Costa Rica; where the Americas meet #1

How to talk about an entire country - especially one as special as Costa Rica - in a single blog post? Well of course I can't meaningfully do so, so I'm going to break it into three posts, the second and third being on birds and other animals. This one will be something of a scene-setter, briefly introducing the origins, habitats and regions of this tiny land  -  well, tiny by Australian standards at least, only about 75% of the area of Tasmania, our smallest state. However it is bursting with diverse tropical life, especially in the rainforests which rise from sea level on both coasts high into the mountains.

Moreover it is fascinating too in other ways, even within the already fascinating context of Latin America. Since independence in the early 19th century there has been a strong narrative of social welfare and justice that put it ahead of much of its time, such as the introduction of eight-hour working days, tenancy protection laws and workplace safety laws in the 1920s. Famously Costa Rica abolished its military in 1949, and diverted a good part of the money saved into education and health, in both of which it is a leader. More recently it committed itself to 'decarbonising' the economy and achieving carbon neutrality, which it had virtually reached when we were first there in 2019. Unfortunately the current president has backed away from that, and weakened Costa Rica's previous excellent stance in responding to COVID, citing a need to 'reassure the private sector'. But in Costa Rica, presidents come and go and it's hard to see this country abandoning lofty social and environmental goals for long. 

That's not my area of competence though, so we'll return to the more natural aspects of the country.

Rich cloud forest at 1400 metres above sea level at Monteverde, on the
northern central Pacific slopes.

Central America is a somewhat amorphous concept - it is certainly not a continent, but the southern end of North America. The UN defines it as the area (including eight countries) between the top of Mexico and the top of Colombia; another definition excludes Mexico, leaving only, from north to south, Belize, Guatemala, Honduras, El Salvador, Nicaragua, Costa Rica and Panama.

The not-Mexico version (low resolution) of Central America, which is fine for our purposes.
Map courtesy of geology.com.

Until recently - probably no more than 4.5 million years ago - as South America drifted west, North and South America were separated by the Central America Seaway, between the Pacific and Atlantic Oceans, in which were volcanic islands being pushed up from the sea floor by the movement of the Cocos Plate (west of South America) forcing itself beneath the Caribbean Plate. Sediments from both continents washed into the narrow sea, gradually filling the gaps between islands and forming a bridge between them. South America's ancient isolation had ended, and nothing would be the same again for its unique fauna.

Nine-banded Armadillo Dasypus novemcinctus, one of the very few ancient South American
larger mammals to not only survive the collision with North America, but to establish
itself in the north as well.

This fauna included a rich and varied mammal array, such as large marsupial carnivores like the doglike borhyaenids and Thylacosmilus, which looked surprisingly like a saber-toothed cat. There were giant sloths and hoofed mammals with passing resemblances to elephants, horses and tapirs, but entirely unrelated to those groups. Very few of these fabulous beasts survived the invasion of the tough North American invaders when the isthmus closed and formed a bridge; these invaders were very used to competing with invaders from Asia while the South Americans had long had the place to themselves. Among the large mammals only the giant sloths survived - at least until humans arrived. The northern birds on the other hand had much less success in establishing themselves in the south. 

 

The movement was in both directions of course but, apart from the fierce competition, those rainforest dwellers who moved north had to contend with the deserts and a barrier range of high volcanoes across Mexico. More on this in the next couple of posts, with reference to specific groups, but it goes a long way to explaining why Central America, including of course Costa Rica, is so rich in wildlife, as animals (and plants) from both north and south mingle there. Many South Americans got this far north but not much further.

There are is no single mountainous spine, such as the Andes provide in South America, but there are three actively volcanic main ranges being, from north to south (or more precisely north-west to south-east), the Cordilleras de Guanacaste, Central and de Talamanca. Within the central range is the big Central Valley, within which lies the capital San José and the other major cities and most of the population, and much of the important coffee crop.

Part of the Cordillera Guanacaste, from Monteverde.

The country is entirely within the tropics, so it's warm and humid all year round, though of course cooler in the mountains. The Caribbean coast is very wet throughout the year (6000mm a year at Tortuguero for instance), while the Pacific coast is more seasonal, with rainfall decreasing to the north.

Rainforest forms the predominant original vegetation, and the country has done a superb job in protecting what is left and also undertaking massive reforestation projects, beginning in the 1980s when forest cover had fallen to about 24%. The program was based in large part in rewarding farmers for foregoing clearing and replanting, at an agreed rate per hectare. Today the forest cover is up to 57%, which is apparently the maximum possible given both the land that was never forested, and land which is either urban or agriculturally productive (coffee, pineapples and bananas are important export earners). It is striking, when driving around the country, how much of the time is spent within forest. 25% of the country is protected in public conservation reserves, the highest proportion in the world and three times the developed world average, in addition to many private reserves.

Lowland rainforests dominate up to about 500 metres above sea level (masl) all along the Caribbean coast, and the southern half of the Pacific coast.

Massive buttress in primary rainforest in Carara NP, on the mid Pacific Coast.

One of the many walking tracks through Carara NP. Wildlife, from poison dart frogs
to big Spiny-tailed Iguanas and Fer-de-lances to antbirds and woodpeckers, is everywhere
in this forest, and in all the rainforests

Here are some more low elevation rainforest photos from different parts of the country. 

Rainforest crowding the banks of the canals in Tortuguero NP, which provide the only
access to the coast here. These canals were dug in the 1940s to connect natural
waterways, and Tortuguero to the towns to the north and south along the coast.
They were originally designed to move rainforest timber; this logging
industry ended in the 1970s and now tourists flock here, especially to see
the Green Turtles which lay eggs on the beaches at night.

A small forest pool in rainforest at Esquinas Lodge in Piedras Blancas NP
in the far south near the Pacific coast.

Rainforest along the Puerto Viejo River, from the footbridge over it at La Selva
Biological Research Station, just 60masl, though it is 60km inland from Tortuguero.
This superb destination (which provides public accommodation) is run by the
Organisation for Tropical Studies, a consortium of over 50 universities in Costa Rica,
the US, Mexico, Peru and South Africa. Its 1600ha of largely primary rainforest adjoins
the northern edge of the 47,000ha Braulio Carrillo NP, and contains some 60km of
walking tracks. A must for anyone reading this blog when you visit Costa Rica!

Baird's (or Central American) Tapir Tapirus bairdii, a widespread though not usually
easy to see inhabitant of the rainforests, though it can also be found
to above the tree line.

Rainforest canopy at Tapirus Lodge, a private reserve to the south of La Selva,
still on the Caribbean slope and on the eastern boundary of Braulio Carrillo NP.
This was taken from the remarkable canopy-level cable car (or 'aerial tram')
which offers an hour return trip, with the option of disembarking at the top.

Morning mist over the rainforest along the access road to Tapirus Lodge.
The lodge is at 500masl, so at about the elevation where lowland rainforest
gives way to highland cloud forest on the Caribbean slopes, though this
happens at somewhat higher elevations on the Pacific side.

Cloud forests cover some 16,000ha of mountainous Costa Rica, from the upper level of the lowland rainforests to the tree line at about 3000masl. In the north they are dominated by many species of laurel (family Lauraceae) while further south two species of oak provide up to 80% of the canopy cover. I find this particularly interesting, having never thought of oaks as being tropical, though I now belatedly know that there are species throughout south-east Asia as far as New Guinea.

Cloud forest living up to its name at 1800masl on the Pacific slope
of the Talamanca Mountains, above and below.

Climbers are characteristic here, as they are at lower elevations.

Also characteristic of cloud forests are epiphytes - both these and the climbers are using
the structure of the trees to get up to the essential sunlight. This superb display of bromeliads
is seen from the deck at the excellent Paraiso Quetzal ('Quetzal Paradise') Lodge.
This wonderful lodge is perched on the mountainside at 2650masl at the head of the
Savegre Valley, south of San José on the Pacific slope of the Cordillera Central.

Canopy epiphytes from the cable car at Tapirus Lodge - this really is an
excellent way to experience the canopy.

Another way is from the three kilometres of walking tracks at Selvatura Park in Monteverde, featuring eight suspension bridges over deep gullies, so that we're looking down on the canopy.

Cloud forest from above; Selvatura Park suspension bridges, Monteverde.

A remarkable perspective of a female Mantled Howler Monkey Alouatta palliata
and baby from a Monteverde suspension bridge.

The walking tracks between the bridges are also deep in rich cloud forest.

The Savegre Valley, below Paraiso Quetzal, is a superb introduction to the southern oak cloud forests.

Walking tracks through the oaks follow the Savegre river and its streams...

... while vantage points enable us to admire the distinctive oak canopy.

The most famous of the cloud forest dwellers is undoubtedly the wonderfully-named Resplendent Quetzal Pharomachrus mocinno, a magnet for birders everywhere. It is the largest of the trogons, a family of colourful birds found throughout the tropical forests of the Americas, Asia and Africa.

Male Resplendent Quetzal, Savegre Valley. This was from the balcony of a restaurant!
The iridescent feathers look blue in this dim under-canopy light, but bright green in the sun.

Above where the cloud forests end, at about 3000masl, is the páramo, a relatively small treeless region beginning with a zone of dwarf bamboo and low shrubs and grading into heathland and grassland.

Bamboos Chusquea spp. at the edge of the páramo at 3200masl in the Talamanca Range.

Heathland páramo at 3400masl.

Green Spiny Lizard Sceloporus malachiticus at 3400masl (and it was bleak and
cold at the time!), one of the few reptiles that can survive at this altitude and
quite common in the highlands.

At Carara National Park (see above) the southern lowland rainforests begin to give way to drier forests - there is still a high annual rainfall but there is also an extended dry season. In Australia we would call this more open dry rainforest 'monsoon forest', such as is common around Darwin. Much of it has been cleared for agriculture, but there are still significant areas of it protected in the north.

Partially cleared dry forest west of Monteverde.

The understorey - here in Rincón de la Vieja NP in far north-western Costa Rica -
is more open than in rainforest, with often thorny small trees and shrubs.

Overstorey trees however can be 30 metres high, like this fig...

... and many species of pea, such as have covered the forest floor with
flowers here (and below).

As we might expect, there are many animals in these north-western dry forests that are not found elsewhere, such as this beautiful motmot.

Turquoise-browed Motmot Eumomota superciliosam, Rincón de la Vieja NP;
this is the national bird of Nicaragua.

Rincón de la Vieja is also the name of an active volcano in the park - we were however not there in the dry season, and I didn't ever get a chance to take a photo of it without a total cloud shroud. However we walked on its lower flanks, and saw plenty of evidence of its activity.

Steam and gases being emitted from a fumarole on the hillside above a bubbling pool.

Bubbling mud in a hot pool of it, above and below.

+

Irazú Volcano, very close to San José, is Costa Rica's highest active volcano, at 3400masl. It has erupted more than 20 times in the past 300 years, most recently in 1994. Due to its proximity to the national capital, and its easy access, it is a popular destination. Technically you can see both coastlines from the top, but I suspect that doesn't happen very often, and certainly didn't while we were there.  Everything you will read about it mentions the chemically-green lake in the crater, but in fact at the moment it is dry.

This, the main crater, is 750m across and 270m deep, and currently the floor
is covered with volcanic sand and ash. The rim and surrounds are covered
with typical páramo vegetation.

Probably more famous however is the Arenal Volcano at the eastern end of the Guanacaste Range, in a 12,000ha national park. A classic volcanic cone, it is very much alive and in 1968 exploded spectacularly, killing 87 people in nearby villages. The Arenal Observatory Lodge, which is a very nice place to stay indeed, grew from a small accommodation centre provided on private property for scientists studying the aftermath of the explosion. The deck outside the restaurant looks down on a busy fruit feeder for birds, and up at the still largely bared slopes of the volcano.

Arenal Volcano from the Observatory Lodge.

Much of the surrounding forest, with many excellent walking tracks, is secondary forest recovering from the 1968 eruption.

Post-eruption regrowth forest on the lower slopes of Arenal Volcano.

50km to the north, Arenal still dominates the southern horizon, from the open spaces of the lakes of Caño Negro which are the focal point of a Ramsar-listed wetlands site up near the Nicaraguan border. The Frio River feeds it, and flows on into mighty Lake Nicaragua, just across the border. In the wet season the river overflows the plains. This wonderful complex of swamplands, forests and grasslands is only accessible by boat.

Arenal Volcano, 50km away, seen from the lakes at Caño Negro.

Forest-lined lake shore from a boat at Caño Negro.

Another wetland a little to the east, near the cryptically named town of
Medio Queso (ie middle cheese!).

Least Bittern Ixobrychus exilis from the boat in the Medio Queso channels;
this is not an easy bird to see normally. It is the smallest American heron,
and one of the world's smallest.

So far when I've briefly mentioned rivers, it's been in the context of the forests surrounding them, but of course any river trip, of which there are some worthwhile ones in Costa Rica, has its own interest and habitats. One good one is the trip from La Pavona, which is literally the end of the road, via the Rio Suerte ('Lucky River') to the channels which eventually take us to Tortuguero on the Caribbean coast. Here was our highlight of that trip.

Neotropical River Otter Lontra longicaudis focussed on a fishy snack by the Rio Suerte.

Another very worthwhile river trip is on the Tarcoles River. Your first sight of this river is likely to be where the highway crosses it near to Carara NP on the Pacific coast, and where every tour bus stops and disgorges its passengers to walk onto the bridge (just centimetres it seems from passing trucks) to admire the very rare American Crocodiles which loaf hopefully below.

American Crocodile Crocodylus acutus below the Tarcoles River bridge.

However a much more relaxing, rewarding and safe way to see the river is by tour boat, several of which leave from downstream and go through the forest to the river mouth.

Mangroves with 'stilt roots' by the Tarcoles River.

Roseate Spoonbill Platalea ajaja - surely the world's most beautiful spoonbill -
preening by the Tarcoles River. (And the apparenly odd species name is based
on a Tupi name for the bird, from Brazil.)

Brown Pelicans Pelecanus occidentalis at the mouth of the Tarcoles River,
with the Pacific Ocean behind.

Well that's a brief introduction to a fascinating - and to my mind entrancing - country. As I've already promised, there will be two more offerings to introduce some of its superb wildlife, but I'll probably come back to Australian topics before and between them. Meantime, if you have a world wish list and are as fascinated by the natural aspects of as much as I am, Costa Rica deserves a place on that list. 

NEXT POSTING THURSDAY 21 SEPTEMBER

 

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