The amazement of it all. The last thing you see   Leave a comment


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

Felipe del Bosque Blog Aug 28 2010

Temp High 82°F  Low 73°F          Precipitation 1.0 ins

Today I saw for the first time a Long-tailed Woodcreeper, (Deconychura longicauda).  It is not a common bird in the South Pacific region of Costa Rica, which is the same for a lot of the plant and animal life here.  In terms of biodiversity, there tend to be a lot of species but not many individuals of any one species, you may have heard the saying, “Common trees are rare, rare trees are common”.  Nonetheless for a biologist out in the field every day, which is where I have been for the past ten years, it is still a thrill to see something new.  And to that effect, I am, therefore, thrilled on an almost daily basis; there is always something new to see.  First time visitors to the tropics will be captivated by many new sightings, almost everything will be a first time experience, plants and animals only ever seen in books or on T.V.  For a resident in these forests though, the daily viewing of monkeys, coatis, agoutis, macaws, and toucans can sometimes render you complacent of their presence.  It is not until something like a Long-tailed Woodcreeper appears that makes me once again contemplate the marvel of it all, nature, its diversity and all the complex interactions that exist within the system.  Take any one element out of the system and, although it may not be obvious, the system will be diminished.

Along with the woodcreeper, this week I have seen for the first time Turquoise Cotingas, (Cotinga ridgwayi) and White-lined Tanagers, (Tachyphonus rufus).  For only the fourth time in ten years, I saw the Eyelash Viper, (Bothriechis schlegelii).  But, my main interest is with the butterflies.  I have been fascinated by butterflies since the age of three, (I am now fifty three).  I don’t know what it was that ever first captivated me, but whatever it was has had a very strong hold on both my imagination and natural curiosity.  On the grounds of Bosque del Cabo, over a ten year period I have inventoried 340 species of butterfly, all at ground level.  Most butterflies live at the level of the tree tops, so imagine how many more species I could add to that list.  The species inventory for the nearby Corcovado National Park is 220 species.  Once in a while I will get one, two or perhaps three new species turn up in a week.  That puts a spring in my step and a smile on my face.  It amuses me when I am leading a guided tour through the forest and I stop everyone in their tracks, then move slowly towards something that has caught my eye.  The onlookers, paused with baited breath wait for me to signal for them to come forward and see the elusive and hidden form of some large cat, only to be shown a small, almost imperceptible, but never before seen by me,  species of skipper or hairstreak.  Each to their own, but that sighting will certainly have made my day.

Philip is a biologist, writer and photographer at Bosque del Cabo Rainforest lodge on the Osa Peninsula, Costa Rica

Photo Feature

Wandering spiders, (Cupiennius spp), are nocturnal spiders.  As darkness descends, they emerge from their daytime hiding places and set up their position for the night.  They prefer plants with broader leaves and some form of cavity, perhaps a hollow stem, which they use as a daytime refuge away from the drying sun and wind.  They do not build webs, they are ambush predators.  The Wandering Spiders are finely tuned killing machines; they have vibration detectors and sensitive hairs on the legs that alert them to the presence of prey in their vicinity, any cockroach or cricket that may pass by.  The vibration detectors sense the movement of its prey on the leaf surface.  The hairs on the legs are very sensitive to miniscule eddies in air currents close to the spider.  The unfortunate insect is unaware of the imminent danger, the spider remaining motionless until the last moment, the spider’s leg borne sensory apparatus giving precise information about the insect’s proximity.  When the prey comes within range, the spider moves with lightning quick speed, it pounces forward and grabs the prey with its front two legs which hold the unfortunate victim in a vice-like grip while it sinks its fangs, chelicerae, into the hapless individual.  After envenomation, the prey is held at legs length away from the spider to prevent it retaliating with a bite or sting of its own against its assailant.  It is held above the leaf surface so that it has nothing to struggle against in an attempt to wrest its freedom.  The whole attack took less than 0.2 seconds.  The venom works quickly on the prey’s nervous system, paralysing it into a state of immobility and finally death.  In terms of energy expenditure, venom is very expensive for the spider to produce and generally nature does not waste energy.  If the prey is small enough and poses no threat to the spider, then it will simply be overpowered and killed without the spider resorting to its precious venom supplies in order to subdue it.  Spiders do not have mouth parts capable of chewing, so digestive juices are pumped into the prey converting the insect’s tissue within its shell-like exoskeleton into a soup which the spider eventually proceeds to suck out. Some of the larger wandering spiders will feed on the smaller frogs by the pond and have even been seen jumping on and biting the snakes.  They also have the unnerving ability to jump and snatch flying moths straight out of the air.  There are no spiders or scorpions in Costa Rica capable of killing you, but wandering spiders can inflict a nasty bite which will result in a localised ulceration.

Text and Photographs are taken from the forthcoming book:

The Natural History of Bosque del Cabo

Species List for the Day

Mammals

Howler Monkey

Spider Monkey

Agouti

White-nosed Coati

Red-tailed Squirrel

Birds

Red-lored Amazons

Scarlet Macaws

Long-billed Hermit

Chestnut-backed Antbirds

Black-hooded Antshrike

White-tipped Dove

Fiery-billed Aracari

Chestnut-mandibled Toucans

Long-tailed Woodcreeper

Blue-crowned Manakin

Green Honeycreeper

Cherrie’s Tanager

Palm Tanager

Blue-grey Tanager

Bay-headed Tanager

Golden-hooded Tanager

Mourning Warbler

Roadside Hawk

Laughing Falcon

Yellow-headed Caracara

Great Tinamou

Black Vulture

Reptiles

Northern Cat-eyed Snake

Amphibians

Marine Toad

Red-eyed Green Treefrog

Banana Frog

Smokey Jungle Frog

Fitzingers Rainfrog

Black and Green Poison Arrow Frog

Butterflies

Anartia Fatima

Heliconius cydno

Heliconius erato

Heliconius hecale

Heliconius sapho

Hermeuptychia hermes

Morpho menelaus

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Posted August 29, 2010 by felipedelbosque in Philip's Nature Diary

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