La nostra guida introduttiva sulla Costa Rica (english version)
THE ECOLOGICAL PICTURE
• Costa Rica measures only about 300 km across at her widest point
• 4 mountain ranges divide her like a backbone:
1.CORDILLERA DE TALAMANCA: is the oldest mountain range, located in the southern Central America. The highest point is the Mount Chirripò (3700m). Much of Range is included in the La Amistad International Park, which also is shared between the two countries. Much of the region is covered by the forest.
2.CORDILLERA VOLCANICA CENTRAL : is made up of volcanoes Turrialba, Irazù (3432 m), Barva and Poas. The Central Rang continues the Continental Divide east of Cordillera de Tilarán. More than half of the 3.8 million inhabitants live in the Central Valley, whose fertile soil was created by the activity of the volcanoes over the last 2 million years.
3.CORDILLERA DE TILARAN: is part of the Continental Divide east of Lake Arenal and the nearby active volcano Arenal, and running into the Cordillera Central range further east. It is located in the province of Guanacaste. At the edge of the range is the Monteverde cloud forest preserve, a major ecotourism destination.
4.CORDILLERA DE GUANACASTE:is in northern Costa Rica near the border with Nicaragua. The range forms part of the southern region of the Continental Divide, the highest peak being the extinct stratovolcano Miravalles at 2,028 m. Peaks include: Miravalles Volcano(2,028 metres) Orosí Volcano (1,659 metres) Rincón de la Vieja Volcano (1,916 metres- now being used to generate geothermal energy).The Continental Divide of the Americas, or merely the Continental Divide or Great Divide, is the name given to the principal, and largely mountainous, hydrological divide of the Americas that separates the watersheds that drain into the Pacific Ocean from those river systems that drain into the Atlantic Ocean.
• Costa Rica is a very small country, but it boasts the most diverse selection of flora and fauna in the hemisphere.
• There are several reasons for this diversity: thopography ranges from the bleak 3650m above the sea level, to rainforests on the coasts only 80 km away, with countless microclimates in between.
• Costa Rica’s latitude contributes steady temperatures year-round, and abundant precipitation creates hospitable conditions for many forms of life.
• It’s a kind of land bridge between North and South, where migrating animals and plants meet.
• There are animals here that have evolved nowhere else in the world for example:
◦pacas and agoutis (cousins of guinea pigs)
◦dantas (huge tapirs)
• Costa Rica is home to a wide range of ecosystems, a term used to describe a community of living organisms and their complex interactions with their environment.
• related to the summits of Costa Rica’s southern Talamanca mountain range.
• Just as the foliage is tough and small, which protects it from the elements and conserves energy.
• The animals that live here are mostly small rodents and tiny lizards activated by strong sun.
• Paramos originally were limited to the highest peaks of Costa Rica, but due to deforestation, this bleak zone is extending downward.
• the highest rainforest blanketing the slopes of the Continental Divide, are called coud forests because they are nearly always veiled in clouds.
• Scientists postulate that global warming is making the clouds rise higher over the divide, depriving cloud forests of their mist. They think that this drying effect might be responsible for the disappearance of moisture. Sensitive frogs and toads,
• Monteverde is the most famous cloud forest (Los Angeles Cloud Forest, Bosque de Paz, braulio Carrillo national park).
• The Atlantic Coast and the Corcovado Peninsula are home to the rainforests: very tall trees with vines twisting up their girth, hanging roots of philodendrons whose leaves are high above.
• Many reserves in the Sarapiqui and Guapiles areas: Tirimbina Wildlife Refuge, Selva Verde, La Selva, Rara Avis.
• The Heliconias Reserve (north of Canas on the road to Upala) is one of the most beautiful in the country.
• Carara and Manuel Antonio national parks are the most visited rainforests, due to their easy accessibility.
• The forest has several levels: from ground-covering fern and mosses, to short bushes and tree ferns, to canopy species stunded by a lack of light, to trees that reach a certain height and provide a mid-canopy, to the canopy trees which can reach up to 50 m in height
• Canopy trees are able tophotosynthesize relatively rapidly due to abundant light, so it supports the majority of primary productivity in forests.The canopy layer provides protection from strong winds and storms, while also intercepting sunlight and precipitation, leading to a relatively sparsely vegetated understory layer. Forest canopies are home to unique flora and fauna not found in other layers of forests. The highest terrestrial biodiversity resides in the canopy of tropical rainforests.
Many rainforest have evolved to live solely in the canopy, and never touch the ground.
• Seeds are eaten or carried by birds or monkeys that travel through the forest and drop them along the way.
• Many seedlings flourish in the shade at ground level.
• Species that demand much light will flounder in the relatively dark forest floor until an old tree dies or falls, and leaves a “light gap”. At that point, the light demanding species will shoot up until one reaches the canopy and fills the hole.
• A true rainforest is evergreen: trees will never all lose their leaves at once.
DRY PACIFIC FOREST
• It is deciduous, shedding its leaves during the severe dry season to conserve water
• The canopy is significantly lower than in the rainforest.
• When the trees are bare, it’s often easier to see wildlife here.
• Many of the animals that frequent the dry pacific forest are seasonal visitors from other ecosystems.
• Tropical dry forests occur only in Guanacaste (Santa Rosa, lomas Barbudal, Palo Verde).
• they are found in intertidal zones at river mouths and estuaries where fresh water and saltwater meet.
• The different types of mangroves (red, black, white, tea and buttonwood) are actually from 4 unrelated families.
• They resist osmosis by maintaining a higher concentration of salt in their tissues than in the seawater, and secrete excess salt from their leaves or roots.
• To aerate mangroves have aerial roots with multiple buttresses.
• By preventing large predators from entering, their tangle of roots provides a habitat for many species of marine life at their most vulnerable stages of development.
• Baby oysters (ostriche) and sponges attach to the roots. Algae generated in the nutrient rich mud is abundant food for your crabs (granchi), lobsters (aragoste) and shrimps (gamberi).
• Some types of mangroves gradually turn a wet intertidal zone into dry land.
• As their leaves drop onto silt collected in the roots, a layer of soil slowly develops.
Eventually the mangroves are stranded on dry land and die.
• However unique floating seedlings with weighted bottoms are carried in the water until they can lodge in the mud. Because seeds germinate while still on the tree, they quickly take root, in a never ending quest for new territory.
• Best areas to observe mangroves:
• the Estuaries of the pacific Coast
• the Rio Sierpe boat trip to Drake Bay
• the Atrocha route between Golfito ans Zancudo
• the canals just north of Moin on the way to Tortuguero
• on Isla Chira in the Gulf of Nicoya
• Mangroves filter sediment-rich river water so that much clearer water flows into the ocean. • In some areas off the coast, where the water is very clear, coral reefs develop.
• Coral reef are animals, plants, and geologic formations all in one.
• They create habitats of rich biological gardens populated by many different life forms (damselfish pesce pulitore).
• The coral structure is formed by unique plantlike animals that live within it, filtering water to obtain nutrients then excreting calcium carbonate, which becomes the coral skeleton.
• The coral reef itself breaks waves, creating a calm interior thick with sea grasses, and important nutrients for turtles and manatees (tipo foche) for ex.
• Manuel Antonio has calm waters and lovely reef,
• the Manzanillo reef south of Puerto Viejo has only recently been mapped.
• One of the best places to dive and snorkel is isla del Cano (20 km off drake bay) which has 5 coral platforms.
• Costa Rica is home to an incredibility diverse selection of flora, each type adapted for life in a particular ecosystem.
• In RAINFORESTS the predominant colour is green, but at eye level there are brightly coloured and fragrant flowers.
• An epiphyte is a plant that grows upon another plant (such as a tree) non-parasitically or sometimes upon some other object derives its moisture and nutrients from the air and rain and sometimes from debris accumulating around it, and is found in the temperate zone
• branches and treetops covered with orchids, mosses, ferns, lichens, bromeliads.
• Epiphytes: plants whose roots grasp tree branches and absorb their nutrients from leaf matter and water dripping off the canopy.
• Drip tip leaves will drain water collected on them so that their surface is dry, making it difficult for mosses to colonize.
• Drip tip leaves are slippery and slick so that when the rain drips on to them, the water just drips straight off. They help provide water for the rest of the rainforest, and help in the process of evaporation.
• Ferns are a category of flowerless epiphyte (800 types in Costa Rica).
• The 1500 species of orchids that are found in Costa Rica are the showiest epiphytes, with intricate and spectacular flowers.
• Because they do not have eatable pollen to offer their pollinators, orchids rely either on an alluring strong scent or mimicry to deceive insects into believing they are something they are not.
• Bromeliads are epiphytes that collect and store water in their tightly joined leaf bases, or trap tiny droplets in their hairlike trichomes. This water is rendered nutrient-rich when particles fall into it or when mosquitos and other insects that breed in it die and decompose there.
• The 170 species of bromeliads found in CR provide niches for up to 250 forms of life.
• CR offers a variety of flowering plants, many of which have developed very specific traits for survival.
• they lean out over the beach to reach more sunlight and to drop their nuts where the waves will pick them up.
• Coconuts can float in the ocean for several months and land on another beach far away.
• The infant plant is nourished by the rich coconut milk and mat, and once leaves emerge and photosynthesis begins, thousands of roots emerge from the nut and anchor (fissano) the young tree to the beach.
• New leaves grow and old ones are shed about once a month.
• Recognizable by its prominent orange-red roots, the milk or cow tree is common in the rainforest of Corcovado National Park (Brosimum utile).
• Its fruit is eatable and its wood is useful for construction.
• The indigenous people of the area used its bark to stay warm: they would cut a portion of bark from the tree, soak it, then dry it and beat it to make a warm, soft blanket.
Indio Desnudo (naked indian – sunburned gringo)
• bright orange bark
• the leaves fall off during the dry season, but chloroplasts under the bark’s surface allow photosynthesis to continue.
• Each tree produces a bounty of between 600 and 6000 fruits, which are savoured by white faces monkeys.
Ceiba or Kapok Tree
• is one of the fastest-growing trees known, climbing as much as 4 m a year to a maximum recorded height of 60 m.
• its seed pods contain envelops of cottony fibers that enclose the seeds. The envelops are carried by the wind and eventually the seed falls out.
• Its fiber has long been used as stuffing for pillows, saddles, and clothing.
• The wood is too light for construction, but is used for canoes and coffins.
• are parasitic tree like plants that begin as epiphytes on a tree limb when a seed from a bird dropping takes root in a hospitable nook.
• Once the seedling is established, it sends roots that surround the host tree trunk in a close embrace, and branches reach to cover the upper branches of the host tree.
• The host tree eventually dies, probably not because of strangulation, but because the fig’s branches block the host tree’s light source.
• The Original Canopy Tour in Monteverde begins with a climb inside a hollow strangler fig tree.
REPTILES AND AMPHIBIANS
• rainforest amphibians generally have toxins in their skin. The mildest poison just taste bad, while the strongest can kill predators (including humans) by causing vasoconstriction, respiratory paralysis, hypertension, and other mortal conditions.
• The toxin may be ingested through the mucous membranes of the mouth of throat, or through the pores in the skin.
• spends entire life high above the rainforest floor.
• Bromeliad water vessels serve as the frog’s breeding grounds, protecting the developing tadpoles (girini)from predators.
• At the end of the 2 month gestation period, an adult dart frog emerges from the plant shelter with a fully developed system: its skin glands exude a poison that rolls off its back like drops of sweat.
• The frog’s brilliant red colour serve as warning.
• Other toxic amphibians warn predators with flash colours, brightly coloured legs or groin areas, which are revealed only when the animal jumps. This startles the predator, and might dissuade it from attacking.
• Pacific or olive ridley turtle at Playa Nancite in Santa Rosa National Park and at Ostional near Playa Nosara.
• The Green Turtle at Tortuguero
• The Leatherback at Playa Grande near Tamarindo, Tortuguero, the Pacuare Reserve near Parismina, and the Gandoca-Manzanillo Wildlife Refuge in Talamanca.
• Caymans grow no longer than 1 meter, live in creeks, ponds, mangrove swamps and beach lowlands (Corcovado Area)
• Crocodiles are the larger animals, reaching up to 10 meters in length (rivers in the Northern Zone, on the boat trip to Tortuguero, on the Rio Sierpe, at the Carara National Park near Playa jaco).
Due to their camouflage and wariness of humans, you are not likely to see snakes in a brief visit to the forest.
• Boa Constrictors
◦are long (15 meters) fat snakes with dark squares on a light brown or grey background
◦they sit and wait until a likely prey appears (lizard, tanagers, opossums, porcupines, deer) and then they strike, impale the animal on their fangs, lift it,strangle it, then swallow it head first.
• Fer-de-lance (terciopelo) snake
◦is a venomous resident of rainy jungles, large rivers and overgrown fields.
◦Brown and black with a white x pattern running down their back, which make them almost impossible to see among the twigs and leaves.
◦When disturbed, this aggressive 6 meters snake bites anything that moves, and its bite can be fatal.
◦Its usual diet consists of mammals and birds.
• Eyelash viper
◦is no named for a visor-like scale that extends beyond its eyes,
◦small and come in green, brown, rust, grey, light blue, with a darker diamond pattern on the back.
◦Hangs in trees.
◦with striped on its neck and diamonds on its back.
◦Mostly found in Guanacaste.
• most famous cloud-forest bird
• large, brilliant green bird whose males sport a two-foot-long wispy tail.
• They are non very easy to spot because they remain very still high up in the trees.
• During their mating season from February to April they are more visible
• cannot live in captivity, a poetic quality that has made them a symbol of freedom for the people of Central America
• The Resplendent Quetzal was considered divine, by Pre-Columbian Mesoamerican civilizations. Its iridescen green tail feathers, symbols for spring plant growth, were venerated by the ancient Aztecs and Maya, who viewed the quetzal as the “god of the air” and as a symbol of goodness and light.
• Mesoamerican rulers and some nobility of other ranks wore headdresses made from quetzal feathers, symbolically connecting them to Quetzalcoatl. Since it was a crime to kill a quetzal, the bird was simply captured, its long tail feathers plucked, and was set free. Quetzalcoatl was the creator god and god of wind, often depicted with grey hair. In several Mesoamerican languages, the term for quetzal can also mean precious, sacred, or erected.
• Resplendent Quetzal cannot be bred or held for any long time in captivity, and indeed it was noted for usually killing itself soon after being captured or caged. For this reason it is a traditional symbol of liberty.
• Quetzals migrate during the year to follow ripening fruits of trees in the avocado family.
• follow ripening fruits up and down the mountains
• gets its name from its bell-like voice and the three wattles or wormlike pieces of skin that flop over its beak.
• This bird eats the same avocado-like fruits as the quetzal, and also migrates to lower elevations after breeding in the cloud forest.
Bare-necked umbrella bird
• males are large and black with big fluffy pompadour headdresses and bright red featherless throats that they inflate to attract the much less ornate females.
• this large, dull-coloured bird with yellow tail wave long, sac-like nests on dead tree branches
16 species of this raucous family inhabit Costa Rica.
• is monogamous and mate for life.
• Used to live throughout the lowlands of Costa Rica, but massive deforestation and poaching have restricted the few remaining birds to Carrara national Park and the Osa Peninsula.
• used to range through the entire Atlantic lowland region of Costa Rica, nesting in giant almendro trees.
• Until recently these trees were left by lumbermen bacause their wood was too hard to process as lumber. However, new technology has been developed and the trees at an alarming rate.
• The habitat has been reduced by 95%, the International Union for the Conservation of Nature has been working to save the remaining birds and their habitat.
• Of the 330 species of hummingbird known to exit in the world, almost 1/5 are found in Costa Rica.
• These tiny nectar-eaters have unusual wings that can rotate at the shoulders, allowing them to fly in any direction or hover over a flower while they fit their beak
into the floral tube and suck out the nectar.
• Almost any pink, red or orange flower attracts them. • La Paz Waterfall Gardens on the eastern slopes of Poas volcano.
about a quarter of Costa Rica’s 850 species of birds are seasonal visitors from North or South America. They fly to the tropics to escape scarcity during harsh winters, making long, arduous journeys over land and sea.
• they do an amazing non-stop 500 mile flight over the Gulf of Mexico.
Raptors: hawk – falcon – eagle
• They fly over Costa Rica on their way south every October.
• The best hours of the day to see birds are before 8 am and for an hour or 2 before sundown.
• the largest Costa Rican carnivores, are most common in the areas where there has been little human penetration.
• the vegetarian animal has been considered one of the finest delicacies, so the mammals are also in danger of extinction.
• this animal hardly moves. It just eats leaves, so it needs to carry out a low-maintenance lifestyle.
White faced monkey (mono cariblanco)
• this insect-eating monkey inhabits the Caribbean lowland rainforest.
Howler Monkey (mono congo)
• so named because their bellows resonate through the forest, making them sound like much more terrifying animals than the vegetarians they are.
Spider Monkey (mono colorado)
• they have long, prehensile tails with a fingerprint-like imprint at the end, adapted for gripping.
• Their increased agility allows them to leap up to 30 feet.
• These monkeys love physical contact so much that they sleep in a big heap.
Squirrel Monkey (mono titi)
• these tiny monkeys live in the Pacific lowland area and are highly social, living in bands up to 30 strong.
• they are diurnal and easily seen in open areas.
• Agile in trees, they are competent ground dwellers as well.
• Female and young live in band, adult males are solitary.
• living in groups of 3 to 30, they greet one another by rubbing their heads to the scent glands near their tails, and sleep together to conserve heat.
• they are visible in Drake Bay on the Osa Peninsula and in Gandoca on the Caribbean.
• they are visible off the Pacific coast, especially at Ballena National Park in Uvita de Osa and in in Drake bay. They come to give birth between mid-December and mid-April.