MARINE TOAD: BEAUTY AND THE BEAST   3 comments


Wildlife, nature, fauna and flora of Costa Rica.

The dawn broke this morning with the prospect of a very overcast and rainy day but by the time breakfast was over, the sky had brightened and things were looking up.  The recent rains had prevented me getting a weekly butterfly count done.  Normally I conduct the counts on Wednesdays, so much so that even if people have forgotten what day it is, and that is not hard to do around here, when they see me dressed and equipped to go out counting butterflies they know it’s Wednesday.  The weather though, occasionally throws a spanner in the works and I can’t get out until later in the week.  If I don’t complete a count on or before Saturday, then I regard it as lost.  In ten years of counting, the weather has only prevented me completing a count on one or two occasions.  So off I went this morning armed with binoculars, camera and handheld tape recorder.

The promise of the day was not fulfilled by the butterflies, there are not that many species or individuals this time of year, you need to come in February/March to see clouds of butterflies, but it was a good day for the birds.

One more migrant has arrived, yet another warbler, the Prothonotary Warbler, (Protonotaria citrea).  The beauty of bird is not matched by its unusual name, although the two are linked.  The bright lemon yellow head and breast of the male are supposedly reminiscent of the yellow robes worn by the protonotarii officials of the Catholic Church.

Trogon sightings are not uncommon at on the Osa Peninsula; we have four species present in the immediate area.  Normally found in woodland habitat I saw both the Black-throated and the Violaceous Trogons today.

One more bird worthy of mention, the Violet-crowned Woodnymph, (Thalurania colombica).  Hummingbirds were blessed by having those naming them possessing some degree of descriptive imagination. I watched a male continually re-visiting the same patch of Heliconias to feed.  Although the bird looks, at times, black, he is in fact a gorgeous deep violet/blue-black.  On his chest he sports a scintillatingly iridescent blaze of emerald green.

At the end of the day, the butterfly count was not as low as I thought it was going to be. So it was certainly worth waiting out a few days of rain to be able to spend the day in the company of some beautiful birds and butterflies.

Marine Toad: Beauty and the Beast

Rain forest animals. Rainforest amphibians. Marine Toad. Anura. Bufonidae. Chaunus marinus. Costa Rica.

Female Marine Toad, (Chaunus marinus)

The sun set some hours ago.  Everyone gathered in the dining room for the evening meal.  It had been a tiring day.  Some walked the trails, others took on the task of walking down to the beaches but wherever the adventure took the guests, the one thing they now had in common is that they had stoked up an appetite.  Everyone was now famished.  The buffet table was laid out with a range of dishes, each one complementing the other and all looking delicious.  The meal began.

Gazing out at the scene from nooks and crannies  all around the restaurant were eyes, not human eyes but rather those of another creature waiting for the feast to end.  And for another feast to begin.  They would not emerge while the lights were ablaze, but those lights are important for what would happen later.  While the diners fed, talked and laughed their way through the evening they were unaware of something happening around them.

From the depths of darkness in the surrounding forest, insects were being attracted, like the proverbial moth to a flame, towards the bright and beckoning illuminations.  Once there, they would settle.  Normally using the light from celestial bodies to navigate, these flying insects had unwittingly been drawn to an artificial source of light and having arrived there were fooled by its brightness into thinking it was day.  So there they stopped.  The eyes were still watching though and the watcher was waiting.

Presently the meal and following conversations ended.  Sated and ready for bed, the guest proceeded to leave for their cabins, leaving the staff to clear the tables.  The time was getting closer.  Eventually with the floor swept, the dishes washed and the tables set for breakfast the following day, the staff left the building and the final action was to turn off all the lights.  Now something stirred, eyes blinked patiently waiting for the security that no human had been left behind.

Given a few minutes of darkness and silence, movement can be detected.  From behind books in the library something comes hopping across the floor.  From under the low levels of the shelves and from the surrounding flower borders more movement can be seen.  There are creatures moving into the now empty confines of the restaurant to start what will be tonight’s second sitting.  The new set of diners have dry, warty skins and hop across the tiled floor to the areas of the turned off light fixtures.  These are Marine Toads, (Chaunus marinus), and they have come to eat the insects that were attracted to the lights over the course of the early evening.

Rainforest animals. Rainforest amphibiand. Marine Toad. Bufonidae. Chaunus marinus

Close up head shot of female Marine Toad, (Chaunus marinus)

They are called Marine Toads as you can find them down on the beach but they are not tolerant of salt water so you won’t find them in the sea.  They are not generally found in the forest but rather around human habitation.  Also, they do not always need the stimulus of movement to feed, as do most amphibians, so they can take food from pet bowls that have been left overnight.  Males will grow to about a year old, females will continue to grow to about four years old.  At four years, the female Marine Toad can be anything up to 3 lbs in weight, making this the largest of the Costa Rican amphibians.

They are very poisonous; the two main poison glands appear as large expanded areas , one behind each eye.  These are the toads that were introduced into Australia in the 1930’s to clear the cane beetles from the cane fields.  The Australian predators had never come across them before, fed on them, were poisoned and died.  That left Australia with a much bigger problem than it had originally, a massive explosion in the mouse and rat populations.  They have been introduced to Hawaii, Florida, Australia, Papua, and some Caribbean Islands, all resulting in the same problems, not the fault of the toad as we take them there.

No-one in Australia thought to talk to a biologist about that biological control technique, as the cane beetles they were introduced to feed upon live at the top of the cane stems whereas the toads live at the bottom.  From that time to this, despite the Australian governments attempt to introduce measures to reduce the populations of Marine Toads, it has continued to be an ecological disaster of  the countries own making.

Marine Toads return to the water to reproduce and each female can lay upto 13,000 eggs.  That many eggs with no predators means the Marine Toads can get out of control very quickly.  Here in Costa Rica though the Marine Toad is native, it does have predators.  Opossums will catch them, split them open and leave the skins and some snakes are immune to the toxin.  Not too many will initially take a look at a toad and appreciate its beauty, but just before you vent you disgust have one more look deep into that eye, perhaps then you will see something different.

There have been recorded instances of people trying to make a meal of this toxic amphibian, the consequences of which ended with dire results.  The following passage describes the ill-fated attempt by a family to cook and eat this particular amphibian.

“About 10 a.m. all four members of the family began to vomit……The mother and sister were prostrate, and their lips and fingers were blue; pustules had formed on the sister’s lips.  The abdomens of the mother and the sister appeared bloated and their bodies were hot and quite rigid.  They were pronounced dead by 12 noon…..The Peruvian intern in charge believed death was due to ‘cardiac seizure”, preceded by respiratory difficulties”.

The milky white toxin secreted from pores in the skin is Bufotoxin which causes massive vaso-dilation and poisoning of the cardiac muscle tissue.  So Marine Toad pie is off the menu.

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

 

 

Advertisements

3 responses to “MARINE TOAD: BEAUTY AND THE BEAST

Subscribe to comments with RSS.

  1. More great knowledge Phillip, thanks for teaching us.

    Like

  2. Phil, I loved the marine toads and saw some beauty in them, I was also surprised at their size, they are the biggest toad I have ever seen. Grace loves reading your diary, in fact we all do, the pictures are amazing and the information very interesting.

    Like

  3. Oh yeah…. biiggg toad. We said hello to one after dinner upon returning to Sol. Sitting quietly in the corner of the room – but since it didn’t pay it’s share we decided he needed to leave for the evening. The small trash can and and the book in the room worked as a transportation device – but you could see the power of its jumps as it shook as my husband carried it out of the room. He went on to spend his evening back in the wilds.

    Like

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

%d bloggers like this: