A Legless Tiger & Robbing Victims of Life   Leave a comment

Felipe del Bosque Blog Oct 01 2010

Temp High 82°F  Low 72°F          Precipitation 0.0 ins

Today was a dry and bright day.  The sun made an occasional appearance and there were one or two light showers, but for the most part it is was a lot drier than it has been for several weeks.

One of the first things that caught my eye as I walked around the grounds was a paper wasp nest that had been constructed on the side of a Guapinol Tree was now almost completely de-constructed.  There was a small group of wasps, 10 or so in number standing on the site of the former nest, some of them chewing the remains of the carton shell.  I cannot say whether they were the original inhabitants or simply opportunists taking advantage of an abandoned abode, utilizing the material to aid in the building of a new nest in a different location, much in the same way that long forsaken mediaeval castles had their masonry removed and then incorporated into the buildings of surrounding towns.

Two Crested Caracaras took to the air, the large heavy wing beats made laborious work of getting these impressive looking birds into the tree top.  Under the same palm tree in which the Crested Caracaras landed, was a Yellow-headed Caracara feeding its fully grown, but nonetheless noisy and demanding juvenile.

Crested Caracara

The Green Urania Moths have turned up in huge numbers.  As you walk on the paths from the restaurant to the cabins they will fly up from their perches, circle a few times then land in the same spot.  Immediately in front of the restaurant is an Australian Bottle Brush Tree which is in bloom.  The moths seem to find the red brush shaped flowers enticing and will dance from bloom to bloom in search of a feed of sugary nectar.

I took a couple out this morning on the “Primary Forest Tour”.  It proved to be quite an exciting excursion, if you like snakes that is.  I normally tell people that the chance of seeing snakes is remote, unless you go out with me in the evening.  We sometimes have people visiting Bosque, having come equipped with the complete complement of snake hunting accessories who head off into the forest with high hopes and expectations only to return crestfallen and disappointed because there were no snakes to be found.  Invariably those who head out with little or no desire to see snakes are the ones that will happen across them.

So there we were on the “Zapatero Trail”, walking down towards a small wooden bridge over the creek, only to find something else was crossing the bridge in front of us, a Tiger Rat Snake, (Spilotes pullatus).  This was a very nice specimen with a seven feet long lithe glossy black body crossed with yellow bands giving it the name Tiger Rat Snake.  The head is mostly beautiful lemon yellow broken up by black bands.   I was sure it had not seen us because if it had it would have disappeared very quickly.  For an animal lacking limbs, rat snakes can move at an astonishing speed.

We watched it move across the forest floor, over fallen branches and then ascend a tree that had fallen across the creek.  As we followed its progress, we were momentarily distracted by a grey chicken-sized ground living bird, a Great Tinamou, which ran in front of us.  When we looked back, the rat snake was using the fallen tree as a bridge across the stream.  I slowly lowered myself into the creek bed and reaching out one hand managed to get hold of the snake.  In general snakes don’t like being grabbed but in this case, because I had picked it up very gently it wasn’t as snappy as they sometimes can be.  All the same it wasn’t entirely happy either as its tail was lashing and shaking wildly, an obvious sign of displeasure with its ignominious plight.  Anyway the couple out with me obtained some good photographs.

A little later on the same trail, we found a small Brown Spot-bellied Litter Snake, (Coniophanes fissidens).  These harmless little inhabitants of the fallen leaf litter are feeders on insects, small frogs and lizards.

Brown Spot-bellied Litter Snake

Finally, as we were coming to the end of the tour, just to the side of the path by our feet was a coiled four foot long Terciopelo, (Bothrops asper).  These are extremely venomous pit vipers and certainly not something you would want to accidentally step on.  They are ambush predators and will often sit for days on end in the same spot awaiting the approach of an unwary rodent.  Another set of photographs were taken before I picked up a stick and with a great deal of respect gently encouraged the snake to move to a new location far away from human traffic.


After lunch I decided to take advantage of the clement weather and go on a photography outing of my own.  I did not manage to get much of great value, the best being some images of the Leaf-cutter Ant waste disposal girls hard at work bringing refuse and excavated material from deep within the nest and dumping it outside.

The day had remained dry throughout and as a final farewell, the sky turned a deep blood red throwing into silhouette the low lying clouds before all plunged into darkness.

Philip is a biologist, writer and photographer as well as the onsite naturalist guide at Bosque del Cabo Rainforest lodge on the Osa Peninsula, Costa Rica.


Photo Feature

There are a myriad of insects in the tropics, some of them are large and obvious, some of them small and inconspicuous.  Some insects like ants and termites occur in substantial numbers.  When I was out this morning, the temporary dry spell had noticeably spurred the Leaf-cutter Ants into action.  There had been very little by way of cutting and carrying of leaf over the past few weeks but today there were moving lines of green on all of the trails I visited.  The Army Ants too were out in force, their incessant lines moving, always with intent across the forest floor.

There are other insects which may not be present in such huge numbers but will capture your attention in other ways.  As you walk through the forest, something might fly up in front of you and then land again not too far away.  You may not have seen exactly what it was but it is still there, inviting closer examination.  Again, it lifts off and then settles not too far away from you once more.  All of a sudden, a small butterfly flits past.  The subject of your interest takes off again and with rapid precision captures the unfortunate lepidopteran.  You have just witnessed a Robber Fly in action.

Robber Fly

Robber Flies belong to the Dipteran family Asilidae.  Typical of Robber Flies is the bristly moustache and the stout bristly legs.  They are winged assassins with sharp piercing mouth parts. When they capture their prey they inject saliva which contains a powerful immobilizing neurotoxin as well as digestive enzymes which liquidize it into a nutritious soup.

Robber Fly

There are over 7,000 species of Robber Fly distributed around the world.  This one I found not too far away from my cabin.

Text and Photographs are taken from the forthcoming book:

The Natural History of Bosque del Cabo by Philip Davison

Species List for the Day


Howler Monkey

Spider Monkey

Capuchin Monkey

White-nosed Coati


Red-tailed Squirrel


Red-lored Amazon

Scarlet Macaws

Grey-necked Wood-rail

Pale-billed Woodpecker

Purple-crowned Fairy

Bright-rumped Atilla

White-tipped Dove

Short-billed Pigeon

Chestnut-backed Antbird

Black-hooded Antshrike

Chestnut-mandibled Toucan

Blue-crowned Manakin


Green Honeycreeper

Cherrie’s Tanager

Bay-headed Tanager

Golden-hooded Tanager

House Wren

Riverside Wren

Masked Tityra

Crested Caracara

Yellow-headed Caracara

Roadside Hawk

Black Vulture


Golfo Dulce Anolis

Four-lined Ameiva

Barred Ameiva

Central American Whiptail


Mediterranean House Gecko

Brown Spot-bellied Litter Snake

Tiger Rat Snake


Northern Cat-eyed Snake


Marine Toad

Red-eyed Green Treefrog

Banana Frog

Milky Frog

Black and Green Poison Arrow Frog


Anartia fatima

Anartia jatrophae

Caligo eurilochus

Dryas iulia

Eueides lybia

Heliconius erato

Heliconius hecale

Heliconius ismenius

Heliconius sapho

Hermeuptychia hermes

Morpho menelaus

Phoebis argante

Pierella helvina

Pierella luna

Pyrrhogyra crameri

Posted October 2, 2010 by felipedelbosque in Philip's Nature Diary

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