Archive for the ‘Craugastor fitzingeri’ Tag

Pluvial Songs   6 comments

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

After four months of continual sun and no rain the weather briefly changed.  Over the course of the last week the clouds had been gathering, a portent of what was about to happen.  There were several nights with a brief light drizzle, not enough to dampen the ground but just enough to wash the layer of dirt covering the plant leaves.  Then one night the sky grew dark and a heavy shower dropped enough water to soften the hard, dry ground.  Finally, one afternoon a really heavy deluge poured out of the heavens, two and a half inches is as many hours.  Immediately the Fitzinger’s Rain Frogs, (Craugastor fitzingeri), started calling.  This was to herald a sudden coming to life of several amphibian species.

Fitzinger's Rain Frog. Felipe del Bosque. Osa Peninsula. Costa Rica.

Fitzinger’s Rain Frog, (Craugastor fitzingeri)

Over the next few hours the calls of the Milky Frog, (Trachycephalus venulosus), began increasing in number and intensity.  The sun was setting, the daily environmental trigger that stimulates the frogs into emerging from their daytime hiding places, but over the dry season only one or two individuals of few species.  Now, however, a greater number of participants was joining the choral gathering.

Milky Frog. Philip Davison.

Milky Frog, (Trachycephalus venulosus)

The Banana Frogs, (Dendropsophus ebreccatus), which for the past four months had been restricted to a solo, forlorn crooner was now accompanied by many more to form a backing group.  The loud nasally calls of the Masked Smiliscas, (Smilisca phaeota), entered to swell the ever-increasing cacophony.  All semblance of rhythm, cadence and orchestration disappeared as more and more frogs entered into what was becoming a free for all, each male trying to drown out his neighbor.  Up in the tree tops the Red-eyed Green Tree Frogs, (Agalychnis callydryas), were chirping from all quarters.  Down on the ground boomed the loud whooping of Savage’s Thin-fingered Frogs, (Leptodactylus savagei).  The sound of a mini jackhammer that is the mating call of the Marine Toad, (Chaunus marinus) along with the chucking calls of the rain frogs completed the din.

As the evening progressed, it was however, the calls of the Milky Frogs that became so intense that they could be heard from some distance away.  The ruckus continued well into the night.  The next morning the surface of the pond was covered in a gelatinous film containing the eggs of the milky frogs.  These are some of the fastest developing amphibian eggs I have ever encountered.  Within 24 hours the tadpoles have hatched and entered the water where they can be observed as wriggling black swarms just beneath the surface.  After several weeks they will be seen everywhere as tiny, newly emerged froglets sitting on the vegetation surrounding the pond.

Sadly for the amphibians, that one wet night was all they got.  The next day it was back to normal dry season conditions.  It won’t be long before the rains truly arrive though.  One other creature to be seen around the pond at night, sleeping on top of the vegetation are the juvenile Green Iguanas,  (Iguana iguana), newly hatched.  Their comatose, lime-green bodies can be found at the ends of the long branches but a lingering flashlight beam will soon stir them into a state of semi-consciousness ready to jump off and run away at the slightest disturbance.  If you are lucky you will also catch sight of the newly emerged Common Basilisks, (Basiliscus basiliscus).  They are harder to see as they sleep vertically and are more muted in coloration.  The hind legs sticking out sideways from the stems where they sleep is quite often a giveaway as to their presence.

Green Iguana. Sauria. Felipe del Bosque.

Green Iguana, (Iguana iguana)

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


Supplementary Surprise   4 comments

Felipe del Bosque Blog May 28th  2012

Inevitable Change

It has been a mixed bag with the weather this week.  There have been showers, sun and cloud cover.  This week has also seen the first violent thunderstorm of the season.  In the small hours of Thursday morning, for two hours the sky was lit and the buildings were shaken by the thunder and lightning directly overhead.  This was accompanied by an inch and a half of rain.  But as dawn broke and the sun rose, so did the clouds eventually disappear and it turned out to be a beautiful day.

Amazing Finds

We had a couple staying this week that were evaluating the potential of Bosque del Cabo as a suitable location for clients booking holidays through their travel agency.  Their clients are more nature oriented, which fits the profile of most of Bosque’s visitors; people come because of Bosque’s reputation as one of the best and most biodiverse rain forest lodges in Costa Rica.

Having completed the hotel inspection, it was time to hit the trails.  It wasn’t long before their eyes were opened as to why Bosque has achieved its renowned status.  Once again, as so many visitors before them, they were walking the Titi Trail watching an abundance of monkey activity, when from down the trail came walking towards them a Puma, (Puma concolor).  The cat came closer and closer, it then stopped, looked at them, turned and walked off into the forest.  From the description, “It had a short tail”, it was almost certainly the resident female Puma “Half tail”.

The excitement was not over for the day though.  After relating the tale of their amazing experience over dinner, they returned to their cabin only to be attracted to something making a noise in the tree outside.  They went out onto the deck and there was a Northern Tamandua, (Tamandua mexicana), using its powerful front legs and long sharp claws to rip into the bark of a tree in order to access and feed on the termites inside.  They didn’t manage to get a picture of the cat but they did get a good photograph of the anteater.

Odd Sighting

The Titi Trail seems to be an endless source of great wildlife sightings.  Not long after the Puma episode, one of the Bosque staff was working on the trail when he had waddling down the path towards him a large animal about the size of Shetland Pony, with small ears and a long snout.  This description fits only creature, Baird’s Tapir, (Tapiris bairdii).  I have been walking the trails of Bosque for 12 years and have occasionally come across tapir tracks, even as close as my cabin, but I have never seen a tapir in the flesh on the grounds.

Tapirs are odd-toed animals related to horses and rhinoceroses; they all belong to the mammalian order Perissodactyla.  Baird’s Tapir is the only odd-toed mammal native to Central American.  They are browsers, feeding on low lying vegetation and fruit.  Water is essential to the life of the tapir, they like pools in which they can wallow.  Bosque is at the top of a hill and there is no lying water so this individual was probably a transient on its way somewhere else.

Mango Surprise

The mango trees are now hanging with fruit which is starting to ripen.  This is attracting the attention of many fruit eating animals or those that would just take the opportunity of partaking of the frugivorous feast.  One night while I was walking near the mango orchard I could hear a lot of movement coming from the uppermost branches.  As I stood watching, a creature fell to the ground with a bump along with several of the mangoes.  Initially all I could see was the bright orange eye-shine reflecting back from my flashlight beam.  The fall did not seem to have caused it any trauma as it progressed to climbing back into the tree.

By the time it made its way up in the branches again I could see what it was, a Kinkajou, (Poto flavus).  This one was not alone; several more made their presence know, not by coming into view, but by the distinctive nasal snort followed by short high pitched whistles.  There must have been 3 or 4 above my head which may have been a family all gorging themselves on the abundance of succulent mango flesh surrounding them.

Raining Frogs

It might come as no surprise but when the rains arrive it stimulates the rain frogs into calling.  The rain frogs can be heard throughout the year but with increasing wet conditions, more species and more individuals are induced to call.  This time of year, all night long you will hear the Tink Frogs, (Diasporus diastema), with the distinctive metallic “tink” song.  As the sun sets, you will quite often be aware of soft “chuck, chuck, chuck, chuck” sounds coming from a variety of locations.  These are male Fitzinger’s Rain Frogs, (Craugastor fitzingeri), both calling for a mate and telling other males to stay away.  Unfortunately, the calls also alert those night time predators on frogs, the Fringe-lipped Bats, (Trachops cirrhosus).  The calls usually echo back and forth with a regular time interval which makes it difficult for the bat to isolate where the call is coming from.

         Craugastor fitzingeri         Craugastor fitzingeri

Fitzinger’s Rain Frog is not a very large amphibian but despite its size is quite robust.  It has a mottled fawn and brown skin with small black spots and covered in small raised warts.  As with many frogs they are mostly nocturnal.  The rain frogs also don’t need to return to the water to reproduce.  They pair up and then deposit 10-30 large, yolk-filled eggs in the leaf litter on the forest floor.  The larvae develop within the egg, (there is no free-swimming tadpole stage), until about 8 weeks and then emerge as fully formed but tiny copies of the adults.

Craugastor fitzingeri

This individual I inadvertently disturbed early in the morning.  I took advantage of the good lighting and the fact that he didn’t seem too keen to hop away, or at least not till I had taken some good profile shots of him.

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

Protein Supplement

Sadly, as far as I am concerned, with the rainy season the butterfly numbers are past their peak.  There are still enough around but the figures are on the downturn.  One morning, the sun was shining and didn’t have a tour, so I decided to head out with the camera and see what may be around.  I wasn’t looking for anything in particular just whatever happened to be there.  At one point I came across at longwing passionflower butterfly, (Heliconius cydno), flitting from flower to flower searching for and feeding on the nectar that provides the butterfly with energy for flight.  I also noticed that this individual had its proboscis coated with a large deposit of aggregated pollen.

Heliconius cydno         Heliconius cydno         Heliconius cydno

Butterflies of the subfamily Heliconiinae are known as “passion vine butterflies” as many species use the genus Passiflora as a larval host plant.  But they are also the only butterflies known to also feed on pollen, specifically from several species of the cucumber vine family, Cucurbitaceae.  The passion vine butterflies have excellent eyesight and color vision allowing them to find the cucumber vine flowers in the forest.  Nutrients in the pollen are essential for egg production and to maintain the health of the females‘ovaries which subsequently enable multiple matings.  Daily feeding on pollen, from which amino acids are derived also allow the Heliconius butterflies to live anything upto 9 months which is almost Methuselah-like in butterfly terms.  They are also metabolized into the production of defensive toxins stored in the butterflies’ body.  The bright colors worn by the Heliconiinae are warnings, (aposomatic coloration), signaling that the insect is not a suitable food item.

Heliconius cydno

Heliconius butterflies are trapliners, visiting several plants, but over the same route, every day.  However if the food plants are in short supply, they become more stationary and defensive of their particular patch of vine.


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 0.53 ins.  Total Weekly Rainfall 3.68 ins

Average Daily Rainfall 13.3 mm.  Total Weekly Rainfall 93.2 mm

Species List for the Week


  • Howler Monkey
  • Spider Monkey
  • White-faced Monkey
  • Agouti
  • Red-tailed Squirrel
  • Vesper Rat
  • Kinkajou




  • Mealy Amazon
  • Red-lored Amazons
  • Scarlet Macaws
  • Grey-necked Woodrail
  • Great Curassow
  • Black Hawk
  • Crested Caracara
  • Great Black Hawk
  • Laughing Falcon
  • Roadside Hawk
  • Yellow-headed Caracara
  • Golden-naped Woodpecker
  • Lineated Woodpecker
  • Pale-billed Woodpecker
  • Chestnut-backed Antbird
  • Black-hooded Antshrike
  • Streak-headed Woodcreeper
  • Wedge-billed Woodcreeper
  • Common Paureque
  • Brown Pelican
  • Short-billed Pigeon
  • White-tipped Dove
  • Long-billed Hermit
  • Blue-crowned Manakin
  • Red-capped Manakin
  • Fiery-billed Aracari
  • Chestnut-mandibled Toucan
  • Golden-crowned Spadebill
  • Great Kiskadee
  • Great Tinamou
  • House Wren
  • Slaty-tailed Trogon
  • Masked Tityra
  • Black Vulture
  • King Vulture
  • Turkey Vulture




  • Central American Whiptail
  • Central American Smooth Gecko
  • Common Basilisk
  • Five-lined Ameiva
  • Golfo Dulce Anolis
  • Green Iguana
  • Litter Snake
  • Northern Cat-eyed Snake
  • Mediterranean House Gecko
  • Snub-nosed Anolis
  • Tropical Bird-eating Snake




  • Banana Frog
  • Black and Green Poison Arrow Frog
  • Gladiator Frog
  • Golfo Dulce Poison Arrow Frog
  • Marine Toad
  • Masked Smilisca
  • Red-eyed Green Tree Frog
  • Smokey Jungle Frog




  • Anartia fatima
  • Eueides lybia
  • Glutophrissa Drusilla
  • Heliconius erato
  • Heliconius hecale
  • Heliconius ismenius
  • Heliconius sapho
  • Hermeuptychia hermes
  • Marpesia berania
  • Metacharis victrix
  • Morpho menelaus
  • Opsiphanes tamarindi
  • Parides erithalion
  • Philaetria dido
  • Phoebis argante
  • Phoebis sennae
  • Pierella luna
  • Pseudolycaena damo
  • Pyrgus oileus
  • Strymon megarus




  • Bamboo Orchid Flowering
  • Lacmellea panamensisFruiting
  • Crestentia alata flowering and fruiting
  • Cannonball Tree Flowering and Fruiting
  • Cashew Flowering and Fruiting
  • Clusia valerii Fruiting
  • Gustavia brachycarpa Flowering
  • Apeiba tibourbou Flowering and Fruiting
  • Naucleopsis ulei Fruiting
  • Symphonia globulifera Fruiting
  • Virola koschnyi Fruiting


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