Rincón de la Vieja,

 Costa Rica

Marietta College Biology and Environmental Science Department Field Trip 2005/2007

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Rincón de la Vieja - literally "the place of the old woman" is a national park centered around the volcano of the same name.  The area is fascinating for its wildlife, volcanic features, and topography which blends the dry countryside of Gunacaste with a lush rainforest wherever the mountains channel water from the prevailing winds.  We visited this park in both 2005 and 2007.

The road up the mountain is steep, and, on one route, lacking a bridge.  Here Eladio checks out the recently flooded stream.

Mallory was always very curious about the local folks, particularly one of Eladio's drivers, Johnny.
   

In 2007 the van Eladio rented got a flat, allowing us some time to explore the vicinity of the road.

A beautiful stone fence along the road.
   

Gabby takes the opportunity to catch up with her journal...

While Mike catches up on some sleep.
   

Eladio's own vehicle was made of stouter stuff.

 

A Central American Parrot Snake (Leptophis ahaetulla) takes a frog in the rainforest canopy.

 

   

A climax forest has roots close to the surface.  In any event, nutrients are readily available in the rich volcanic soils.

 

A hot spring on the slopes of this still-active volcano.  Below, mudpots were bubbling away.

 

Volcanic steam rises over the rainforest.  Areas touched by volcanism may be very dry and support a very different plant community, as can be seen in the foreground.

 

Lizards were out in force; above is the Central American Whiptail Lizard (Ameiva festiva); we saw this species all over Costa Rica.  Below, the Green Iguana (Iguana iguana) was less common.  This is a juvenile, with bright green coloration.
   

We saw a lot of insects on both trips, ranging from fascinating beetles such as the Chrysomelid (above right) and the Pleasing Fungus Beetles (below right) to the colonial termites (Isoptera, above) and Hymenoptera (right and below).

In 2007 we say several swarms of bees and wasps outside of their nests (photo at right).  These individuals are swarming around a queen, whose pheromones (chemical signals) keep the group together while scouts seek out a new nest site.  These individuals have left their former nest, leaving a number of workers and another queen behind; in this way a hive "reproduces".

An interesting beetle (Rhipiphoridae?).

Below, leafcutter ants (Atta cephalotes) were common everywhere we went in Costa Rica, including the capitol, San Jose.

   

No lunch for you....  In 2005, we ate our boxed lunches at the country store with the great view (on a clear day you can see the Pacific); in 2007 we decided to simply buy our lunches there.  Well, when we got there we found out they were no longer serving food, but would be happy to sell us chips for about $6 a bag.  We went without (and splurged on a trip to the heladaria in Liberia later that evening).
   

There are several trails in the park.  We never tried the trail to the summit (maybe in 2009?) but we went to two "swimming holes", the Poza Rio Blanco in 2005 and Catarata (waterfall) la Cangreja in 2007.  There is nothing like swimming in a cold mountain stream after a long hike in a volcanic rainforest!

 

 

Poza Rio Blanco (Pozo means pool, Rio Blanco is the White River) was a small stream cascading down the volcano.  The poza made a decent swimming hole  and the whole gang jumped in.

Above is an image of the main swimming hole; to the right is an underwater shot of the clear water of the mountain stream.  Upstream of the main swimming hole was a small waterfall that Drs. Brown and McShaffrey explored along with Josh and Carrie.  Below, Josh (left) and Dr. Brown (right) taking a shower; Below center a showeree's view of the falls.

 

Not shown:  77mm lens cap on bottom of poza!

 

Dr. Brown gives an impromptu waterfall-side lecture.

View from below the waterfall.

 
Catarata  la Cangreja (Waterfall of the Crab?) was our goal in 2007.  The blue waters are apparently due to copper salts in the water coming down off the volcano.  

View from behind the waterfall.

 

 

The cabuya is a relative of the Agaves, some of which are the source of tequila.  Another famous Agave is the Century Plant, which waits a ling time before developing a huge flower spike, after which the plant dies (they may flower in less than the implied century). The cabuya is a similar plant, with the long spiky leaves well armed with thorns along their edges(left).  After a long growing season with a conventional whorls of leaves, the flower spike grows suddenly to the size of a small tree (right); after this the plant dies (above).  We saw many of these on the trail to the waterfall, usually near the intersection of dry grasslands and moister forest pockets.

Another relative of this plant is the Yucca.

 
 

The Coati (Nasua narica) is a relative of the raccoon (both are in the family Procyonidae).  This species is found from the southern United States through Panama.  They are diurnal, foraging on the forest floor; this male was digging in the litter near the trail.

 

Most of our hike in 2007 was on the western (Pacific) flanks of the volcano.  The trail ran from grassy highlands to ravines full of rainforest; these microhabitats are the result of the interplay between the topography of the mountain and the prevailing winds and weather patterns.  Guanacaste Province in general has a pronounced dry season due to its proximity to the relatively cool Pacific (which does not have much moisture to give up) and the fact that during much of the years trade winds blowing from the Caribbean side lose all their moisture when climbing the slopes on the eastern side (see diagram below).  The "rainy season" in Guanacaste is really an unsettled time of year when the trades weaken and intense storms can form; often the yearly rain in any given location is the result of just a few torrential storms rather than a prolonged period of rainy weather.  On the slopes of the volcano the results of the clashing air masses are played out with obvious differences occurring in distances measured in meters.  Ravines and draws may allow moisture rich wind to pass over the mountain and bring clouds and rain; the water that falls is trapped in the ravine and nourishes rainforest where the intervening ridges are exposed to dry winds and have no source of subterranean water.  In the photo above, a rainforest-filled ravine fills the gap between two grasslands; the rainforest is nourished by cool, moist air spilling over the volcano as well as the water coursing down the stream at the center of the ravine.  

The image below shows a dry ridge with the hikers preparing to descend into a small forest-filled ravine.

   

Among the most spectacular trees at Rincon were the Strangler Figs.  These trees start as epiphytes; figs are consumed by birds and monkeys who then defecate the seeds high in the forest canopy.  Here, exposed to sunlight and with plenty of water, the figs grow as vines spreading out over the leaves of the host tree.  At the same time, the fig sends long shoots down to the ground; once there they form roots and begin to send minerals up to the leaves far overhead.  With a source of minerals in hand, the fig grows explosively, often completely shading out its host.  Additional roots seek the ground; where the roots meet they fuse (see right), enveloping the trunk of the host tree, which may be dead by now.  The descending roots form buttresses (to help prop up the fig); the strangler below has roots enveloping a neighboring tree as well.

 

This strange growth form allows the fig to solve one of the biggest problems in the rainforest - how to get light when starting out from the shady forest floor.  By using an established tree, the fig gains a tremendous advantage.  Eventually, the old tree dies and the strangler stands as a tree in its own right, often with a hollow core. 

Buttresses are a common growth form inrainforest trees; here the soils are often thin and the trees are very tall.  A buttressed shape helps prop the tree up under such conditions.  The tree to the right may be a very old strangler whole roots have fused to form a solid-appearing trunk (or it may be a related tree species).  Whichever, it obviously has extensive buttress roots.

 
 

Below, the class in 2005 in front of a particularly spectacular strangler; this one looks almost as if one strangler is trying to overgrow another.

Above: an old strangler or just a tall tree?

 

Speaking of stranglers, we saw this guy on our way back from the cataract in 2007.  This was a large Boa Constrictor, probably close to 6 feet (2m) long.  Very heavy-bodied and strong.  We were able to get a number of photos, but it was not a cooperative specimen and many of the pictures were "posed" in that I had a firm grip on the tail of the snake, using the technique popularized by the late Steve Irwin.  You can see the stirring video of this meeting of man and beast by clicking on the link to the right.

The bite of the boa is fierce, but that is not how it overwhelms its prey. Boas, of course, being constrictors, suffocate their prey by throwing their bodies around the prey and squeezing tightly, preventing the prey from breathing.  Provided the prey is warm-blooded and small (and thus with a high metabolic rate), the prey will pass out before the snake does, and it can then be swallowed.  The snake's mouth has a large number of sharp, backwards-pointing teeth that help restrain and pin the prey (and keep it from backing out if it should revive); the jaws themselves can be unhinged to allow large prey to be swallowed.  A snake this size could probably eat an agouti or a rabbit.

Crickey!  A touching boa video.
   
   
   
   
   

Below - view through the rainforest.
   
   

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