Archive for the ‘Banana Frog’ Tag

A New Season of Discovery   10 comments

Philip Davison. nature diaries. Osa Peninsula. Costa Rica.

After a five week period away from the Osa Peninsula I am back to carry out another year of research.  For the past sixteen years I have been monitoring populations of both butterflies and amphibians in the forests of Cabo Matapalo on the tip of the Osa Peninsula in South West Costa Rica.  I collect the daily weather data and compare changes in amphibian populations against precipitation and butterflies populations against temperature in an effort to evaluate how or whether climate change effects the fauna of a tropical rain forest.

Marine Toad. Amphibians. Osa Peninsula. Costa Rica.

Marine Toad, (Chaunus marinus)

As I live in the forest and can be found constantly walking the trail systems, camera in hand, it provides ample opportunity to photograph the diversity of life that surrounds me.  I am generally photographically prepared for small things so unless I am going out specifically to capture images of mammals or birds then my photographic galleries generally consist of reptiles, amphibians, all manner of arthropods as well as any plant and fungi features that catch my eye.

Savage's Thin-fingered Frog. Frogs

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

This blog acts as an expanded form of my nature diaries which are simply daily recordings on Excel spreadsheets.  I enjoy sharing my experiences with those who read my blog and over the years the number of subscribers constantly increases.  If you are a first-time reader, then welcome and I hope you enjoy the content and the photos.  I am not a professional photographer but I do try and take the best composed shots I can.

Banana Frog. Wet Season.

Banana Frog, (Dendropsophus ebreccatus)

The blog also allows visitors to the area an insight of what they might expect to see in their absence or when they arrive as well as providing a small amount of information about the natural history of the organisms I feature.  I try to post one blog a week but sometimes time constraints means there may be occasions when this is not possible.

Small-headed Frog. Pond life.

Small-headed Frog, (Dendropsophus micracephalus

For me the year does not begin on the January 1st but rather on my return to the area in November.  At this time of year we should be moving out of the main rainy season, which is what caused me to leave for a month or so, and into the dry season.  There is no exact date and sometimes the rains hang on until December while other times the sun has started to shine constantly by mid-November.  Anyway, here we go with the opening blog of the 20016/17 season.

Olive-snouted Treefrog. Philip Davison

Olive-snouted Treefrog, (Scinax elaeochrous)

First things first.  November normally heralds the ending of the rainy season.  Sometimes the wet period may continue into December but by now we are looking towards a drying of the forest.  Not so this year.  This has been, without doubt, the wettest November I have recorded in 17 years, 185 inches of rain fell in that 30-day period.  The area was briefly closed down as bridges were not crossable, roads were not passable and the local town of Puerto Jimenez and its attendant landing strip were closed due to being under water.  This may bode well for the coming dry season when for 4/5 months the area receives little or no rain whatsoever but at the moment the forest floors have rivulets with running water everywhere.

Red-eyed Green Tree Frog. Costa Rica

Red-eyed Green Tree Frog, (Agalychnis callidryas)

The daily torrential downpour has made wildlife spotting rather difficult.  It is neither easy to see or hear anything in those conditions.  In the inter deluge periods I have been out searching for whatever I could find and it may come as no surprise that the amphibians most certainly have enjoyed the excess water.  All the usual members of the pond community have been out calling; Banana Frogs, Small-headed Frogs, Red-eyed Green Tree Frogs, Parachuting Red-eyed Green Tree Frogs, Savage’s Thin-fingered Frog, Marine Toads and Masked Smiliscas.  Even the largest tree frogs in Costa Rica, the Milky Frogs have been coming out, which is unusual this time of year.  Away from the pond the Tink Frogs and Fitzinger’s Rain Frogs call as soon as the sun sets.  Here are some photographs of the amphibians you may be lucky enough to see if you visit the Osa Peninsula now.

Parachuting Red-eyed Green Tree Frog. Torrential Rain.

Parachuting Red-eyed Green Tree Frog (Agalychnis spurrelli)

Tink Frog. Frog chorus.

Tink Frog, (Diasporus diastema)

Gladiator Frog. Mud puddle nest

Gladiator Frog, (Hypsiboas rosenbergi).

Bolivian Frog. Foam nest.

Bolivian Frog, (Leptodactylus bolivianus)

Masked Tree Frog.

Masked Smilisca, (Smilisca phaeota)

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

Deadly Nectar   2 comments

Felipe del Bosque Blog August 12th 2013

title copy

Beach Weather

Weatherwise the past week has been one of sunshine and showers.  The week started wet but as we progressed through the days then the sun became more and more of a feature until finally over the weekend the days were warm and cloudless.  We even managed a few nights without rain. The rain that did fall was not too heavy, just enough to keep things moist and help maintain a flow of water in the creek.

Building Blocks

Over recent years there has been a downturn in the fortunes of the White-nosed Coatis, (Nassua narica).  Their numbers fell precipitously and for a period of several years the individuals that were seen appeared to suffering some sort of disease.  Their fur was sparse and mangy-looking and their demeanor seemed lethargic and lacking their normal inquisitive vitality.  Last year the males, which are solitary, (the name of a single male coati is Coati Mundi), were back sniffing around the grounds in search of whatever they could find.  This year the grounds have been home to roaming bands of gregarious females with a plethora of young in attendance.  It would seem that whatever malady had apparently been affecting them seems to have run its course and now people can see them with relative ease on most of the trails.  The Australian Screw Pines, (Pandanus sp), have been fruiting recently and it is not uncommon to see one the male White-nosed Coatis at the top of the plant ripping the exotic pinecone-looking fruit to pieces.

Screw Pine

Another animal whose numbers appear to be on the increase are the Collared Peccaries, (Tayassu tajacu).  They can be seen on any of the trails but the Titi Trail seems to be their preferred habitat.  Everyone walking the Titi Trail will invariably come into contact with the peccaries.  The Bosque Trail Camera Project has given us the opportunity of observe 24 hours/day, 7 days/week the animal movement at least on that one trail.  Each week when the camera memory is downloaded there is an air of anticipation and excitement as to what will have passed by over the previous week.  Inevitably it is the peccaries, coatis and the Agoutis, (Dasyprocta punctata), that take centre stage in regards to numbers and frequency with some lesser players in the weekly cycle of activity who taking up the supporting roles.


We did get our first photo of a Puma, (Puma concolor), this week on the Titi Trail.  It will come as no surprise to regular readers of this blog that it looks like the resident and distinctive female “Half Tail” that walked through the cameras field of vision.  Unfortunately she did so in such a fashion that she triggered the camera as she was passing and so we are missing her head.  For reasons as yet unknown, wildcats have a predilection for the scent “Calvin Klein Obsession for Men”.  To that effect the lodge has purchased a bottle of said perfume to spray in front of the cameras with a view of holding the cats attention for long enough that we get some photos with her head on her shoulders.

M2E39L137-136R408B319         M2E39L137-137R408B319         M2E44L157-157R410B311

M2E1L0-0R350B300         M2E34L106-106R398B311         M2E1L0-0R350B300

M2E1L0-0R350B300         M2E45L35-35R350B300         M2E42L155-155R411B309

Yellow Peril

The rain combined with constant warmth has resulted in a lot of the fungi producing fruiting bodies, mushrooms and toadstools.  Some of the fungal fruiting bodies are so obscure that they resemble something more alien in form than most people are used to seeing  Many times people don’t even know it is a fungus they are looking at.  Then, of course, there are the more familiar parasol-shaped mushrooms that occur in all sizes and colors, many of which are diagnostic features in helping identify the specimen to species level.

Leucocoprinus bernbaunii.

Growing saprophytically on the rotting wood of dead trees it is not uncommon to see the bright yellow granular caps of Leucocoprinus birnbaunii.  It is found throughout tropical regions as well as growing in glasshouses in more temperate areas.  It is quite surprising how many fungi know few boundaries and have a global distribution.  Despite its resemblance to a marzipan cake decoration it is inedible and regarded by some authorities as deadly poisonous.  As with many fungi it is always best to look and not touch.

Leucocoprinus bernbaunii

Banana Song

The rains have continued to fall so the frogs have continued to call.  Last week I posted a photo of a Small-headed Frog, (Dendropsophus micracephalus).  Located in the same area amongst the Water Hyacinth and Water Lettuce as well as all around the back of the pond is almost identical looking Banana Frog, (Dendropsophus ebreccatus).  Morphologically the frogs can be distinguished with close scrutiny.  The Small-headed Frog has a line running along the uppersides of the body while the Banana Frog has a small yellow patch under the eye.  But it is when they are calling that the males can be readily discerned.  The Small-headed Frog has a high pitched “eek eek eek eek” call while the male Banana Frog is more of a longer “neeurk”.

Banana Frog

Both species utilize the same areas to lay their eggs on the upper leaf surfaces of plants floating on the water.  They are small flat masses of leaves numbering about 50 eggs.  The eggs develop until about a week, the egg mass liquidizes and the tadpoles wriggle off into the water to complete their developement.

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 

Crabby Behaviour

Sometimes you witness aberrant animal behavior that allow you to identify that something outside of the norm in happening.  I was passing the patch of Lantana camara near the Bosque pond one day and was idly watching the butterflies that had been summoned by the sun.  I noticed a butterfly that was resting on a flowerhead but at a strange angle and with no wing movement.  Most of the other butterflies were warmed by the solar radiation and were flitting from one flower to the next, stopping only briefly to imbibe some of the nectar.  This individual, a White-banded Fatima, (Anartia fatima), was not.  I knew fron experience what was likely to have happened and luckily had the camera with me so took a closer look.

Thomisidae sp

Sure enough my thoughts were confirmed, a beautiful Crab Spider was positioned at the top of the flower head, its chelicerae, (fangs), buried in the body of the butterfly which must have succumbed to the quick acting venom.  Crab-spiders are placed in the arachnid family: Thomisidae and they are ambush predators that also the masters of disguise.  This one had a body colored in a fashion to match exactly the flower in which it was lurking, bright yellow.  Butterfly vision allows them to see color and movement but they don’t readily determine image.  This unfortunate individual would not have know what hit it until too late.

Crab Spider

The Crab Spider unlike its butterfly prey which has large compound eyes has small simple eyes that only produce sharp vision up close but can discern movement from some distance away.  They don’t build webs but use a silken line to secure them to the blooming flower.  Female Crab Spiders can change their color to a certain degree to match them to the flower.  They sit and wait with large strong front legs outstretched until the prey alights then grab it, hold it tight and inject the venom. The liquefied juices of the prey are sucked out of the puncture wounds.  They attain their name of Crab Spider due to their uncanny ability to walk sideways.

Anartia fatima

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 0.38 ins.  Total Weekly Rainfall 2.63 ins

Average Daily Rainfall 10.4 mm.  Total Weekly Rainfall 82.8 mm

Highest Daily Temp 88°F.  Lowest Daily Temp 74°F.

Highest Daily Temp 31.1°C.  Lowest Daily Temp 23.2°C.

Species List for the Week


  • Mantled Howler Monkey
  • Spider Monkey
  • Squirrel Monkey
  • White-faced Capuchin Monkey
  • Nine-banded Armadillo
  • Tamandua
  • Common Tent-making Bat
  • Western Red Bat
  • Northern Raccoon
  • White-nosed Coati
  • Agouti
  • Paca
  • Red-tailed Squirrel
  • Underwood’s Pocket Gopher
  • Collared Peccary
  • White-lipped Peccary


  • Mealy Amazon
  • Orange-chinned Parakeets
  • Red-lored Amazon
  • Scarlet Macaw
  • Gray-necked WoodRail
  • Great Curassow
  • Crested Caracara
  • Yellow-headed Caracara
  • Rufus Piha
  • Black-hooded Antshrike
  • Chestnut-backed Antbird
  • Short-billed Pigeon
  • Red-Capped Manakin
  • Chestnut-mandibled Toucan
  • Bright-rumped Atilla
  • Golden-crowned Spadebill
  • Great Kiskadee
  • Great Tinamou
  • Black-throated Trogon
  • Black Vulture
  • Turkey Vulture


  • Barred Ameiva
  • Cat-eyed Snake
  • Central American Smooth Gecko
  • Central American Whiptail
  • Common Anolis
  • Common Basilisk
  • Clawless Gecko
  • Four-lined Ameiva
  • Green Iguana
  • Golfo Dulce Anolis
  • Litter Skink
  • Mediterranean House Gecko
  • Mussarana
  • Pentaprion Anolis


  • Banana Frog
  • Black and Green Poison Arrow Frog
  • Golfo Dulce Poison Arrow Frog
  • Fitzinger’s Rain Frog
  • Gladiator Frog
  • Masked Smilisca
  • Marine Toad
  • Milky Frog
  • Parachuting Red-eyed Green Tree Frog
  • Red-eyed Green Tree Frog
  • Savage’s Thin-fingered Frog
  • Small-headed Frog


  • Anartia Fatima
  • Anartia jatrophae
  • Colobura dirce
  • Dryas iulia
  • Glutophrissa drusilla
  • Heliconius erato
  • Heliconius hecale
  • Heliconius ismenius
  • Heliconius sapho
  • Hermeuptychia hermes
  • Mesosemia zonalis
  • Morpho cypris
  • Morpho helenor
  • Morpho menelaus
  • Parides erithalion
  • Phiaethria dido
  • Phoebis sennae


  • Alamandra  cathartica Flowering
  • Alpinia purpurata Flowering
  • Apeiba tibourbou Fruiting
  • Arachis pintoi Flowering
  • Arundina graminifolia Flowering
  • Attalea rostrata Fruiting
  • Bauhinia variegata Flowering
  • Brosimum utile Fruiting
  • Caryocar costaricense Flowering
  • Cascabella thevetia Flowering and Fruiting
  • Citrus spp  Fruiting
  • Clusia rosea Flowering and Fruiting
  • Clusia vallerii 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
  • 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
  • Inga spp Fruiting
  • Ixora coccinea Flowering
  • Lantana camara Flowering and Flowering
  • Lagerstroemia speciosa Fruiting
  • Morinda citrifolia Fruiting
  • Musa acuminate Flowering and Fruiting
  • Nephelium lappaceum Fruiting
  • Pachira quinata Flowering
  • 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
  • Zammia sp Flowering



Bosque del Cabo April 2011 Nature Review   1 comment

Felipe del Bosque Blog April 2011 Review

The high temperatures experienced in February and March continued into April.  This year the rains came a little earlier than would normally be expected. On one or two occasions we had torrential thunderstorms occurring overnight this month.  The heavy rain caused some very large trees to fall.  One large Monkey Comb tree fell not too far from the suspension bridge.  Even though the rain was lashing down so heavily it was hard to hear anything outside your immediate vicinity, everyone standing in the bar heard that particular crash.

In response to the first rains for 4 months, the amphibians were stimulated into action.  Huge breeding aggregations of Milky Frogs, (Trachycephalus venulosus),  filled the ponds with a choral cacophony of amorous males, each calling for a mate with such voluminous gusto, that their collective sound could quite easily be heard by guests taking their evening meal in the lodge restaurant.

Trachycephalus venulosus

Trachycephalus venulosus

Although the Milky Frogs were the most numerous and vociferous of the pond inhabitants, there were other frogs too vying with them for some breeding space.  We had our first sightings for the impending wet season of the Banana Frogs, (Dendropsophus ebreccatus) and the Masked Smilisca, (Smilisca phaeota).

Dendropsophus ebraccatus

Smilisca phaeota

There are many orchids around the grounds of Bosque, unfortunately most of them growing up at canopy level, but there is one species which grows closer to the ground.  Lady of the Night, (Brassavola nodosa), can be found growing in clumps on several trees close to the restaurant.  Once or twice a year it produces long white trumpet shaped flowers that give off a sweet perfume once the sun has set.  The scent attracts in night flying hawk moths with long proboscises that can be inserted into the deep into the flower searching for the sugary nectar.

Brassovola nodosa

In comparison, one of the trees on which we find the orchid growing is the Calabash Tree, (Cresentia alata), which flowers and fruits all year round.  Also in contrast to the orchid, the Calabash is a bat pollinated tree and consequently has large pale colored, night flowering blossoms that emits the bat attracting scent of sweaty cheese.

Cresentia alata

Paper Wasps can be identified to species level by the form the wasp’s nest takes.  In general wasps in the genus Polistes have open nests while those in the genus Polybia have enclosed nests.  This nest I found under a leaf with only one female in attendance, probably the dominant reproductive female whose close relatives and nest mates may have been away foraging for food.  You can see eggs and larvae in the open cells while one closed cell contains a pupa.

Paper Wasp

Over the course of the year the numbers of butterflies fluctuates greatly.  Some butterfly species you expect to see almost every day of the butterfly season but others you only see once or twice.  It may well be that they exist in small numbers or they may be secretive or they may inhabit areas such as the canopy where it is difficult to record them without resorting to bait trapping.   Even that may not work as not all butterflies are attracted to the bait.  This particular species, (Callicore lyca), of the Biblidinae subfamily I see only on one or two occasions a year.  This individual was on the Titi Trail and I could never get close to it, the image being captured from some distance using a 100mm macro lens.

Callicore lyra

That same lens was used to capture this White Hawk, (Leucopternis albicollis), which landed above my head in one the open garden areas.  White Hawks can generally be found in the company of moving troops of monkeys.  They have no interest in the monkeys themselves, it is the insect life that the monkeys scatter as they move through the vegetation that make an easily picked off meal for this beautiful raptor.

Leucopternis albicollis

Text and Photographs are taken from the forthcoming books:

The Natural History of Bosque del Cabo by Philip Davison

The Small World of Bosque del Cabo

The Colors of Bosque del Cabo

A Children’s Guide to Bosque del Cabo Rainforest Lodge

Temperature and Rainfall

Average M Temp High 94°F.  Average Daily Temp Low 74°F.

Average Daily Rainfall 0.04 ins.  Total Monthly Rainfall 1.28 ins

Average Daily Temp High 34.3°C.  Average Daily Temp Low 23.0°C.

Average Daily Rainfall 1.0 mm.  Total Monthly Rainfall 32.5 mm


Milk Is Not the Solution   4 comments

Felipe del Bosque Blog April 24th 2011

The last few weeks have been so busy that it has been almost impossible for me to sit down and write up my daily nature diaries in the form of a blog.  Now, with spring break and Easter over, I should be able to get back to normal.  This blog is the summary of all that has happened in the natural world forming my immediate surroundings over the last three weeks and so the species lists and total rainfall figures may seem somewhat inflated compared with my recent weekly summaries.

Curious Cats and Kinkajous

Over the past three weeks, there have been several Puma, (Puma concolor), sightings at various locations around the grounds.  Leaving the hotel one night after work, the restaurant employees saw a young male Puma on the main driveway by Casa Miramar.  He stood in the middle of the road and then headed into the undergrowth and watched the departing staff from the safety of the dense low growing vegetation.  Some visitors saw a Puma on the Titi Trail and yet another one, or perhaps the same individual, was spotted in the Citrus Garden behind the restaurant.

Kinkajou, (Potos flavus), activity has started to increase; their noisy whistles and honks adding to the nightly rustlings in the trees above your head.  After dinner, if you hear the sound of something moving in the vegetation above you, and you then direct the beam of your flashlight upwards, invariably a curious Kinkajou will run down the branch to take a look before disappearing quickly into the tree tops again.

Several mammals tend to be seen following the sunset rather than during the day.  The commonest of these are the Nine-banded Armadillo, (Dasypus novemcinctus), and the Virginia Opossum, (Didelphis virginiana), both of which I regularly observe on nightly outings with people on the Sunset Tour or when undertaking my nocturnal amphibian counts.

One morning, a noise which I had heard on many previous instances, was coming from outside my cabin, an arrhythmic thump, thump thump.  I went outside to find the cause of the sound which I knew, in fact, would be a large caviomorph rodent, the Agouti, (Dasyprocta punctata).  When danger threatens, in the same fashion as frightened rabbits, the Agouti thumps its foot against the ground.  On most other occasions this has revealed, upon closer scrutiny of the area around the disturbed rodent, a snake, generally a Boa of greater or smaller dimensions.  This time I could not find the subject of the Agoutis consternation but I am sure it was going to be around somewhere.

After The Deluge

The past three weeks has experienced some of the first heavy downpours of the impending rainy season.  There were several nights when we were subjected to some early evening deluges.

Milky Frog

The resulting reaction to this saturating stimulus is an explosion in amphibian numbers, both in respect to individuals and species.  We had two particularly intense drenchings separated by a week or so.  Both occasions drew the same response, a huge number of Milky Frogs, (Trachycephala venulosus), which seemingly arrive from nowhere, their numbers been very limited on normal count nights.  Following the heavy rain, they appear in dozens, the surface of the pond hosting a dreadful cacophony of calling males whose sole intention is to quickly find a single available female with whom to mate.  Many of them obviously succeed because the following morning the pond and floating aquatic vegetation is covered with their small black eggs.

Most frog eggs in the tropics hatch after a period of about a week, but not so the Milky Frog.  Their eggs are remarkable in as much as they hatch within 24 hours, after which the pond will be filled with small black tadpoles.  Following a further 6 – 8 weeks, the newly metamorphosed golden green colored froglets emerge from the pond.

Last year we had the first time appearance of Olive Tree Frogs, (Scinax elaeochroa), at the pond.  Their presence was of brief duration, but enough to fox me for several nights with the new calls I could not recognize until seeing one out in the open calling with gusto.  Their temporary occupation of the pond must have been successful as I have just seen a juvenile in amongst all the other pond regulars.

Not long after the vocal manifestation of the Rain Frogs heralded the approaching rainy season, the first actual rains encouraged out of hiding for the first time in five months the nightly sound of little ringing metal bells, that particular sound created by the Tink Frog.  Noticeable by their absence during the dry period, we will now have seven months of dusk till dawn chiming, their calls infinitely preferable to the dreadful din of the Milky Frogs, which thankfully only occurs once or twice at the onset of the rains.  In Spanish the Tink Frog is known as the Martallito, the little metal hammer, because its call closely resembles the tinny ring of a small hammer hitting an anvil.

One other frog to emerge in rain induced numbers are the Banana Frogs which will now be present in greater or smaller numbers at least until December.

Mating Banana Frogs

Fading Beauty

The butterfly season is on the downturn now.  Most numbers of individuals and species occur throughout February and March.  The start of the rains can severely deplete numbers seen but extended periods of sun between the showers will see the numbers rise once again but not to the peaks of the dry season.

One thing that I will notice though is the frequency at which I will encounter a few species of butterfly that I will only see maybe once or twice during the course of the year.  It is always nice to renew this re-acquaintance as well as recording species that I have previously not monitored on the grounds of Bosque del Cabo.

The swirling and frenzied clouds of Green Urania Moths are now diminishing in numbers too.  They will have mated, laid eggs, the adults are dying and the resulting new offspring upon emergence will fly off is search  of new Omphalia vine hence continuing that verdant migration back and forward throughout Central America.

One particular moth has been capturing the attention of some of the visitors walking the trails if only for its initial shock value, the Bird Wing Moth, (Thysania agrippina).  When disturbed it vacates its perch on the side of a tree trunk, taking to flight some enormous floppy bat flying away from you down the forest path only to suddenly disappear from in front of your eyes as quickly as it appeared.  If you approach slowly, you will see the moth has alighted on the trunk of the tree, its wings aligned up to down, its body horizontal.  The wings are patterned with a series of wavy lines that look to all intents and purposes like the bark of the tree.  Only the visually acute will spot them in this position.

Broken Blossoms

There is a constantly changing flux of plants flowering and fruiting.  The recent blooms of Lady of the Night Orchid have momentarily faded.  Walking through the forest you will happen upon many fallen blooms and fruits from vines, trees and their associated epiphytes.

Minute white flowers of the Hobo or Hog Plum, (Spondias mombin), carpet the forest floor like confetti from a secretive woodland wedding ceremony.  The Legato Negro is also in flower, its blooms appear to a rich prize for the Leaf-cutter Ants which harvest them from the tops of the tree crown, descend and carry them over large distances, finally returning to the nest where they will be processed into compost along with any other plant material that enters the subterranean Attine domain.

In recent weeks I have seen the bases of Ajo trees, (Caryocar costaricense), littered with their fallen green fruits.  The fruits have an oily nutritious pulp that the rodents enjoy eating.  The presence of high rodent numbers can attract in another, less welcome by some, visitor to the base of the trees, snakes, in particular, the Terciopelo, (Bothrops asper).  These large pit vipers are ambush predators that sit and wait, sometimes for days on end, for a meal in the form of a small furry creature to pass by.  It is one reason why you should check the base of trees before complacently stepping in to have your photograph taken against some of the giant buttresses.

Two species of Nutmeg Trees have recently been producing the “Golden Fruits” that give the trees their name, Fruta Dorada.  The golden fruits are the hard shelled nuts that upon ripening and splitting reveal the seed that is the nutmeg and the bright red membranous aril that surrounds it.

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

The shorted and stuttered rain induced breeding frenzy of the Milky Frogs was witnessed by many of the visitors to Bosque, some of whom could not contain their curiosity and simply had to go and investigate what was causing the unfaltering ruckus they were hearing over the course of their dinner.  For one young boy the effect was overwhelming, reducing him to tears, seriously disturbed by a sight he, (as far as he is concerned), hopefully will never witness again.

Milky Frog

It is almost impossible for me to give the spoken part of the Sunset Tour over the top of such a din, and I often have to retire to the quieter confines of the garage across the road before I can make myself heard.

Milky Frogs are the largest of the Costa Rican Tree Frogs.  They are sometimes referred to as Marbled Tree Frogs because of the handsome mottled browns and beige of the body color.  As documented above it is an explosive breeder.  I only count it in small numbers, if at all around the pond, but they are obviously there because as I have mentioned, with the first torrential rain, they come out in force, up to 50 or 60 individuals.  It is another frog that has the ability to glide from the tree tops to ground level using widely spread and heavily webbed fingers and toes.  This allows the frog to take advantage of perfect breeding conditions very rapidly.  Significantly other frogs such as the Smoky Jungle Frog were present in much smaller numbers than normal while the one off Milky Frog invasion occurred.  The males grab anything that moves and I think that overzealous behavior may have kept other amphibians at bay.

Milky Frog

When disturbed, the Milky Frog gives off from glands in its skin, a thick white secretion that can prove to be highly irritating especially if making contact with mucus membranes such as mouth, nose and eyes.  In fact it can cause temporary blindness.

It occurred to me that I should go along after dinner and photograph the event.  So after I finished up in the office, I returned to the pond at 11:00 pm.  Just as I arrived, an incredible thing happened, as one all of the frogs stopped calling.  It was so simultaneous that it seemed like an off switch had been hit.  Not only that, but as I tried to compose some exposures, the frogs made a mass exit from the water and ran up the side of the trees like small mice on amphetamine sulphate.  Within a matter of minutes the pond have had been vacated with the same alarming rapidity with which it was occupied only a few hours earlier.

Red-eyed Green Tree Frog Spawning     Red-eyed Green Tree Frog Spawn     Red-eyed Green Tree Frog Spawn

It was while I stood marveling at the truly amazing scene unfolding in front of my eyes that I noticed a pair of amplected Red-eyed Green Tree Frogs that had made their way, despite their boisterous co-inhabitants, under a low lying leaf and they were beginning to lay eggs.  I couldn’t quite get in at a good angle to record the event but managed to get at least several shots.

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 86°F.  Average Daily Temp Low 74°F.

Average Daily Rainfall 0.32 ins.  Total Weekly Rainfall 6.73 ins

Average Daily Temp High 31.2 °C.  Average Daily Temp Low 23.0 °C.

Average Daily Rainfall 7.9 mm.  Total Weekly Rainfall 166.4 mm

Species List for the Week


  • Howler Monkey
  • Spider Monkey
  • White-faced Monkey
  • Central American Squirrel Monkey
  • Alfaro’s Pygmy Squirrel
  • Red-tailed Squirrel
  • Agouti
  • Nine-banded Armadillo
  • Kinkajou
  • Tayra
  • Puma
  • Collared Peccaries


  • Orange-chinned Parakeet
  • Red-lored Amazon
  • Scarlet Macaws
  • Grey-necked Woodrail
  • Great Currasow
  • Pale-billed Woodpecker
  • Crested Caracara
  • Laughing Falcon
  • Mangrove Black Hawk
  • Roadside Hawk
  • White Hawk
  • Magnificent Frigatebird
  • Stripe-throated Hummingbird
  • Wedge-billed Woodcreeper
  • Chestnut-backed Antbirds
  • Black-hooded Antshrike
  • Common Paureque
  • Spectacled Owls
  • Rufus Piha
  • Short-billed Pigeon
  • White-tipped Dove
  • Blue-crowned Manakin
  • Red-capped Manakin
  • Chestnut-mandibled Toucan
  • Fiery-billed Aracari
  • Cherrie’s Tanager
  • Grey-headed Tanager
  • Bright-rumped Atilla
  • Great Kiskadee
  • Masked Tityra
  • Great Tinamou
  • Black-throated Trogon
  • Slaty-tailed Trogon
  • Black Vulture
  • King Vulture
  • Turkey Vulture


  • Barred Ameiva
  • Four-lined Ameiva
  • Central American Whiptail
  • Green Iguana
  • Golfo Dulce Anolis
  • Central American Smooth Gecko
  • Clawless Gecko
  • Mediterranean House Gecko
  • Boa constrictor
  • Cat-eyed Snake
  • Litter Snake
  • Salmon-bellied Racer
  • Terciopelo
  • Tropical Bird-eating Snake


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


  • Adelpha cytherea
  • Adelpha heraclera
  • Adelpha serpa
  • Aeria euromedia
  • Anartia Fatima
  • Anartia jatrophae
  • Anastrus naearis
  • Anatrytone potosiensis
  • Anthoptus Epictetus
  • Antirrhea philoctetes
  • Arawacus lincoides
  • Archaeoprepona demophon
  • Astraptes egregious
  • Astraptes fulgerator
  • Battus polydamus
  • Caligo eurilochus
  • Callicore lyca
  • Callimormus radiola
  • Calycopis isobeon
  • Catonephele numilia
  • Cissia confusa
  • Colobura dirce
  • Copaeodes minima
  • Dione juno
  • Dryas iulia
  • Eueides aliphera
  • Eueides lybia
  • Euphyes vestris
  • Eurema albula
  • Eurema daira
  • Glutophrissa Drusilla
  • Heliconius cydno
  • Heliconius erato
  • Heliconius hecale
  • Heliconius ismenius
  • Heliconius sapho
  • Heraclides cresphontes
  • Hermeuptychia hermes
  • Hyalyris excelsa
  • Junonia everete
  • Laparus doris
  • Magneuptychia libye
  • Marpesia berania
  • Mechanitis lysimnia
  • Mechanitis polymnia
  • Melinaea scylax
  • Mesosemia zonalis
  • Metacharis victrix
  • Morpho helenor
  • Morpho Menelaus
  • Morys valerius
  • Nastra Julia
  • Panoquina evansi
  • Pareuptychia ocirrhoe
  • Parides erithalion
  • Philaethria dido
  • Phoebis agarithe
  • Phoebis argante
  • Phoebis sennae
  • Pierella luna
  • Polites vibex
  • Pompeius pompeius
  • Pseudolycaena damo
  • Pyrgus oileus
  • Pyrrhogyra crameri
  • Quasimellena balsa
  • Rhetus arcius
  • Saliana fusta
  • Siproeta stelenes
  • Temenis laothoe
  • Tigridia acesta
  • Urbanus proteus
  • Urbanus simplicius
  • Urbanus tanna


  • Almendra Fruiting
  • Balsa Fruiting
  • Barrigón Fruiting
  • Black Alligator Tree Flowering and Fruiting
  • Cashew Flowering and Fruiting
  • Calabash flowering and fruiting
  • Clusia Vine Fruiting
  • Monkey Comb Tree Flowering and Fruiting
  • Garlic Tree Fruiting
  • Candlestick Plant Flowering.
  • Cannonball Tree Fruiting
  • Figs Fruiting
  • Guanacaste Tree Fruiting
  • Gustavia Flowering
  • Hog Plum Flowering
  • Inga Fruiting
  • Lady of the Night Orchid Flowering
  • May Tree Flowering
  • Manglillo Fruiting
  • Nutmeg Fruiting
  • Passion Vine Flowering
  • Pochote Tree Flowering
  • Psychotria Fruiting
  • Rubber Tree Flowering and Fruiting
  • Santa Maria Flowering
  • Sombrerito Fruiting
  • Stinky Toe Fruiting
  • Ylang ylang Flowering

Eyelash Viper and Tropical Frogs   2 comments

Local weather conditions may differ drastically from year to year and during 2009 the Osa Peninsula experienced a particularly rainless dry season.  Normally, from December through to April, there is at least some rain, not much; it is after all the dry season, but last year, barely a drop.  This was then followed by a very dry wet season.  When the rains should have arrived in May, they did not, and this condition carried on unabated throughout June and July.  For visitors to the Osa Peninsula, the conditions could not have been more perfect, lots of hot, sunny days, perfect vacation weather.  But that interruption in the natural rain cycle was having a profound effect on the fauna and flora of the area.

Rain forest trees are very dependent on their water source and if this becomes limited in supply, they begin to suffer environmental stress.  The first obvious sign is that they will shed leaves.  Should the stress continue, they begin to shed branches.  Finally, if we end up, as we did in 2009, with a drought in a rain forest, the trees divert a lot of energy into reproduction to ensure the passing on of their genetic material lest they themselves die.

That is exactly what we saw in 2009.  Visitors were treated to a canopy high display of flowering, rarely equaled, with a veritable kaleidoscope of color; yellows, reds, purples and pinks painted like a pastel infusion among the normal mix of greens at the treetops.  Some of the trees did not just flower once; they produced blooms two or three times throughout last season.  The exuberant flowering display led in turn to a profusion of fruiting, the trees were quite literally hanging with fruit.

This series of events led in turn to a very good reproductive year for those animals whose diet depends to a greater or lesser extent on nectar or fruit, such as Spider and Howler Monkeys, Toucans, Hummingbirds and Manakins.  This year visitors have been treated to the sight of huge flocks of toucans and a great many of the female Spider and Howler Monkeys carrying young ones.

But what a difference a year makes.  In a complete reversal of last year, 2010, so far, has been a wetter than normal year.  Rather than the tired looking yellows and browns evident in last year’s vegetation, this year has remained luxuriously verdant and that bodes well for another group of animals; the amphibians.  Despite a myriad of problems causing global declines in amphibian populations, here on the Osa Peninsula, the frogs are still holding their own.

Veridion-Adventures Red-eyed-Green-Tree-Frog Agalychnis-callidryas Nature Photography Travel Adventure Holidays

Mating pair of Red-eyed Green Tree Frogs, (Agalychnis callidryas)

There are certain species that one can almost rely upon to be present right throughout the year; Marine Toads and the picture postcard child of Costa Rica, the Red-eyed Green Treefrog.  With the onset of the rains though, all those species that have been noticeable by their absence for the previous five months emerge once again, sometimes in numbers so large that it begs the question, “Where has such a biomass of amphibian life been hiding for almost half the year?”

When they do emerge, it is with only one thing in mind; reproduction.  Around the breeding pools, the cacophony of the calling males renders it all but impossible to make yourself audible.  The initial heavy rains of the season immediately encourage a response from Costa Rica’s largest treefrog, the Milky Frog.  Within hours on the evening of the first downpour a full breeding choral congregation of males, in numbers upwards of fifty will have accumulated in the pond.  The deafening din of their ardor can be heard from great distances.  After several nights of this repeat performance, they once again decline in numbers until it is only a very occasional chance sighting that you will experience during the remaining rainy months.

Now is the time of the frog though and during the next seven months we are treated to a nightly chorus of serenading males of different species, some of them more melodious than others; the jackhammer mating call of the Marine Toad, the chuck of the Red-eyed Green Treefrogs, the sound of little metal bells tinkling from the Tink Frogs, clipped chirps of Banana Frogs and what you would swear sounded like two blocks of wood being knocked together that announce a Gladiator Frog male is looking for a mate.

Veridion-Adventures Banana-Frog Dendropsophus-ebreccatus Nature Photography Travel Adventures Holidays

Banana Frog, (Dendropsophus ebreccatus)

Yet there is one more amphibian phenomenon that only a lucky few experience; the explosive breeding display of Parachuting Red-eyed Green Tree frogs.  This is the second species of Red-eyed Green Tree frog to be found on the Osa Peninsula.  They are rarely, if ever seen, living as they do at the tops of the trees, but several times during the rainy season following several days of concerted torrential rain out they come, and they come in their hundreds.  They receive the parachuting part of their name from having large hands and feet that are extensively webbed.

Veridion-Adventures Parachuting-Red-eyed-Green-Tree-Frog Agalychnis-spurelli Nature Photography Travel Adventure Holidays

Parachuting Red-eyed Green Tree Frogs, (Agalychnis spurelli). Mating pair

Taking the monsoon-like conditions as their cue, they launch themselves from above, opening the hands and feet, spreading the webbed fingers and toes, allowing them to effectively ‘glide’ to the lower levels.  The males and females pair up and then not long before dawn they start to lay eggs, everywhere, covering the surfaces of the leaves overhanging the ponds.  The eggs develop for seven to ten days, liquidize, slip off the leaves and plop into the water which is where the normal tadpole stage will then take place.  The explosive breeding frenzy has to end before sunrise; the frogs need to take shelter from the drying effect of the sun’s harmful rays on their delicate skin.

If you are out early enough you will be awestruck by the sight of hundreds of pale green frogs trying to climb up into shadowy parts on the underside of leaves.  Sometimes the weight of such huge numbers will snap the vegetation in which they are attempting to seek refuge.  It really does have to be seen to be believed.

Eyelash Viper Feature

Veridion-Adventures Eyelash-Viper Bothriechis-schlegelii Nature Photography Travel Adventure Holidays

Eyelash Viper, (Bothriechis schlegelii). Gold phase – Oropel

In all my years living on the Osa Peninsula I have seen the elusive Eyelash Viper, (Bothriechis schlegelii), on only four occasions.  It is not necessarily because they are rare but more to do with the fact they are very cryptically colored, the point of which being, to avoid being seen by both predator and prey.  Although they come in several color forms, the ones I have seen at Cabo Matapalo have all been the green mottled morph. The camouflage coloration blends the contours of the body perfectly against the moss covered branches of the plants where they sit as ambush predators awaiting the approach of a small lizard, frog, bird or rodent on which they feed.

The most distinguishing feature of this small pit viper are the two spine-like scales protruding over the eye giving it the name Eyelash Viper.  There is no definitive answer as to why it has these scales, possibly to push vegetation out of the way which may scratch the snake’s unlidded eyes.  One other eponymous feature  to the pit vipers is the small hole on the front of the face between the nostril and the eye.  These house acute sensory apparatus that detect very small changes in background infrared radiation allowing the snake to detect the presence and location of it prey.

Veridion-Adventures Eyelash-Viper Bothriechis schlegelii Nature Photography Travel Adventure Holidays

Eyelash Viper, (Bothriechis schlegelii). Motteld phase- Bocaraca

The Eyelash Viper is a small snake, especially given the size some other vipers can grow to.  It is a nocturnal predator and will take a variety of prey ranging from frogs, lizards, birds and mammals. Unlike terrestrial vipers which envenomate their prey, release it, then seek it out after it has died, the arboreal vipers have a strongly prehensile tail and tend to hold on to their prey after biting.

Eyelash Vipers are distributed from Mexico down through Central America into Venezuela.  They prefer shrubby vegetation found in secondary growth.  In Costa Rica the yellow morph is know as the oropel, (golden skin), while the mottled morph is known as the bocaraca.

Due to its size, cryptic coloration and preference for resting during the day in the lower areas of vegetation it is responsible for biting those people who work in those areas.  Although deaths from the bite of an Eyelash Viper are rarely fatal, there can be some long term issues with impairment of movement particularly if bitten on the hands.  Viper venom varies between species and can be quite complex in chemical make-up.  Generally they contain a cocktail of fast acting proteolytic enzymes that cause a multitude of effects including tissue necrosis and death.


%d bloggers like this: