Archive for the ‘Golfo Dulce Poison Arrow Frog’ Tag

Drops of Colored Poison on a Leafy Bed   Leave a comment

Felipe del Bosque Blog February 11th 2013

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The Patter of Tiny Feet

The dry conditions continue but with the bonus of some rain at night which is enough to keep things green.  That hint of dampness is enough to tempt the Halloween Crabs, (Gecarcinus quadratus), out from the dark dank tunnels in which they reside beneath the surface of the forest floor.  They may be land crabs but they breathe through gills which have to remain moist to function effectively, so even though they may have escaped the confines of their aquatic environs and adopted a terrestrial habit, they have not fully adapted to totally dry conditions.  It always remains something of a surprise for people who had never heard of land crabs, and consequently only associate these crustaceans with the rocky coastal shorelines, to find the forest floor crawling with them following a summer shower.

It is not only those creatures in possession of 10 legs that have been spurred into action; the six-legged life forms of the social kind have suddenly become more obvious by their untiring activities.  Leaf-cutter Ants, (Atta cephalotes), familiar to most visitors to Bosque del Cabo due to the mesmerizing lines of slightly wavering fragments of leaf being carried in what seems like a slow moving river of green through the lawns and across the forest floor, have caught a second wind.

Normally at the height of the dry season the Leaf-cutter Ants cease their assiduous cutting and carrying during the daylight hours and recommence once the sun has set.  The dry season in the south west of Costa Rica can quite often result in very little rain for five months of the year and sometimes none at all during February and March.  At this time of year, should the ants cut and carry leaf, the distance over which it has to be transported and the time required to do so can result in the leaf drying out.  If the leaf contains small quantities of toxic compounds, as it dries these may become more and more concentrated thereby constituting a lethal cocktail for the ant or the fungus grown on the leafy mulch that provides staple diet of the ants.  This time of year those leaves delivered to the nest that were tasted and recognized as being unsuitable by the quality control ants are brought back to the surface and dumped on top.  The further we go into the dry season, the higher these mounds of dried leaves will built up around the entrances of the nest.

Leaf-cutter Ant

Currently the waste disposal ants in the colonies seem to be hard at work too.  In many of the nests around the trails excavation has been taking place at a heightened level of activity.  If you were to walk the trails on a daily basis you would see the heaps of earth accumulating in ever increasingly sized mounds.  Take a closer look and you will see the ants whose allocated employment is to remove excavated earth and waste products from inside the nest and bring it to the outside.  Each one is carrying a fragment larger than her own head.  Where the waste tip issues from the side of a hill or bank you will see the friable piles tumbling down, in ant terms each mouthful the size of a boulder, to the base.

Feeding of the Ravenous Hordes

The leaf-cutters are not the only ants that have been stimulated into action over the past week or so.  At various points on several trails long columns of ants moving quickly, deliberately and determinedly have been seen.  These are army ants, (Echiton spp), one of the forests most formidable mini predators.  Army ants have no nest, they are nomadic.  They have to periodically change the location of their temporary headquarters due to the fact that being such a super efficient predator, were they to remain in any one area for a protracted period of time they would deplete the locality of all small forms of life.

They may be encountered in one of two phases of activity; translocation or foraging.  When on the move to a new hunting area the whole colony including the queen is on the march.  There appears to be an endless river of ants streaming across the forest floor, insects in fluid form.  The workers carry the immobile pupae like swaddling aliens in their mandibles.  When virgin territory is reached the army ants ball up, linking their legs together to form a living bivouac, generally somewhere in a sheltered spot such as a hollow log or under a large fallen branch.  The queen moves to the centre, swells up and starts to lay about 60,000 eggs a day.

When the first larvae emerge, they emit a pheromone which causes a change in the behavior of the other workers.  They are stimulated into a hunting response which results in the mustering of half a million murderous assassins swarming through the forest slaughtering all that find themselves so unfortunate to be in their path.  The ravenous hordes surge relentlessly across the forest floor, up trees and scouring every nook and cranny.  The foraging front can be anything up to 60 feet across and 3 feet in breadth.

Army Ant

The ant’s progress will be heralded by flocks of exciting birds gathering as if at a tickertape parade.  You will hear the calls of antbirds, ant-thrushes, antwrens, woodcreepers, woodpeckers and tinamous.  If ever you see Grey-headed Tanagers you will see army ants, they are obligative followers of the army ants.  None of the birds are here to eat the ants.  As the front moves forward so many creatures are flushed, fleeing for their lives only to meet their end in the bill of a hungry bird.

Even if they escape those two terminal hazards, a third gruesome fate may await.  Clouds of parasitic flies, Phorid flies are flying in droves at the head of the advancing front.  The hum of their countless buzzing wings can be heard in the air.  They fly in and lay an egg on any victim attempting to escape the melee of death beneath.  The fickle hand of fate has played them a cruel hand.  They may have escaped mandibles, bills and jaws but the insidious cargo they now carry will now become their executioner.  When the egg hatches the fly maggot will eat its victim alive.

The ants push forward, unrelenting in their pursuit of fresh meat.  Whatever they come across they have, spiders, scorpions, centipedes, beetles, cockroaches, crickets, small frogs, small lizards, small snakes and even fledgling birds, it matters little to the ants.  There is no hiding place; the only choice is to run.  Once found, the prey is overwhelmed in a seething mass of frenzied killers, the ant’s venom laden stingers plunging through the victim’s skin time and time again and within seconds it will have been done to death.  Then it will be butchered on the spot, the slashing mandibles of the ants acting like meat cleavers to dismember the cadaver.  The separate parts of its now mutilated corpse will be carried back along feeder columns from the foraging front to the bivouac to feed the hungry carnivorous larvae.  Once the larvae pupate, the hunting response is turned off and away they go nomadically through the forest until they reach new and rich killing fields from which they will steal the lives of countless unfortunate creatures now dwelling there in blissful ignorance of their rapidly approaching fate.

Swollen With Indignation

Snakes are never the easiest animal life form to find in the forest.  They are ever-present but tend to elude those who want to see them but ironically make an appearance for those who don’t.  As with everything else, once you overcome your aversion to these reptiles, then they become fascinating creatures evolutionarily modified for a unique legless life-style.

One reasonably common snake around the grounds of Bosque del Cabo is the Neotropical Bird-eating Snake, (Pseustes poecilonotus).  They can grow up to six feet or more in length, are a pale blue-grey in color with a yellow belly and quite often a dark head.  If approached they put on a defensive display that involves flattening the neck laterally and turning the head side on so that they look larger than they are.  They are also very snappy snakes and are inclined to readily strike out and bite if molested, a characteristic of both juveniles and adults alike.

Tropical Bird-eating Snake

As the common name suggests, the bird-eating snake feeds on chicks and eggs from nests.  The breeding success of many birds at Bosque is hampered by these lithe predators whose forked tongue allows them to locate the presence of prey very quickly.  Many times around the restaurant area where Cherrie’s Tanagers and House Wrens nest and raise their offspring, it is almost a certainty that before too long the bird-eaters will turn up.

Pseustes poecilonotus

This individual I happened across this week when returning to my cabin.  It was lying across the path and I could see it ahead so just stood and watched for a while.  Its tongue was flicking constantly in and out tasting the air for scent particles.  It moved very slowly its head face down intently following what seemed to be a trail across the ground.  Then it lifted its body and flattened its neck, still its tongue rapidly flicking to taste the air and leaf litter in front as if something was bothering it.  I could see no sign of other life.  It looked like its attention was going to be held in this area for a while so I fetched the camera, lowered myself to the ground and took some close ups of its head before letting it slowly slither off into the undergrowth.

Unexpected Visitors

As the forest is so full of life it is no surprise that things turn up all over the place all of the time.  If I was to sit on the patio of my cabin and take time to look around I will see a myriad of small animals each one of which can capture your attention and then hold you thrall to its actions which can be observed, noted and later analyzed.  It may produce nothing more than an air of idle curiosity but when you delve a little deeper then most subjects however large or small have a fascinating life history and natural biology.

Jumping Spider

This week I was sat reading in the shade and noticed a line of minute ants making their way up and down the outside wall of my abode.  They were little more than moving specks and in typical ant fashion were following in a fairly strict line in both directions.  There was nothing unusual in this per se and my attention was concentrated more on where they were coming from and consequently where they were going to before returning again.


Off to one side of the ant column was another small dark speck that I could make out as having eight legs.  Tiny as it was, its form and behavior suggested that of a jumping spider, Family Saltacidae.  As I sat watching a small drama unfolded.  One of the ants broke ranks and the maverick spirit took a line of its own deviating away from the main caravan.  This was to be its undoing.  Small prey attracts small predators; nature is red in tooth and claw at every size level.  This ant that had left behind the safety in numbers that comes with a being part of a group had now exposed itself as a target.  That error did not escape the attention of the spider.

Jumping Spider

Despite its minute dimensions, the jumping spider is an evolutionarily adapted hunting and killing machine.  Looking at it face on you will find the front of the head bears huge eyes which in spider terms are visually acute.  It’s not very often that the spider prey will see these eyes as the jumping spiders are as stealthy as a cat.  Once they have singled out their victim they sneak up on it at the last moment launch into the air landing on the hapless prey.  Needle sharp chelicerae inject a powerful immobilizing venom and digestive enzymes which both kill the prey as well as reducing its innards to a soup that the spider can suck from its now dead shell.

That is what happened to the ant.  It would not have even registered that anything was happening.  The attack was lightning fast.  The ant did not know what hit it and it was dispatched in the blink of an eye.  The tragedy played out on the mini stage before me was one of countless such encounters that you can witness all around if you choose to redirect the focus of your attention.

Bat Sac

Despite their numbers, abundance and diversity bats are not always the easiest animals to find.  When you do find a bat, without having it in your hand it may not always be the easiest animal to identify to species level.  Costa Rica has a very diverse bat fauna, 111 species in total of which 80 species live on the Osa Peninsula.

Some bats are so distinctive though that their identity leaves little ambiguity as to what it is you are looking at, the Greater White-lined Bat, (Saccopteryx bilineata), falls into this category.  One morning while walking on the Zapatero Trail with a group of guests, we stopped to watch two bats flitting around between the giant buttresses of the tree.  They would settle momentarily then flit off again to land not so far away.  When they did land it was face down but with the head pushed out at almost a right angle to the body.  This is the characteristic poise of the Greater White-lined Bat.  After the tour had ended I headed back in the hope of getting some photographs.  My luck was in, the bats were still there.  They were not keen on my presence and kept moving but with a little perseverance I managed to capture several images.

Greater White-lined Sac-wnged Bat

The Greater White-lined Bat is one of the sac-winged bats belonging to the Family Emballonuridae.  They are insectivorous bats and are normally communal roosters having one male guarding a harem of one or more females.  Quite often there can be several roosts in close proximity.  They are called sac-winged bats as the male has a small pouched scent gland on the wing in front of the forearm.  This emits a smelly secretion which is used in both territorial and mating displays.  The male can be seen during the course of the day flying up and down in front of the females serenading them with releasing scent from his ‘sac’.

Philip is a biologist, writer and photographer as well as the onsite naturalist guide at Bosque del Cabo Rainforest lodge on the Osa Peninsula, Costa Rica.

Photo Feature

Localised Poison

There are two species of poison arrow frog to be found at Bosque del Cabo; the Black and Green Poison Arrow Frog, (Dendrobates auratus), and the Golfo Dulce Poison Arrow Frog, (Phyllobates vittatus).  Both are visually unique, both have different calls and they inhabit different habitats so there should be no confusion as to what you are looking at when you find one.

Black and Green Poison Arrow Frog

Currently on the forest floor behind the restaurant where the Creek Trail enters the forest the Black and Green Poison Arrow Frogs can be seen without little difficulty.  You just have to walk ten yards or so then stop and look down by your feet and invariably you will see at least one but often several hopping around.  They are not inclined to be shy either, quite often making their way across the open expanse of the cleared trail or jumping around on the leaf litter to the sides.  The Golfo Dulce Poison Arrow Frogs can be a little more difficult to locate.  They prefer damper habitat and can be found by the creek beds.

Both species have different calls.  The black and green has a high pitched trill which is produced in a very broken stuttering fashion.  The golfo dulce calls with a long unbroken trill.  At certain times of the year you can hear the golfo dulce constantly calling but that is not always going to lead you straight to them.  They are more retiring than their black and green relatives and usually call from under fallen leaves, hollow logs or small spaces in the banks.  Also due to their inherent ability with regards to ventriloquism they seem to be in a different location to where the calls are emanating from.

The poison arrow frogs are diurnal.  For a frog to be found hopping around on the forest floor during the light of day would normally make it an easy target for predators.  These frogs have evolved toxic skin secretions to protect them against predation.  But there is little point having a toxic skin secretion if the predators are not aware of it.  If the frog gets eaten it is too late for both the frog and the animal naïve enough to eat it.  The glowing colors that they sport make them stand out clearly against the background.  If something is so deliberately drawing attention to itself it is not inviting predators to dine on it but rather warning them off.  These are warning colors, aposematic coloration.

Golfo Dulce Poison Arrow Frog

The black and green secretes a lipophilic alkaloid skin toxin which if you get it on your skin can cause burning and itchiness of cuts and scrapes.  Woe betides you if you get it on any mucus membranes such as eyes, nose or mouth.  Put two of these frogs in a bag together and they will die.  The golfo dulce is the most poisonous of the Costa Rican poison arrow frogs.  The skin toxin is a batrachotoxin which poisons heart muscle causing a painful death.  Do not attempt to handle these frogs but by all means admire them for their toxic beauty.

Text and Photographs are taken from the forthcoming book:

The Natural History of Bosque del Cabo by Philip Davison

Temperature and Rainfall

Average Daily Rainfall 0.04 ins.  Total Weekly Rainfall 0.29 ins

Average Daily Rainfall 1.1 mm.  Total Weekly Rainfall 7.4 mm

Highest Daily Temp 96°F.  Lowest Daily Temp 75°F.

Highest Daily Temp 35.9°C.  Lowest Daily Temp 24.8°C.

Species List for the Week


  • Mantled Howler Monkey
  • Spider Monkey
  • White-faced Monkey
  • Agouti
  • Alfaro’s Pygmy Squirrel
  • Red-tailed Squirrel
  • Greater White-lined Bat
  • Collared Peccary


  • Crimson-fronted Parakeet
  • Red-lored Amazon
  • Scarlet Macaw
  • Great Curassow
  • Crested Caracara
  • Mangrove Black Hawk
  • Roadside Hawk
  • White Hawk
  • Crested Owl
  • Spectacled Owl
  • Chestnut-backed Antbird
  • Short-billed Pigeon
  • White-tipped Dove
  • Blue-crowned Motmot
  • Rufus Piha
  • Long-billed Hermit
  • Red-capped Manakin
  • Chestnut-mandibled Toucan
  • Grey-headed Tanager
  • Bright-rumped Atilla
  • Dusky-capped Flycatcher
  • Black-throated Trogon
  • Great Tinamou
  • House Wren
  • Black Vulture
  • Turkey Vulture


  • Barred Ameiva
  • Cat-eyed Snake
  • Central American Smooth Gecko
  • Central American Whiptail
  • Clawless Gecko
  • Four-lined Ameiva
  • Golfo Dulce Anolis
  • Mediterranean House Gecko
  • Pug-nosed Anole
  • Tropical Bird-eating Snake


  • Black and Green Poison Arrow Frog
  • Golfo Dulce Poison Arrow Frog
  • Marine Toad
  • Masked Smilisca
  • Red-eyed Green Tree Frog
  • Savage’s Thin-fingered Frog
  • Stejneger’s Dirt Frog


  • Anartia Fatima
  • Anartia jatrophae
  • Archaeoprepona demophon
  • Caligo eurilochus
  • Colobura dirce
  • Dryas iulia
  • Eueides aliphera
  • Eueides lybia
  • Eurema albula
  • Glutophrissa drusilla
  • Heliconius erato
  • Heliconius hecale
  • Heliconius ismenius
  • Heliconius sapho
  • Heraclides cresphontes
  • Hermeuptychia hermes
  • Morpho helenor
  • Morpho Menelaus
  • Parides erithalion
  • Pierella helvina
  • Pierella luna
  • Pierella argante
  • Phoebis sennae
  • Philaethria dido
  • Pyrisitia proterpia
  • Pyrrhogyra crameri
  • Temenis laothoe


  • Alamandra  cathartica Flowering
  • Alpinia purpurata Flowering
  • Apeiba tibourbou Flowering
  • Arachis pintoi Flowering
  • Arundina graminifolia Flowering
  • Attalea rostrata Fruiting
  • Bauhinia variegata Flowering
  • Cascabella thevetia Flowering and Fruiting
  • Citrus spp  Fruiting
  • Clusia rosea Flowering and Fruiting
  • Clusia vallerii Flowering and Fruiting
  • Cocos nucifera Flowering and Fruiting
  • Crestentia alata flowering and Fruiting
  • Costus speciosus Flowering
  • Couroupita guianensis Flowering and Fruiting
  • Dypsis lutescens Flowering and Fruiting
  • Etlingera elatior Flowering
  • Ficus citrifolia Fruiting
  • Ficus insipida Fruiting
  • Jacaranda mimosifolia Flowering
  • Heliconia chartacea Flowering
  • Heliconia latispatha Flowering
  • Heliconia pogonantha Flowering
  • Heliconia psittacorum Flowering
  • Heliconia rostrata Flowering
  • Hibiscus rosa-sinensis Flowering
  • Hymenaea coubaril Fruiting
  • Hymenocallis littoralis Flowering
  • Ixora coccinea Flowering
  • Lantana camara Flowering and Flowering
  • Lagerstroemia speciosa Fruiting
  • Morinda citrifolia Fruiting
  • Musa acuminate Flowering and Fruiting
  • Nephelium lappaceum Fruiting
  • Piper auritum Flowering and Fruiting
  • Piper nigrum Fruiting
  • Piper umbellatum Flowering and Fruiting
  • Pleiostachya pruinosa Flowering
  • Plumeria rubra Flowering
  • Psychotria sp Fruiting
  • Stachytarpheta frantzii Flowering
  • Virola guatemalena Fruiting
  • Zammia sp Flowering



Poison Hidden From Owl Eyes   Leave a comment

Felipe del Bosque Blog Dec 5th 2011

Almost But Not Quite

The wet season just will not go away.  We keep having meteorologically false promises when the rain abates; the sun comes out for a day and then back comes the rain.  That has been the story of this week.  But at least the rain has been reduced to light showers rather than the heavy downpours of late.  As I write, the sun has been out all day, a continuation of yesterday but with a brief shower last evening.

As You Were

It has been a bit of a slow week in terms of animal sightings but we have had some good ones.  The first Puma sighting of the season was recorded late Saturday afternoon not too far from the restaurant area by the cabin occupied the girls working on the sustainability certification.  Two nights earlier the night watchman while doing his rounds saw a Margay, (Leopardus wiedii), up in a tree.

A palm and a fig tree in front of the restaurant are providing a nonstop source of subject material for our visitors to the lodge.  We have had and currently have groups of wildlife photographers staying with us.  Their work has been made very easy for them by the continual to and fro of Chestnut-mandibled Toucans, Great Kiskadees and a wealth of other bird life.

The monkeys too are performing well.  Troops of Spider and White-faced Monkeys, many of the females carrying young on their backs, have been making their daily arrival for a feed.  The Spider Monkeys prefer the figs while the White-faced Monkeys have a definite preference for the coconuts.  If you have ever tried to open a coconut, you will appreciate that it is no easy task, certainly not for us.  For a White-faced Monkey, it is normally a case of biting through the husk, ripping the husk off and biting through the shell to get to the milk inside, which they scoop out with their cupped hands until the vessel is completely drained.

The White-faced Monkeys also provided another diversion for the photographers.  The toucans come to feed but that is not without a certain danger.  The monkeys have learned how to catch the toucans as they land and quickly dispatch them.  As the photographic group was having breakfast one morning they were treated to the sight of two toucans reaching an untimely end.  One stunned individual hit the ground but the monkeys followed it straight down and it wasn’t long before the alpha male was feeding on toucan flesh.  The carcass stripped of its best meat was then passed around the remaining members of the troupe to clean off the bones.

At least once a year I get to see a Swainson’s Thrush, (Catharus ustulatus), and I did just that earlier this week as I was walking through the forest from my cabin.  The bird was at about head height and I knew what I was looking at as soon as I lay eyes on it.  I may see another one at some point but this individual filled the normal annual quota.

One of the photographic groups enlisted my services to take them on a private tour to the Pacific waterfall in search of a small amphibian endemic to this area; the Golfo Dulce Poison Arrow Frog (Phyllobates vittatus).  They had been to Bosque on previous occasions and had photographed the Black and Green Poison Arrow Frog which can found more commonly on the forest floor but I knew where to find the object of their desires even if it does require the turning of many rocks and logs to locate them.  On the walk down the Pacific Trail, I happened to mention looking into the rolled leaves of the Heliconias, Marantas and Bananas in the hope of seeing Spix’s Disc-winged Bats, (Thyroptera tricolor).  The first group of Marantas that we passed, I looked down an as yet unfurled leaf and sure enough there were the bats and they got their pictures.

Walking down the beach we found a lot of the Sally Lightfoot Crabs on the rocks, parting and running before us in droves.  There was any number of Hermit Crabs at the back of the beach.  Those quick growing, colonizing trees that line the upper shore line, Balsa Trees, were in flower.  We stopped to have a look in one of the caves for the White-lined Sac-winged Bats, (Saccopteryx bilineata), that sometimes inhabit them, one male and a harem of females generally hanging head down from the walls, but on this occasion we had no luck.

We finally made it to the creek and the search began.  The initial turning of rocks and logs in likely looking spots produced nothing but it didn’t take long before one hopped from its hiding place under a dead leaf.  Taking the pictures was not as easy as finding the subject.  Every time one of the photographers set up and framed the frog, off it hopped.  But with patience and endeavor the required images were captured and everyone returned tired but happy from the experience.

Philip is a biologist, writer and photographer as well as the onsite naturalist guide at Bosque del Cabo Rainforest lodge on the Osa Peninsula, Costa Rica.

 Photo Feature

Owl Eyes

An unusual insect turned up in my cabin this week.  I have seen several over the years but had not managed to photograph one.  This insect looks every bit like a damselfly except for the long, clubbed antennae.  The very distinctive feature though are the huge hemispherical eyes after which it is named, the Owl Fly.  The owl flies belong to the family Ascalaphidae of the order Neuroptera which includes the Lacewings and Antlions.

Owl Fly

As well as superficially resembling dragonflies and damselflies, the owl flies also hunt like their odonate lookalikes.  Those large compound eyes quickly observe any movement and if it happens to be a prey item of the right size, the fly seizes it out of the air.

Owl Fly

Text and Photographs are taken from the forthcoming book:

The Natural History of Bosque del Cabo by Philip Davison

Temperature and Rainfall

Average Daily Temp High 83°F.  Average Daily Temp Low 72°F.

Average Daily Rainfall 0.46 ins.  Total Weekly Rainfall 3.23 ins

Average Daily Temp High 27.9°C.  Average Daily Temp Low 22.2°C.

Average Daily Rainfall 11.72 mm.  Total Weekly Rainfall 82.04 mm

Species List for the Week


  • Howler Monkey
  • Spider Monkey
  • White-faced Monkey
  • White-nosed Coati
  • Agouti
  • Red-tailed Squirrel
  • Spix’s Disc-winged Bats


  • Orange-chinned Parakeets
  • Red-lored Amazon
  • Scarlet-fronted Parakeets
  • Gray-necked Woodrail
  • Pale-billed Woodpecker
  • Great Currasow
  • Crested Caracara
  • Roadside Hawk
  • Laughing Falcon
  • White Hawk
  • Yellow-headed Caracara
  • Black-hooded Antshrike
  • Chestnut-backed Antbird
  • Common Paureque
  • Wedge-billed Woodcreeper
  • Plain Xenops
  • Short-billed Pigeon
  • Long-billed Hermit
  • Stripe-throated Hermit
  • Spectacled Owl
  • Chestnut-mandibled Toucan
  • Blue-crowned Manakin
  • Swainson’s Thrush
  • Cherrie’s Tanager
  • Gray-headed Tanager
  • Summer Tanager
  • White-shouldered Tanager
  • Bright-rumped Atilla
  • Dusky-capped Flycatcher
  • Great Kiskadee
  • Great Tinamou
  • Black-throated Trogon
  • Riverside Wren
  • Black Vulture
  • Turkey Vulture


  • Cat-eyed Snake
  • Common Basilisk
  • Clawless Gecko
  • Golfo Dulce Anolis


  • Marine Toad
  • Red-eyed Green Tree Frog
  • Black and Green Poison Arrow Frog
  • Fitzinger’s Rain Frog
  • Golfo Dulce Poison Arrow Frog
  • Smokey Jungle Frog
  • Stejneger’s Dirt Frog


  • Anartia Fatima
  • Heliconius sapho
  • Hermeuptychia hermes
  • Morpho Menelaus
  • Pyrgus oileus


  • Aphelandra golfodulcensis Flowering
  • Bamboo Orchid Flowering
  • Black Alligator Tree Fruiting
  • Calabash flowering and fruiting
  • Cannonball Tree Flowering and Fruiting
  • Clusia rosea Flowering
  • Golden Trumpet Vine Flowering
  • Heisteria fruiting
  • Inga Flowering
  • Monkey Comb Tree Flowering
  • Figs Fruiting
  • Mountain Rose Flowering
  • Ox Eye Vine Fruit
  • Stinky Toe Fruiting


Beautiful Deceptions: Poison or Not   Leave a comment

The weather continues to favor the visitors to the Osa Peninsula.  August normally sees the transition from rain to really heavy rain which continues through September into November. But the days remain hot and sunny, and certainly not every night, but definitely last night, we were entertained by an electric storm with lots of lightning illuminating the forest.  This morning though, as the sun rose over the Golfo Dulce, it did so without a cloud in the sky, promising yet another beautiful day.

Rainforest Rhythm

The storm seemed to have dampened the enthusiasm of the animal life as there were not many birds active at first light and the butterflies made a slow start to the day.  As the sun rose in the sky normal activity was resumed.  The Scarlet Macaws were making their usual raucous din and a large flock of Golden Hooded Tanagers made their way from one fruiting tree to another, eagerly feeding on the ripening feast now available to them.

Several fig trees have been producing a copious amount of fruit for several weeks now.  Toucans arrive by the flock on a daily basis.  There are large mixed flocks of multiple tanager species, dacnis, honeycreepers and manakins.  The ever-present large white blooms of the Crepe Gingers are continually attracting the attention of resident Rufus-tailed Hummingbirds and Purple-crowned Fairies which feed on the nectar they provide.  Despite their small size, the Rufus-tailed Hummingbirds zealously guard their food supply, pugnaciously putting much larger invaders of their territory to flight.  The Hermits, both Long-billed and Stripe-throated, are more tranquil by nature, and “trapline” the Heliconia blooms, making their daily rounds, flitting at high speed from flower to flower, hovering briefly at each one to take a sip of nectar.

The Hobos or “Hog Plums” have been another month’s long source of fruit now and the Cannonball Tree which has recently been flowering is now starting to produce the distinctive large cannonball shaped fruits from which the tree derives its name.

Rain in A Rainforest:  Life Goes On

This is not the best time of year to see butterflies but nonetheless there are some persistent species, particularly some of the brightly colored long-wings.  I don’t tend to put many guarantees on wildlife sightings, but I can be pretty sure that a visit to one of the constantly flowering Lantanas will reward you with at least four or five species, each taking it in turn to move between the orange and yellow flower heads.

Monkeys, coatis and agoutis are not going to be to far away on the Osa Peninsula.  Many people ask what the animals do during the rainy season.  It is a rainforest, it rains seven months out of twelve so the animals go about their daily lives as normal.  The Humpback Whales have been giving a fine display today with several females and calves close to the shore.

Wildlife spotting is a bit of a hit or miss affair.  No nature guide in his right mind would give cast-iron guarantees about seeing any one particular animal, even it is has inhabited the same spot for a long period of time.  Animal life is not always compliant with ones wishes to see it.  Despite the high levels of biodiversity in tropical rainforests, notoriously they do not reveal their secrets very readily.  It is not like being on the African savannahs inhabited by large mega fauna.  If mammals don’t want to be seen, you will not see them.  I have lived here for twenty years and I walk these trails on a daily basis.  In the wet season I can see what has been walking before me from the tracks they have left in the soft earth.  I have seen the tracks of Baird’s Tapir on more than a few occasions.  It is an animal about the size of a Shetland Pony and despite having seen their tracks, even close to my cabin, I have never seen a tapir in this area.

Aposematic Coloration

However there are animals that do want to be seen.  One can think of the bright red color of the Scarlet Macaw.  Along with many other species of parrot, macaws are gregarious birds.  Red is the complementary color to green, the background color of the forest, so it probably aids the macaws as a visual signal within the group.  Think of all those brightly colored, slow flying butterflies, the Heliconiids or Long-wings.  Why would a butterfly want to appear so visibly obvious, they are patently not trying to hide?  The reason is that they contain cyanide.  It would not be in the interests of any predator to feed on the butterfly and nor would it do the butterfly any good to have such a toxic chemical deterrent if nothing new about it.  So those bright flashy colors are warning colors and animals sporting them are said to display aposematic coloration.

Veridion-Adventures Nymphalidae Heliconiinae Heliconius-sapho Nature Photography Travel Adventure Holidays

Sapho Longwing, (Heliconius sapho)

This situation very nicely lends itself to two forms of mimicry.  Batesian mimicry is the term applied to non poisonous butterflies mimicking poisonous butterflies.  This form of mimicry only works where there are far more poisonous butterflies or the predators would never learn.  Mullerian mimicry is where all the poisonous butterfies across the board are co-mimics of one another.  And mimicry really does work, quite often you need the butterflies in your hand to assess subtle differences in markings or coloration to allow you to identify one species from another.

Most amphibians are nocturnal, so any diurnal amphibian hopping around on the forest floor during the day is going to be a fairly easy target.  To this effect many diurnal amphibians have evolved very toxin skin secretions.  But once again, there is no point having a toxic skin secretion if none of the predators know about it.  If they eat the frog it is too late for them and too late for the frog.  Diurnal frogs such as the poison dart frogs have evolved very bright warning colors, another example of aposematic coloration.  The colors tend to be neon-like and almost glow from the forest floor.  If something is sitting there glowing, it is not inviting itself as a meal, it is telling you to keep your distance.

Rainforest Poison Dart Frogs Costa Rica. Amphibia. Anura. Dendrobatidae. Oophaga granuliferus)

You can’t miss it – Granular Poison Dart Frog, (Oophaga granuliferus)

Costa Rican Poison Dart Frogs. Amphibia. Anura. Dendrobatidae. Pyllobates vittatus.

Endemic Golfo Dulce Poison Dart Frog, (Phyllobates vittatus)

Rainforest Frogs. Amphibia. Anura. Dendrobatidae. Dendrobates auratus.

Quite literally – Black and Green Poison Dart Frog, (Dendrobates auratus)

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