucking bug, with a long extension on its head.

I was lucky enough to spot this tiny Opossum which froze long enough for me to get a few snaps. It looked very similar to our pygmy possums in Australia.

Sibon nebulatus, a snail-eating snake

Our first wild tarantula in Costa Rica. Not sure what species this one is yet, but I did manage to get a good look at when I tickled the edge of the burrow with a fine grass stem – she shot out and tried to catch what she thought was an insect passing by. 

A tiny predatory katydid; the front legs are armed with spines to capture prey.

The Amblypygids here are about the size of huntsman spiders. We have seen quite a few so far and are one of the species we will by using in the TV series.