Archive for the ‘Philip Davison’ Tag

An Orgy of Green Pain   6 comments


Philip Davison Nature Diaries. Bosque del Cabo Rain Forest Lodge.

Parachuting into an Orgy

The past week has been a mixture of sun and rain.  The days have been gloomy with heavy, brooding overcast skies.  Occasionally the clouds part and the sun has shone down to light up the shadows.  But the menacing grey blanket that covering the area from north to south and east to west always threatened to unleash a downpour.  Sometimes the drizzle filled the air from dawn to dusk but you knew there was more to come.  By late afternoon the light rain would turn to heavy and by the time the sun had set below the horizon then the heavens would open drenching one and all.

The amphibians have been enjoying the onset of the rainy season, their numbers increasing over the last month but these more persistent nightly deluges have had the frogs collecting in huge numbers and rejoicing in a reproductive frenzy.  One frog that responds to torrential rain is the Parachuting Red-eyed Green Tree Frog, (Agalychnis spurrelli).

Agalychnis spurrelli. Hylidae. Pseudomedusinae.

Parachuting Red-eyed Green Tree Frog, (Agalychnis spurrelli)

One evening, just after sunset it started to rain heavily and by next morning we had experienced 11 inches of rain.  That was the trigger that stimulated hundreds of Parachuting Red-eyed Green Tree Frogs to leave the canopy, which is where they reside out of view, and launch themselves into the air.  This frog has a uniformly colored dark mossy green upper side.  Its flanks are a pale lemon yellow.  It has large heavily webbed hands and feet of the same buttery hue and, of course, it has the large red eyes.  As they leap out of the canopy they spread the fingers and toes so the webbing is stretched tight, quite literally into a parachute of living tissue, which allows the frogs to glide down to the vegetation surrounding the pond without ill effect.

Each male quickly establishes a territorial perch from which he begins to call in an attempt to entice an egg-laden female his way.  The call is a short, soft, almost electronically-sounding sound.  Selecting a male on the quality of his call, the deeper the sound the better, the female makes her way over to the chosen chorister, he jumps on her back and they set off to visit the pond.  The female absorbs water through her skin and fills her bladder.  Now the female, not only with a body full of eggs but also carrying the male on her back, makes her way to a deposition site.  She chooses a broad leaf overhanging the surface of the pond and she commences to lay a sheet of eggs across the leaf.  At the same time as she releases the eggs from her body the male fertilizes them.  This normally take place just before daylight.

Parachuting Red-eyed Green Tree Frog. Osa Peninsula. Costa Rica. Philip Davison.

Parachuting Red-eyed Green Tree Frog Eggs.

As dawn breaks and the sun rises, the frogs have to get out of the light and into the dark as quickly as possible.  They don’t have time to get back to the canopy, parachuting down was a quick descent but the ascent involves a 100 foot climb and there is little time.  The sun continues to steadfastly climb in the sky.  Hundreds of frogs are now scrambling desperately to escape the skin-drying effects of its harsh rays.  This was the point at which I arrived, just in time to see countless small green goblinesque figures running along branches in a desperate effort to find a not already fully accommodated shelter.  I was not the only one.  A Bare-throated Tiger Heron had found itself an early morning breakfast bonanza and was picking off the unfortunate amphibians one after the other.

The larvae will develop in the eggs for about 7 or 8 days before the gelatinous mass liquidizes and the wiggling tadpoles drop into the pond water.  There they will complete the tadpole stage and if they make it through the aquatic stage will finally emerge after 7 or 8 weeks as a tiny froglet which will eventually have to make its way to the tree tops.  The Parachuting Red-eyed Green Tree Frog is an explosive breeder and these episodes can only be witnessed following those biblical-like rain storms.

Agalychnis spurrelli. Bosque del Cabo.

Parachuting Red-eyed Green Tree Frogs After Sunrise

Showing Off in the Green Room

The forest flora can be flamboyant and gaudy or subtle and subdued.  The blooms may appear abruptly in a visual feast or occur in small numbers isolated and hidden in the dark green depths the subcanopy.  Some plants flower but once a year, a spectacular show drawing the eye like a beacon which is setting the tree tops ablaze and illuminating the forest canopy in a patchwork of color on natures silvian canvas.  It is no wonder that the largest percentage of insect life resides and thrives at the tree tops.  Here you will find a kaleidoscope of dancing butterflies waltzing from bloom to bloom in search of the energy rich nectar, so vital in allowing these ephemeral beauties to complete the final stage of their short adult lives.  Other plants may flower continuously throughout the year but only producing one or two blooms at a time.

It is not just the butterflies that rely upon the flowers.  Many other insects are attracted by their rich colors and evocative scents.  The plants will sometimes target birds or mammals to do their bidding.  The plants offer the animals rewards but there is method to their bribery.  These are windless forests; a zephyr is the strongest a current of air that will move through the trees.  Pollen needs to be transported from one plant to another in order for the plants to reproduce.  It helps if the plant can target and reward a specific agent to enable its pollen to be deposited in the flower of the same species.

The plants cannot rely on wind for seed dispersal either.  Once more they have evolved the means by which to encourage animals into becoming innocent vectors of transfer and movement of the seeds that will potentially give rise to the next generation.

Over the last week as I was walking along the paths through the forest I could see some of those secretive flowers blooming in the shadows as well as some bright vivid forms, their colorful flower heads breaking up the somber borders of the trails.  One of the more subtle blooms was that of the Spiral Ginger,  (Costus scaber).  The flowering head is a rather stout, deep red spike composed of bracts, each of which will produce a bloom.

Costus scaber. Costaceae. Osa Peninsula. Costa Rica.

Spiral Ginger, (Costus scaber)

The fiery orange, yellow-tipped flower sticking out of the bract attracts in hummingbirds which are the principal pollinator of this species.  The colors red, orange and yellow are commonly used by plants to attract hummingbirds, these being the colors in the spectrum that are complementary to the background green of the leaves.  These are also very hot colors whereas green is a cool color and so they readily stand out, particularly to animals that have keen color vision such as birds.  The hummingbirds hover in front of the flowers and probe within searching for the nectaries.  As they do so, the head and bill pick up pollen from the anthers which is transferred to the stigma of the next flower it visits thereby effectively pollinating the plant.

The family Costaceae is closely related to the ginger family: Zingerberaceae.  Most gingers are Asian but there are some gingers native to the Neotropics.  Most costas are American but there are some costas that are native to Asia.  There are 23 species of costa native to Costa Rica, 14 of which are found on the Osa Peninsula.  As they all look similar it is not too hard to identify them as costas but it is a little more difficult to identify them to species level.

Queen of Pain

Insects are fascinating creatures to photograph.  Once you have downloaded the image and zoom in, as long as the picture is in sharp focus, then the body form and colors become compelling.  All of the joints, the body plates and the detail of the head and wings will keep the naturalist mesmerized.  You can conjecture as to the function of all those different hairs and how the body parts articulate.  Not only that but how does the creature live, what is life history and what are the multitudinous, complex interconnected threads that tie it into the ecosystem of its habitat.  Insects complete their lives in almost as many ways as there are species.  Many insect’s lives are a mystery to us, we simply have no idea how they get from egg to adult.  That is not surprising as there are more species of insect on the planet than any other group of animals.  Because we don’t know, then that makes us more eager to study and discover more information to unravel those mysteries.

One groups of animals, the Hymenoptera, bees, wasps and ants, provide an endless source of material for research.  Many of them have well documented life histories and they work to a general pattern but there are variations.  I saw this wasp guarding its brood in a nest under a leaf in the tropical garden.

Although the wasp appeared to be alone, it was one of the social wasps belonging to the family: Vespidae.  The nest is made of carton which is a chewed up fibrous vegetable material, quite often wood, which forms the cells into which the eggs are laid.  The egg hatches and the larva develops, growing rapidly on a diet of chewed up insect prey captured by the queen.  The queen only uses her sting for defense, the prey is caught and chewed-up in the mandibles.  A pale larva lacking in pigment, can be seen in one of the cells.   When the larva pupates, the entrance of the cell is capped by a carton lid from which a new adult will emerge sometime later.

Polistinae sp. Hymenoptera. Vesperidae. Polistinae.

Paper Wasp Queen on Nest, (Polistinae sp)

There were, in fact, two wasps sitting on the nest.  This suggests that they belong to the subfamily: Polistinae.  These colonies consist of one or two queens both of which are responsible for the construction of the nest and raising the offspring without the aid of other workers.

Even if nobody told you, then you would learn very quickly from painful experience to leave wasps alone.  The black and yellow coloration of bees, wasps and hornets is the most visible of all color combinations.  As I have already mentioned, the wasp does not use its sting to subdue prey but rather uses it to defend itself.  But, as in many cases, it is better to use a deterrent rather than become involved in a physical battle where even though you may win, the probability is that you will sustain some damage yourself.  To ward off any potential threat, the wasps use threatening coloration.  It does not take too many painful encounters before most creatures would learn to avoid anything sporting that vividly distinctive black and yellow.

Philip Davison Is a Biologist, Writer and Photographer Based in Costa Rica

The Savage Death of a Velvet Cat   2 comments


Philip Davison Nature Diaries. Bosque del Cabo Rain Forest Lodge.

Sunny Days are Back Again

The weather has most certainly turned a corner.  After the record-breaking deluge that occurred continually over the course of the last five weeks we now have the opposite situation, no rain.  Not a single drop of rain has fallen over the past week.  The skies have been clear and bright blue.  The sun has been shining brightly.  The temperatures are on the rise.  The night skies have been clear and filled with stars.  Just within the space of seven days, the formerly soft muddy trails have started to harden up.  There are, of course areas where the ground is stiff soft and in places water continues to run off but these are now few and far between.  One trail had a new lake form as the water was unable to run off.  Walking along a familiar path I was finding myself waist deep in water.  I imagined that this new water feature may persist for months before the ground was exposed once more.  I was wrong.  Walking the trail a few days ago, all the water had gone.  The path was very muddy but no longer submerged.

Bosque del Cabo Rain Forest Lodge. Osa Peninsula. Costa Rica.

Zapatero Trail at Bosque del Cabo Rain Forest Lodge.

It was fortunate that the heavy rain stopped as the flowering season for many of the trees commences in December.  Should the trees bloom and then become bombarded with persistent downpours, the flowers can be knocked from the trees before they have been pollinated.  The result of this is a lack of fruit later in the dry season as the plants have not set seed.  There are many animals whose lives depend on the bounteous supply of mixed fruits that comprise their diet that should the flowering and fruiting seasons fail then they simply starve to death.  This happened in 2005 when substantial numbers of Spider Monkeys and Toucans were, quite literally, just dropping out of the trees.  Necropsies carried out by veterinarians showed that they were suffering from very low body fat.  They were starving to death.  Everything looks good at the moment for a bumper harvest as I have seen many trees starting to produce blooms.

Golfo Dulce. Cabo Matapalo. Osa Peninsula. Costa Rica.

The Sun is Shining Over the Golfo Dulce Once More.

Caught in the Eye of a Cat

The frogs are still out in numbers but those numbers will start to dwindle as we head into the dry season.  There are creatures that feed on frogs and they too have been out and about at night, the snakes.  One of the commoner snakes around the pond after sunset is the Cat-eyed Snake, (Leptodeira septentrionalis).  It feeds on frogs at all stages of their life history.  More particularly it searches out clumps of Red-eyed Green Tree Frog eggs which it finds suspended beneath the leaves overhanging the water.  The gelatinous masses are stuck in position and when the tadpoles reach about 7 or 8 days in age, the jelly liquidizes allowing the tadpoles to drop into the water where they complete the initial stage of their life history before emerging as froglets.  Frogs eggs make a perfect meal for the snake, they don’t run away or fight back and are packed with protein.  At the height of the amphibian breeding season, May, June and July, there are so many egg masses that the snakes start to look well fed and bloated.  Now, because there is little amphibian reproduction taking place, the snakes also fish for the tadpoles from beneath the water surface, take froglets as the emerge from the water and if they get the opportunity they will eat the adults too.

Red-eyed Green Tree Frog.

Red-eyed Green Tree Frog, (Agalychnis callidryas)

Agalychnis callidryas eggs

Red-eyed Green Tree Frog Eggs

Cat-eyed Snake

Cat-eyed Snake, (Leptodeira septentrionalis)

Leptodeira septentrionalis

Cat-eyed Snake. Close up.

The Fatal Velvet Kiss

Whereas the Cat-eyed Snakes feed on the smaller frogs, there is a much larger snake which feeds on the larger frogs.  One of the largest frogs in Costa Rica is the Savage’s Thin-fingered Frog, (Leptodactylus savagei).  A huge amphibian might make a satisfying for meal for any number of creatures.  To lower the risk of being predated upon Savage’s Thin-fingered Frog has several defenses.  It has a toxic skin secretion that can cause intense irritation of mucus membranes.  Should this prove ineffective it has a secondary defensive measure.  When it is caught, it issues a loud cry not dissimilar to a crying baby.  More importantly the call resembles the distress call of young caiman.  If there any adult female caiman in the area they charge in to defend their young, which means hopefully as far as the frog is concerned, it can then make its escape as its attacker is attacked.

Savage's Thin-fingered Frog

Savage’s Thin-fingered Frog, (Leptodactylus savagei)

But there are predators from which there is generally no escape.  It is not uncommon to see by the pond at night some substantially large sized Terciopelos, (Bothrops asper).  They are large pit-vipers in the same subfamily as rattlesnakes.  Like rattlesnakes they have a venomous bite that spells certain death for any prey victim it strikes.  An adult female can reach up to 6 feet, (2 meters), in length.  A snake that size demands a big meal and the Savage’s Thin-fingered Frog fits the bill.

Once the sun sets out come the Terciopelos.  They place themselves around the pond where an encounter with a frog is likely.  They are ambush predators; the cryptic coloration of muted browns and greys camouflage them perfectly against the background.  They remain motionless, camouflage works best if it is still.  Frogs, being mostly nocturnal, have large light gathering eyes.  They rely on movement to find food which is usually anything smaller than themselves, particularly arthropods, but sometimes smaller frogs too.  But the only movement they will detect from a hungry coiled Terciopelo will be one that is over in a flash.

Terciopelo. Crotalinae.

Terciopelo, (Bothrops asper)

The pit-viper is not so visually acute especially at night although its eyes will detect close movement.  Once the feeding response has been stimulated then the tongue comes into play, slowly flicking out then in again, each time tasting the air.  The tongue can detect parts per million of scent particles in the air and because it is forked it can pick up the gradient of a scent plume.  You and I may not know what a frog smells like but the snake does.  Then there are the pits that give it the sinister name pit viper.  These lie one on either side of the head between the eye and the nostril.  They are lined with cells that detect minute differences in background infra-red radiation.  They work best at responding to the presence of warm blooded prey such as rodents but their efficiency could also differentiate the small difference in body heat of even a cold-blooded creature such as a frog against the background temperature.

The unsuspecting frog passes by.  The snake has already drawn its head and neck into tightly sprung S-shaped.  The strike happened so fast that it would probably have been unaware, there would have been no time to react, no chance of escape.  As the snake’s head shoots forward and the jaws open, two long hinged fangs that lie flat against the upper part of the mouth now swing down.  They are simply two hypodermic syringes attached to glands that contain virulent life-ending cytotoxic venom.  The fangs puncture the skin like two needles, the force of the bite pushes them deep into internal tissues and organs.  The snake quickly recoils to avoid any retaliatory action by the victim in its final moments, not that a frog could inflict any damage but the bite of a rodent might.  The quantity of venom injected will spell doom and instant death for the unfortunate amphibian.  It probably would not feel anything from this lethal injection, the effects of which would most certainly be instantaneous.

The frog takes one or two steps forward then collapses dead in its tracks.  The snake is in no hurry.  The meal is ready whenever it would care to dine.  Lying patiently in the shadows the Terciopelo begins to smell the air with its tongue once more.  Once it is feels secure in the demise of its victim it slips forward, the tongue constantly flicking in and out over the cadaver.  It is searching for the head.  Snakes have no way of rendering a meal into small pieces and must swallow the prey whole.  Savage’s Thin-fingered Frog is a giant among amphibians, its body larger than the snakes head.  To deal with this inconvenience the snakes lower jaw disengages at the midpoint as do the upper and lower jaws where they hinge together at the side of the head.  Now the snakes gape can accommodate the huge frog body.  The snakes skin is highly elastic allowing it to stretch as it moves forward over the meal and with continuous backward moving S-shaped waves the feast is delivered finally to the stomach.  The snake moves away back into the shadow of the undergrowth where it will lie motionless for some time until it has digested the hearty dinner.

Terciopelo. Leptodactylus savagei

Terciopelo eating a Savage’s Thin-fingered Frog

Payback Time

There are times when even the top predators can become prey.  Where there are snakes then there might be snakes that eat snakes.  Sure enough on occasion by the pond where the Terciopelos lie in wait there is a hunter that actively seeks them out.  A hunter that is immune to the deadly venom.  A hunter that can overpower with impunity its adversary.  That hunter is the Mussurana, (Clelia Clelia)..

The Mussurana is a snake with a solidly muscled body.  It has a beautiful deep gloss grey color which radiates a fabulous deep blue iridescence.  The underside is a soft eggshell cream.  It is a powerful constrictor.  The teeth at the back of the jaws are strong and allow it to hold onto its writhing victim while it throws around it those ever-tightening coils.  This is a non-contest, the Terciopelo has little or no chance.  Finally, it succumbs and expires.  The hunter has become the hunted and the frogs have one less problem in their territory.

Mussurana.

Mussurana, (Clelia clelia)

Philip Davison is a Biologist, Writer and Photographer Based In Costa Rica

Cracking New Nymphs and Dwarves   2 comments


Philip Davison. Costa Rica. Blog. Nature Diaries

Wet Nights

The heavy rains have continued through into this week.  The heavens generally open later in the evening which is an ideal situation as the next morning the sun rises with a blue sky which leaves the day free to explore and take photographs. Well that happens on some days but progressively it has been raining late afternoon and sometimes continuing over night into breakfast time.  The creek is running with water again, at least in the upper and lower stretches but it will take a little longer for the full flow to resume.

An Explosion of Nymphs

One noticeable feature of this week has been an explosion in butterfly numbers both in terms of species and individuals.  More particular this has been the case with three particular species of butterfly in the Nymphalid family; the White-banded Peacock, (Anartia fatima), the White Peacock, (Anartia jatrophae), and the Tropical Buckeye, (Junonia evarete).  Not one of these three species is rare or uncommon and they can be found in greater or lesser numbers throughout the year depending upon season.  They do have cyclic emergences which suggest two broods may occur over the course of a year but over the last week significantly all three have suddenly emerged in huge numbers.

Anartia fatima

White-banded Peacock, (Anartia fatima)

Anartia jatrophae

White Peacock, (Anartia jatrophae)

It may well be that the rains arriving in April along with high temperatures have meant that the larval food plant of these three species has been able to produce a lot of vegetative growth which in turn has provided a sufficiently adequate amount of food to support a greater number of caterpillars.  The White-banded Peacock and the White Peacock caterpillars both feed on similar plants, namely those in the family Acanthaceae.  The Tropical Buckeye feeds on plants in the family Verbenaceae but in Costa Rica it is not known of which species.  Significantly all three species are found in open habitat such as grasslands rather than within the forest.  For that reason their presence is more obvious in the gardens around the lodge.

Junonia evarete

Tropical Buckeye, (Junonia evarete)

A New Cracker

As well as all of the peacock and buckeye butterflies flying around there are also large numbers of the Green Urania moths still residing in the locality.  But they are not the only lepidoptera to be observed.  This wet season seems to have been favorable to many other species, some of which live in the forest and others at the top of the canopy.  I have lived in the area for sixteen years and part of my research is the monitoring of butterfly populations.  In that time I have recorded 380 species at ground level in the area.  Some of those species occur regularly but there are others that I have only seen once and then never again.

There are several species of cracker in this locality.  They most certainly are not a commonly observed butterfly.  Last week I was returning to the lodge after photographing some other butterflies when I noticed on the side of a tree a species of cracker that I had not previously recorded from this area, the Red Cracker, (Hamadryas amphinome).  It is always sod’s law that if I see a new butterfly species that I am generally not carrying the camera.  This time I was.  The lighting was good and the subject was in the perfect position so I got a good shot.

Hamadryas amphinome

Red Cracker, (Hamadryas amphinome)

The male crackers typically perch on the side of tree trunks with the head facing down.  The name refers to their habit of emitting an audible cracking sound.  Research has shown that the cracking sound is made following the upsweep of the wings which make contact at high speed at the top of the stroke.  One of the wing veins is expanded which acts as a resonating chamber to amplify the sound of the crack.  It is assumed that the cracking is made by the males as part of the territorial or mating behavior but results are not as yet conclusive.

Sleeping Sulfur

One butterfly commonly seen flying around the garden areas is the Cloudedless Sulfur, (Phoebis sennae).  It bright lemon yellow coloration is immediately catches your attention as it flutters its way across the lawns.  But despite the fact that it is reasonably common it is extremely difficult to photograph.  The adult rarely seems to land and when it does it is only for fleeting moment before it is off again.  You have to be fortunate enough to be in the right place at the right time.

Phoebis sennae

Cloudless Sulfur, (Phoebis sennae)

At night however they sleep, for the most part under wide leaves close to the ground.  As long as you work without too much disturbance this then provides an ideal opportunity to capture its image as it is not moving at all.  Too much light will cause it to wake and it may fly off in a very bewildered fashion.

Confusing Swallowtails

There are two species of butterfly to be commonly found in this area which are almost impossible to tell apart.  They are both commonly known as Giant Swallowtails.  The two species in question are Heraclides thoas and Heraclides cresphontes.  The males can be distinguished under close scrutiny but the females provide more of a challenge.  In fact the best way to distinguish the females is to watch and see which plants they visit to lay their eggs; H. thoas only uses plants in the pepper family; Piperaceae whereas H. cresphontes uses a whole variety of genera in the family; Rutaceae.

Heraclides thoas

Giant Swallowtail, (Heraclides thoas)

The caterpillars are quite distinct and the fact that they feed on different food plants makes identification easier.  They both resemble bird droppings being shiny and brown with creamy patches.  H. thoas has one creamy patch while H. cresphontes has two.  I found this group of H. cresphontes caterpillars quite low to the ground on a small shrub which within a day or two they had consumed and the caterpillars themselves had disappeared.  A bird dropping is not going to appeal as a food source to many animals so the caterpillars can feed in the open without too much concern of being preyed upon by larger predators such as birds and lizards.  The deception might not prove successful against parasites and parasitoids though.

Heraclides cresphontes

Giant Swallowtail, (Heraclides cresphontes), caterpillars

Galling Sight

A close look at some of the plants as you walk around the trails will reveal various oddly shaped structures which suggest something has gone wrong with the leaf development.  To a certain degree this is true.  These weird, and to some people, ugly growths are leaf galls.

Leaf galls are the plants reaction to the invasion of another organism and there are many organisms that can induce gall development including bacteria, fungi, nematodes insects and arachnids.  The appearance of the gall is host specific so for those who study galls, cecidologists, the organism causing the gall can be identified very quickly.  Sometimes an infestation may occur but for the most part the gall producers do not harm the host.

Plant Gall

Unidentified Plant Galls

With insect induced “closed” galls, the adult lays an egg within the leaf tissue.  The egg hatches and when the larva emerges contact between the larva and the meristematic vegetative tissue causes excess cell multiplication thereby forming the gall.  The larva develops within the gall protected by its walls and feeding from the underlying starch and sugar rich tissue.

Because the gall causing agents are so numerous it requires the eye and the knowledge of an expert to be able to effect an identification.  My guess is that these galls were caused by an insect possibly in the Order: Diptera.  I would welcome any input from a gall expert who may be browsing these pages to help reveal the causal organism of these galls.

Lying Low

Bird nests are one of those things that can generally only be found serendipitously.  Hummingbird nests despite their small size are the most commonly seen of the nests as they tend to be built in more open locations either secured to a small branch or fastened with spider web beneath the tip of a Heliconia or palm leaf.

However on occasion something will catch your eye that isn’t all that it seems.  Only about eight feet off the ground just to the side of the trail I found what looked like a tangle of fallen vegetation.  But there was something about the way it was lying in the fork of a small tree that did not appear random.  A look with the binoculars I could see that top of a birds head poking out above a moss-lined cup on top of the tangle.  There was not much to see but I was reasonably sure it was a female Golden-crowned Spadebill.  I returned several times to hopefully get a picture of her sitting on the nest but with no luck.  I didn’t want to cause any disturbance so I just photographed the nest without its owner.

Platyrinchus coronatus

Golden-crowned Spadebill, (Platyrinchus coronatus), nest

Raining Dwarves

One evening in the restaurant following the nightly deluge a small distinctively patterned  snake was found lying on the wall, a Dwarf Boa, (Ungaliophis panamensis).  It is not a snake that is frequently seen as it inhabits the canopy where it can be found occupying the inner recesses of larger bromeliads.  I have found them around the lodge several times over the years.  This one may have been knocked out of the tree tops by the torrential downpour that had just occurred.

Ungaliophis panamensis

Panamanian Dwarf Boa, (Ungaliophis panamensis)

They are called Dwarf Boas because they never grow to a size larger than 2 feet in length.  Due to the small size the adults probably prey upon frogs and lizards found amongst the epiphytic growth at the top of the trees.

Philip Davison is a Biologist, Writer and Photographer based in Costa Rica.

A Poisonous Tropical Tiger   1 comment


Felipe del Bosque Blog July 3rd 2011

 

No Change

The wet season continues with overcast days and nightly rain.  The rain hasn’t been too heavy this week and towards the end of the week we had some nice sunny days with the rain falling at night.  The temperatures continue as expected for this time of year, reaching a maximum in the day of the lower nineties and at night consistently dropping to the lower seventies.

A Walk in the Woods

While I was walking on the Titi Trail last week, at one point I had a Collared Peccary, (Tayassu tajacu), standing right on the path in front of me.  It simply looked at me and then walked into the forest, but only just off the trail.  As I continued on my way, the peccary walked without too much concern slightly in front and to my right.  When I first arrived at Bosque 11 years ago, this situation would never have happened.  As soon as the peccaries caught drift of your presence they would scatter with great speed, teeth clacking and grunting, in the opposite direction.  Now they seemingly couldn’t care less about your being there.

There are two species of peccary on the Osa Peninsula, the Collared Peccary, which we find on the grounds of Bosque del Cabo and the White-lipped Peccary, which inhabits the forests of the the National Park, Corcovado.  Only once in 11 years have I seen the White-lipped Peccaries at Bosque.  That was a herd that had migrated east along the coast from the park and passed by my cabin while doing so.

The Collared Peccary is normally found on the Titi Trail in numbers of 7 or 8, but occasionally as many as 20 have been seen together.  They are generalist feeders, taking lots of fruit and seeds but they will feed on animals as well, grubbing up arthropods from the ground and even rodents and birds.  In the damper areas of Bosque, grows a plant that we are familiar with as a common house plant, Dumb Cane, (Dieffenbachia sp).  These are deadly poisonous plants, the leaves of which contain crystals of Calcium Oxalate, which doesn’t do your kidneys any good.  Collared Peccaries are particularly fond of Dumb Cane and eat large quantities without suffering any ill effects, the digestive systems obviously having evolved to safely metabolize the Calcium Oxalate.

Not that much further along the trail, I could hear the soft whistles of a group of ground living birds, the Great Curassow, (Crax rubra).  It was a group of turkey sized females sporting plumage of mottled creams and browns.  Just like the peccary, they were in no particular hurry.

That has not been the case at night though when I leave the office late.  For the past week, as soon as I step down from the office steps, some startled creature has gone crashing underneath the deck.  I had an inkling of what it might be; we only have one nocturnal animal that will make that kind of noise, somewhat like a tank crashing through the undergrowth, a Nine-banded Armadillo, (Dasypus novemcinctus).  Sure enough, one night, just after the crashing, I could see the armadillo on the other side of the deck where it emerged.  Armadillos have a short term memory of little more than a nanosecond and recommence their noisy activities regardless of whether or not the potential danger has passed.

Cracks are Forming

The Milky Tree that fell last month has now started showing signs of drying out.  All the milky resinous sap that initially leaked out has gone, mostly taken by bees of various species for nest construction.  Now we have the first level of obvious decomposers moving in, the beetles.  Rather than the adults, it is the larvae that feed on the dead wood, hastening its decomposition.  At the minute though lots of species of beetle are pairing up on the face of the now exposed heartwood which is where they will lay their eggs.

Broad-nosed Weevil          Weevils

In the Comfort Zone

The Long-billed Hermit, (Phaethornis longirostris), that had started to construct her nest by the kitchen entrance last week has completed her task and is now incubating eggs.  She is completely unperturbed by the constant comings and goings of the lodge staff in the area, and the traffic is constant all day long.  It could well be that is why she opted to build the nest in that particular location.  The human non-predators may well be seen as keeping any potential predators of her, the eggs or her chicks at bay.  Having said that though, many of the birds’ nests that are built in or around the restaurant area, sooner or later attract the attention of the Tropical Bird-eating Snakes, and they too have little regard for the big pink monkeys wandering around the concrete and stucco jungle.

Long-billed Hermit

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.

www.bosquedelcabo.com

Photo Feature

Flying Tigers

One night when I went back to my cabin I was greeted by an unexpected by pleasant surprise.  Two brilliantly colored Tropical Tiger Moths, (Belemnia inaurata), were resting on the screen of my door.  The next day those colors, that the night before had been so bright, now became even more scintillatingly beautiful.  So I had to get a photograph.

Nature tends to produce bright colors for a reason, generally that of communication, either within the species or between species.  Most species of butterfly and moth that exhibit bright and flashy colors are suggesting that you give them a wide berth.  These colors are warning colors and in the case of butterflies or moths you are normally being warned that the insect is packed with poisons.  Some of the brightly colored butterflies we found around the grounds of Bosque, the Heliconiids, contain cyanide.  The Tropical Tiger Moth in the larval stage feeds on plants containing pyrrolizidines, (which damage the liver), and cardenolides, (which cause heart failure).  These are stored in the body and passed through to the adult stage where they serve to make the moth unpalatable.  If a bird or a lizard ignore the warning coloration and feed on the moth, they are rewarded, not with a tasty treat but rather with a foul tasting shock that will have them think twice before taking something sporting those colors again in the future.

Tropical Tiger Moth

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 89°F.  Average Daily Temp Low 73°F.

Average Daily Rainfall 0.53 ins.  Total Weekly Rainfall 3.71 ins

Average Daily Temp High 31.1°C.  Average Daily Temp Low 22.7°C.

Average Daily Rainfall 13.3 mm.  Total Weekly Rainfall 93.0 mm

Species List for the Week

Mammals

  • Howler Monkey
  • Spider Monkey
  • Capuchin Monkey
  • Virginia Opossum
  • Nine-banded Armadillo
  • Agouti
  • Red-tailed Squirrel
  • Collared Peccary

Birds

  • Red-lored Amazons
  • Scarlet Macaw
  • Long-billed Hermit
  • Rufus-tailed Hummingbird
  • Stripe-throated Hermit
  • Great Currasow
  • Crested Caracara
  • Laughing Falcon
  • Black-hooded Antshrike
  • Chestnut-backed Antbird
  • Common Paureque
  • Rufus Piha
  • Short-billed Pigeon
  • White-tipped Dove
  • Red-capped Manakin
  • Chestnut-mandibled Toucan
  • Cherrie’s Tanager
  • Great Tinamou
  • Riverside Wren
  • King Vulture
  • Black Vulture
  • Turkey Vulture

Reptiles

  • Barred Ameiva
  • Four-lined Ameiva
  • Golfo Dulce Anolis
  • Clawless Gecko
  • Mediterranean House Gecko
  • Cat-eyed Snake
  • Litter Snake
  • Tropical Bird-eating Snake

Amphibians

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

Butterflies

  • Anartia Fatima
  • Astraptes fulgerator
  • Battus belus
  • Callimormus radiola
  • Cithaerias pireta
  • Colobura dirce
  • Euphyes vestries
  • Eurema albula
  • Eurybia lycisca
  • Glutophrissa drusilla
  • Heliconius erato
  • Heliconius hecale
  • Heliconius ismenius
  • Heliconius sapho
  • Heraclides cresphontes
  • Hermeuptychia hermes
  • Laparus doris
  • Marpesia berania
  • Morpho menelaus
  • Pareuptychia ocirrhoe
  • Phoebis argante
  • Phoebis sennae
  • Pierella luna
  • Pyrgus oileus
  • Saliana esperi
  • Siproeta stelenes
  • Urbanus tanna

 

Plants

  • Black Alligator Tree Flowering and Fruiting
  • Calabash flowering and fruiting
  • Cedrillo Fruiting
  • Clusia Vine Fruiting
  • Dinner on a Plate Fruiting
  • Monkey Comb Tree Flowering and Fruiting
  • Candlestick Plant Flowering and Flowering.
  • Figs Fruiting
  • Lechoso Fruiting
  • May Tree Fruiting
  • Manglillo Fruiting
  • Nutmeg Fruiting
  • Santa Maria Flowering and Fruiting
  • Yayito Fruiting

Smelling a Rat   2 comments


Felipe del Bosque Blog Feb 7th 2011

Boa constrictor

A Light Sprinkling

The temperatures continue to rise with daily highs in the region of 94 °f (23°C).  The rains have all but stopped, any precipitation now being negligible, a result of early morning condensation.  This is regular dry season weather; hot, dry and sunny.  It also means that the forest floor is rapidly drying up.  In the gardens around the Bosque restaurant, the gardening team has set up the water sprinklers which come on at night providing a little light refreshment for the thirsty plant life.

Otter and Skunk

the beginning of the month, generally finds me making that once a month trip into town to purchase another 30 days supplies of non comestibles.  On this occasion, while approaching a small river that we have to cross, we noticed something running upstream in the shallow water.  This time of year the water level is low and therefore too shallow for anything of great size to swim.  This particular creature despite having its head beneath the surface, we could make out as an otter, a Neotropical Otter.  It was running against the current and more than likely chasing small fish.  It came out of the water, turned around, walked back and entered the water again, repeating the cycle of activity.  I have lived here for eleven years and this was my first ever sighting of an otter.

A few days later, while lying in my bed, having just retired for the evening, I could hear something snuffling around outside my cabin.  As I was not quite asleep, I got out of bed, took my flashlight and went outside to see what it could be.  The stems of the heliconias were shaking as whatever it was moved through, so I just stood and waited.  Emerging from the vegetation in front of me was a Striped Hog-nosed Skunk.  It paid me no heed whatsoever and continued on its nocturnal perambulations into the forest.

The Boa Bar – Quite Literally

One night in the restaurant, halfway through the evening meal, a group of seated diners became distracted by movement in the roof above their heads.  Moving sinuously and furtively from the dry leaves of the thatch was a juvenile boa, (Boa constrictor).  It provided not a little consternation and a great photographic opportunity.

Two days later the boa turned up in the aptly named “Boa Bar”.  We had some Danish visitors staying at the lodge who had previously visited us ten years earlier.  On the occasion of their first visit, I had found a large boa with which the two young girls had been photographed, me holding its head.  Now ten years later and in their late teens, they could recreate the scene but with a decade of difference between.

A Profusion of Biodiversity

On one morning tour as the group I was leading exited the Zapatero Trail into the Tropical Garden, we had a big monkey performance.  Spider Monkeys manically made their way swinging through the tree tops, psychotically screaming and screeching as they went, in typical Spider Monkey fashion.  A troupe of Howler Monkeys languidly sat at the top of a large fig tree, tolerant of the Spider Monkey antics, so long as they didn’t get too close.  At a lower level, at the where the forest edge borders the garden, a large troupe of Squirrel Monkeys searched for insect prey.

As the group were watching the monkey display, a beautiful Double-tooth Kite, flew in and snatched from the air a katydid that had been flushed by the monkey activity.  Down on the beach some our visitors had been watching a Mangrove Black Hawk fish a large eel from a pool which it then proceeded to consume.

Dry season activity continues unabated.  Mammals, birds and butterflies are out in abundance.  With every week, the butterfly numbers continue to increase, almost doubling in individual numbers every seven days.  During this week’s butterfly transect count, I recorded 374 butterflies of 40 species in the morning, 225 butterflies of 33 species in the afternoon, giving a total species count for the day of 52 different butterflies.  We have yet to reach the zenith of butterfly activity, so I am expecting those numbers, as incredible as it may seem, to increase substantially over the next few weeks.

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.

www.bosquedelcabo.com

Photo Feature

Boa constrictor

Boa constrictors are not uncommonly found around the grounds of Bosque del Cabo.  Smaller juveniles are quite often encountered in and around human habitation where they find small rodents which constitute the bulk of their prey.

Larger individuals are normally found in the forest or in the gardens.  They attain an adult length normally in the region of 6 – 9 feet and a weight of 40 – 60 lbs.  The adults will feed on Agoutis, opossums and the occasional coati.

Although when seen out of context, the coloration of a boa are rich in hue and pattern, when placed on the forest floor amongst dead leaves, it would take a very keen eye to pick out the camouflaged serpentine form which blends perfectly with the background.

Boa constrictor

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 93°F.  Average Daily Temp Low 72°F.

Average Daily Rainfall 0.00 ins.  Total Weekly Rainfall 0.02 ins

Average Daily Temp High 33.5 °C.  Average Daily Temp Low 22.3 °C.

Average Daily Rainfall 0.1 mm.  Total Weekly Rainfall 0.5 mm

Species List for the Week

Mammals

  • Howler Monkey
  • Spider Monkey
  • Capuchin Monkey
  • Central American Squirrel Monkey
  • Agouti
  • Neotropical Otter
  • Stripe Hog-nosed Skunk
  • Virginia Opossum
  • White-nosed Coati
  • Red-tailed Squirrel

Birds

  • Red-lored Amazon
  • Scarlet Macaw
  • Great Currasow
  • Lineated Woodpecker
  • Pale-billed Woodpecker
  • Crested Caracara
  • Double-tooth Kite
  • Laughing Falcon
  • Roadside Hawk
  • Rufus Piha
  • Chestnut-backed Antbirds
  • Black-hooded Antshrike
  • Common Paureque
  • Crested Owl
  • Short-billed Pigeon
  • White-tipped Dove
  • Rufus-tailed Hummingbird
  • Fiery-billed Aracari
  • Chestnut-mandibled Toucan
  • Cherrie’s Tanager
  • Bright-rumped Atilla
  • Great Kiskadee
  • Great Tinamou
  • Black Vulture
  • Turkey Vulture

Reptiles

  • Basilisk
  • Four-lined Ameiva
  • Central American Whiptail
  • Golfo Dulce Anolis
  • Clawless Gecko
  • Mediterranean House Gecko
  • Cat-eyed Snake
  • Boa Constrictor
  • Tropical Bird-eating Snake

Amphibians

  • Marine Toad
  • Red-eyed Green Tree Frog
  • Banana Frog
  • Smokey Jungle Frog
  • Milky Frog
  • Black and Green Poison Arrow Frog
  • Fitzinger’s Rain Frog
  • Rough-skinned Dirt Frog
  • Stejneger’s Dirt Frog

Butterflies

  • Adepha basiloides
  • Adelpha cytherea
  • Anartia Fatima
  • Anthanassa ardys
  • Arawacus lincoides
  • Battus polydamus
  • Caligo eurilochus
  • Callimormus radiola
  • Calycopis isobeon
  • Cissia confuse
  • Colobura dirce
  • Dione juno
  • Dryas iulia
  • Eueides aliphera
  • Eueides lybia
  • Eueides procula
  • Euptychia westwoodi
  • Eurema albula
  • Eurema daira
  • Glutophrissa Drusilla
  • Gorgythion begga
  • Heliconius erato
  • Heliconius hecale
  • Heliconius ismenius
  • Heliconius sapho
  • Heraclides cresphontes
  • Hermeuptychia hermes
  • Hyalthyrus neleus
  • Junonia everete
  • Magneuptychia libye
  • Marpesia berania
  • Mechanitis polymnia
  • Morpho helenor
  • Morpho menelaus
  • Morpho theseus
  • Nastra julia
  • Pareuptychia ocirrhoe
  • Parides erithalion
  • Perophthalma lassus
  • Philaethria dido
  • Phoebis agarithe
  • Phoebis argante
  • Phoebis sennae
  • Pierella luna
  • Polites vibex
  • Pyrgus oileus
  • Pyrisitia nise
  • Pyrisitia proterpia
  • Pyrrhogyra crameri
  • Siproeta stelenes
  • Staphylus mazans
  • Temenis laothoe
  • Urbanus simplicius
  • Urbanus tanna

Plants

  • Golden Cortez flowering
  • Calabash flowering and fruiting
  • Monkey Comb Tree flowering and fruiting
  • Black Alligator Tree Fruiting
  • Garlic Tree Flowering
  • Candlestick Plant Flowering.
  • Cannonball Tree Flowering
  • Heisteria fruiting