Archive for the ‘Osa Peninsula’ Tag

RAINFOREST DIVERSITY: SOMETHING FOR EVERYONE   2 comments


Veridion Adventures. Philip Davison. Rainforest animals. Rainforest plants

There is still no let up in the rainy conditions.  The good news is that the days are more overcast than dark and the rain is now falling more as a drizzle rather than a deluge.  As with recent weeks the sun has been shining once in a while so hopefully as we move into December the rains will abate and we will be able to say the dry season has started.

Rainforest Diversity – Beetles

The wet conditions have kept me indoors more than I would like.  On those occasions that I have been out and about there was not too much animal life to point the camera at.  When you read about the diversity of fauna and flora contained within a tropical rainforest you would expect to be surrounded by a non-stop progression of subjects.  That is not always the case.  However if you persist and concentrate on looking a little more closely at the vegetation then something is bound to turn up.

Beetles are the most numerously named group of animals on the planet.  Surely there have to be beetles wherever you look.  Well they aren’t as obvious as you might imagine.  Many of them are secretive, ground-living or wood-boring insects.  Looking diligently at the leaves as I made my way along a sunny path and hoping for at least one or two individuals of any insect to be out I saw a small beetle that I had never seen before.  Given that Costa Rica has 47,000 named species of beetle and I would never profess to being a specialist coleopterist, then the fact that I did not know what species I was looking at should come as no surprise.

Rainforest beetles. Coleoptera. Cerambycidae. Cerambycinae. Long-horned Beetle. Costa Rica. Philip Davison. Veridion Adventures.

Long-horned Beetle, (Cerambycinae sp)

I can generally make an immediate I.D. to family level and that was not hard with this one.  The length of the antennae were the give away, the very long length, far longer than the body.  This was a small Long-horned Beetle, family: Cerambycidae.  This one also had a long pronotum, (the area behind the head), and a very long body.  I was guessing it belonged in the subfamily: Cerambycinae.  I now had to go and research online to see if I could find the genus and species.  Alas, my scrutinizing a great many photographs failed to result in a match but at least I have the image should I find further reference material in the future.

Rainforest Diversity – Fungi

The beetles are matched by the fungi in terms of numbers and also a lack of reference material for the non-specialist to identify them to species level.  Many of the biologists working with tropical taxa tend to be specialists.  I am more of a generalist and enjoy all forms of life; plants, animals, fungi and no matter whether they are extant or extinct.  My areas of specialty are butterflies, reptiles and amphibians.  It can be frustrating sometimes when a name cannot be found as that might reveal information about the life-history of the organism and its role in the ecosystem.  Essentially it helps establish those links that increase our understanding of the system, what happens if those links are severed and conservation management strategies that would be required to stop the system collapsing.

Rainforest fungi. Agaricales. Hygrophoraceae. Costa Rica. Osa Peninsula. Philip Davison. Veridion Adventures.

Dried Mushroom, (Hygrocybe sp?)

So it was that I found a mushroom growing from the side of a rotten tree trunk.  I had seen and photographed this species before and, like so many others, had not been abled to identify it to species level.  There are 2000 named species of fungi in Costa Rica but estimates of how many species actually exist in this small country are as high as 70 000, so you can see the problem, you may be looking at one of the 68 000 estimated species that have not as yet been discovered.

This specimen was somewhat dried out and partly eaten.  The aspect gives a good view of the gills under the cap.  Given the features I have to work with I would guess the genus to be Hygrocybe, but I would not be held to that.  Within the gills you can also see a fungus fly.  These are flies that lay their eggs in the mushroom and when the larvae emerge they are surrounded by a ready food supply.

Rainforest Diversity – Spiders

Spiders are the eighth most numerously named group of animals on the planet.  As with the beetles and fungi, reference material is sparse for Costa Rican species.  However, this was one I did know.  It is not an uncommon spider.  They are nocturnal and build very distinctive horizontal webs.  It is an Orchard Spider, (Leucauge venusta).

They are not large spiders and can be easily overlooked.  But if you get up close you will find it has rather lovely markings.  The opisthosoma is patterned with curving bands colored with white, red, yellow and blue.

Rainforest Spiders. Arachnida. Araneae. Tetragnathidae. Leucauge venusta. Orchard Spider. Osa Peninsula. Costa Rica. Philip Davison. Veridion Adventures.

Orchard Spider, (Leucauge venusta)

Orchard Spiders are prone to being parasitized by Ichneumonid Wasps.  The wasp finds the spider and injects an egg into its abdomen.  The egg hatches and the wasp larva proceeds to suck the spider’s internal bodily fluids.  Outwardly this does not seem to affect the spider’s behavior and it continues web building as normal.  But then something insidious happens.  The wasp larva produces a chemical that allows it to sequester the spiders brain.  The chemical changes the spiders web building behavior and it produces a web which is not conducive to capturing insects but rather acts as a protective silken home for the pupating wasp.  The zombified spider, now of no value to the wasp, dies.  Nature can be both cruel and fascinating at the same time.

Rainforest Diversity – Butterflies

For someone passionate about butterflies I am in the right country.  Rainforests cover 6% the total land surface of the Earth and yet contain an estimated 50% of the worlds biodiversity.  Costa Rica, with only 0.3% of the planets terrestrial area is estimated to house 5% of the world’s total biodiversity.  The Osa Peninsula in the south west of the country is one of the most biodiverse localities in Costa Rica.  There are a lot of butterflies here.  I have recorded approximately 400 of the 1250 species to be found in this small Central American Republic, that is 32% found at Cabo Matapalo, the tip of this tiny piece of land sticking out into the Pacific Ocean.

Even here on Cabo Matapalo there is a large diversity of habitat and different butterflies prefer different conditions.  Many of the butterflies live up at canopy level and are beyond daily recording techniques.  There are butterflies that prefer open sunny gardened areas, some can be more commonly found along forest edges.  Then there are those presence will only be recorded in the gloomy and shadowy world that exists beneath the canopy, some at higher levels and some always hugging the ground.

I have nothing against bright, gaudy coloration but my liking is for more cryptic and subtle forms which when examined close up are every bit as beautiful as their showy cousins.  Among the more subdued colored butterflies are the Browns or Satyrs belonging to the family: Nymphalidae, subfamily: Satyrinae.  The Satyrinae are notable for the number of eyespots on the underside of the wings.  The ground colors are browns and grays patterned with ochres and umbers.

Rainforest Butterflies. Nymphalidae. Satyrinae. Pareuptychia ocirrhoe. Two-band Satyr. Osa Peninsula. Costa Rica. Philip Davison. Veridion Adventures.

Two-band Satyr, (Pareuptychia ocirrhoe)

The Two-banded Satyr, (Pareuptychia ocrirrhoe), has white dorsal wing surfaces and a bouncy flight close to the ground which gives it a flickering appearance.  I found this one flying along the forest edge on a very overcast day.  They respond quickly to movement so you have to approach slowly and deliberately in order for them to stay perched.

The Two-banded Satyr is normally found singly.  The larvae feed on grasses, (Poaceae), and the adults feed on rotting fruit and fungi, a diet that may account for them living longer, (several weeks), than other butterflies, (several days).

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

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ARMY ANTS:  A LIVING WAVE OF BLACK DEATH   6 comments


Veridion Adventures. Philip Davison. Rainforest animals. Rainforest plants

November is upon us.  The wet season continues, relentless heavy rain falling if not all day then at least part thereof.  One day last week over 14 inches of rain fall in an overnight deluge.  The following day the forest trails were more akin to newly formed streams, the water flowing downhill until it reached a point where it could tumble into the main creek that runs through the grounds, swelling its volume and increasing its velocity to that of a raging torrent.   There have been some dry, sunny days and if the weather continues its normal pattern then progressively as we move through the month the number of rainless days should increase.

I have been away for a month and upon my return, as with each and every year, the first thing I hear is the call of the Summer Tanager, (Piranga rubra), which has spent the summer in North America.  Not much has changed in the area while I was away.   The resident wildlife can still be found without any effort.  The White-nosed Coati, (Nasua narica), populations are growing at a steady and sustained rate.  I have never seen as many wandering the grounds as I do now.  The solitary males are normally bold creatures, but the females tend to be shy and retiring.  Now, however, the females and their young will allow you to approach very close without scurrying off into the shelter of the trees.

Rainforest lizards. Costa Rica. Polychrotidae. Anolis osae. Osa Anole. Philip Davison. Veridion Adventures.

Osa Anolis, (Anolis osae)

The wet conditions have proved to be conducive in allowing the amphibians to continue their courtship and breeding.  There are not so many egg masses present as in the main breeding period, (May – July), but there are still several species spawning on a nightly basis.  Feeding on the eggs are the Cat-eyed Snakes, (Leptodeira septentrionalis), which can be found every night by the pond.  The ever-present anoles of several species can be seen in the forest.  The commonest and most obvious is the Osa Anole, (Anolis osae), with its bright orange dewlap.  If one male is signaling to another to leave his territory then you can’t miss that flash of color against the dark background.

Ants Are Everywhere

Ants are ubiquitous insects in the forest.  On the trees you will see lines of Tiger Ants, (Camponotus sericeiventris), walking in line, foraging for food.  They receive their name from the black and yellow coloration rather than an aggressive nature.  In the lawns you would be well advised to avoid stepping in those small powdering mounds of earth that betray the presence of Fire Ants, (Solonopsis sp), living just beneath the surface.  I have never known anything so small cause so much pain as the fire ants.  The problem is that they are so small you don’t know you are covered in them until they start to bite and they all do so together.  It would be almost impossible to miss the presence of Leaf-cutter Ants, (Atta cephalotes), in these forests, whether it be descending the tree trunks with freshly cut leaf fragments or seeing lines of ants moving as a green river, snaking across the forest floor as they make their way back to, the nests with, what essentially is composting material for their fungus gardens.  Leaf-cutter Ant nests occur every 100 meters or so in whatever direction throughout the forest and can easily be identified by the large waste tips of excavated material marking the nests’ peripheral boundaries.

Rainforest insects. Hymenoptera. Formicidae. Atta cephalotes. Leaf-cutter Ant. Philip Davison. Veridion Adventures.

Pebble-capped towers formed by heavy rain on Leaf-cutter Ant nest waste tip

Army Ants:  A Living Wave of Black Death

It is a warm day, the rain has stopped, the sun is shining and you are quietly walking through the forest, binoculars strung around your neck and camera in hand.  The air is still and there is little sound bar the occasional call of a bird here and there and the soft white noise of calling insects which is not too intrusive.  You walk in a state of reverie, not thinking about anything in particular, your eyes scanning the vegetation for small subjects to photograph or watching for movement that may indicate a bird or mammal is moving across your path.  It is a day for enjoying your surroundings and contemplating the life contained within.  You are blissfully unaware of the carnage being carried out in the forest ahead.

As you make your way forward you start to hear more birds calling.  Some of the sounds you are familiar with; a Black-hooded Antshrike, (Thamnophilus bridgesi), Bicolored Antbirds, (Gymnophythis leucaspis), and Chestnut-backed Antbirds, (Myrmeciza exul).  This seems as if it might provide some good photographic opportunities so you make sure the camera is ready with the correct settings.  Now some other birds fly past you and land on the tree trunks, most of them a variety of treecreepers; Streak-headed, (Lepidocolaptes souleyetii), Tawny-winged, (Dendrocincla anabatina), and Ruddy, (Dendrocinclo homochroa).  The bird calls are increasing in intensity, excitement and volume as you make your way to where they seem to be congregating.  As you approach you can see them briefy dropping from the vegetation to the ground and back up again.  There is another sound, a hum which pervades the air.  Having left your dreamlike state and become more acutely aware you see that you are surrounded by flies buzzing everywhere. You see one or two Gray-headed Tanagers, (Eucomectis penicillata), amongst the mixed bird flock, the presence of which along with the flies provide the clues as to what is happening.   Finally you hear, a sound like softly falling rain and yet there is not a cloud in the sky.  From about 5 meters in front of you and advancing rapidly towards you like a sheet of black polythene being pulled across the forest floor is a foraging front of Army Ants, (Echiton burchellii); a living wave of black death.

Rainforest ants. Hymenoptera. Formicidae. Dorylinae. Eciton burchellii. Army Ant. Costa Rica. Philip Davison. Veridion Adventures.

Army Ant, (Eciton burchellii), on the march

The feet of thousands of miniature assassins moving as one across the dried leaves give the illusion of rain falling.  You stand dumbstruck by the scene playing out in front of you.  As the procession of annihilation moves closer you can see down by your feet beetles, cockroaches and crickets running for their lives.  These are the lucky few.  The killers are insatiable.  Any small creature unfortunate enough to caught in their unrelenting path will be overwhelmed, stung to death, and then decapitated, dismembered and disemboweled.  The wickedly sharp mandibles of the army ant hunters slash and cut through exoskeleton, muscle and connective tissue.  The victim’s mutilated body fragments are then carried away by the mindless insect ghouls to provide a feast macabre for the larvae.  As fascinating to witness as this bloodbath at the macro level is, you had better move.  The ants are now crossing the path all around your feet. You might be too big for them to tackle, but the long stinger and virulent toxin can cause a lot of pain.

Rainforest insects. Hymenoptera. Formicidae. Dorylinae. Eciton burchellii. Army Ant. Costa Rica. Philip Davison. Veridion Adventures.

Army Ants, (Eciton burchellii), carrying severed spider leg back to feed larvae

For those insects capable of flight and able to escape the ravaging mandibles of the ants, the danger is not over.  The birds were attracted to the ant swarm to take advantage of the free meal they provide by flushing insects from their hiding places.  Gray-headed Tanagers are obligative followers of the army ants.  Wherever they are, you will find the tanagers.  The flies are there for the same reason.  These are Coffin Flies, (Phoridae sp).  When an insect attempts to escape by taking flight, the parasitic phorid fly swoops in, lays an egg and flies out again.  The eggs will hatch and the grub will eat the victim.

Army Ants are one of the major predators in the forest.  They rank alongside Boa Constrictors, Harpy Eagles and Jaguars as one of the top of the food pyramid predators in the forest.  They are a nomadic ant and they have to be nomadic because being such a super-efficient predator, should they settle in any one area for any length of time, they would deplete it of all small forms of life very quickly.

They have 2 three week cycles; a nomadic stage when they move in a flowing column of ants, the queen travelling with them, until they find a new hunting ground.  They do not construct a nest, they make a bivouac, generally at the base of a tree, which is a huge ball of ants held together by the interlinking of legs. The queen moves to center and swells up.  She starts to lay approx. 60, 000 eggs per day.  When the eggs hatch and the larvae emerge, the emit a pheromone which elicits a hunting response from the other workers.  They then move through the forest in a front anything up to 60 feet, (20 meters), across and take all small forms of life in their path: insects, small frogs, small lizards, small snakes, fledgling birds, if it is there then they will have it.  Once it has been butchered into small pieces, these are taken back via feeder columns to the bivouac to feed the larvae.  When the larvae pupate, the hunting response is switched off and  they return to the nomadic stage making their way through the forest once again.

A New Assassin

Rainforest ants. Hymenoptera. Formicidae. Dorylinae. Nomamyrmex sp. Army Ant. Costa Rica. Philip Davison. Veridion Adventures

Army Ant, (Nomamyrmex sp) carrying pupa from Leaf-cutter Ant, (Atta cephalotes), nest

There are many species of Army Ant and the species described above is the most commonly found in the area Echiton burchellii.  Last week I found a species that I had never seen before.  As well as slaughtering prey items on the forest floor, army ants will also enter the nests of other ants and take out the eggs, larvae, pupae, workers and queen.  They one ant they fight shy of taking on are the Leaf-cutter Ants.  There may be several hundred thousand in an army ant colony, there can be up to 8 million in a leaf-cutter ant colony.  The soldier leaf-cutters are huge and equipped with razor sharp mandibles.  They are programmed to fight to the death.  The army ants would lose so many of their own numbers if they were to raid a leaf-cutter ant nest.  Even if they come across them on a trail they will not interfere with them.

Rainforest animals. Hymenoptera. Formicidae. Atta cephalotes. Leaf-cutter Ant. Philip Davison. Veridion Adventures.

Leaf-cutter Ant, (Atta cephalotes), soldier

It was to my surprise therefore when last week a watched for the first time an army ant raid on a leaf-cutter ant nest.  Luckily I had the camera in my hand and found a place to lie down and take photos.  On this occasion the leaf-cutters seemed to be helpless to stop the nest being ransacked.  When I downloaded the images and looked at the images I did not recognize the species at all.  Despite their distinctive flat, square heads, extensive searching produced no I.D.  Eventually I found one photo and some information.  The genus is Nomamyrmex and it contains two species.  I am not sure which one I had been watching but I was happy to have witnessed an event I had never seen before being carried out by an ant I had never seen before and had the photos to prove it.

Rainforest insects. Hymenoptera. Formicidae. Dorylinae. Nomamyrmex sp. Army Ant. Philip Davison. Veridion Adventures.

Army Ants, (Nomamyrmex sp), raiding Leaf-cutter Ant, (Atta cephalotes), nest

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

 

OGRE-FACED SPIDER: STARING YOU DOWN   4 comments


Wildlife, nature, fauna and flora of Costa Rica.

The weather is beginning to change.  There are now more rainy days with brief intervals of sun, generally shining in the morning.  Most of the nights are wet, with the rain beginning in the early hours of the evening then continuing through till dawn.  The rain is not heavy but it is constant.  This will now be the pattern until mid-November.  The opportunities to get out and take photographs is going to become more and more limited as the days and weeks go by.

Ogre-faced Spider

Sometimes you just have to be lucky and find yourself in the right place at the right time.  Many years ago I had taken some photographs of a particular species of spider and since then had been hoping to see this species again to get a close up of one of its startling features, the eyes.  I have come across it several times over the years but, unfortunately, never when I was carrying the camera.  Last week my luck changed and I found one without actually looking for it and I did have my camera in hand.

The spider in question is an Ogre-faced Spider, (Deinopis sp), of the family: Deinopidae.  Once you see the spider in close up then the reason for the name will be revealed.  Those two large, forward-facing eyes give the appearance of a mythical ogre staring at you.

Rainforest animals. Rainforest Spiders. Ogre-faced spider. Deinopidae. Costa Rica.

Ogre-faced Spider, (Deinopis sp), easier to see at an angle

The Ogre-faced spiders are not typical orb-weavers, they belong to a group known as lace-web weavers and have evolved a different means of employing silk to catch prey.  There are only 57 species of Ogre-faced spiders but they are found throughout the tropics.  They have long legs and a long abdomen, (opisthosoma).  If they do move, it is slowly and deliberately.  The coloration matches the tree bark on which they are commonly found hanging in a head down position.  During the day they lie flat against the tree to avoid being seen.  But as the sun sets they move into position and set about constructing the ingenious part of its prey capturing trap which is held between the front two pairs of legs.

These four legs have a dry silk frame strung between them.  Attached to the frame is a net made from sticky elastic silk.  An unsuspecting prey item passing below the spider is in for a nasty surprise.  The spider, connected by a dragline drops and opens the front four legs which extend the net.  It is dropped onto of the victim and when the legs are drawn together again the net closed and ensnares the spiders next meal.  The web is shaken a few times to ensure the prey is completely enmeshed, all the while the spider is wrapping in more silk from the spinnerets and continually biting its prey to inject the venom.  The secured and now deceased prey is held in the palps while the spider feeds and at the same time constructs a new net ready for the next meal to arrive.

Spiders. Rainforests. Costa Rica. Ogre-faced Spider.

The long-legged, long-bodied Ogre-faced Spider

The feature I was interested in were the eyes.  At 1.4mm in diameter, these forward-facing eyes are the largest simple eyes possessed of any land invertebrate.  The eyes have an equivalent camera f/stop of 0.6 which enable them to see very well in dark conditions, the time when the spider hunts.  This, combined with retinal receptors capable of absorbing the smallest amount of ambient light, 2000 x more than other spiders, means they can hunt in, what to you and I, is total darkness.  You can’t see the spider but the spider can see you.  Also, this one was a male as can be seen from the enlarged pedipalps under the front of the head.  These are used during spider mating.

Rainforest animals. Rainforest Spiders. Spiders. Deinopis sp. Ogre-faced Spider. Costa Rica.

Now you can see those eyes and the features that give it the name; Ogre-faced Spider

Weirdness on the Web

It has been a spidery kind of week.  When I was out walking the trails I noticed a small web strung across the path with what I first thought was a small spider removing the papery veil of a Jacaranda seed that had landed there.  In the past I have seen various orb-weavers cutting the silk securing an unrequired piece of material that had land in the web, hold it out with their legs until free of the web and let it drop to the ground.  Not too far down the same trail I saw a similar thing so I decided to take a closer look.  The spider itself was very small and with the naked eye it looked strange, I had not seen this species before and could not quite make out the form.  Something just wasn’t right.

Rainforest animals. Rainforest Spiders. Micrathenidae. Micrathena gracilis. Costa Rica.

Spiny Micrathena hanging from web, viewed from behind

I took several photographs and looked on the camera screen.  The body of the spider was unlike any I had previously seen.  The abdomen, (opisthosoma), was drawn up dorsally and expanded laterally.  It was covered in a series of fleshy, thorn-like protuberances.  I was looking at a Spined Micrathena, (Micrathena gracilis).  During the course of the day I found 3 of these spiders, which is strange because I had never seen this species before.  Later, when back online and researching more information, I learned it is quite common and widespread.  Oh well, new for me and happy to have finally made its acquaintance.

Rainforest animals. Rainforest Spiders. Micrathenidae. Spiny Micrathena. Costa Rica.

Dorsal view of Spiny Micrathena Spider

Only a few meters down the trail from where I photographed the Spined Micrathena I found another web traversing the path at about 6 feet above the ground.  Sitting in the center was yet one more spider that I was unfamiliar with.  I knew it was one of the Spiny-bodied Spiders, of which I have found a variety of different species over the years.  Unlike Micrathena gracilis above, most Spiny-bodied Spiders are brightly colored and elongated with spines and thorns projecting from the body, sometimes giving them an arrow-shape.  I knew this was a Micrathena, the body was long with black centered red spots on a yellow background and with only two more fleshy spines pointing backwards from the abdomen.  Extensive searching failed to produce a name for this species.  So two new spiders in one day and within several feet of each other.

Rainforest animals. Rainforest Spiders. Spiny-bodied Spider. Micrathenidae. Costa Rica.

Strange Spiny-bodied Spider, (Micrathena sp), awaiting identification

Finally I noticed a small web strung not too far above my head in the open garden area.  In the center of the web was a small brightly-colored but very distinctively spider.  The abdomen was vivid lemon yellow with a series of black spots drawn out sideways into an oval shape bearing ferocious looking thorns around the edge.  This was another Spiny-bodied Spider, (Gasteracantha cancriformis).

Rainforest Spiders. Rainforest animals. Gasteracanthinae. Spiny-bodied Spider. Costa Rica.

Spiny-bodied Spider, (Gasteracantha cancriformis)

They are a very common species but are so small that you generally don’t notice them until you walk into the web.  To avoid this situation the silken strands securing the web are flocked with fluffy pieces of silk to make it more obvious to larger creatures.  They come in various color, yellow, white and red being the commonest.  They are very widespread, being found from southern U.S. to northern Brazil and everywhere in-between including the Caribbean Islands.

It is a very short-lived spider; the females die after producing an egg cocoon and the males die a short time after mating.  In certain locations it is another spider that has a reputation it does not deserve.  Some of the native populations regard it as being very venomous.  It is quite harmless.

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

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 Dragon Hunters   Leave a comment


Philip Davison. Costa Rica. Blog. Nature Diaries

Monday 18th January 2016

Hair Trigger

Arachnid. Costa Rica.

Spiders are an amazingly diverse group of animals, the eighth most diverse group of animals of the planet in actual fact.  It doesn’t take long while poking around in the undergrowth to come across a spider.  Some build webs and some don’t but they can all spin silk, the orb weavers having the ability to spin upto seven different types of silk.  The non-orb weavers tend to be ambush predators, remaining motionless in a strategic location where potential prey may wander innocently by unaware of the imminent life threatening danger.  The ambush position could be on the side of a wall, atop a leaf or sitting on a flower head.

Arachnid. Costa Rica.

This Wandering Spider, (Cupiennius sp), was sitting perfectly still on a blank white wall at night.  As many spiders are nocturnal predators the eyes play a lesser part in the identification and capture of a meal but that does not imply the spider is without the means by which to locate the exact location of its prey.  The body, which at first sight looks smooth, upon closer examination can be seen to be covered in hairs of different lengths.  These hairs form part of a battery of sensitive sense organs responsive to touch, vibration and moving eddies of air currents that allow the spider to detect a passing meal in the darkness.

Wandering Spider. Araneae. Ctenidae. Costa Rica.

The majority of hairs covering the body, which give most people the heebie-jeebies with regards to spiders, are tactile and touch sensitive, the stimulus of which will cause the spider to attack or run away.  Between the shorter hairs, particularly on the legs are long fine hairs called trichobothria.  These are super sensitive to the slightest movement in air currents which can be a giveaway for any larger creature passing by which could make a nice meal.  The Wandering Spiders can even detect insects such as moths flying overhead which they jump and grab straight out of the air.

For those more stealthy prey items whose movements are too slow to disturb the air, they cannot avoid causing small vibrations of the substrate and the spiders are attuned to this also.  Around the body but more particularly around the leg joints are slit sense organs which allow the spider to detect any vibrations moving through the substrate upon which it is placed.

Whereas the Wandering Spiders rely on their tactile senses at night during the day there are spiders that actively hunt down their prey visually.  The Jumping Spiders prefer to hunt in full sun.  The most obvious feature are the large anterior eyes with which they can locate and subsequently stalk their victims.  They stealthily approach to the point where the potential meal is within striking distance.  The spider braces itself and then pounce.  The fangs are embedded upon impact, pumping venom into the victim which is held in a death grip by the front pair of legs.

Salticidae. Jumping Spider. Costa Rica.

Hunting the Hunters

The spiders may be highly adapted carnivores with specialized hunting techniques but they too in turn have predators specialized to catch and eat them.  Not the least of these are the giant Helicopter Damselflies, (Megaloprepus caerulatus), the largest damselflies on the planet.  They can be seen flying along the sunlit trails through the forest.  The peculiar motion of the blue/black tipped wings gives the impression of rotating helicopter blades.  What may at first seem like a somewhat erratic flight pattern actually has design.  The more astute observer will notice that they have the ability to fly vertically up and down as well as horizontally in and out.  But what are they seeking?  The large eyes and acute vision are scanning spider webs in front of which they momentarily hover scanning for the silken structures builder.  Once located the spider is grabbed in the legs of the damselfly which goes into reverse gear before biting off the spiders head and legs to finally gorge itself on the soft body parts.

Helicopter Damselfly. Pseudostigmatidae. Costa Rica

The damselflies can be recognized when they alight by the habit of folding the wings together over the body.  Their cousins, the dragonflies keep the wings held out to the sides when at rest. During the day it is not too often that they do rest.  Each individual has a perch from which it frequently takes off to investigate any passing creature that might make a meal or another dragonfly that might prove to be a mate or another dragonfly that might be a rival for that meal or mate.  They make aerial sorties swooping at speed, hovering in place and if unmoved to action return to the perch for a short while before they are off again on another sortie.

Dragonfly. Libellulidae. Costa Rica.

They differ from the more delicate damselflies not only by how they hold their wings but also in the structural placement of the eyes.  Damselflies have two large compound eyes widely separated on either side of the head.  Dragonflies have two large compound eyes that meet together for a greater or lesser part of their margins on top of the head.  However no matter where the eyes are placed they allow for excellent diurnal vision which combined with the unsurpassed aerobatic proficiency make these some of the masterful airborne hunters.

As we move into the dry season the hot and parched conditions stimulate many of the plants into flowering.  This is most certainly true of the orchids.  There are two orchids that can be seen blooming at the moment in the area.  One is a non native terrestrial orchid, the Bamboo Orchid and the other is a native epiphytic orchid.

Orchidaceae. Costa Rica.

The Bamboo Orchid is a native of South East Asia but is planted in many parts of Costa Rica as a beautiful ornamental edging plant.  Bamboo refers to the long erect stalk that resembles that a of a bamboo grass.  The attractive purple flowers appear throughout the year giving a nonstop display of color for the back of a flower border.

Orchidaceae. Costa Rica.

The majority of orchid species in Costa Rica are epiphytic, that is they grow on the outside of trees without harming them.  Generally to see orchids you need to be at the top of the canopy, 88% of Costa Rica’s 1400 orchid species are to be found there.  Many of the orchids flower from December into January but some may be seen flowering at any time of the year.  This particular specimen was found growing close to the ground near the base of a large tree. Due to the diversity of genera and species the identification of orchids, like so many tropical plant and animal taxa, is the realm of specialists.  For most visitors it is enough to see and enjoy the exotic blooms should you be lucky to encounter them.

Philip Davison is a biologist, writer and photographer based in Costa Rica.

 

A New Age Begins   3 comments


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Week Ending 11th December 2015

Weekly Weather

Average High Temp 101ºF (38.3ºC)               Average Low Temp 75ºF (24.3ºC)

Average Rainfall 1 ins (25.4mm)                    Total Rainfall 7 ins (177.8mm)

Wet and Dry

The dry season at Bosque del Cabo Rain Forest Lodge always experiences a stuttered beginning.  The lodge is located on the south west tip of the Osa Peninsula, Costa Rica overlooking the Pacific Ocean to the south and the Golfo Dulce to the east.  The region is covered by some of the last remaining tropical forest on the Pacific Coast of Central America.  Due to the pronounced seasonality of the area having a profoundly dry five months followed by a wet seven months the forests here are more correctly classified as tropical seasonal forests as opposed to tropical rain forests which are not subject to the annual dry period.

The heaviest rains of the year fall between September and November.  By December the daily deluge abates and we gradually see more of the sun.  It is easy to be lulled into a false sense of “the summer is here” as commonly a few dry, bright days with blue skies will be followed by another week of torrential downpours.  But eventually the faltering weather passes through the transitional phase and settles into a more predictable pattern.  Given a few weeks of steady, dry heat and the plant life will begin to flower.  The number of butterfly species and individuals that had dropped in the wet season begins to build once more so the days are now filled with beautiful, brightly colored wings adorned in poster reds, yellows and orange dancing around the flower heads.

There is never a shortage of mammal or bird sightings.  Currently there are many migratory warblers and tanagers chattering noisily in mixed flocks as they move from tree to tree in search of insects or fruit to eat depending on their specific diet.  The resident bird populations do not mind those long distance travelers returning to spend the winter in the warmer climes of the tropics and join quite readily with their travelling cousins in large flocks.  Monkeys abound in the trees, constantly on the move looking for food whether it is flowers, young leaves, fruit or insects.  Under the trees the large ground living rodents, Agoutis, feed on the fallen fruit and large heavily coated seeds.  Solitary male White-nosed Coatis are on the lookout for anything they can get their paws on; grubs, crabs, bird’s eggs and chicks as well as fruit or discarded food in the bins of the restaurant.  The gregarious females with young patrol in large foraging packs looking for the same food as the males but not with the same bold abandon.

The peace of the hot still sultry afternoon atmosphere is occasionally permeated by the call of a mammal or bird.  The ever active Spider Monkeys let out a series of high-pitched shrieks which sporadically turn into a hysterical frantic screaming match.  From deep in the forest the doleful Howler Monkeys bark and roar their disapproval of some irritation.  The White-faced monkeys oblivious to the presence of human observers chitter and chatter amongst themselves.  Coming from the surrounding vegetation are the chirps and cheaps of the warblers and tanagers.  But for the most part the soporific pulsating heat and the throbbing silence serve to create a languid attitude for visitors to the tropics.

Feed Me

All of a sudden the siesta is interrupted by a harsh ear-piercing screech.  Several birds of prey inhabit the area and neither the hawks nor the falcons have been blessed with a melodious call.  Commonly seen sitting at the top of the palms or on the ground are the Yellow-headed Caracaras, (Milvago chimachima).  Despite their raptorial appearance these elegant members of the falcon family are generally carrion feeders.  They can also be seen riding the backs of cattle feeding on bovine ticks.  Due to their association with cattle they are commonly seen in open pastureland.  Until 1973 they had not been recorded in Costa Rica but following widespread deforestation their distribution and geographical range spread north from Panama into Costa Rica and they can now be seen in Nicaragua.

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That nasty nasal screech was an adult Yellow-headed Caracara calling from on the ground but there was another call, similar yet more urgent.  Not too far from the adult was a newly fledged youngster that was making its first foray from the nest.  It had not yet mastered the art of flight and was demanding food from the parent bird that was watching warily over its offspring’s pitifully laborious progress hopping and jumping across the ground.  The brown speckled shabby looking youngster bore little resemblance to its sleek yellow-faced dark-browed parent standing guard over its precarious and vulnerable position.

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From Sublime to Ridiculous

Another bird seen either high or low is the Turkey Vulture, (Cathartes aura).  As you look up into the deep blue tropical sky it is likely that you will see flocks of birds soaring on the thermals.  Silhouetted against the azure background the shapes and shades circling above you will help discern the different species present.  Long thin wings bent back from the center like a Batman motive combined with a forked tail easily characterize the Magnificent Frigatebird.  A huge bird with broad, wide wings fingered at the end and divided into a monochrome white leading edge and black trailing edge leave no mistake that this is a King Vulture.  Similar in shape but uniformly dark except for grey fingered tips is the Black Vulture.  Soaring with them with the same wing form but with longer tail and complete grey trailing edge is the Turkey Vulture.

On the ground there is no mistaking the Turkey Vulture for its head bare of feathers is bright red.  Like the Yellow-headed Caracara the Turkey Vulture feeds on carrion but unlike its falcon cousin which locates food visually, the vulture has a highly developed olfactory sense and can locate the chemical signature of decomposition following the plume of molecules of death to their source hidden beneath the forest canopy.  They can often be seen beneath the palm trees feeding on the fallen palm fruit.

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Vultures are not everyone’s favorite bird but they play a vital ecological role in disposing of rotting carcasses and rubbish that won’t make to a landfill site.

Fruit and Nuts

Sitting beneath the palm trees in the company of vultures one will more often than not see Agoutis, (Dasyprocta punctata).  These large ground living rodents are related to Capybaras, Coypus, Pacas and more familiarly Guinea Pigs.  Along with the vultures they are waiting for the palm nuts to fall.  Agoutis are essentially seed eaters and have the ability to sit back on their haunches while holding the seed in their front paws which they can manipulate and turn allowing them to easily gnaw through very tough seed coats such as nuts.

At the moment there are a lot of fruits on the grapefruit tree which when ripe fall.  Eagerly awaiting this softer option dropping from above there are some Agouti individuals that pick up the sizable citrus prize in their mouths and carry it off to be eagerly consumed.  They do not eat the peel but rather the soft juicy segments inside.

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Whereas during the day vultures and Agoutis can be seen frequenting the palm trees at night it is possible to see another creature that utilizes the palms.  If you look a little more closely at what might seem like old and dropping palm fronds you will see that they will have had another force at work.  Something has nicked through the veins of the frond to be point where it folds over.  Take a look inside and there you will most likely find the culprit responsible for this chiropteran topiary – the Tent-making Bats, (Uroderma bilobatum).

The Tent-making Bats use the tents as either day roosts or night roosts.  If they are using them as a day roost there can be as many as forty bats hanging under the frond.  They regularly change the location of each roost they are using as predators would quickly figure out where to get an easy meal.  One of the commonest predators of the tent making bats are the Squirrel Monkeys.  During the day they identify which roosts are being used by the bats climb to the fronds above and then drop onto the roost.  The startled bats come fluttering from underneath where they are picked off by the monkeys.

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Currently they are being used as night roosts.  Once the sun has set the bats leave the day roosts and fly to the selected night roosts where they wait until it is very dark before they go foraging for food.  The Tent-making Bats are fruit-eating bats and use night roosts which are never more than 80 – 100 meters away from the nearest fruiting trees which in this area are figs.  The carry the figs in their mouths back to the night roosts whereupon landing they then hold the fruit between their wings, peel off the skin with the teeth and eat the pulp.  Just before the sun rises they leave the night roosts and return to the day roosts where they will pass the day sleeping.

Philip Davison is a biologist, writer and photographer based in Costa Rica.

Deadly Nectar   2 comments


Felipe del Bosque Blog August 12th 2013

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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.

Bingo

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.

www.bosquedelcabo.com

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

Mammals

  • 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

Birds

  • 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

Reptiles

  • 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

Amphibians

  • 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

Butterflies

  • 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

Plants

  • 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

 

 

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