Hidden Nightime Aphrodisiac   1 comment

Felipe del Bosque Blog April 30th  2012

Why Change?

The weather continues in the same pattern with a day of rain followed by several more days of dry and sunny conditions.  With every prolonged spell of dry weather the land crabs and frogs, which are at first abundant, reduce steadily in numbers.  Then with the rain, out they come again.  At the pond at this time of year it is always the Milky Frogs, (Trachycephala venulosa), that come out, pair up and lay eggs within hours of an evening of heavy precipitation.  Their periodic spawning should ensure an adequate food supply for the Cat-eyed Snakes, (Leptodeira septentrionalis), at least for the near future until the normal pattern of rainfall is resumed.

The Black and Green Poison Arrow Frog, (Dendrobates auratus), numbers also wax and wane with the sun and rain.  Most days they can be found on the Creek Trail behind the Bosque bar and in especially large numbers if it has rained the night before.

When the crabs do emerge in large numbers they run the risk of attracting an equally large increase in the number of predators coming into their vicinity to feed upon them.  White-nosed Coatis, (Nasua narica), are related to raccoons and just like their cousins will take most eating opportunities afforded them.  As the crabs are now moving freely on the surface of the soil in broad daylight, the coatis have no problem picking them off with ease.  Subsequently there are currently a lot of remains in the form of discarded crab legs and carapaces lying around the grounds and a lot of well sated coatis.

Expected Visitors

There was excitement from the staff one night at the bar while all the guests were eating.  I was called over to see a coral snake.  It is not uncommon to see coral snakes but they do tend to be nocturnal in habit and so not always active when people are around.  They are also very secretive and despite the brightly colored bands warning you of their potentially lethal bite, they are normally found under leaf litter or around the compost heap which is where they seek their preferred prey items which include sleeping lizards and smaller snakes.

This individual was an Allen’s Coral Snake, (Micrurus alleni), the largest of the Costa Rican coral snakes and this one was long, being a good 3 feet in length.  None of the staff had seen a coral snake this size before.  It made its way along the edge of the path, its tongue constantly flicking in and out, sampling the scent in the air.  It finally found a small hole in a rotten tree trunk into which it quickly slipped and disappeared.

I had a pleasant surprise one day by my bathroom, an Eyetail Moth, (Sematura luna), was resting on the wall.  The wall is a stark bright white but the moth was at the perfect height to get the spread of its wings full in the frame of the picture.

Eyetail Moth

The wings are a rich purple brown color with two pale bands and a concentric series of scalloped creamy colored lines.  It has two distinctive tails, each one sporting the large eyespot at its base that gives the moth its name.

The Eyetail Moth is a nighttime flying moth related to the day flying Green Uranias, (Urania fulgens).  Despite the fact that they are not necessarily rare, very little is known about the early life history of this moth.

There have been a few other visitors in the vicinity of my garden over the past week, all nocturnal.  Later in the evening up in the tree tops by my cabin and over the course of several nights, I could hear Kinajous, (Poto flavus) moving around, their presence being announced not only by moving vegetation but also the distinct nasal “honk” followed by soft whistling.

The Fire Beetles are still around, two bright green bioluminescent spots punctuating the darkness as they crawl around on the bark of trees.  If they fly, then the abdomen lights up a glowing fiery orange, unmistakable as they swirl through the darkening dusk air.

Fire Beetle

One more visitor that not everyone likes, but I have a certain fondness for, is the Terciopelo, (Bothrops asper).  For the past two weeks one has been coming out and curling up in the same place, then disappearing for a few days.  Given some respect and some distance, you should not have any problem with them.  Just as with most snakes they would rather shun the company of humans.  This one allowed me to photographic it before registering its displeasure by moving off.  Every time I set the camera to get another shot, it moved once again, so eventually I gave up and left it in peace to go about its own business.


Don’t Whip Poor Will

One bird that I have been meaning to photograph and add to bestiary of nocturnal creatures that I regularly see on the night tour is the Common Paureque, (Nyctidromus albicollis).  These birds are related to night hawks, whip poor wills and goatsuckers.  They are nocturnal, insectivorous birds that both roost and nest on the ground.

The coloration of the plumage is a mixture of browns, tans and grays which are then subtly suffused with pale spots.  This cryptic coloration is very effective at blending the bird in with the background of dead leaves amongst which it sits on the forest floor during the day, perfectly camouflaging its presence from predators.

Common Paureque

The Paureque has another trick under its wing; it doesn’t give off an odor.  Most ground living predators find their prey through sight and scent so with the Paureque they can neither see them nor smell them, so the bird is very well adapted to living on the ground.

One of the basic principles of camouflage is that you don’t move because to do so would blow your cover.  If they are caught in the beam of a flashlight, the Paureque sits quite still hoping that you cannot see it.  But as anyone who has been out on the night tour with me will know, the eye shine of a Paureque is not dissimilar to two flaming coals in the darkness, so we can spot them a long way off.

The Paureque reproduces in February – March.  At that time the female will have a scrape in the ground which will serve as a nest.  She generally sits on two eggs.  If you approach at night when she is incubating the eggs, she sits tight and hopes that you will pass by without having seen her.

Once the chicks hatch, every night they will be approximately 10 feet away from where they were the night before, they are continually moving from one night to the next.  Now is you approach the female she will jump up and down in front of you, but always just out of reach.  She drags her wing, feigning injury.  She will lead you further and further away from the chicks and once she thinks you are at a safe distance; up she goes into the sky and disappears.

Common Paureque

At the moment there are still several males who sit at various points around the grounds.  Earlier in the year they were quite vocal but now just sit in silence.  They have a characteristic flight where they flutter up, catch an insect and flutter back down again.  When they do fly, they are silent.  The males have a distinctive white wing bar which can clearly be seen as the phantom-like avian insectivore silently takes to the air and almost hovers over your head before heading to a safer refuge further away.

I had to approach the bird quietly and try to set up the camera equipment with one hand while holding the bird in the flashlight beam.  Normally as soon as the light beam is removed, the bird goes without a sound.  I managed to get two shots before it took flight but fortunately it didn’t land too far away.  Again, going through the same procedure I managed to get the camera in place and get one shot before the bird again left but this time to an unseen location.

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

 Love Dust

One day at around noon, I was down by a patch of Lantana photographing butterflies for a new book of butterflies at Bosque.  Being midday, the sun was overhead and intensely bright which doesn’t generally make for good photos, there being a very high contrast between light and dark.  Also at that time of day the butterflies don’t stay still for very long, they momentarily land, feed and flit off again.  Nonetheless I was trying to get some images of the many longwing butterflies that commonly visit the Lantana and was using the shade of the plant along with flash to get the pictures.

Two butterflies caught my attention.  One butterfly was sitting on a leaf, wings extended and its abdomen raised.  The other was hovering directly above it moving up and down as if attached to a spring suspended beneath a higher branch, its wings fluttering continuously.  This was the courtship behavior of Tiger-striped Longwing, (Heliconius ismenius), and as luck would have it right in front of the lens of my camera. I have reported on this behavior before and it is not uncommon to see male butterflies courting a female but it is not always easy to get the shot.

Heliconius ismenius

The male butterfly initially has to recognize a female of his own species which is generally a visual cue, before he can court her.  To solicit a positive mating response from the female, the male now has to woo her with chemical aphrodisiacs, (pheromones), called “love dust” emitted from specialized glands, androconia, (modified scales), normally found under his wings.  As he is fluttering up and down, the rain of olfactory stimulants will coat the female’s antennae.

Most female butterflies will mate within a short time after emerging from the chrysalis.  There is a good chance, as in this case, the female will already have accepted a suitor and has no interest in the male now attempting to entice her.  She signals her lack of desire by spreading her wings and holding her abdomen high.  This male will have to try his luck elsewhere.

Agraulis vanillae         Agraulis vanillae         Heliconius sapho

Dryas iulia         Heliconius hecale         Heliconius cydno

Text and Photographs are taken from the forthcoming book:

The Natural History of Bosque del Cabo by Philip Davison

Temperature and Rainfall

Average Daily Rainfall 0.03 ins.  Total Weekly Rainfall 0.21 ins

Average Daily Rainfall 0.08 mm.  Total Weekly Rainfall 5.30 mm

Species List for the Week


  • Howler Monkey
  • Spider Monkey
  • Capuchin Monkey
  • Agouti
  • Red-tailed Squirrel
  • Nine-banded Armadillo
  • White-nosed Coati


  • Red-lored Amazons
  • Scarlet Macaws
  • Great Currasow
  • Lineated Woodpecker
  • Pale-billed Woodpecker
  • Chestnut-backed Antbird
  • Black-hooded Antshrike
  • Common Paureque
  • Short-billed Pigeon
  • White-tipped Dove
  • Stripe-throated Hummingbird
  • Blue-crowned Manakin
  • Red-capped Manakin
  • Fiery-billed Aracari
  • Chestnut-mandibled Toucan
  • Cherrie’s Tanager
  • Bright-rumped Atilla
  • Buff-rumped Warbler
  • Great Kiskadee
  • Great Tinamou
  • House Wren
  • Black-throated Trogon
  • Masked Tityra
  • Black Vulture
  • Turkey Vulture


  • Allen’s Coral Snake
  • Barred Ameiva
  • Central American Whiptail
  • Common Basilisk
  • Five-lined Ameiva
  • Clawless Gecko
  • Golfo Dulce Anolis
  • Green Iguana
  • Northern Cat-eyed Snake
  • Terciopelo
  • Tropical Bird-eating Snake


  • Banana Frog
  • Black and Green Poison Arrow Frog
  • Fitzinger’s Rain Frog
  • Marine Toad
  • Masked Smilisca
  • Milky Frog
  • Red-eyed Green Tree Frog
  • Smokey Jungle Frog


  • Agraulis vanillae
  • Anartia fatima
  • Arawacus lincoides
  • Archaeoprepona demophon
  • Battus belus
  • Calycopis isobeon
  • Dryas iulia
  • Eurema daira
  • Eueides lybia
  • Heliconius cydno
  • Heliconius erato
  • Heliconius ismenius
  • Heliconius sapho
  • Heraclides cresphontes
  • Junonia everete
  • Morpho Menelaus
  • Nymphidium
  • Philaetria dido
  • Phoebis sennae
  • Urbanus teleus


  • Bamboo Orchid Flowering
  • Black Alligator Tree Flowering and Fruiting
  • Calabash flowering and fruiting
  • Cannonball Tree Flowering and Fruiting
  • Cashew Flowering and Fruiting
  • Clusia rosea Flowering and Fruiting
  • Hog Plum Flowering
  • May Tree Flowering
  • Monkey Comb Tree Flowering and Fruiting
  • Mountain Rose Flowering
  • Passion Vine Flowering and Fruiting
  • Stinky Toe Fruiting

One response to “Hidden Nightime Aphrodisiac

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  1. Great joy to read your reports Phillip. It was just back over the Christmas holidays when we were down there at Bosque for a visit. Miss it soo much. Your reports and photos take me back there. : )

    I am doing what I can to help with naturalization of the woody and marsh zones around here in Ontario. Would like to see more people appreciate nature like us, but not sure that will happen. Sue and I are reporting on Bluebird nesting in the area as part of a province wide study and Bluebird encouragement plan. They have box nests along certain country roads and we go there to report on who is taking up house in them.
    Take care man. Paul


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