Tuesday 2nd February 2016
Senna to Sleep
Over the past few weeks many of the trees have started to flower. The increasingly dry conditions stimulate blooming at this time of the year but because most of the floors are 100 foot up in the forest canopy then the only time the visitor has to see them is when flying over the forest or when the spent blooms fall to the ground and lie littering the forest floor amongst the dry leaves. However there are some smaller trees, shrubs and herbaceous plants that grow beneath the canopy or in more open conditions. Here you can get to see the floral display at a closer proximity.
One of those small trees generally found growing along sunny paths and roads is the Saragundi, (Senna reticulata). Its bright yellow flowers tinged with a hint of orange stand upright like fat golden candles giving the whole of the tree crown an overall fiery glow against the green background of the forest or azure blue of the sky. Stand beneath the tree and you will hear the constant buzz of bees attracted by its flowery display as they come to take nectar and pollen.
Despite its showy appearance Saragundi is not a welcome part of the native flora as far as farmers are concerned. It is a rapidly growing weedy tree that will quickly invade and take over open areas such as pasture land and nor is it easy to eradicate. It is little wonder that the local gardening team around here hates them with a vengeance and cut them down as soon as they germinate.
Should you see a Saragundi later in the day, more towards dusk, you will notice that the leaves start to droop and the plant goes to “sleep.” This is a feature common to many plants in the Fabacaea family, (legumes), and it is known as a nastic response. The base of each leaflet has a fleshy elbow called a pulvinus. During the course of the day the rhythmic flow of potassium ions causes water to either enter or exit the cells of the pulvinus. In the morning the large water holding cells become full of water making the pulvinus turgid which holds the leaflet out straight. At dusk water exits the cells making the pulvinus flacid and so the leaflet folds down appearing as if to go to sleep. It is not known what evolutionary benefit this nyctinasty conveys on the plant but it most certainly looks like some of the forest trees are dozing off for the evening.
A Rod of Gold
Growing along the currently dusty roadsides or lining the forest edge abutting the gardens are weedy long-stemmed plants that have a crown of yellow flowers atop. These are the Jackass Bitters, (Nuerolaena lobata). It belongs to the Aster family which includes the daisies and dandelions. It is one of the most species rich families of plants on the planet rivaled only by that of the orchids.
The flowers heads are composites; each individual head is a group of flowers, the greater display of many flowers together provide a more attractive visual target to potential pollinators.
There is a lot of folk medicine currently based on the supposed curative properties of Jackass Bitters but none that has any scientific backing. However its anti diabetic qualities are being scrutinized in a laboratory situation with regards to its ability to exert some control over blood sugar levels.
Canna Look at Your Lily
Tucked under the shady conditions beneath the taller vegetation where the garden meets the forest edge are a low growing plant with yellow flowers. These are the Canna Lilies, (Canna x generalis). It is mostly a hybridized form cultivated to bring a splash of color to leafy green flower borders. It is not obvious from which natural species of Canna that this variety has been hybridized but it is possible that it may be a Neotropical native Indian Shot, (Canna indica). You will seeing this variety growing freely in many garden situations around the country.
Going Bats for Garlic
Going for a walk through the forest this time of year may certainly cause a stimulation of your olfactory senses. There are many scents and odors that seem vaguely familiar but you cannot quite put bring to mind what it is simply because it out of context. Currently walking through the forest there are areas where you experience the definite smell of chives, or is it onions, no wait a minute it is garlic. What would garlic be doing growing in a tropical rain forest situation?
Here and there along the forest trail there are patches of yellow flowers littering the forest floor en masse. At this point the aroma of garlic is very strong. The flowers lie for some distance concentrically around the base of a large tree which given its appearance looks more like a tree from higher temperate forests. The bark is rough and deeply fissured, closely resembling an Oak Tree than a smooth bark tropical tree. This is the Ajo or Garlic Tree, (Caryocar costaricense), so named because its flowers give off a scent reminiscent of garlic.
There is very little wind in the Pacific lowland forests of Costa Rica so the plants have to rely on animal agents for pollination and seed dispersal. Bats are very important pollinators and seed dispersers but bats prefer musky smells rather that sweet smells which is why there are some very strange odors in the forest. It is the scent of garlic that attracts the bats in so the Garlic Tree is a bat pollinated tree.
Seeing Things in a Different Light
On the hot sunny days of the dry season many butterflies can be seen flying around the garden areas. There are several species that are noticeable due to their striking yellow coloration. These could be the “butter” flies. These are the sulphurs and they are not easy to tell apart species wise unless you have them in the hand.
Sulphur butterflies belong in the Subfamily: Coliadinae of the family: Pieridae. To the human eye the butterflies all have yellow coloration to a greater or lesser extent. Some may appear to be more creamy-yellow, others lemon yellow and yet others orangey-yellow but without exception – yellow, hence the name sulphur. But that is not how they look to other butterflies.
Butterflies, unlike humans see light at the ultraviolet wavelength of the electromagnetic spectrum. The dorsal surface of the male sulphurs wings are colored with a yellow pigment. This re-enforces a reflective ultra violet component that covers most of the dorsal wing surface and appears to sexually attractive to females which only have a small amount of ultra violet reflectance on their wings in comparison. The ultra violet patterning is used by the males in courtship displays. To human eyes the butterfly appears as a dancing honey colored piece of confetti. The females however see something different. Larger males with bright reflective radiance appear to be more attractive to larger females. In the world of the sulphurs flashy show offs get the girls.
Philip Davison is a biologist, writer and photographer based in Costa Rica.
Felipe del Bosque Blog December 16th 2013
Summertime
There is no longer any doubt about the fact that we are in the dry season. We are now receiving very little rain if any at all. It won’t be long before the dry conditions stimulate the trees into flowering. Some of the December blooms are already starting to appear. The distinctive yellow blossoms of the Ajo Tree, (Caryocar costaricense), are beginning to fall and cover the forest paths in various areas. Once the Ajo trees are flowering en masse, the scent of garlic from which they derive their name can be smelled everywhere in the forest.
Towards the end of last week more and more clouds started to gather on the horizon until one morning the sun was blotted out and the rain fell continuously till lunchtime. The afternoon remained very dark and gloomy. In total the amount falling didn’t amount to much but it did serve to dampen anyone out walking in it.
Prickly Pig
The female White-lipped Peccary, (Tayassu pecari), still comes around every day in front of the restaurant, generally at breakfast and lunchtimes, to feed on the fallen palm fruits. The much larger male has wandered further afield and I have been seeing him around the area at the entrance of the Zapatero Trail.
The Titi Trail is still alive with Collared Peccary, (Tayassu tajacu), activity. There is a large herd that can be easily seen when walking the trail. They are no longer inclined to move too far from the path when approached. They don’t seem to mind human presence if they can see you coming. If they are startled then they grunt, crack their teeth and trot off into the low growing vegetation.
All the usual mammals are around the grounds but this week on the Titi Trail the cameras caught on video a Tome’s Spiny Rat, (Proechimys semispinosus). The spiny rats are caviomorph rodents in the Family: Echimyidae and are therefore more closely related to the agoutis and pacas than to the mice and rats most visitors are familiar with, (Family: Muridae).
The spines that give the rat its name lie flat in amongst the fur. Tome’s Spiny Rats also have the ability to break the tail should that be the part of the body the predator grabs. The tail does not regenerate so more often than not spiny rats are seen with short tails or none at all.
Blurring the Lines
While out last week conducting the butterfly counts my attention was captured by some movement in amongst the vegetation of a low growing shrub. With closer scrutiny I could see a small bird, obviously a female, hopping between the branches and plucking the snow white fruits of one of the Psychotria sp one after the other, mashing them up in her bill and swallowing the pulp. This was the drab green female Red-capped Manakin, (Ceratopipra mentalis). Within a few seconds she was joined by a male who ostentatiously overcompensates for his plain partner. The male is a small jet black bird with a bright red head and fluorescent yellow legs. It is not easy to ignore his presence.
The manakins in general are fruit-eating birds. Normally in terms of sexual selection with birds the female with select which male she is going to mate with depending upon the quality and quantity of food a male presents to her during the courtship period so that she can see how good of a provider he is going to be. Being fruit-eaters if the male were to present fruit to the female she would not be particularly impressed as she is surrounded by the stuff and so it is not so hard to find.
To show off the quality of their genetic viability the male manakins, like a lot of fruit-eating birds around the world, have evolved very flamboyant plumages and very elaborate dances. They all gather together in a lek. Each male sets up his own dance platform. The females sit on the ground and watch the performance. The dance of the mle Re-capped Manakin takes place on the horizontal branch coming from the side of a trunk. His like a tiny Michael Jackson on amphetamine sulphate moonwalking at double quick speed. He moves very quickly backwards along the branch and then stops and throws in a little bit of Flamenco. He raises his wings which causes a loud repeated clacking sound. The females watching this display choose the male with the best dance moves. They give him the nod, he jumps down mates with her and then continues to dance.
Sometimes when you are walking through the forest you will see a male manakin dancing on his own. There is no lek, there are no females. It is the young ones practicing their moves because if he doesn’t get the steps right he won’t score with the girls.
Sun Dancers
The clouds of Green Urania moths, (Urania fulgens) that have been prevalent over the past month have now dwindled in number. You can still see and odd one or two which take to the air when approached, flutter around and then alight once more on a sunlit leaf.
On the sunniest of days the butterflies can be seen flying on whichever trail you are walking. Most of the butterflies are found at the top of the canopy. At the forest edge, essentially that area where the canopy descends to the ground, the is the opportunity to see those species that would otherwise only be seen 100 feet above your head. There are also patches of plants around the gardens that provide an attractive supply of nectar for the butterflies. It is not uncommon to see many individuals of many species of many families feeding from the bright orange and yellow flowers of the Lantana, (Lantana camara). Here you will find the gaudy primary colors of the Longwings which are so visibly obvious mixed with the more subtly colored satyrs and the occasional hairstreak. But the dry season has only just started. By the time we get to February there will be so many butterflies to dazzle the visitors with not only a visible treat but a stunning wealth of diversity.
True Colors
As I mentioned above many of the trees will be starting to flower soon. Some of them already have. There are a lot of plants around the grounds that flower year round, for this reason they are used as decorative ornamentals. Not all of the plants in the grounds are native to Costa Rica, the gardens boast a variety of exotics from all corners of the tropical world. Within both the native and non-native species there has been a great deal of selective breeding going on to produce hybrids that have more colorful and showy blooms than their natural counterparts. Some of them have been manipulated to produce strangely shaped vegetative or flowering parts.
The Canna Lily, (Canna spp), is found in the flower beds bordering some of the paths in the tropical garden. This is one of those ubiquitous hybrids found growing in gardens the length and breadth of Costa Rica. Its fancy flower with brown speckled yellow petals provides year round color to any flower border.
At the bottom of the tropical garden, in the vicinity of the pond there is currently a riot of red. The Poro tree, (Erythrina lanceolata), is currently in full bloom. The very distinctive clusters of shocking red scimitar-shaped flowers are held at the tip of the long slender branches. Once the blooms have been pollinated then long reddish tinged pendulous pods housing the beans are produced. The Poro trees are currently bearing both flowers and beans. If you want to see hummingbirds this would be the place to go as there are a variety of species visiting the flowers.
Sometimes the fruit of a tree can be just as diagnostic as its flowers. As many of the trees bloom at the top of the canopy it is not always easy to see the flowers. There a several nutmeg producing trees in the forests of Bosque del Cabo. They don’t have the same aroma or flavor of the Indonesian nutmegs, (Myristica fragrans) which we use it our kitchens but they do belong to the same family: Myrisicaceae. The nutmegs of Bosque all belong to the genus: Virola. There are lots of Virola species and each has one has a slightly different looking fruit. The one that has been fruiting recently is Virola sebifera. This produces clusters of green fruits which when they ripen then split apart to reveal the seed, the nutmeg. This is surrounded by a bright red membrane called the aril.
Birds have acute color vision and the bright red color of the aril attracts the attention of fruit-eating birds like the Chestnut-mandibled Toucan, (Ramphastos swainsonii). The aril is very tasty and very nutritious. Once the toucan has digested the aril it is left with a gut full of big heavy nutmegs which is not conducive to flight so they regurgitate them hence dispersing the seeds.
Philip is a biologist, writer and photographer at Bosque del Cabo Rainforest lodge on the Osa Peninsula, Costa Rica.
www.bosquedelcabo.com
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 0.19 ins
Average Daily Rainfall 0.69 mm. Total Weekly Rainfall 4.85 mm
Highest Daily Temp 88°F. Lowest Daily Temp 75°F.
Highest Daily Temp 31.2°C. Lowest Daily Temp 25.1°C.
Species List for the Week
Mammals
- Mantled Howler Monkey
- Spider Monkey
- White-faced Capuchin Monkeys
- Greater White-lined Bat
- Tent-making Bat
- Nine-banded Armadillo
- Agouti
- Tome’s Spiny Rat
- White-nosed Coati
- Collared Peccary
- White-lipped Peccary
Birds
- Red-lored Amazon
- Scarlet Macaw
- Crested Guan
- Great Curassow
- Crested Caracara
- Laughing Falcon
- Yellow-headed Caracara
- Pale-billed Woodpecker
- Northern Barred Woodcreeper
- Black-hooded Antshrike
- Chestnut-backed Antbird
- Rufus Piha
- Short-billed Pigeon
- White-tipped Dove
- Long-billed Hermit
- Rufus-tailed Hummingbird
- Stripe-throated Hermit
- Blue-crowned Manakin
- Red-capped Manakin
- Chestnut-mandibled Toucan
- Grey-headed Tanager
- Summer Tanager
- Bright-rumped Atilla
- Dusky-capped Flycatcher
- Golden-crowned Spadebill
- Great Kiskadee
- Riverside Wren
- Black-throated Trogon
- Great Tinamou
- Black Vulture
- Turkey Vulture
Reptiles
- Barred Ameiva
- Basilisk
- Cat-eyed Snake
- Four-lined Ameiva
- Golfo Dulce Anolis
- Litter Skink
- Mediterranean House Gecko
- Terciopelo
Amphibians
- Banana Frog
- Black and Green Poison Arrow Frog
- Fitzinger’s Rain Frog
- Marine Toad
- Milky Frog
- Red-eyed Green Tree Frog
- Rough-skinned Dirt Frog
- Savage’s Thin-fingered Frog
- Stejneger’s Dirt Frog
Butterflies
- Adelpha cytherea
- Anartia fatima
- Anartia jatrophae
- Antirrhea philoctetes
- Archeaoprepona demophon
- Battus polydamus
- Corticea corticea
- Dryas iulia
- Eurema albula
- Eueides aliphera
- Eueides lybia
- Eurema albula
- Glutophrissa drusilla
- Heliconius erato
- Heliconius hecale
- Heliconius ismenius
- Heliconius sapo
- Heraclides cresphontes
- Hermeuptychia hermes
- Morpho helenor
- Morpho menelaus
- Pareuptychia ocirrhoe
- Parides erithalion
- Philaethria dido
- Phoebis agarithe
- Phoebis argante
- Phoebis sennae
- Pierella helvina
- Pierella luna
- Pyrisitia nise
- Pyrgus oileus
- Pyrrhogyra crameri
- Siproeta stictomenes
- Urbanus tanna
- Vehilius stictomenes
Plants
- Anthurium salvinii Flowering and Fruiting
- Alpinia purpurata Flowering
- Allamandra cathartica Flowering
- Apeiba tibourbou Flowering
- Aphelandra golfodulcensis Flowering
- Arachis pintoi Flowering
- Aristolochia gaudoti Flowering
- Arundina graminifolia Flowering
- Attalea rostrata Fruiting
- Baltimora recta Flowering
- Brownea macrophylla Flowering
- Brunfelsia grandiflora Flowering
- Calathea marantafolia Flowering and Fruiting
- Cananga odorata Flowering
- Canna x generalis Flowering
- Cascabella thevetia Flowering and Fruiting
- Chrysobalanus icaco Flowering and Fruiting
- Citrus spp Flowering and Fruiting
- Clusia rosea Flowering and Fruiting
- Clusia vallerii Flowering
- Cocos nucifera Flowering and Fruiting
- Costus osae Flowering
- Costus speciosus Flowering
- Couroupita guianensis Flowering
- Cresentia alata Flowering and Fruiting
- Crotolaria retusa Flowering and Fruiting
- Emilia fosbergii Flowering and Fruiting
- Etlingera elatior Flowering
- Ficus citrifolia Fruiting
- Ficus insipida Fruiting
- Guatteria amplifolia Flowering
- Hedychium coronarium Flowering
- 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
- Pleiostachya pruinosa Flowering
- Plumeria rubra Flowering
- Rhynchospora nervosa Flowering
- Solanum aturense Flowering
- Stachytarpheta sp Flowering
- Thunbergia erecta Flowering
- Tocoyena pittieri Fruiting
- Virola guatemalensis Fruiting
- Virola sebifera Fruiting
- Zingiber spectabile Flowering
Veridion Adventures 