Scorpions: A Tale With A Sting   4 comments

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

This morning I went out for my daily excursion on the Bosque del Cabo Zapatero Trail which runs through a nice section of primary rainforest.  The tour I was leading was the “Primary Forest Tour” which for the first time visitor to the tropics, or even the tenth time visitor, is a nice introduction to how the forest works.  The purpose of this four hour walk is to educate, entertain and inform the participants of the interactions between the plants, animals and their biological and non-biological background.

For many visitors to Bosque it is their first experience of a rainforest and they may have many apprehensions and misinformed notions.  Hopefully by the time they get back to the lodge for lunch some of the apprehensions will have been allayed and the misinformation has been corrected.  There are those too who are very well informed and so the tour will take a different turn as we indulge in the cut and thrust of intellectual discussion and debate regarding rainforests and the politics behind their conservation.

As I only have four hours to cover a subject as vast as tropical rainforest ecology, some questions remain open and unanswered.  This may be because I don’t have the answer.  One thing to always remember is due to the complexity of interactions between all of the elements composing a rainforest, however much we know, it is probably only a fraction of what we need to know in order to fully comprehend the intricacies the make the system function.  There is so much more work to be done to be able to fully fit the puzzle together.  And this is not just a two dimensional puzzle, it has three special dimensions and the forth being time, which allows to see how the system developed over the eons.

There is also a human element to it all and despite the fact that many people still regard humanity as apart from nature, we are most certainly and inextricably a part of nature.  Whatever man does impacts upon the system and, unfortunately, generally never in a positive manner.  We have seen for the past 500 years, rainforest being reduced from 12% the land surface of the earth to its current 6%.  Most of that loss has occurred in the last 100 years and exponentially so.  As we do not fully understand how the system functions, and given that we are a part of the system, how can we fully assess the implications and repercussions that may occur as a result of our actions?

Two Bark Scorpions to Choose Between

For a lot of people to whom spiders instill a sense of fear, scorpions seem to generate a sense of both fear and revulsion.  Many people have never actually had contact with a scorpion and so their jaundiced views are colored by exaggerated tales from sensationalist literature.  Scorpions, like spiders, are arachnids.  They are unmistakable and therefore instantly recognizable. Scorpions probably more closely resemble any imagined alien life form than any other variety of wildlife that one is going to come across in the tropics.  They have eight legs and two large pincers which they hold in front.  The body is long and segmented with the tail, familiar as most people’s vision of a scorpion, sometimes extended behind but often arched over its back.  The tip of the tail is armed with a bulbous and barbed sting.

Rainforest Scorpion. Arachnid. Scorpiones. Buthidae. Costa Rica.

Bark Scorpion, (Centruroides limbatus)

As the sun sets, the interior of the forest darkens very quickly.  You would be well advised to have left the forest trails and be back at the lodge before dusk. A walk through the forest at night requires a good flashlight.  In the gardens, even though it is dark, you are still out in the open.  Once you venture beyond the wall of trees that marks the boundary to the forest your vision is now severely limited not only by the trees themselves but also by the canopy above which blocks any light from penetrating down to help illuminate your way.  After about half an hour your eyes will have adjusted to the conditions enabling you to see better in these ultra low light levels.  Although our ability to see in the dark is not great we do nonetheless have some capacity for night vision.  As soon as any artificial light is used it takes away the acquired night vision capability which will need about another half hour to be restored again once the light is switched off.

Costa Rican Bark Scorpion. Centruroides limbatus. Osa Peninsula.

Watch you fingers. Bark Scorpion, (Centruroides limbatus), ready for action

Searching the forest floor or trees with rough and flaky bark with a flashlight you may notice something crawling along that will make you catch your breath.  Scorpions which remain hidden during the day emerge at night to find food.  They are active hunters and slowly move amongst the leaf litter on the forest floor or beneath loose tree bark, their pincers held in front, waiting to make contact with some small insect, spider or smaller scorpion that makes up the bulk of their diet.  Once it makes contact with a prey animal, the scorpion grabs it with the pincers, and then using its mouthparts the scorpion will render it into smaller edible pieces.  If the prey is strong and puts up a struggle, the scorpion’s barbed tipped tail, which is held over the top of its body, now lashes down and strikes home against its target, injecting a lethal dose of neurotoxin venom.  The struggle does not last too long and the vanquished captive is subsequently consumed.

Rainforest Scorpion. Costa Rican Bark Scorpion. Centruroides bicolor. Osa Peninsula.

One of the larger scorpions in the area, Bark Scorpion, (Centruroides bicolor)

As with the spiders, Costa Rica is thankfully lacking in scorpions capable of causing a sting lethal to humans.  They do however hurt when they sting.  You will know immediately when you have been stung by a scorpion because the initial pain is acute.  This subsides after a matter of a few minutes and you will then be left with a cold, dull, throbbing ache at the site of the sting for several hours.  Similarly to nocturnal spiders, scorpions need damp living conditions.  They seem to have a liking for damp towels as well as the dark, damp refuge that the insides of boots provide.  It is therefore somewhat prudent to shake out your footwear in the morning before slipping them onto your feet and also a good idea to shake the towel before drying yourself following a shower.

Costa Rican Scorpion. Rainforest Scorpion. Bark Scorpion. Centruroides bicolor.

Are you brave enough? Bark Scorpion, (Centruroides bicolor)

Scorpions do not exhibit eye shine and so are not visible by flashlight using that technique.  There is a trick we can use to find them though.  Not everyone is going to be carrying a hand held black light on vacation but it is an excellent instrument to have in aiding the location of scorpions at night.  Scorpions fluoresce an eerie greeny blue color under short wave ultra violet light.  This can be picked out at some distance and the pallid blue form of the hunting scorpion can be seen rambling about in search of a meal.

Rainforest scorpion with black light. Scorpion under ultra violet.

Bark Scorpion, (Centruroides limbatus), observed under black light

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


4 responses to “Scorpions: A Tale With A Sting

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  1. Excellent stuff, Philip!


  2. Phillip, I read all of your postings tonight. Excellent job. I am forwarding the site to a few friends that are coming and a few that are thinking about coming. I think it is a great thing you are doing. Looks like you all are having a lot of rain and it should be a good thing in the long haul… Keep up the good work.


    • Thanks Arralee. Glad you like it. I had 170 read yesterdays blog. I may not be able to keep up the daily output in the busy season, possibly weekly then. We shall wait and see. But right now I am having a lot of positive feedback.
      Regards, Philip


  3. BTW, posting on facebook when you have a blog update is an excellent idea. Otherwise, I would forget to come back and check.


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