Land Conservation and Forest Restoration, Science and Research

Georeferencing Trees in the Osa Peninsula

Peltogyne Purpurea: An endemic species of Costa Rica and Western Panama, now very scarce because of overexplotation for its valuable timber.

Visiting a tropical forest can be overwhelming because of the enormous number of species found there, especially if you are talking about the Osa Peninsula, one of the most biologically diverse places in the world. This diversity is especially evident amongst plants which, as immobile organisms, are easily observed.  This same diversity, however, can be distressing for a person interested in identifying a species if they don’t have previous knowledge of the area.  This is why, for the last six months, I have been working at Osa Conservation’s Piro Research Station and Greg Gund Conservation Center identifying trees on site, georeferencing various individual trees of distinct species, and creating a digital catalog of the most common species found on the trails (among other things).  Osa Conservation is using all of this information to educate researchers and visitors about tree diversity in the Osa rainforest and for their forest restoration program.

With over 700 species of trees in the Osa rainforest, identification can seem very complicated for those without experience in the field.  A digital collection indicating the most significant characteristics of various species allows for easier recognition of species.  There are many simple characteristics that aid in identification, including the type of leaves and the position of the stem, the presence or absence of secretion, translucent dots, glands, or pubescence (“hairs”) which together can facilitate the recognition of families, genera and even species.  We’re also adding photographs and dried plant samples to this information to help us compare and verify the species with which we are working.

Georeferencing various trees at Osa Conservation will give researchers and education groups interested in finding and studying a certain species the ability to locate it effortlessly and, once there, see the living specimen and characteristics that are impossible to detect in a photograph or  plant sample (ie. trunk or secretion).  Georeferencing individual trees is also assisting Osa Conservation’s forest restoration program, which is carried out in partnership with NRDC and the Wisconsin Natural Resource Foundation.  Georeferencing allows us to easily locate and observe the fructification process of certain tree species whose seeds we collect and nurture on site in the OC nursery, better enabling us to restore degraded habitats with native species.

Within a determined site, there are generally groups of very common species while others may be very scarce.  For the more common species, and for the majority of individuals who are curious about tree identification yet lack previous knowledge, a digital catalog will be very useful; for the scarcer species, and for those individuals with more knowledge in the field (ie. researchers), georeferencing is fundamental, as locating the trees would otherwise be very difficult.

Birds

Featured Bird: Pale-billed Woodpecker

Pale-billed Woodpecker Male. Photograph by Alan Dahl

Of the eight woodpecker species that are found on the Osa Peninsula, the Pale-billed Woodpecker (Campephilus guatemalensis) is the largest with a length of 35 cm (14 inches) rivaling only the superficially similar, and range overlapping Lineated Woodpecker (Dryocopus lineatus).  In fact, the Pale-billed Woodpecker is most closely related to the extremely elusive north temperate species the Ivory-billed Woodpecker, both belonging to the same genus, Campephilus.  This species ranges from southern Mexico to Western Panama.

The Pale-billed is distinguished from the Lineated by its fully red head.  Only the female, pictured here, has a black center crown, neck and throat while the male’s head is completely red.  When their bright red crest stands up on end they look like the punk hoodlums of the bird world.

These birds are actually quite common here on the Osa and can be found right here at the Osa Biodiversity Center anywhere between the Greg Gund Conservation Center and Piro Research Center.  There is a pair that is excavating a nest right now in the month of September in our NRDC forest restoration plot located approximately 6 meters up in a snag.

Pale-billed Woodpecker Female. Photograph by Gianfranco Gomez

The nesting period typically ranges from August to December.  Pale-billed Woodpeckers excavate their own nests, but are sometimes taken over by Araçaris while under construction.  Both parents incubate the two eggs typically layed and also care for their young.  They roost in large cavities similar to those used for nests and can use the same cavity for roosting for several months.

They commonly eat the large larvae of wood boring beetles excavated from the trunks and limbs of large trees and dead and decaying wood.  When not eating beetle larvae they have been known to take fruit from Melastome trees.

Sounds include the vocal “bleating” sound and the non-vocal drumming “double-rap” similar to that of other Campephilus species such as the Ivory-billed Woodpecker.  The NRDC pair is in the habit at the moment of counter-rapping with its nearest neighbor who is only about 100 meters away.

We would like to thank Alan Dahl from Focused on Nature photography and Gianfranco Gomez from the Drake Bay Rainforest Chalet for allowing us to show off their amazing photographs of the Pale-billed Woodpecker.

Birds

Featured Bird: White-whiskered Puffbird

White-whiskered Puffbird by Gianfranco Gomez

Not only does the White-whiskered Puffbird (Malacoptila panamensis) rank pretty high on the cuteness scale, it is also an interesting species from an ecological perspective.  Puffbirds are most closely related to jacamars, toucans and woodpeckers.  They are primarily insect and arthropod eaters and are considered to be flycatching birds along with tyrant flycatchers, and nunbirds.  Even though they eat spiders, frogs and lizards taken from the ground they are known for sitting perfectly still in the forest understory until a flying insect meal passes by when it darts out to catch its prey in midair.  It will then take it back to its perch to beat it against the branch before swallowing it.  Their apparent lethargy, as they sit and wait for prey to come by, is really a honed hunting behavior.

You can find either White-necked Puffbirds or White-whiskered Puffbirds here on the trails of Friends of the Osa’s Osa Biodiversity Center between Piro Research Station and the Greg Gund Conservation Center.  Both species separate themselves vertically in the forest.  You’ll find the White-necked Puffbird higher up in the canopy and the White-whiskered Puffbird down low where they don’t directly compete with each other for food resources.  In either case however they are difficult to see for their stealthy style.

Puffbirds build their nests in active termite nests or dig out a burrow in the ground or on the side of a small hillock with a short entrance tunnel with twigs and dead leaves extending out an additional 3 inches.  The actual nest is lined with leaves.  Those that build in termite nests seem to tolerate termites crawling all over them during incubation (From Alexander Skutch’s book of Birds of Tropical America, 1983).  Ground burrows can be as long as 22 inches.

So why are they called puffbirds?  As you can see from the photo, they are stout birds with fairly large heads and their feathers have a puffed-out appearance.  When they get excited they puff out and swing their tail back and forth.  Their abundant puffy plumage makes their short legs almost invisible.  Note the striking red eyes as well!

We would like to thank Gianfranco Gomez for allowing us to showcase his photographs.  You can find more of his work at The Drake Bay Rainforest Chalet website.