Summer’s Muted Color Collection   Leave a comment


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THURSDAY 14th JANUARY

Blue and Brown

As the wet season fades into memory and the dry season progresses then the number of butterflies increases.  Week by week as the weather becomes warmer and drier you will start to see more and more species of butterflies and not only that but also an increase in the number of individuals.  The best place to observe the most colorful of these constantly fluttering confetti-like insects is in the open areas particularly around the nectar plants that they favor which in this area happen to be the orange/yellow flowers of Lantana camara.  Here bright poster colored, slow flying heliconiids painted in yellow, orange and red are conspicuously flitting from sunlit flower head to flower head.  The casual observer will not fail to be impressed by the constant swirling to and fro of so many different species.  Flying overhead but not landing are the sulphurs, butterflies dressed, as the name suggests, in vibrant yellows and creams.  They exhibit ultra violet markings, invisible to us, but seen by other butterflies or by humans with a U.V. filter.

Down by your feet, visiting and taking nectar from the flowers of low growing herbaceous plants, are butterflies so small as to be barely discernible.  Concentrate your attention to the level of the grass and there will be revealed a motion of tiny flicking blue wings, butterflies smaller than a fingernail.  These are some of the Lycaenids, the Cenaurus Blue, (Hemiargus hanno), and the Eastern Tailed Blue, (Cupido comyntas).  Their delicate form and intricately patterned wings decorated with dark spots, pale dashes and splashes of red can only really be appreciated if you lie down at their level and watch them close up.

Butterflies. Lycaenidae. Costa Rica.Butterflies. Lycaenidae. Costa Rica.

Moving into the forest beneath the umbrella of the canopy which casts the forest floor into shade a whole other group of ground hugging butterflies can be seen, but once again only with patience and a sharp eye.  Most of these butterflies disappear as soon as they alight amongst the dead leaves or on the textured bark of trees.  The satyrs have a ground color in shades of grey and tan.  Overlying this are streaks of browns in ochres and chestnut.  They look like the leaves amongst which they settle.

Butterflies. Satyrinae. Costa Rica.

Butterflies. Satyrinae. Costa Rica.Butterflies. Satyrinae. Costa Rica.

There are several species of butterfly in the same subfamily as the brilliant Blue Morphos that do not have the bright blue coloration.  One of them, the White-signed Morphet, (Antirrhea philoctetes), looks more like a satyr than a morpho.  It is a beautiful tan and chocolate brown with darker dashes, black dots and a white stripe across the underside of the fore and hind wings.  It also sports a distinct eyespot.  Just as the earthy colored satyrs, the White-signed Morphet never flutters more than a few inches above the ground.  When it lands it remains motionless blending in perfectly with the background.

Butterflies. Morphinae. Costa Rica.

Another butterfly that remains unmoving on the side of tree trunks is the Owl Butterfly.  Having been unnoticed the close proximity of a walker on the trail may cause the butterfly to take to the air.  But not for long as it quickly settles head up on the trunk of another tree.  If you approach slowly you can see the intricate patterning of browns, tans, creams and yellow overlain with wavy black bands.

Butterflies. Morphinae. Costa Rica.

The most distinctive and distinguishing feature is the large eyespot on the underside of the hind wing that gives the butterfly its name – Owl.  The large dark bordered ring with a central pupil, along with white spots that mimic a catch light look just like an eye.  The illusion is deliberate.  This is a bullseye, a target for potential predators.  A bird, a lizard or a mouse will attack in the area of the eye because normally lying behind the eye is the major part of the central nervous system – the brain.  Wipe out the brain and the prey is killed instantly.  In the case of the butterfly the target is placed on a non vital area of the hind wing that the butterfly can afford to lose without it hindering its ability to fly.  All the predator disappointedly ends up with is a tatty piece of wing membrane.  As can be seen in the photo the Gold-edged Giant Owl, (Caligo atreus), the hind wing shows evidence of a previous attack.

Everywhere and Nowhere

A common question asked by visitors to the tropical forests is “Where are all the mushrooms?”  The fungi are most certainly here, the extensive mycelia of which permeate the soil reaching into and spreading throughout any dead organism whether it be animal or vegetable aiding in that process of rapid decay and decomposition.  But in these warm wet forests conditions are ideal all year round for the production of those familiar reproductive spore producing bodies – the mushrooms and toadstools.  In higher latitudes the almost overnight appearance of such a rich variety of fungal fruiting bodies is a visual treat for hikers in the forests and mountains.  But it is an all at once autumnal phenomenon.  Within a month or so the event has ended.  Here if you look carefully there will be mushrooms but not in such profusion or rich abundance.

Fungi. Agaricales. Costa Rica.Fungi. Agaricales. Costa Rica.

Fungi. Agaricales. Costa Rica.Fungi. Agaricales. Costa Rica.

This was a group of agaricales that were found growing on decomposing lawn mowings which had been discarded at the forest edge.  They were in various stages of fruiting from small and unopened to fully extended caps.  Actually the mushroom will grown very quickly overnight, open, shed millions of spores into the air and can have gone within 24 hours.  There are many animals that enjoy taking advantage of this sudden appearance of a tasty meal with flies laying eggs from which the larvae emerge very quickly to feed and develop.  Mice and squirrels enjoy the fungal feast as long as they are not poisonous, something humans have to be very wary of as there are some deadly toadstools out there.  Better to appreciate and enjoy the texture, form and function of these interesting ephemeral appearances than risk sampling the terminal flavor of an exotic final meal.

Jumping to an Identification

Orthoptera. Acreidae. Costa Rica.

Crickets, katydids and grasshoppers can be found in all tropical terrestrial ecosystems during both day and nighttime hours.  They might not be the easiest things to see but hearing them is unavoidable.  Although they all belong to the order: Orthoptera there are differences between the three groups.  Most familiar grasshoppers are brown or green and have short stubby antennae.  Grasshoppers make raspy sounds known as stridulation by rubbing the femur of the hind leg against either the front or hind wing.  Katydids are an elegant group consisting of many forms and colors.  Some not only have the green coloration of vegetation but have evolved remarkable mimicry with the wings resembling the veins and patterning of leaves against which they are almost indistinguishable.   Katydids, along with crickets, stridulate by rubbing the forewings together.  Katydids tend to have more pleasant calls than the grasshoppers but are not as melodious and musical as the crickets.  Both katydids and crickets tend to have long filamentous antennae.  Grig is an older English term for the jumping insects of the order: Orthoptera but these days generally refer to a separate family of katydids.

Orthoptera. Tettigoniidae. Costa Rica.

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

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