Hovering Over Sensitive Changes   Leave a comment

Felipe del Bosque Blog November 18th 2013

title copy

Trying Times

This week started as the last week ended with lots of rain.  Previously the rain had been falling at night but over the first few day of this week it started pouring day and night.  Then a profound change occurred the sun came out and continued to return every morning to give us three days of beautiful dry conditions.

The transitional period between wet and dry season certainly make predictions difficult.  Many aspects of plant and animal behavior rely on abiotic  or environmental cues.  Once we move into the dry season those changes will stimulate many of the plants to flower.  Consequently there will be a lot of hummingbird, bat and insect activity around the nectar producing blooms.  But as yet we are waiting for that change to occur.

Present and Correct

It has been quite a quiet week as far as mammal sightings are concerned.  All the four species of monkey were spotted at many points around the grounds.  Agoutis, (Dasyprocta punctata), can be seen on a daily basis near the Bosque restaurant.  One was seen with a baby this week.  Red-tailed Squirrels, (Sciurus granatensis), can be seen around the open areas of the lodge while Alfaro’s Pygmy Squirrel, (Microsciurus alfari), can be found without too much searching in the forest.  These plain brown, sparse tailed, small chipmunk sized squirrels hop around at low levels of the forest and more often than not will cling head down on the side of a tree trunk and chatter ferociously at you.

Sing For Your Supper

The migrant birds, many of which are tanagers and warblers are still arriving.  Summer Tanagers, (Piranga rubra), have set themselves territories in the gardens in front of the restaurant.  Here they are joined by Cherrie’s Tanagers, (Ramphocelus costaricensus), males with their bright scarlet rumps being followed by harems of orange-brown females.  Up in the branches of the trees are noisy flocks of Golden-hooded Tanagers, (Tangara larvata).

The army ant swarms continue their relentless marches through the forest at several locations on the property.  They attract a lot of attendant bird life, many species of woodcreeper, trogons and of course the ever present Grey-headed Tanagers, (Eucometis penicillata).

Flying in the Face of Confusion

The migratory Green Urania, (Urania fulgens), moths are continuing to build in numbers.  Butterfly numbers increase when the sun is shining but it will be several months before they hit their peak.  Around the pond the dragonflies are starting to be seen more frequently, the bright blues and reds of these agile aerial hunters dart to and fro before settling momentarily of a leaf.  Their heads turn this way and that, the acute vision with which they are gifted allows them to see predator, prey, mates and rivals, the presence of which causes the observer to react very quickly.  Predators they avoid, prey they will catch, mates and rivals they will chase.

Within the darker confines of the forest flies an insect that both mesmerizes and inspires awe in those seeing it for the first time.  Damselflies would be considered by most as being the smaller, more delicate relatives of the dragonflies.  Here in the forests surrounding Bosque del Cabo  flies the largest damselfly on the planet, the Helicopter Damselfly, (Megaloprepus caerulatus).

Megaloprepus caerulatus

The first words used by guests upon returning from the forest where they have witnessed this spectacular creature for the first time are “I saw something flying like a helicopter”, or there were two large insects flying round each other.

The body is long and needle-shaped.with a broad tip.  The wings are heavily veined and made of thin transparent tissue like clear cellophane.  As the creature flies the wings catch the light and glint in the sun.  But the confusing part about what is being seen is in no small part due to the bluey-black and silver-tips to the end of all four wings.  When in flight they give the impression that the wings are moving in the same fashion as the rotor blades of a helicopter, hence the name.

The Helicopter Damselflies are spider-eating specialists.  They have the ability to fly vertically up and down as well as horizontally in and out which you will see them do in front of a series of spider webs.  When they find the silk spinner, they grab it in their legs, reverse backwards, nip of the head and legs then proceed to devour the softer body parts.

It is not uncommon to see the Helicopter Damselflies along the trails but it is not the easiest insect to photograph.  When at rest they fold their wings back and over the body.  This is your opportunity as it was mine.  There is a smaller species, Mecisogaster ornata, which is also frequently seen and has yellow tips to the wings.

Little Flower

This week I decided to take a look at and photograph some of the plants that grow next to the roadside and are so often ignored.  They are there every day and most flower continuously year round but everyone just walks by and doesn’t notice.  But if you sink to your knees and go down to their level then you will see that they are just as pretty as the large showy blooms sported by many of the shrubs and trees..

One low growing herbaceous plant with deep green foliage offsetting its tiny yellow flowers is the Florecilla, (Baltimora recta).  It belongs in the daisy family (Asteraceae).  Another plant is the same family is the Dandelion, (Emilia fosbergii).  It is not a plant native to the Americas, its origins belong in the Old World, but now its delicate pink and purple flowers can be seen decorating any sunny roadside throughout the country.

Baltimora recta         Emilia fosbergii         Sida rhombifolia

There are several sprawling ground huggers to be found everywhere on the Bosque verges.  One has small yellow cup shaped flowers, Escobilla, (Sida rhombifolia).  This plant is found all over the planet in tropical and subtropical open areas.  Being so common you would think it would be familiar to a lot of people but probably only the discerning botanist would notice it.  In many situations growing beside the Escobilla is a plant with small pink pom-poms as flowers.  It is not the flowers that normally catch the attention with this plant but rather the leaves.  When touched, the leaves instantly fold up and the stem droops.  The reason for this is not entirely understood but there are several theories.  It could be to escaped grazers but I can’t see why a folded leaf would not be consumed over an open leaf.  When it rains the pounding of the droplets may damage the leaf so again it folds.  Finally at night the leaves close.  This may aid in reducing transpiration but once more in the evening when the temperature drops, the relative humidity of the air increases so I am not sure about that one either.  Nonetheless it certainly remains a feature that in particular fascinates children.

Mimosa pudica

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


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 0.37 ins.  Total Weekly Rainfall 2.61 ins

Average Daily Rainfall 9.50 mm.  Total Weekly Rainfall 66.3 mm

Highest Daily Temp 89°F.  Lowest Daily Temp 74°F.

Highest Daily Temp 32.2°C.  Lowest Daily Temp 23.7°C.

Species List for the Week


  • Central American Squirrel Monkey
  • Mantled Howler Monkey
  • Spider Monkey
  • White-faced Capuchin Monkey
  • Common Tent-making Bat
  • Central American Woolly Opossum
  • Agouti
  • Red-tailed Squirrel
  • White-nosed Coati
  • Collared Peccary


  • Red-lored Amazon
  • Scarlet Macaw
  • Great Curassow
  • Black Hawk
  • Black-hooded Antshrike
  • Chestnut-back Antbird
  • Common Paureque
  • Lineated Woodpecker
  • Pale-Billed Woodpecker
  • Blue-crowned Motmot
  • Short-billed Pigeon
  • Long-billed Hermit
  • Purple-crowned Fairy
  • Stripe-throated Hermit
  • Red-capped Manakin
  • Streak-headed Woodcreeper
  • Wedge-billed Woodcreeper
  • Fiery-billed Aracari
  • Chestnut-mandibled Toucan
  • Summer Tanager
  • White-shouldered Tanager
  • Bright-rumped Atilla
  • Dusky-capped Flycatcher
  • Golden-crowned Spadebill
  • Great Kiskadee
  • Great Tinamou
  • Black-throated Trogon
  • Black Vulture
  • Turkey Vulture


  • Basilisk
  • Cat-eyed Snake
  • Central American Smooth Gecko
  • Clawless Gecko
  • Common Anolis
  • Four-lined Ameiva
  • Golfo Dulce Anolis
  • Mediterranean House Gecko
  • Terciopelo


  • Banana Frog
  • Black and Green Poison Arrow Frog
  • Fitzinger’s Rain Frog
  • Masked Smilisca
  • Marine Toad
  • Red-eyed Green Tree Frog
  • Savage’s Thin-fingered Frog
  • Stejneger’s Dirt Frog
  • Tink Frog


  • Anartia fatima
  • Anartia jatrophae
  • Cithaeria pireta
  • Dione juno
  • Dryas iulia
  • Eueides aliphera
  • Eueides lybia
  • Glutophrissa drusilla
  • Heliconius erato
  • Heliconius ismenius
  • Heliconius sapho
  • Heraclides cresphontes
  • Junonia evarete
  • Morpho helenor
  • Morpho menelaus
  • Parides erithalion
  • Perophthalma lassus
  • Pierella luna
  • Pyrgus oileus
  • Pyrisitia nise
  • Saliana esperi
  • Urbanus simplicius


  • Acmella oppositifolia Flowering
  • Allamandra cathartica Flowering
  • Alpinia purpurata Flowering
  • Anthurium salvinii Flowering
  • Apeiba tibourbou Flowering and Fruiting
  • Aphelandra golfodulcensis Flowering
  • Arachis pintoi Flowering
  • Arundina graminifolia Flowering
  • Attalea rostrata Fruiting
  • Baltimora recta Flowering
  • Bauhinia variegata Flowering
  • Brunfelsia grandiflora Flowering
  • Calathea marantifolia Flowering
  • Cananga odorata Flowering
  • Canna sp Flowering
  • Cascabella thevetia Flowering and Fruiting
  • Castilla tunu Flowering
  • Chrysobalanus icaco Fruiting
  • Citrus spp Flowering and Fruiting
  • Clusia rosea Flowering and Fruiting
  • Clusia valerii Flowering
  • Cocos nucifera Flowering and Fruiting
  • Costus speciosus Flowering
  • Couroupita guianensis Fruiting
  • Cresentia alata Flowering and Fruiting
  • Crotalaria retusa Flowering
  • Cyclanthus bipartitus Flowering
  • Emilia fosbergii Flowering
  • Etlingera elatior Flowering
  • Guaterria amplifolia Fruiting
  • Hedychium coronarium Flowering
  • Heisteria accuminata Fruiting
  • Heliconia chartacea Flowering
  • Heliconius clinophylla Flowering and Fruiting
  • Heliconia latispatha Flowering
  • Heliconia longiflora Flowering
  • Heliconia pogonantha Flowering
  • Heliconia psittacorum Flowering
  • Heliconia rostrata Flowering
  • Hibiscus rosa-sinensis Flowering
  • Hymenaea coubaril Fruiting
  • Ixora coccinea Flowering
  • Lantana camara Flowering and Flowering
  • Mimosa pudica Flowering
  • Morinda citrifolia Flowering and Fruiting
  • Musa acuminata Flowering and Fruiting
  • Pandanus sp Fruiting
  • Piper hispidum Flowering and Fruiting
  • Pleiostachya pruinosa Flowering
  • Plumeria rubra Flowering
  • Psychotria solitudinum Fruiting
  • Sida rhombifolia Flowering
  • Spathodea campanulata Flowering
  • Spondias mombin Flowering
  • Stachytarpheta sp Flowering
  • Thunbergia erecta Flowering
  • Thunbergia fragrans Flowering
  • Tocoyena pittieri Fruiting
  • Virola sebifera Fruiting
  • Zingiber spectabile Flowering

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 )

Google+ photo

You are commenting using your Google+ 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 )


Connecting to %s

%d bloggers like this: