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, (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, (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.
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, (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, (Psidium guajava) Flower
Philip Davison Is a Biologist, Writer and Photographer Based in Costa Rica
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, (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, (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, (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, (Anolis osae). Male.
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.
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.
Unidentified Jumping Spider, (Salticidae). Dorsal View.
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, (Thysania agrippina)
Philip Davison Is a Biologist, Writer and Photographer Based in Costa Rica
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, (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, (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, (Iguana iguana)
Philip Davison Is a Biologist, Writer and Photographer Based in Costa Rica
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.
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 – 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, (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, (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, (Parides childrenae)
Philip Davison Is a Biologist, Writer and Photographer Based in Costa Rica
The dry season continues unrelentingly. The daytime temperatures are still hitting the 100⁰F, (40⁰C), mark. There was a fleeting downpour one lunchtime that lasted little more than an hour. That same evening, with the momentary increase in humidity as the ground remained damp, the Halloween Land Crabs responded by emerging from their burrows in large numbers. The following night however they were once again noticeable by their absence as whatever precipitation had fallen once again evaporated and the bone-dry situation persisted.
The gardens are visibly showing signs due the effects of the extreme heat and arid conditions. The lawns are now more or less devoid of any greenery, all that exists is a broad area of parched brown burnt grass. The herbaceous plants are suffering too. Many of them have lost leaves and if they have not fallen over and died then they are most certainly looking limp and in distress. They will have to wait for a while yet for any relief as the rains do not normally start until mid-April or May.
Many of the creatures I photograph are found serendipitously. I rarely go out to photograph something specific unless it is a plant or animal that I have seen while out walking that I think will remain in place until I return with the camera. The weekly blog is written from the point of view of accidental discovery. I never know what I am going to write about until I find it.
This week I came across two different species of bugs on the same day. One was a Big-legged Bug of the family: Coreidae and the other was a stinkbug nymph of the family: Pentatomidae. The term big-legged bug perfectly describes these heteropterans. The femur of the rear legs is stout and bear spike-like projections. The tibia is flattened. They are herbivores and can sometimes become a pest feeding in large numbers on crops. This individual belongs in the genus: Acanthocephala but I am not sure of the species. There are twenty-four named species of Acanthocephala of which seven species live in Central America.
Big-legged Bug, (Acanthocephala sp)
The stinkbugs are named after their ability to produce a repugnant smelling secretion from glands in the abdomen. They are sometimes called shield bugs due to the body shape. I found this particular species in the nymphal stage. There were several of them living gregariously together sucking sap from the leaves of a passion vine. The stinkbugs go through five nymphal stages before becoming adults.
Stinkbug, (Family; Pentatomidae)
Flower and Fruit
The Guacima tree, (Gauzuma ulmifolia), is found growing at the forest edges here at Bosque. It is easy to miss the flowers but the fruits are more visible. Currently they are lying all over the ground in the areas where the trees are growing. The fruits are very hard and are only occasionally fed upon by White=faced Monkey. The tree is more commonly found growing along roadsides where livestock feed on the fallen fruits.
Guacima, (Guazuma ulmifolia). Fruit.
A tree that is flowering throughout the forest at the minute is the Jacaranda, (Jacaranda copaia). The bright lilac-colored bell-shaped flowers are covering large areas of the forest floor like a violet carpet. Jacaranda as well as Guacima are both native to Central America.
Jacaranda, (Jacaranda copaia). Flower
The Mayo Trees, (Vochysia ferruginea), have started to flower. The crowns of the mature trees in the canopy are covered in an umbrella of bright yellow. The Mayo Trees are so named because they supposedly flower in Mayo but that has not been my experience in the last seventeen years of living in Costa Rica. Soon the canopy will be awash with patches of bright pastel colors like a giant watercolor painting.
Philip Davison Is a Biologist, Writer and Photographer Based in Costa Rica
No change in the weather this week. We have had another seven days of hot, sunny weather. There were two days when the clouds had formed and the sky remained overcast but no rain resulted although the temperatures plummeted from 104⁰F to 96⁰F.
The butterfly numbers are increasing but still way below what would be expected for this time of year which is normally the peak of butterfly activity. Around the pond at night, the Savage’s Thin-fingered Frogs are starting to gather in greater numbers. The pond is the last remaining damp area on site. The flowering period for many of the trees has finished and now some of them have started fruiting.
The major excitement this week has been the presence of a female Puma, (Puma concolor). She had been seen in several different locations around the grounds. The high-pitched barking alarm call of the Spider Monkeys is always an indication of where the cat is passing by. One day, as the sun was setting, the alarm calls of agitated monkeys and agoutis started the fill the air. The cat was on the prowl.
She left the cover of the forest and walked through an open garden. That is where I spotted her. She was in no hurry and it was patently obvious that she could see me. She crossed the driveway and made her way into some dense vegetation. The monkeys settling down in that area for the evening were suddenly stirred into action and more alarm calls began to build eventually reaching a fever pitch.
She emerged from the tangle of dense vegetation and slowly walked toward the edge of the cliff overlooking the ocean. An Agouti that was in the same vicinity saw the cat, let out a loud shriek and ran off with its hair stood on end. The cat immediately looked alert but then just as quickly lost interest. She sat down and started to clean herself before lying down for a few minutes. She then rose to her feet, turned her back on me and walked off into the rapidly darkening forest.
There was another predator that I managed to get very close to this week. Very close. While I was out conducting my butterfly counts I found a juvenile Broad-winged Hawk, (Buteo platypterus), sitting on a low cut tree stump on a trail through an open area of forest. It was an ideal opportunity to take a photo. I fully expected the bird to take off and fly away but it remained where it was and just looked at me. I approached closer and closer but very slowly, each time taking a photo. Eventually I ended up lying on the ground within touching distance but the bird never even flinched. I kept a wary eye to my surroundings as it was not beyond the possibility that the parent birds would be keeping watch and attack should I get too close but nothing happened.
Juvenile Broad-winged Hawk, (Buteo platypterus)
Broad-winged Hawks are migratory throughout North, Central and South America. They tend to hunt in the understory of the forest from where they swoop down and take small rodents and lizards from the ground. The broad wings and short tail are a good visual identification feature.
Close up of Juvenile Broad-winged Hawk, (Buteo platypterus)
A New Passion For Flags
Along the forest trails there are several species of Passion Vine currently in flower but this week I found one species that I had never seen before. I returned with the camera and took photos for the record and to identify this new species. –
There are sixteen species of Passion Vine to be found in the forests of the Osa Peninsula. One is seen throughout the year at Bosque del Cabo Rain Forest Lodge, the Scarlet Passion Vine, (Passiflora vitifolia). It is hard to miss the bright red flowers suspended on thin, fleshy, green stems that grow up from the ground and entwine the vegetation. Two others flower only occasionally.
The new species, Passiflora pittieri, is normally found in primary forest but at the top of the canopy or in light gaps. The flower is very distinctive with its pale cream petals and a corona of yellow-tipped orange filaments and pink-flushed anthers. This one appears to be insect pollinated as I could see bees visiting the blooms.
The leaves of this species are highly cyanogenic. When physically damaged they release cyanide which would normally deter most creatures from eating them. But where there is a system then there is a way round the system. There are many species of longwing butterfly the larvae of which feed on the leaves of various species of passion vine. The larvae have an enzyme that allow them to sequester the cyanide molecule and use it in turn as a toxic defense. The caterpillars can only eat the young leaves as the older leaves will have become too unpalatable.
Cydno Longwing, (Heliconius cydno)
Sapho Longwing, (Heliconius sapho)
Another insect associated with passion flowers are the flag-legged bugs. These phytophagous, or leaf-eating, members of the Order: Hemiptera, Su
border: Heteroptera and Family: Coreidae can usually be found clustered around the flowers of passion vine. Their rearmost legs have a large expanded flat and colored section.
Flag-legged Bug, (Anisoscelis flavolineata)
Flag-legged Bug, (Coreidae sp)
If a predator approaches a Flag-legged Bug, then the insect will wave one of its two brightly colored expanded rear legs. This provides a target for the attacker which will end up with little more than a leg for its efforts while the bug will have flown away. Many Flag-legged Bugs will be observed with either one or both rear legs missing.
The Pit of no Escape
This time of year with the ground having become very dry and friable, there are many small crater-like pits that have appeared all over the trails. It would appear as if a miniature meteor storm had hit the area. Further investigation, more particularly by disturbing the sides of the crater wall, will result in small grains of sand erupting upwards towards the source of the disturbance. Buried and hidden at the bottom of the pit is a larva of an insect closely related to Lacewings and Owlflies, the Antlion, and it is this larva which is responsible for throwing the sand grains.
Antlion, (Myrmelon sp), Pit
The Antlions belong to the Family: Myrmeleotidae within the Order: Neuroptera. Only antlions of the Genus: Myrmelon create the pits. The larva excavates the steep-sided pit and places itself at the bottom, just beneath the surface and covers itself with the fine sand. They don’t just feed on ants, any small insect venturing within the crater rim will find itself struggling to leave. The more it struggles to climb out, the more loose material it will dislodge causing it to slip towards the bottom. The predatory larva lying in wait will now begin its performance of death to bring down the final curtain on the life of its victim.
Mandibles of Antlion, (Myrmelon sp), Larva Grabbing Hapless Ant
Using the front legs the larval antlion flicks sand up at the ant desperately trying to escape the steep sided crater. This serves to drag it further down towards the bottom of the pit. When it finally slips all the way down, then the mandibles of the larva snap shut around the prey’s body. This is what I was observing. The unfortunate ant was struggling to escape the deadly grip of the mandibles but to no avail. Sharp projections on the inside of the mandibles pierce the ants body and the larva sucks the juice out of the ant. Once it has finished the remaining dry and drained carcass is flicked out of the pit while the larva awaits a fresh potential food item to enter.
Philip Davison Is a Biologist, Writer and Photographer Based in Costa Rica
Last week continued to be hot and sunny. There was not a drop of rain. The trails through the forest are now becoming heavily cracked. The lawns around the lodge are definitely more brown than green. The forest however remains vibrant, there is no sign of drought stress. The huge volume of water that fell as rain last November has ensured that the creek is still running quite well, more so than would be expected for this time of year. The dry season is typically when a lot of leaf fall occurs. That is the case at the moment. The trails are cleared and a few days later there is a layer dry, brittle brown leaf covering the path once more. Some of the trees that have been in bloom over recent weeks are coming to the end of the flowering period.
The Forest Floor is Rapidly Drying and Cracking Up.
Brushing Toxic Hair
Although I spend my days monitoring butterfly populations and see plenty of the adults flying around, it is only very occasionally that I see the larvae or caterpillars. It may well be that because I am not actively searching for them that I am not seeing them. There are over 7,000 named species of butterfly in the Neotropics and that number is dwarfed by the number of moth species. Many butterflies and even more moths have unknown life histories. Quite often we don’t know what the larval form looks like or what host plant they feed on.
Unidentified Moth Caterpillar
Caterpillars are the feeding and growing period of the butterfly or moth life cycle. Feed and grow they do and at an amazing rate. Caterpillars are quite often restricted to feeding on a single species of plant, sometimes on a few species within one genus or sometimes several species in the same family. Each species does not have a large variety of choices. After hatching from the egg, the caterpillar can increase in size by over a hundred times before it pupates.
Being a large, constantly and rapidly growing creature, the caterpillar has to remain unseen by predators or if seen, then has to have a secondary range of defenses such as irritating spines or hairs or to feed on plants poisonous to other creatures, store the toxins within its own tissues and warn off potential predators with bright warning, (aposomatic), coloration.
Over recent weeks I have stumbled across several caterpillars as I was out walking around the forests of the Osa Peninsula. I was not looking for them, they just happened to catch my eye. Any caterpillar sporting a battery of spines or hairs is one that you should avoid handling. The spines and hairs may exude toxin secretions that can cause intense irritation.
Saddleback Moth, (Acharia hyperoche), Caterpillar.
The caterpillar of the Saddleback Moth, (Acharia hyperoche), usually hides on the underside of the palm leaves on which it is feeding. It has green coloration that helps it blend in with its background. The saddle marking may help to break up its outline. If the ruse does not work and it is spotted by a keen-eyed predator, then it has a second line of defense. The body anterior, posterior, laterally and dorsally has fleshy protuberances that carry batteries of sharp urticating spines. The slightest brush against this living, toxic slug-like creature will result in a red itchy rash and a certain degree of pain. Many other species of moth in the same family, Limacodidae, are protected in the same fashion.
Unidentified Limacodidae species.
Another group of species which belong to the Silkmoth family, Saturniidae, more particularly of the subfamily, Hemileucinae and the genus Automeris also have caterpillars which protect themselves in a similar fashion. The body is green and quite literally covered in urticating bristles. The adult Automeris moths are very distinctive too. The dorsal surface of the forewings are colored and patterned to resemble dead leaves. Should anything disturb these particular leaves though they are in for a shock. The forewings swing forward which reveals two large eye-spots on the dorsal surface of the hindwings. As far as the predator is concerned it could well be looking at a much larger predator staring back at it from the ground.
Automeris sp. Caterpillar
Automeris sp. Adult.
Sometimes it may prove prudent to let a potential predator know that you are likely to cause them harm when touched. Some of the Dagger Moths, (Acronicta spp), caterpillars are covered in long lemon yellow hairs with contrasting black tufts. If touched these hairs can break and become embedded in the skin. The longer black hairs are attached to a gland than secretes a toxin that will leave a nasty little rash on human skin.
Dagger Moth sp. Caterpillar.
As well as the finding of caterpillars is difficult, then locating the chrysalis’s is equally, if not more, challenging. Admittedly I don’t go looking for them and so if I do discover one then it is entirely by chance. The one species that I find more than others is the Narrow-banded Owl-butterfly, (Opsiphanes tamarindi). That may be due to the fact that the larvae feed on Heliconia, Maranta and Bananas of which there are many plants around the bar and restaurant areas of Bosque del Cabo. A chrysalis has little by way to defend itself and so crypsis might be the best option. Green coloration is a good way of camouflaging yourself against a background of green vegetation. This one I noticed hanging from the underside of a leaf beside the bar.
Narrow-banded Owl-butterfly, (Opsiphanes tamarindi). Chrysalis.
Grumpy Big Head
There are six species of Anolis lizards living on the Osa Peninsula. On the grounds of Bosque del Cabo Rainforest lodge I have encountered five of those species and the remaining one as an ,isolated population several miles away.
When I was out walking the Titi Trail this week I saw a the Big-headed Anole, (Anolis capito), lying languidly on the root of a large fig tree. As I slowly approached with the camera in hand, it opened one of its eyes and looked at me with a doleful expression as if to say don’t even think of bothering me. But I did take some photographs and each time the flash went off the lizard moved, almost imperceptibly, further around the root in a direction away from me.
Big-headed Anole, (Anolis capito).
The Big-headed Anole is one of the larger anolis lizards in this area. It attains a length of 9 inches including the tail. It’s body color is a mottling of greens, greys and browns. It can be found on the trunks of trees where it normally perches head down waiting for food items, arthropods or small lizards, to pass by.
Slender Anole, (Anolis limifrons).
Two of the more commonly seen anolis lizards are the Slender Anole, (Anolis limifrons), and the Golfo Dulce Anole, (Anolis osae). Both of these species can be commonly found around human habitation. The Slender Anole as the name suggests is a small slim species, mottled brown in color and with a white underbelly. The Golfo Dulce Anolis is slightly more robust and uniform brown in color, (at least the males), with a distinctive white stripe along the body behind the shoulder. Both of these species live close to the ground, again facing head down but usually at the end of large leaves.
Golfo Dulce Anole, (Anolis osae)
Green Canopy Anole, (Anolis biporcatus)
The last two species in this immediate area is the Green Canopy Anole, (Anolis biporcatus), and the Lichen Anole, (Anolis pentaprion). They both tend to live higher up in the canopy. I see the Canopy Anole more often at night where I find it lying asleep on the tops of leaves. It’s bright lime green coloration stands out quite nicely in the beam of a flashlight. The Lichen Anole I have found at the top of the canopy. It is grey in color with pale spots. Both of these two anoles I only find very occasionally whereas the other three can be found without much effort.
Lichen Anole, (Anolis pentaprion)
Philip Davison is a Biologist, Writer and Photographer Based in Costa Rica