Archive for the ‘Tamandua’ Tag

Tamandua Threatening to Kill   4 comments


Wildlife, nature, fauna and flora of Costa Rica.

Over the past week the weather has been consistent with that expected this time of year on the Osa Peninsula, Costa Rica.  The days have, for the most part, been bright and sunny and then as the sun sets the rain begins.  Normally there are heavy showers of short duration but occasionally they will be accompanied by thunder and lightning.  Last week there was 7 inches, (178 mm), of rain, so an average of 1 inch per night.  This has resulted in an elevated level in the creek which has started flowing once more after drying up for several weeks.

Now is an excellent time to see the amphibians as they are out in force at the moment.  Every evening by the pond the sound of the calling males begins as the sun sets and the sky turns dark.  The noise level rises over the next few hours until after dinner when it has diminished once more.

Currently there are a lot of parrots visiting the fruiting trees around the grounds, particularly Orange-chinned Parakeets, Mealy Amazons, Red-lored Amazons and their larger brighter cousins, the Scarlet Macaws. It is also possible to see the Brown-headed and White-crowned Parrots in the trees around the restaurant.  The Black-mandibled Toucans and Fiery-billed Aracaris are present in reasonably large numbers and like the parrots are very vocal.  Many of the palm trees are currently producing fruit and this feast is attracting these long-billed fruit-eating birds.  It also gives photographers an opportunity to obtain some excellent close-range images.

Who Are You Looking At

Rainforests of the Osa Peninsula, Costa Rica are simply teeming with life.  The first-time visitor will have no problem observing mammals such as monkeys, coatis and agoutis.  With a little bit of perseverance Brown-throated Three-toed Sloths can be seen moving slowly through the tops of the trees. There are some mammals that are here but are not seen as often such as Collared Peccaries, Tayras, Pacas, Pumas, Ocelots, Striped Hog-nosed Skunks, Nine-banded Armadillos and Tamanduas.

I normally see the Tamanduas, (Tamandua mexicana), or Collared Anteaters, on video, when, at night, they trundle past the trail cameras located on the forest paths.  Occasionally one will wander past as I am walking the trails or I may hear the sound of ripping wood along with the associated falling wood chips as one tears into a dead tree looking for a meal of termites.  Last week however, I had an individual emerge from the tall grass in front of me and cross the gravel path that runs through the teak plantation.

Tamanduas are not the most aware of creatures, their sensory apparatus appears to fail them.  If you are standing still or even walking slowly and silently, they will have no idea as to the proximity of your presence.  Even if they do detect there is something close to them, they are still not entirely sure of what it is.  As this one was moving quite quickly, (for a Tamandua), I lifted the camera and took the picture.  As the flash went off the dim-witted creature was alerted to what might pose an immediate threat.

For a cerebrally-challenged and relatively slow-moving creature the options of escape are now limited.  Out in the open the choice is not between flight or fight but rather just fight.  The sudden flash of light and movement to its side caused the Tamandua to assume the defense stance.  It stood upright on its back legs and opened its arms wide, wielding a set of razor-sharp claws in front of it.  What was an innocuous, comical and cuddly-looking creature has turned instantly from a termite-eating Dr Jekyll into a dangerous Mr Hyde, adversary warning me to stay out of range or face the consequences of the potentially fatal embrace of death.  Those claws could tear a hole in your windpipe within the blink of an eye.  There are many stories, some apocryphal, of killer predators that have, in a twist of circumstances, become the killed in a fight with an anteater.

Tamandua mexicana. Xenathra. Myrmecophagidae. Osa Peninsula. Costa Rica.

Northern Tamandua, (Tamandua mexicana) prepares to defend itself

This one huffed, puffed and wheezed its objection to my taking its picture.  Everytime the flash went off its arms opened wider.  Drool was dribbling from its mouth.  I noticed that the longest claw from the left hand was missing but that was not going to deter it from making a slashing defense of its life.  I got my pictures and backed away.  The Tamandua sunk to all fours again and trundled off into the undergrowth probably forgetting the encounter ever took place even before it had made it into the denser vegetation.

The anteaters belong to an ancient mammalian order: Xenathra which also includes armadillos and sloths.  This order is entirely confined to Central and South America.  Tamanduas are placed in the family: Myrmecophagidae, literally translated as anteaters.  The anteaters are toothless and use a long sticky tongue to scoop up their diet which consists mostly of termites but sometimes ants.  Tamanduas are both diurnal and nocturnal but the activity is larger a matter of preference for each individual.

Northern Tamandua. Philip Davison. Felipe del Bosque.

Northern Tamandua in full threat display. Watch out for those claws.

Tamanduas are adept climbers and will shimmy quite quickly up a tree in search of a termite nest.  Having found one, they use those long sharp claws to rip a hole in the nest.  The elongated skull terminates in a mouth which is little more than a hole through which the 16 inch long tongue is protruded.  The tongue is coated in a sticky saliva.  The anteater takes a quick feed and then makes a hasty retreat.  Within the termite nest is a caste of soldiers that will defend the nest to the death, either physically or using chemical weaponry.  The anteater will travel in a straight line through the forest visiting several nests during the course of the day, each time it takes a quick feed and then returns to its journey.  This strategy is known as traplining and it allows the anteater to keep a food supply continually in production rather than go in and destroy that food supply.  The anteaters will be found tearing the bark from rotten trees in search of termites as here there will only be harmless workers not accompanied by the defending soldiers.

When you come to Costa Rica and you are walking through the forest, don’t just pay attention to the vocalizations of mammals or the calls of different birds but also listen to other clues as to what might be near you.  If it is ripping wood and falling wood chips there will be a good chance a Tamandua is sating its hunger in a tree above your head.

Praying For A Meal

It is not an uncommon situation for me to be passing a tree and notice on the trunk a small praying mantis.  Should I approach and appear to be paying too much attention to the creature then it will run up and around the back of the trunk, out of sight, to escape further scrutiny.  Last week I encountered an individual that obliged me by remaining stationary.

Mantids are carnivores, voracious carnivores.  They feed mostly on insects smaller than themselves and to obtain their dietary intake of unfortunate victims they lie in wait; they are ambush predators.  Many mantids have cryptic markings and use mottled coloration to camouflage themselves against the background.  Some have evolved shapes and colors so closely mimicking leaves that they are rendered invisible within the vegetation where they are lurking in expectant anticipation of a passing meal.

Mantodea. Litergusidae. Litergusa sp. Osa Peninsula. Costa Rica.

Tropical Bark Mantid, (Litergusa sp). Who is looking at who?

Because there they are so distinctive in their appearance, there is no mistaking a praying mantis when you see one.  They sit with the head-end of the body raised up.  The front legs are folded beneath the body and it is this posture that gives them the aspect as of someone in prayer, hence the name ‘praying mantis’.  Don’t be fooled, those front legs are deadly killing weapons.  The femur is large and lined beneath with wicked-looking sharp spines.  The tibia too has its undersurface lined with spines.  When a victim passes by the mantids reaction is both lightning fast and terminal.  The selected prey is caught and impaled on the spines that come together in a powerful death grip.  They not only hold but also impale the prey’s exoskeleton.  The carnivorous mandibles set to work, rapidly rendering the meal into small consumable pieces.  Within a short space of time it has been eaten and its existence committed to the past.

Mantids are closely related to cockroaches but form a separate order: Mantodea.  There are about 300 species of mantid in the Neotropics.  The one I was looking at was a Bark Mantid, (Liturgusa sp).  It is one of the commoner species found in this area.  Another regularly encountered species that immediately captures your attention is the Leaf Mantid, (Choeradodis rhombicollis).  With its expanded prothorax and wide flattened wings, both of which are bright green, it looks exactly like a living leaf.  The Leaf Mantis often finds its way into the restaurant at night, landing by the lights that illuminate the table of the dining guests.

Mantids make such compelling photographic subjects as they quite often sit still but the head will follow in whichever direction you move.  The structure of eye and the way that light enters it gives the impression, albeit a false one, that it has a pupil.  These along with the large triangular head, lend an almost humanoid aspect to the insect.

Mantodea. Choeradodis rhombicollis Osa Peninsula. Costa Rica.

Leaf Mantis, (Choeradodis rhombicollis), in a perfect pose

Naked and Exposed

There is one animal that for a long time I have had on my list as a subject I needed to have an image of.  It is a reasonably common animal and I see it more often than not when I am walking on the forest trails.  I always think to myself that I should take a photograph.  The animal in question is a small lizard that lives down on the forest floor amongst the leaf litter.  If disturbed it moves in a labored serpentine squiggly fashion across the bare earth until it reaches the safety of the dead leaves covering the ground and then it disappears beneath.  I saw this one do exactly that but the leaf under which it took refuge was isolated with nothing else around it, there was nowhere else for the lizard to go.  I prepared the camera, knelt down and slowly lifted the leaf.  There it was.  It remained perfectly still allowing me to take a series of photos until eventually it squiggled off to reach the safety of a denser covering of leaves.

Reptilia. Squamata. Sauria. Gymnophthalmidae. Leposoma southi.

Northern Spectacled Lizard, (Leposoma southi), briefly exposed from its hiding place

This particular lizard was a Northern Spectacled lizard, (Leposoma southi).  There are only 13 species in the genus Leposoma.  They range from Costa Rica south into Brazil.  They are small and inhabit the leaf litter on the forest floor where they feed on insects and other small arthropods. When seen from a distance they have a dull brown coloration with a matt lustre.  Scrutinized more closely you will see a very distinctive feature, the prominent keeled scales particularly those plates covering the head.  There is another small lizard that inhabits the same habitat and moves in a very similar fashion, the Litter Skink, (Sphenomorphus cherriei).  It is easy to tell them apart as the skink has very glossy smooth scales giving it the appearance of polished bronze.  That is another creature I need to take a photo of.

Northern Spectacled Lizard. Osa Peninsula. Costa Rica. Philip Davison.

Northern Spectacled Lizard – close up showing heavily keeled head plates

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

 

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SLOWLY WRAPPED IN GOSSAMER THREADS   1 comment


Wildlife, nature, fauna and flora of Costa Rica.

Today was a little more typical of what we should be expecting weatherwise for September on the Osa Peninsula.  It started off raining, actually it continued raining from last night, it rained all day and it is still raining now.  It is not the heavy torrential rain that one associates with the 6 pm downpour, but rather that fine indistinct line between drizzle and mist with an intermittent heavier shower.

All of this makes for a very atmospheric feel to the forest and the grounds.  The trees are visible but appear almost phantom-like in a gloomy half light, obscured by mist.  It is as if you are looking at a picture with the color removed, a grayscale image.

The dingy conditions, though, did not deter some intrepid visitors who wanted to accompany me on the “Primary Forest Tour”.  The vegetation is always going to be there, so finding all things botanical to talk about is not a problem.  The dim, murky conditions, however atmospheric for us, seemed to dampen the enthusiasm of the animal life.  Mammals and birds are not easy to see in a rainforest under the most optimum of conditions.  Have you ever wondered why, when people come to the tropics to see tropical rainforest birds, birding guides don’t take them into the forest?  It is because vision is limited to about 15 feet in front of you.  Your view is hindered by lots of tree trunks, branches and leaves.  The irony about watching rainforest birds is that it is done in open areas where the trees have been cut down.  Now add to that a heavy mist and you don’t have conditions conducive to a lot of sightings.

Anteaters – Dimly Engaging

But you never know what will turn up and this morning as we wound our way along the muddy trail through the dank forest, bumbling along at its own pace coming from the opposite direction towards us was a Tamandua, otherwise known as the Collared Anteater, (Tamandua mexicana).  Now, although they are not rare, it is also not that common to see a Tamandua.  Along with armadillos and sloths, the anteaters constitute the mammalian order: Xenathra.  One trait, apparently shared by all the Xenathra is an ostensible lack of awareness for their immediate environment.  I have stood still in the forest and had sibling quads of Nine-banded Armadillos running back and forward over my feet without any fear, I doubt if they even knew I was there.  In the past I have walked alongside a Tamandua, that has remained oblivious to my presence until I accidently stepped on a dead twig, the snapping of which sent it unhurriedly up a tree, only for it to stop about 4 feet off the ground and lift its nose, smelling the air to see if I was still in the vicinity.  And so it was this morning, four people standing on the path and up it came, intent on its own business, searching for a meal of termites, (despite being called anteaters, they prefer a diet of termites), walked straight past us and on to wherever it may have been going.  This was a repeat performance of last night, when I had a Nine-banded Armadillo trundling along in front of me and displaying a complete lack of awareness as to my proximity.  In evolutionary terms I sometimes wonder how they made it this far along the line.

Rainforest animals. Rainforest mammals. Xenathra. Myrmecophagidae. Tamandua mexicana. Osa Peninsula.

Does the Tamandua, (Tamandua mexicana), know I am there

Slowly Wrapped In Gossamer Threads

If other wildlife is not compliant with your wishes to photograph it then look for spiders.  They come in all sorts of shapes and sizes, some that we consider a typical spider and others more weird and bizarre.  Spiders are the eighth most numerically named group of animals on the pl27anet.  You should also be able to find them irrespective of the weather conditions.  Spiders in webs make a good subject, especially if a breeze is not blowing.  If there is the mere breath of a zephyr it makes the task of focusing on a moving object close to the lens a little difficult, if not impossible.  Placed motionless in the center of a web is where an orb spider will normally sit unless disturbed.  That means, if you can avoid touching the web, you should be able to get pretty close.

Rainforest Spiders. Silk. Araneidae. Araneae. Argiope argentata

Silver-orb Spider, (Argiope argentata)

Orb spiders are some of the more evolutionary advanced of the arachnids.  Spiders are posed with two big problems, how to catch prey and how to consume it.  Several groups of arthropods have evolved the use of silk.  People think primarily of butterflies and moths, the caterpillars of which will use silk to make cocoons, (silk comes from Silk Moth caterpillars), or hold the chrysalis to a leaf or twig.  But nothing has perfected the use of silk to the imaginative and creative extent of the spiders.

Silk – Beautiful But Used to Deadly Affect

Silk is a protein.  It can be constructed from two forms of amino acid, a very loopy amino acid which can make it very elastic, or a crystalline amino acid which can make it very rigid.  In the silk glands of the spider, silk is a liquid, once the spider creates a silken thread, it becomes a solid.  Once silk is a solid, it stays a solid, the process cannot be reversed.  Silk is very elastic; it can be stretched to 300 times its own length before it snaps.  It can have the tensile quality half that of the finest steel.  Finally, if you were to take a strand of silk and let it float on a breeze, it would drift 50 miles before it broke under its own weight.  So, all in all, an absolutely amazing and versatile material.

Orb spiders have the ability to spin up to eight different kinds of silk.  To construct a web, the orb spider first spins a rigid silk which will form the framework.  It then moves from the centre to the outside attaching radial lines.  Now it moves in a circular fashion from the inside to the outside spinning a silk which when produced, absorbs water and becomes sticky.  The trap is now set.

Spiders. Webs. Araneidae. Araneae. Eriophora ravilla. Osa Peninsula.

Tropical Orb-weaver, (Eriophora ravilla)

If the web was taut, an insect the size of a large beetle hitting it at high speed would just be bounced off.  The fact that the silk is elastic allows the web to give, thereby removing all the kinetic energy from the impact, it then recoils and the prey is caught in the sticky silk.   That forceful contact will cause vibrations; the spider twangs the radial lines to locate the prey’s whereabouts, quickly goes down, wraps the unfortunate victim in silk and then delivers the poisonous bite.  The venom is a neurotoxin which will quickly quell the struggling of the now silken wrapped meal.  The food parcel is placed in a part of the web where the prey will be digested within the confines of its own skin by digestive enzymes injected at the same time as the venom.  When the prey is ready to be eaten, the spider, sticks in the chelicerae and sucks out the liquid soup.

Rainforest animals. Spiders. Orb-weavers. Araneidae. Araneae. Eriophora sp.

Beetles final moments in the embrace of a Tropical Orb-weaver, (Eriophora sp)

There are some animals though, that have evolved the means by which to escape their seemingly inevitable doomed entrapment.  Butterflies and moths are Lepidoptera, which means “Scaled wings”.  If you look at the wings of butterfly, you will find it is covered in tiny little powdery scales.  If you handle a butterfly you will find the scales come off in contact with your fingers.  If a butterfly or moth lands in a spider web, the scales shed from the wings allowing it to slide down over the web surface and away to freedom.  That is, if the spider is not too quick to detect where they are in the web, otherwise they will share the same ultimate fate as any other insect unlucky enough to have flown into that silken trap.

Golden-orb Spider. Webs. Spider venom. Araneidae. Araneae. Nephila clavipes

Ventral view of a Golden Orb-weaver, (Nephila clavipes), sucking the juices from a butterfly victim

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


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