Archive for the ‘Masked Tree 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.

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


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