A Gruesome End   Leave a comment


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

Life as Normal

The weather pattern has now been set for the next three or four months.  The sun shines during the day and the rain comes down at night.  At least that has been the situation over the past week and if records from previous years tell us anything then that it how things should more or less remain until September.

Life continues here irrespective of the weather conditions.  One question I am asked a lot is “What do the animals do when it is raining?”  The animal life here is adapted to living in a rain forest so what happens is that everything continues as normal.

At the moment there are large groups of White-nosed Coatis, (Nasua narica), around the grounds.  The coatis are related to raccoons and like their cousins will feed on just about anything they find whether it be grubs and land crabs that they dig out of the ground, eggs and chicks stolen from birds’ nests or simply the abundance of fruit that has fallen to the ground.  The males are solitary and I found this one engrossed in a feeding frenzy with the jack fruits that were littering the ground beneath the tree that had produced them.  He was so preoccupied with the sweet treat that my presence was of no concern.

Nasua narica Carnivora Procyonidae

White-nosed Coati, (Nasua narica)

The females are gregarious and can be found in large groups which consist of the adult females and young of varying ages.  They are a little more wary than the males and if approached will run for the cover of dense vegetation.  This week some visitors to the lodge were greeted in the early morning by White-faced Monkeys, (Cebus capuchinus), in the tree over the cabin and a large group of White-nosed Coatis on the lawn in front.  All of a sudden the monkeys went berserk, barking a frantic alarm call.  The coatis bolted for the forest. That was a bad mistake as a few moments later a female Puma, (Puma concolor), emerged carrying one of the baby coatis in her mouth.  The guests experienced mixed emotions of being both sad and thrilled at the same time.

A few weeks ago I had a fledgling male Black-throated Trogon, (Trogon rufus), land beside me as I walked through the forest.  This time it was the turn of a female.  The females are not as vividly colored as the males.  The back is a soft brown and the belly is a pale yellow although it still has the eye ring and the black and white barred tail.

Trogon rufus. Trogonidae

Black-throated Trogon, (Trogon rufus) Female

Eaten Alive

Over many years of having lived in the area there are creatures that I have seen but have never been fortunate to take a photograph of.  It may well have been that I was not carrying the camera or that the sighting was too fleeting or that the subject would not stay in one spot long enough.  For whatever the reason the result was the same, a feeling of frustration.

One such insect that had evaded me for so long was one of the most predatory hymenopterans with a gruesome life history, the Tarantula Hawk.  These are impressively large wasps and one you most certainly not want to be stung by.  The female is the predator and she is constantly on the move in search of prey for her offspring, the living flesh of a spider.  As I am walking around, I have encountered over the years, individuals that land, with the antennae and wings in constant motion.  She alights and then takes flight almost immediately giving no chance of taking a photograph.  They are distinctive in size and tend to be bluey/black in color with bright orange wings.  This one also had orange antennae.

Pepsis aquila. Hymenoptera. Pompilidae. Pepsinae.

Tarantula Hawk, (Pepsis aquila)

This week I was lucky.  I found one resting at night, immobile and easy to trap, with the intention being of photographing her the next morning.  Once the sun rose I chose a suitable spot, set up the camera and tipped her onto the log in front of the lens.  I managed to snap a few images before she warmed up, cleaned herself, climbed up the tree trunk and took to the air.

Tarantula hawks belong to the family Pompilidae which has a large number of species many of which are spider hunters.  The genus Pepsis consists of about 300 species mainly distributed throughout Central and South America.  The adults are commonly seen taking nectar from flowers.

The large size of the Tarantula hawk enable it to hunt larger prey, as the name suggest, tarantulas.  It is thought that the females are particular about the species of tarantula that they hunt.  When a female finds a victim she will touch it with her antennae, the spider has a particular chemical odor that will identify it as the unfortunate chosen one.

Having made her selection the killer wasp grabs the tarantula by the leg and attempts to turn it over so she can inflict the paralyzing sting to the underbelly.  This is not without some danger to the wasp as its large prey can occasionally reverse the role and kill the killer.  Invariably though she delivers the coup de grace and the now immobilized spider can be dragged by the wasp to the spiders own burrow, there she lays a single egg, buries the victim and leaves it to its grisly fate.  While grappling in this life or death battle with the spider, the female wasp emits a pungent odor, the scent of imminent victory, whose real function is unknown.

As if being buried alive was not dismal enough, the egg hatches and because the spider is only paralyzed, not killed, the larva begins to consume the living flesh of the spider.  Eventually, once the feast is concluded, the larva spins a silken cocoon, pupates and sometime later a new assassin will emerge and repeat the process.

I see many smaller Pompilid wasps as I walk the trials.  I have watched them catch, sting and drag Wandering Spiders, (Cuppienius spp), to a burrow in a similar fashion.  Normally they are solitary but last week I noticed a group in a collective frenzy on the forest floor.  There seemed to be something at the center of the group that had captured their attention but I could not make out what it was.  The wasps were tumbling over each other to get at the object of interest but whatever it might have been will remain a mystery.

Pompilid sp. Hymenoptera. Pompilidae. Pepsinae.

Pompilid sp Searching for Something

One final wasp that I saw last week, or rather the nest of a wasp, was the unmistakable construction of a Mud-dauber Wasp belonging to the family Sphecidae.  These wasps are found globally but only six of the known species are native to the Neotropics.  What they may lack in species diversity they make up for in numbers, they are very common.

The tubes are made from mud that the wasp has collected from damp ground and fashioned into elongated cells.  These wasps, like the two species mentioned above are spider feeders.  These ones hunt smaller spiders which are dispatched in the same fashion.  Each of the mud cells is packed with paralyzed victims upon which an egg has been laid.  When the cell is full it is sealed and the spiders are left to suffer in immobilized silence.   These cells I noticed on the side of a tree but it is not uncommon to find them on the outer walls of buildings.

Sphecidae sp. Hymenoptera. Sphecidae.

Mud-dauber Wasp Nest – Cells of Lingering Death

Nameless Wonders

The fungi continue to produce their distinctive fruiting bodies.  Some of them are very eye-catching and some of them are compelling due to their strange appearance.  The stunning yellow mushrooms were found growing from the soil beneath the bamboos.  They were large but brittle, when touched they fell over.  Mushrooms appear overnight and only last a short time as they release the fungal spores into the air.  I found the second group of fruiting bodies growing from a dead branch on the forest floor.  They look like miniature branched corals reaching up and pointing to the heavens.  They were very small but the gregarious, monochrome white-tipped black stipes certainly attracted attention.

Agaricales sp. Osa Peninsula. Costa Rica.

Unidentified Mushroom

Xylaria sp. Xylariaceae.

Candle Snuff Fungus, (Xylaria sp)

Looking But Not Seeing

Harvestmen or Daddy Long Legs are strangely fascinating creatures.  They are, along with the spiders and scorpions, arachnids.  There are approximately 5,000 species of Harvestmen in the Order: Opiliones and most of them are found in the Neotropics.  Many people are familiar with these odd-looking creatures with the small globular body suspended between eight long filamentous legs.  The pedipalps at the front of the head are small and have weak claws at the tips.  They are commonly found on tree trunks where they hunt and feed on small arthropods such as mites and springtails.  They have the undeserved reputation of being one of the most venomous animals on the planet.  There is no factual basis for that claim but once one person says it and another repeats in then it becomes a fact with no standing in reality.

Opiliones

Daddy Long-legs with Legs Covered in Mosquitoes

They would appear to be very vulnerable to predation but they do have ways of avoiding becoming a meal.  They are generally nocturnal and cryptically colored so they blend in with the background.  If physically attacked then they can drop the leg that has been caught, (appendotomy).  The leg continues to twitch serving to hold the attacker’s attention.  They also have repugnatorial glands on the body from which they release a variety of foul smelling chemicals which repel a continuing attack.  If predatory ants are on the hunt, the harvestman lifts itself as high as the legs allow and then remains motionless.  The ants will only attack if they detect motion.

Having taken the photograph and then looked at it in detail I noticed something that I had not seen when I was looking at the animal on the tree, it’s legs were being covered by what appeared to be blood-sucking mosquitoes.  Searching online I could find very few records of mosquitoes feeding on the blood of other arthropods.  Obviously the harvestman has not developed a means by which to keep these specialist predators at bay but without further investigation it may well be that the mosquitoes were simply using the legs as a place to rest.

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

Unseen Wet and Dry Daggers   2 comments


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

Dry Days, Wet Nights

The rainy season has arrived.  The initial rains were not too heavy but persistent.  Last week there was more or less constant rain all day, but light rain.  This week there have been sunny days with the rain falling at night.  For the past four days there has been only one rainy day and the night time skies have been clear and star filled.

The vegetation looks refreshed having been washed of a dry season’s worth of accumulated dust and dirt.  Verdant green is now the predominant color.  A lot of the trees are flowering and fruiting which is good news for those nectar or fruiting eating creatures.  Many of the non-native tropical ornamental plants found growing around the grounds have been planted for the beautiful floral and foliage displays they produce.  At the moment the Queen’s Crepe Myrtle, (Lagerstroemia speciosa), have the low growing crowns covered in deep lilac blooms.  That produces a sumptuous contrast to the deep green background of the forest.

Queen's Crepe Myrtle. Lythraceae. Osa Peninsula. Costa Rica.

Queen’s Crepe Myrtle, (Lagerstroemia speciosa)

The frogs have turned up at the breeding pond in reasonably large numbers.  Whereas in the dry season there are only one or two individuals of one or two species, we are now experiencing the presence of various species that have been noticeable by their absence over the past five months.  As it is only the beginning of the wet season, the intermittent dry days mixed with wet days cause nightly fluctuations in the numbers seen.  Given a few weeks then the amphibian breeding season will really take off and we will start to see large numbers of frog egg masses around the ponds.

Of course, when the number of frogs and frogs eggs increases so will the number of predators that prey upon them.  The number of Cat-eyed Snakes, (Leptodeira septentrionalis), seen around the pond at night has increased many fold.  Last week I found a small Terciopelo, (Bothrops asper), hunting small frogs in the vegetation at the pond edge.  It won’t be long before the large Terciopelos arrive to feed on the larger frogs, more particularly the giant Savage’s Thin-fingered Frog, (Leptodactylus savagei).

There were several Puma, (Puma concolor), and Ocelots, (Leopardis pardalis) caught walking past the trail cameras over the past week.  The cameras allow the lodge to monitor the presence of a great deal of wildlife, mammals more particularly, the roam the trails in the absence of people.

Colored Shelving

Frogs are not the only organism to have been stimulated into action.  The damp conditions have resulted in many fungi mycelia, which ramify throughout the soil and decaying vegetation, to produce fruiting bodies.  Most of them resemble the mushrooms and toadstools that we are familiar with at higher latitudes.  They commonly proliferate through the forests and fields with the oncome of autumn.  Here in the constantly damp conditions of a tropical rain forest you can find fungal fruiting bodies all year round, but at this time of year the sudden increase in humidity encourages a temporary reproductive burst.

Agaricales. Fungi. Costa Rica. Philip Davison

Unidentified Agaric Mushroom

Bosque del Cabo Rain Forest Lodge.

Weird and Wonderful Fungal Fruiting Bodies

In Europe and North America there is a great deal of readily available reference material to help identify mushrooms.  Here that is not the case.  But you don’t have to always put a name to something to enjoy the beauty of its color and form.  As they are relatively immobile they also make good photographic subjects.

Leucocoprinus sp

Leucocoprinus sp

Fungi are one of the vitally important constituents of the forest community and help the rain forest to function in the manner that it does.  The constant warm, damp conditions under the canopy provide an excellent incubator for fungal and bacterial action.  Although by no means are these the only two agents of decay and decomposition they are however two vitally important parts of that process.  Dead organic material rots very quickly, leaves as quickly as two weeks and fallen trees sometimes within two years.  The nutrients resulting from this rapid breakdown enter the soil but do not stay for long in the soil.  They are taken up by the vegetation almost as fast as they are produced.  Rain forest soils, apart from the top inch or so, do tend to be very nutrient poor, most the of the nutrients are above ground, locked up as part of the physical makeup of the plant life.

Fungus. Bosque del Cabo

Unidentified Fungal Fruiting Body

Many plants are rather poor at extracting nutrients from the soil.  To that affect the plant roots have a relationship with a fungal mycelium.  Quite often these relationships are specific, a certain plant species only having a relationship with its own species of fungus.  The fungal mycelium is very efficient at taking nutrients from the ground, a certain percentage of which are passed through the tree roots into the plant.  Fungi on the other hand are not photosynthetic and receive sugars produced by the plants in the reverse direction.

Sulfur shelf Fungus. Bosque del Cabo.

Sulfur Shelf Fungus, (Laetiporus sulphureus)

Not all fungi produce the familiar mushroom.  Take a close look and you will see a huge variety of other forms in the forest such as bracket fungi, cup fungi or cauliflower fungi.  They are all fascinating, not only in their life histories, but also in terms of their aesthetic qualities.

Bracket Fungus. Philip Davison.

Mysterious Bracket Fungus

Once Seen, Not Forgotten

There are some butterflies that I see throughout the year.  There are some butterflies that are seasonal.  Then there are those butterflies I only see occasionally.  Finally there are butterflies I have only ever seen once and then never again.  Many butterflies spend their adult days at the top of the canopy.  Forest edges are always a good location to find butterflies as are nectar plants in gardens.  Some butterflies are secretive and won’t venture out into the open, preferring dark secluded, undisturbed areas within the forest.

Last week I managed to find two of the occasionally seen butterflies on the same day and in the less visited areas of the forest.  Over the course of 17 years living in the area I have only found one or two individuals of these species.  I have not been able to take a decent photograph of either of them.  Last week that changed.

While walking along a forest trail, I noticed a small butterfly flitting back and forth from one plant to the next, always landing beneath the leaf, stopping for a few seconds and then taking flight once more.  I knew I had no chance of taking a photo if it continued in this manner.  I stayed still, camera ready in hand, and waited to see if it would rest for a longer period of time.  My patience was rewarded as it flew beneath a leaf in front of me and stopped.  I slowly lifted the camera to my eye and hoped that I would not disturb it.  My luck was in and it remained in position despite the flash firing so I finally managed to take a reasonable picture.

Callicore lyca. Biblidinae. Nymphalidae. Lepidoptera.

Aegina Numberwing, (Callicore lyca)

This butterfly is an Aegina Numberwing, (Callicore lyca).  The genus Callicore is restricted to Mexico, down through Central America and into South America.  They are generally found in the upper layers of the forest, typically in the subcanopy, and rarely venture down to ground level, only doing so to feed on rotten fruit.  I just happened to be in the right place at the right time to find this individual making a sortie to low levels.

Not so far along the trail a bright blue creature with a texture resembling velvet flashed past me.  By the time I noticed and looked to see what it might be, it had gone.  I continued walking and it seemed that this was to be a lucky day.  The creature, which I could now see as a butterfly, had crossed in front of me and flew over the top of low growing vegetation just a foot or so above the ground.  Once again it would not settle so I stood and watched its wandering path.  Unlike the last species, this one was briefly landing on top of the leaves.  Finally it stopped for a few moments not too far from where I was standing and I managed to capture the image.

Theorema eumenia. Theclinae. Lycaenidae. Lepidoptera.

Pale-tipped Cycadian, (Theorema eumenia)

The butterfly was a beautiful Pale-tipped Cycadian, (Theorema eumenia).  The cycadians belong in the family: Lycaenidae along with the hairstreaks.  They tend to be small butterflies and are quite often overlooked.  Had it not been for the sumptuous blue of the upper wing surfaces then I may have missed this individual.  When perched the wings are closed and the undersurface is black with pale v-shaped spots, shot through here and there with metallic blue.

One final butterfly that I managed to take a photograph of was one of the daggerwings.  This time I was out in the open in bright sunny conditions.  The gravel path was still damp from the previous night’s rain and in several spots there were rapidly drying puddles.  Many butterflies like to visit damp ground to engage in mudpuddling where they imbibe nutrient rich moisture.  That does not happen much in this area but one group of butterflies I do see indulging themselves in this way are the daggerwings of the genus Marpesia.

Marpesia alcibiades. Biblidinae. Nymphalidae. Lepidoptera.

Alcibiades Daggerwing, (Maresia alcibiades)

There are six species of Marpesia I find here, some more frequently than others.  The name reveals the distinctive feature, the tip of the hindwing has a long drawn out dagger-like extension.  Daggerwings are found in North, Central and South America as well as the Caribbean Islands.  This species is Marpesia alcibiades.  It is rarely recorded in the wild but that may be due to the fact that it is easily mistaken for several other similar looking species.  Here I found myself faced with a choice of five individuals at my feet.  I ended up on my belly lying prone on the ground to get the shot.  That fills another blank space in the collection.

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

Mysteries of the Natural World   Leave a comment


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

Frog Chorus

The week has been dry and sunny but with the clouds progressively becoming a more frequent feature.  Increasingly the skies are becoming overcast and the azure blue of the dry season has been replaced by a blanket of grey.  The sun manages to peep through for a while but then is lost once more behind an obscuring haze, only the faint outline of its orange disc visible to the naked eye.

The amphibian population is gathered and ready for the real rains to begin.  There are more male frogs setting up territories at each location around the pond.  The Savage’s Thin-fingered frog and the Marine Toads prefer the pond edge.  The Banana Frogs and the Small-headed Frogs situate themselves on the vegetation floating on the water.  A little higher up the Milky Frogs have taken up their positions on the upper surfaces of the leaves overhanging the water.  Finally the Red-eyed Green Tree Frogs can be heard calling from nearer the tops of the vegetation.  When the rains do arrive, with the typical early May deluges, the activity around the pond will increase exponentially.  More species will arrive, particularly the ones that reproduce directly in the water.  It is just a matter of time.

Red-eyed Green Tree Frog. Hylidae. Phyllomedusinae.

Red-eyed Green Tree Frog, (Agalychnis callidryas). Male. Calling.

Skipping Over Marked Metal

Butterflies exhibit a variety of dimorphisms.  They may be sexually dimorphic, strongly or otherwise, males and females may look like completely different species. They maybe seasonally dimorphic, wet season forms differing from dry season forms.  They may be geographically polymorphic with one species varying in size, color and markings over a wide geographical range to the point where you would once again think you were looking at totally different species.

One of the more commonly seen riodinids, or metalmark butterflies, in the forests of Bosque del Cabo is Metacharis victrix.  I regularly see the fiery orange females but not so often the males which are much more of a deep brick red.  They have the frustrating habit of perching on the underside of leaves so to capture the image you have to get on the ground, lie on your back and point the camera upwards.

Metacharis victrix. Riodinidae. Riodininae

Metacharis victrix. Male.

They are frequently found in bright understory light gaps.  The larval food plant is any one of the Heisteria species of which, Heisteria accuminata, is very abundant in this area.

Heisteria accuminata. Olacacea

Heisteria accuminata. Fruit

The skippers are a difficult family of butterflies to identify too.  A great many of them are very small, sometimes no bigger than an adult human fingernail.  To add to the problem of identity, there are so many of them and they quite often they are muted shades of brown.  It does take a certain level of expertise to identify them to species level.

Last week I had one land close to me and fortunately stay still.  Skippers are prone to taking flight at the slightest disturbance and are also averse to the camera flash going off.  This individual was the Perching Saliana (Saliana esperi).  The earthy brown of the hindwing underside has a contrasting creamy flash.  There are two pale windows in the dark half of the wing.

Perching Saliana. Hesperiidae. Hesperiinae.

Perching Saliana, (Saliana esperi)

It’s a Mystery

As much as I would love to study moths as well as butterflies, time does not allow this luxury.   There are up 14,000 species of butterfly and moth in Costa Rica, the majority being moths.  Many of the moths we have no idea of their life histories.  So when a moth does turn up that I can take a photograph of, if I cannot arrive at an identity then I do not fret over the fact, I just enjoy it for what it is, a beautiful thing to behold.

Unidentified Moth. Philip Davison.

Unidentified Moth

Actually that holds true for many insects.  Costa Rica has an estimated 365,000 named species of insects within its territory, that is 1,000 species for every day of the year, which would require exceptional identification skills.  Identity to species level is best left in the hands of those who specialize in a particular group.  I found a stinkbug sitting on a leaf that made a wonderful subject but I have not been able to name it to species level.

Stinkbug. Hemiptera. Heteroptera.

Unidentified Stinkbug

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

Sisters Singing to Ruffled Youth   Leave a comment


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

Frog Chorus

Once again there have been several nights of rain over the past week.  It won’t be long before the rains become the norm and we move into seven months of the wet season.  The frogs have responded by turning up en masse.  The initial explosive Milky Frog, (Trachycephala venulosa), breeding period will reach an early peak and then they will disappear for the next eleven months, hidden out of sight deep in the vegetation and tree tops.  Throughout the dry season there have been the persistent calls of one or two Banana Frogs, (Dendropsophus ebreccatus).  The calls were in vain as no females were present to respond to them.  Now, however, over the past week many more males have turned up, each one setting up its territory on a seperate Water Hyacinth leaf.  The females have also turned up so the leaves should be covered in egg masses before too long.  Up in the tree tops the forlorn calls of one or two Red-eyed Green Tree Frogs, (Agalychnis callydryas), has turned into a chorus and I have already witnessed several egg laying episodes.  Another frog that has not been heard throughout the dry season turned up at the pond, the Small-headed Frog, (Dendropsophus microcephala).  At first glance it looks like a Banana Frog but it has a yellow line that runs down its sides and lacks the small bright yellow patch beneath the eye on the top jaw that is so distinctive of the Banana lookalike.

Small-headed Frog. Hylidae. Hylinae. Osa Peninsula. Costa Rica.

Small-headed Frog, (Dendropsophus microcephalus). Male.

Finding Rare Sisters

As the amphibian numbers increase, so do the butterfly numbers decrease.  There are still plenty around both in terms of individuals and species but over the next few months these will disappear and dwindle to only occasional sightings.  One butterfly I managed to get a photograph of this week was the Boeotia Sister, (Adelpha boeotia).

Boeotia Sister. Philip Davison.

Boeotia Sister, (Adelpha boeotia)

The genus: Adelpha, commonly known as the “Sisters”, is a notoriously difficult group to identify to species level.  The features distinguishing each species need to be seen in detail and that is generally only possible if they are at rest and that never seemingly is the case, they are very active, always on the wing.  Of course some are more distinct than others and when you are familiar with the species in your area that helps too.  A common feature of the genus is the white band traversing the dorsal surface of the wings which may extend over both wings or be replaced to a greater or lesser extent on the forewing by orange.  There are thirty species in Costa Rica and they are found in almost all terrestrial habitats.  They never occur in large numbers.  The adults feed on rotting fruit and I was lucky enough to find this individual on the ground feeding from fallen fermenting figs.

Disheveled Youth

On my day out walking the butterfly transect, as I returned across the bridge a juvenile Black-throated Trogon, (Trogon rufus), landed right beside my head.  The bridge traverses a ravine running through the canopy.  At this point you are essentially at the top of the trees.  The trogon looked just newly fledged.  Unfortunately I had a macro lens attached to the front of the camera which was set to photograph butterflies at close range.  I couldn’t miss the opportunity being presented though and with no time to change anything I just lifted the camera and pressed the shutter button.  As the flash went off, the young bird took to the air and disappeared.  But I did at least get one photo.

Black-throated Trogon. Felipe del Bosque. Bosque del Cabo.

Black-throated Trogon, (Trogon rufus). Juvenile

The trogons are fairly sedentary birds.  The male and female can normally be found very close to one another so if you find one then the other will not be too far away.  The plumage can be quite spectacular with the males being brighter than the softer colored females.  The Black-throated Trogon male has a bright metallic green head, back and upper chest.  The belly is bright yellow and of course it has the black throat after which it is named.  The bill is bright yellow and it has a blue eye ring.  The call is a soft trilling sound.  They feed on small fruits and insects.

Flower to Fruit

Some of the fruit trees around the grounds have been coming into flower over the last week.  Guavas, (Psidium gaujava), are native to Costa Rica but are cultivated all over the world.  They flower and fruit several times over the course of the year.  The white flowers are found singly and have a faint perfume.  Later the fruits appear.  They are green with a sweet pink flesh inside which contains the seeds.

Guava. Bosque del Cabo.

Guava, (Psidium guajava) Flower

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

Posted April 24, 2017 by felipedelbosque in Uncategorized

Nuts For Giant Green Flags   1 comment


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

Being Yellow and Burning Nuts

Walking along the trails through the forest can sometimes be a visual feast in terms of animal sightings but at other times you may encounter very little at all.  The air is very still and so there is quite often no sound of rustling leaves as when blown in a breeze.  The temperatures are high, not as high as at the top of the canopy, but high enough to make someone more familiar with cooler climes to break into a sweat at the slightest exertion.  The stifling silence maybe permeated by the white noise of calling insects.

At the moment there are many trees in bloom.  The Nance trees, (Byrsonima crassifolia), are currently covered in bright yellow flowers which change to orange after they have been pollinated.  The Nance flowers attract a lot of bees, particularly species of stingless bees native to the area.  Several months from now the trees will bear huge numbers of the small yellow-skinned fruits that are consumed not only by a large number of animals but people too.  The taste is unique and the fruits can be eaten raw or prepared as a dessert or as a refreshing drink.

Nance. Malpighiaceae. Bosque del Cabo. Osa Peninsula. Costa Rica.

Nance, (Byrsonima crassifolia)

One tree that has been flowering for the past month or so and is now producing fruit is the Cashew, (Anacardium occidentale).  It has distinctive large red pear-like fruits beneath which the nut is suspended.  The fruity looking object is the swollen meristem of the actual fruit which is the nut itself.  It is known as the Cashew Apple or Maranon.  This you can eat without concern.  As with the Nance, the flavor is unique.  It can linger for some time at the back of the mouth before fading away.  The nuts are to be treated with a great deal more caution.  Cashew belongs to the same family of plants as poison ivy, Anacardiaceae.  The skin of the nut contains the volatile oil Cardol, which can cause severe blistering when in contact with the skin and more dangerously a burning of the eyes.  Cashew nuts must be roasted or blanched to eliminate the oils.  Even then the utmost caution has to be exercised as the oils can seriously damage the respiratory system, many people who work in the Cashew industry suffer very severe respiratory problems.

Cashew. Anacardiaceae. Philip Davison.

Cashew, (Anacardium occidentale)

While I was looking at the unripe green cashews I noticed another species of Leaf-legged Bug, (Family: Coreidae), that I had not seen before.  A search through the literature would only provide me with the Genus: Acanthocephala.  I have photographed several species in this genus but cannot get them any more specific than that.  This one was feeding on the unripe cashew apple by sticking the dagger-like mouthparts into the flesh and sucking up the juice.

Leaf-legged Bug. Hemiptera. Heteroptera. Coreidae. Bosque del Cabo.

Leaf-legged Bug, (Acanthocephala sp)

Seen As Green With Orange Flags

From here and there bird calls drawn your attention to the distance.  You become attuned to the slight rustles down by your feet.  Further investigation reveals a lizard, one of the whiptails perhaps, scurrying off through dry leaf litter.  Beside you there is a faint buzzing sound, a high-pitched hum.  It is a hummingbird, its wings a blur, coming to scrutinize a piece of red clothing you are wearing.  As far as the bird is concerned this could be a fresh bloom brimming with nectar but no such luck and off it goes.

As I was walking through the forest a quick flash of bright orange caught my eye near the ground.  A male Golfo Dulce Anolis Lizard, (Anolis osae), was displaying to a female.  He catches her attention and tries to gain her favor by flying a bright fiery orange flag, a dewlap, which is a loose piece of skin beneath his chin.  It is supported by a thin rod of cartilage which is attached to the front of the jaw and over which he has muscular control.  The more splendid the dewlap, the better his genetic make-up and the more desirable he will be to father her offspring.  The female is a similar size but lacks the dewlap and has a series of dark diamonds down her back.

Golfo Dulce Anolis. Reptilia. Squamata. Sauria. Polychrotidae.

Golfo Dulce Anolis, (Anolis osae). Male.

Golfo Dulce Anolis. Bosque del Cabo

Golfo Dulce Anolis, (Anolis osae). Female.

While I was lying on the ground photographing the lizards I saw a tiny metallic green fleck moving around.  The movement was jerky as the fleck hopped from one dead twiglet to another.  There was no mistaking that form of movement, it was a jumping spider.  Many of the jumping spiders are minute.  Unless you were looking for them or are familiar with their body movements then it is so easy to miss them.  That would be a shame as they are fascinating little creatures.

Jumping Spider. Araneae.

Unidentified Jumping Spider, (Salticidae). Anterior Eyes.

Normally jumping spiders are inclined to turn and look at you.  This one seemed to be distracted by something else and continually kept its gaze in the opposite direction to me so I could only really photograph its back.  For a fleeting moment it turned to look at me and I managed to get a shot of the huge anterior eyes that the spider relies upon for seeing the prey item that it will actively hunt down.

Salticidae. Osa Peninsula. Philip Davison

Unidentified Jumping Spider, (Salticidae). Dorsal View.

Pussyfooting Around

Mammals, despite their sometimes large size, are notoriously difficult to find.  Monkeys, when active, can make a large amount of noise as they crash through the trees.  They can also be quite vocal.  Coatis and agoutis on the forest floor can be detected b their movement.  Coatis tend to huff and puff a lot as the females with juveniles constantly sniff out any consumable morsel lying in their path.  Agoutis and squirrels can be heard gnawing their way through the shells of various fruit and nuts that form the bulk of their diet.

Cats on the other hand are largely silent.  They are masters of stealth.  Over the past week I have captured videos of an Ocelot walking the Titi Trail.  One of the guests at the lodge crossed the path of a Puma on three different occasions over the last few days.  On one instance the Puma was lying across the trail in front of her and had no desire to move.  She slowly backed away while always facing the cat and finally headed off in a different direction.  The cat could have cared less.  The next day she came across the cat walking down the trail in front of her.  A few days ago the Spider Monkeys were shrieking their cat-specific alarm call and sure enough one the guests staying in the Tropical Garden was lucky enough to see the Puma walking through the forest behind his cabin.

Deceptive Green Stripes and Giant False Bats

The forests, fields, hedgerows and gardens are normally filled with butterflies this time of year and that has been the case.  One distinctive Lepidopteran that has been around in very large numbers over the past month is the Green Urania, (Urania fulgens).  Its striking soot black wings striped with bright metallic green bands make it look so much like one of the swallowtail butterflies that people are surprised when they cannot find it in the butterfly guide books.  It is, in fact, a migratory day-flying moth.

When walking down the forest trails at this time of year people are also fooled by yet another moth.  This moth is so large that it is when it is spooked and takes to the air, its huge wingspan and flapping flight lead people that they are looking at a bat.  This is the largest species of Lepidopteran on the planet, the White Witch Moth, (Thysania agrippina).  If you have the good fortune to see it land you will notice that it orientates itself with the wings up and down.  The light grey ground color of the wings now display in this vertically inclined position darker wavy, zig-zag markings, which if the moth has landed on a pale barked tree, render it almost impossible to see as they resemble crevices in the bark.  Despite they are reasonably common moths throughout Central and South America, very little is known of their life history.

White Witch Moth. Erebidae

White Witch Moth, (Thysania agrippina)

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

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

How to Shoot Butterflies   Leave a comment


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

Shooting Butterflies

Over the course of seventeen years monitoring butterfly populations on the grounds of Bosque del Cabo Rain Forest Lodge, I have inventoried just under 400 species of butterfly.  Most butterflies spend their days as adults at the top of the trees where it is a little difficult to see them so the species I have observed have been at ground level.  Many species I have only seen once and then never again so they have been fortuitous sightings.  It may not be that the butterflies are rare but rather, for whatever reason, found themselves fleetingly making their way from the canopy to ground level.

Most of my monitoring takes place at forest edges which essentially is where the forest canopy comes to the ground.  I do have trails that take me through the forest but the incidence of sightings is much lower here.  Also, the open areas and gardens are always a good place to see butterflies and the opportunity of seeing more species and individuals is increased if there are patches of nectar producing plants to entice them to hang around.

Many butterflies do not seem to land and can be seen on the wing but always fluttering by. Those that do land, once warmed by the sun do not stay in one place for more than a fleeting second or two.  Their wings are constantly moving and after a quick sip of nectar and a few strong wingbeats they are airborne again.

Given the above, when it comes to photographing butterflies there are several problems to overcome.  Butterflies respond to movement and color.  It is rarely that they will stay perched if you are moving in a quick and jerky manner, that is behavior guaranteed to affect their departure.  Nor do they like being chased.  So many people say to me, “I chased the butterfly everywhere but it would not settle”.  There is little chance of obtaining an image if you are pursuing your subject.  The best course of action is to observe the creature’s behavior, to know your subject.

Many of the longwings feed on the nectar of Lantana camara.  Set yourself up, preferably with a tripod but you can do it handheld, and keep the camera focused on one particular bloom.  As long as all of your settings are correct, as soon as the butterfly lands just press the shutter release.  Earlier in the morning is best as the butterflies are not so warmed up at that time and tend to stay still for longer.  Also, the sun is not as fierce as midday so you don’t have to fight bright light and strong contrast.

Inside the forest beneath the canopy there is a different set of problems.  Here the light levels are low and many of the forest species fly close to the ground.  A lot of the species here will be Satyrs and they don’t have the bright, gaudy poster colors of the species that favor open areas.  Here the colors are from a palette rich in earthy browns, ochres and grays.  However, upon close scrutiny you will find that nature has blended this collection of more subdued tones into an array of wonderfully subtle patterns that give the almost feeling of deep rich velvet textures or the appearance of a miniature intricately woven Persian rug.

The problem now faced by the photographer who wants to fill the frame with image is one of gradually lowering yourself to ground level and slowly sneaking up on your belly to get close enough to capture every minute detail.  It can be done but patience is a virtue here.

I always keep the settings on the camera more or less the same.  The shutter speed I keep at 1/30 sec if I am using the camera hand-held unless I am photographing skippers, which tend to react very quickly to flash, in which case I will use anything from 1/150 to 1/200 of a second.  The ISO is set to automatic but not to exceed 400.  The f-stop is the only one I change.  For the butterflies I use a 105 mm macro lens.  If using a tripod, I use manual settings.  If carrying the camera in my hand I use autofocus settings.  I start off taking a shot at f13 and if the subject stays still then I decrease the aperture through f16, f22 and finally f32.  Each time I have to slightly increase the flash by several stops.  If everything works out right and I have a little bit of luck then I can usually get the shot, not always, but a large percentage of the time it does work.

Old and New

Last week when I was out conducting my weekly butterfly counts I managed to get a few photographs.  I only carry the camera when I am doing my research lest I should see a species I cannot identify or an opportunity presents itself to capture a subject that lends itself to an easy shot.  I do not go with the intention of photographing any particular subject as I have no time while walking a timed transect, it has to be quick and easy.

It was lucky that I had the camera with me because I found two species I had not seen before and I needed to see the less than obvious patterning.  The first was a metalmark, family, Riodinidae which flew past me along the forest edge.  These tend to be small butterflies and you quite often have to see smaller diagnostic details to know what you have.  This one was pale blue dorsally when it flew but when it landed the underside of the wings were a drab yellow color with white ovals centered with a black spot.  What I had found was a Blue-based Theope, (Theope virgilius).  There are seventeen species of Theope recognized in Costa Rica, they are by no means common and are very hard to identify.  Luckily I managed some good shots of this individual.

Blue-based Theope. Riodinidae. Felipe del Bosque.

Blue-based Theope

Later that same morning while walking this time on a trail through secondary forest, a small black and white butterfly kept alighting on leaves close to the ground and all the while constantly opened and closed its wings.  So here was a challenge.  I had to get close enough and I also had to make sure I synchronized hitting the shutter button while the wings were open.  Not only did I manage that but then I rolled over on my side at an awkward angle to get a photo of the under-surface while the wings were closed.  Searching through the reference material later that day I was pleased to find that this was the second new record for the area in one morning.  This one was Catilia ofelia, a nymphalid in the subfamily: Nymphalinae.  It is found widespread throughout Central America but is not often seen.  Like so many Neotropical butterflies very little is known about its life-history.

Castilia ofelia. Bosque del Cabo Rain Forest Lodge.

Castilia ofelia

Castilia ofelia. Nymphalidae. Osa Peninsula. Costa Rica.

Castilia ofelia – underwing

As the day progressed I saw a large number of different species, after all this time of year is the peak of butterfly activity.  The sad situation is that over the course of the past seventeen years then the number of both adults and species has declined in a linear fashion year by year.  On the trail through secondary forest I found, at different locations, three species that I had seen many times previously that stayed perched long enough for me to get the shots.

The Orange-rimmed Owl-Butterfly, (Catoblepia orgetorix), is one of the owl butterflies, related to the morphos.  They have a habit of resting head up on the trunks of trees.  This species has two distinct large eye spots on the underside of the hind-wing.  These butterflies have no toxic defense and rely on the fact that they fly in dark, shady areas and more particularly at dusk.  The wings are easily torn and any predator, whether it be a lizard or bird, will strike at the false eyes and only be rewarded with a tatty piece of wing membrane which you can see has already happened to this individual.  The literature cites this as an Atlantic species only but it is not uncommon to find it in the forests of Bosque del Cabo.

Orange-rimmed Owl-Butterfly. Morphinae. Bosque del Cabo.

Orange-rimmed Owl-Butterfly, (Catoblepia orgetorix)

Another butterfly to be found commonly perched, this time head down, on tree trunks is the Dirce’s Beauty, (Colobura dirce).   There is only one species within the genus Colobura.  The underside of the wings have a very obvious pale and dark striping with a broad cream band.  A closer look reveals quite a fabulous abstraction of patterns and color.  It is a widespread species occurring extensively throughout Central and South America.  This is a reflection of its larval host plant, Cecropia of which there are many species.  It is one of the butterflies that will readily land on you to imbibe sweat from your skin.

Dirce's Beauty. Nymphalidae. Philip Davison

Dirce’s Beauty, (Colobura dirce)

Cattleheart butterflies are not always easy to identify when flying.  With time the different species in an area can be distinguished one from the other but it always helps if they land which they rarely do.  Most of them have a pattern of red blocks on the underside of the hindwing and a yellow bar across the underside of the forewing.  The difference in these features is sometimes very subtle.  The similarity of the species and the exhibition of aposematic or warning coloration suggest that they are toxic to eat and are members of a Mullerian mimicry complex – where all co-mimics of toxic species closely resemble each other.  I only ever see Parides species flying in the forest, never in the gardens.  From the features I could not clearly see that I was photographing a Green-celled Cattleheart, (Parides childrenae).

Green-celled Cattleheart. Osa Peninsula.

Green-celled Cattleheart, (Parides childrenae)

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