Science and Research, Sea Turtles

The Continued Threats

By Phoebe Edge, Research Field Assistant (RFA) , Sea Turtle Conservation Program.

Sea Turtle Conservation in Protected Areas

Park guards and lodge employees on the beach for the sea turtle workshop

On all of the morning and night patrols we collect quantitative data from the turtles we encounter, as well as from their tracks and nests. This year we have also begun taking a more active approach protecting as many nests as possible from both natural and unnatural predators. Metal mesh nets are used to cover each nest we find on Piro beach- so far this method has proved extremely beneficial, as all of the covered nests have shown a high rate of success. All of the protected nests have been left unharmed by predators in the area, giving us at FOO a real incentive to extend this method to surrounding nesting areas.

While we are learning more effective ways to curb natural predators of sea turtle eggs, human poaching continues. Having a larger presence on the beach day and night is yet another battle we are looking to conquer. Last week we invited workers from local lodges and 9 members of MINAET, the government body for environmental matters in Costa Rica, for a 2-day course all about our ancient shelled friends. Organized by our environmental education coordinator, Pilar Bernal, the information was focused on sea turtle behavior, current issues regarding their well-being, and what we are doing here at FOO to ensure the longevity of these species… As well as being an extremely informative time, I think we all thoroughly enjoyed ourselves too!

Sea turtle research field assistant

Ashleigh and Tomas at the Piro Research Center

Four members of MINAET stayed at the Piro Research Center for four days after the course to night patrol with us to look for signs of recent poaching and possible culprits. We even learned a little ourselves, like how to crack open coconuts on the beach and enjoy a refreshing beverage compliments of mother nature!

We have just welcomed on board Ashleigh from California who will be staying with us at the Piro Research Center until mid-December as an RFA. She recently graduated from California Polytechnic State University and is quite excited to be able to put all of those hours spent in the books to good use. The Olive Ridleys obviously knew about this as just on her second night patrol we managed to collect data from 21 turtles! It was a perfect night for a patrol, with only a little rain and a full moon´s light to guide us.  Let´s hope it´s the first of many for our newby!

A big thank you to Eliécer Villalta Martínez and Geinor Barquero of MINAET for taking the time to help us here at FOO.  Your time and efforts are genuinely appreciated!

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.

Environmental Education, Miscellaneous

Osa Peninsula Butterfly Workshop

This August 16-19, La Leona Lodge organized a workshop about frugivorous (that means fruit-eating) butterflies with entomologist and curator of Lepidoptera, José Montero of INBio (National Biodiversity Institute of Costa Rica). This workshop was attended by several people in the area, including naturalist guides and employees of La Leona Lodge. José taught us about the methodology that he has been using in different parts of the country with great success for several years and now La Leona Lodge has begun to use, in order to generate information about butterflies of the Osa Peninsula.

Frugivorous butterfly trap on the Osa Peninsula

Frugivorous Butterfly Trap

The methodology used by José consists of traps that are placed in the canopy and the understory that attract butterflies with fermented fruit. Fruit is placed in these traps during the first week of each month. All butterflies captured during this period are identified, which gives a pretty good idea of the species richness in both strata of the forest, if sampling is performed at adequate intervals.

Jose shared with us some of his vast knowledge of frugivorous butterflies of Costa Rica, which, he tells us, make up between 40-50% of all Costa Rican butterfly species. He also told us how the species richness of frugivorous butterflies has greater variation vertically than horizontally; i.e. there is a greater difference between the canopy and the understory of the same site, than there is between different sites at similar heights.

Not content to talk only about butterflies, José also gave excellent lectures on the concepts of diversity, evenness, dominance and beta and gamma biodiversity, all fundamental concepts in the work he has been doing.

I would like to thank La Leona Lodge, especially Ifigenia Garita, for the opportunity to have participated in this activity. I also want to thank José Montero his great willingness to teach and share his knowledge.

Miscellaneous, Science and Research

In Search of Amphibians on the Osa Peninsula

In 2008, in order to determine the distribution and abundance of leaf litter amphibian species, I began a monitoring program around the Piro Research Center along with Federico Bolaños and Gerardo Chaves, herpetologists from the University of Costa Rica. In 2010, with the support of the Mohamed bin Zayed Species Conservation Fund (MBZ), I expanded this project to Los Charcos and Petosa, a private property owned by Bert Kerstetter, an important supporter of Friends of the Osa.

The information generated by this project was included in the latest update workshop of the conservation status of amphibians in Costa Rica for the IUCN Red List, held in San Jose in July this year. The workshop was organized by the University of Costa Rica’s School of Biology and the Conservation Breeding Specialist Group (CBSG) of the Species Survival Commission of the IUCN. The workshop summary will soon be published by the organizers, and we’ll share that report through the blog.

Dermophis occidentalis

As part of this project, and with some good luck, we’ve observed many interesting species of amphibians.  One species in particular which has attracted the most attention is the caecilian seen in this photo.

Caecilians are a group of amphibians that has invaded the underground environment, so that their bodies are elongated, they have no limbs and their eyes are vestigial – all characteristics that allow them to squirm through their subterranean tunnels. Because of their penchant for the underground, these animals are rarely seen, and therefore, little is known about them.

According to the latest review of this group in the Osa Peninsula, there are three species of caecilians, one of these endemic (Oscaecilia osae), which has been reported only twice in Corcovado National Park.

The species that we have been observing, Dermophis occidentali, has been found at both the Piro Research Center, and the Greg Gund Conservation Center (GGCC).  The individual in the photo was found at the GGCC by Kory Kramer, in one of the buildings. This was in early July, when the onset of the rains saturates the ground forcing caecilians to surface.  If you’re lucky, you’ll see one. On this occasion, all Friends of the Osa staff were gathered for an activity so that everyone had the opportunity to observe this rare species.

Birds

Featured Bird: Chestnut-backed Antbird

Chestnut-backed Antbird. Photo by Alan Dahl

Chestnut-backed Antbirds (Myrmeciza exsul) are common residents of the Osa Peninsula and one of the most abundant species found here.  It is difficult to walk outside here at Friends of the Osa’s Osa Biodiversity Center and not hear two or three individuals counter-singing.  Often times when the rest of the forest has become fairly quiet you can always count on a Chestnut-backed Antbird to let you know that all is as it should be.

The signature look of three species of Antbird found on the Osa Peninsula of Costa Rica is the blue orbital skin (the skin surrounding the eye).  The Chestnut-backed Antbird is one of these species and is distinguished from the others by its slate colored head and chestnut back.  The other antbird that you are likely to see here with the blue orbital skin is the Bicolored Antbird, but it is distinguished by its white neck and belly.

As you can tell by the name, Chestnut-backed Antbirds follow army ant swarms; however, they only do this occasionally and are not considered obligate, or professional, army ant followers.  They are strongly associated with the dark undergrowth of wet tropical forests within dense vegetation especially near overgrown treefalls or dense thickets.  They often join mixed species flocks but won’t necessarily move along the forest with the flock, but will rather join them while ant swarms are moving through the dense thickets in which the Chestnut-backed Antbirds are found.  Once the army ant swarm or the mixed species flock is gone, they will remain in the undergrowth found in their territory.  Many tropical birds follow army ant swarms to pick up insects flushed by the ants, not to eat the ants themselves.  Chestnut-backed Antbirds mainly hop along very low lying perches or along the ground and peck their prey, which mainly consists of insects and spiders from the ground or near the ground vegetation.

Chestnut-backed Antbird. Photo by Gianfranco Gomez

They are territorial throughout the entire year and both the male and female sing duets back and forth to each other and in response to their nearest neighbors.  When disturbed, they will pump their tail downward, droop their wings, and fluff up their feathers.  They nest low in small bushes or debris during the rainy season from April to October.  They usually lay two eggs and both parents incubate and tend to their young.

We would like to thank both Alan Dahl from Focused on Nature and Gianfranco Gomez from the Drake Bay Rainforest Chalet for allowing us to showcase their photographs.

Community Outreach, Sea Turtles

Second Annual Osa Peninsula Sea Turtle Festival

On Sunday September 12 we celebrated the Second Annual Osa Peninsula Sea Turtle Festival on Carate Beach. The objectives of this annual event are to raise community awareness about the importance of joint actions in the conservation of the sea turtle species that frequent the beaches of the Osa Peninsula in the months of nesting, and to share the objectives and results of Friends of the Osa’s Sea Turtle Conservation Program with the community.

Osa Peninsula Sea Turtle Festival Carate

Children made sea turtle sand sculptures

This year at least 120 people from the communities of Carate, Rio Oro, Piro, and Puerto Jimenez participated in the festival.

Puerto Jimenez students presented the play, “Survival of the Sea Turtles,” which told of the dangers that sea turtles are exposed to from the moment they are born. Educational games were played with children in which they acted out different parts of the sea turtle nesting process and lifecycle. Younger children and their parents made sand sculptures of leatherbacks and adults participated in the presentation about the Sea Turtle Conservation Program Piro-Carate.

We also announced the winners of the drawing contest “Survival of the Sea Turtles,” that was held with students from the Piro and Rio Oro schools. On this sunny day participants also played soccer, beach volleyball, sang karaoke and enjoyed a great picnic prepared by the community.

Community Outreach, Science and Research, Sea Turtles

Party in the jungle!

By Phoebe Edge, Research Field Assistant of the Sea Turtle Conservation Program

We are officially half way through this year´s turtle season and it has been a very busy 3 months indeed! Within this time, we have been continuously patrolling our beaches morning and night to help our favorite reptiles. There seems to never be a dull moment, even the walks to the beach prove exciting! Already, we´ve been fortunate enough to have encountered jaguarundi, coati, caiman, anteaters, armadillos, as well as a variety of beautiful and rare frogs and snakes. Last week on a morning patrol in Carate, Greivin and Phoebe were lucky enough to see a group of 6 humpback whales pass by. It really is like a party in the jungle at the moment! Apparently whales can be camera shy so a group photo was out of the question but here´s a shot of one of the females:

Photo by Carlos García

Of course seeing these animals is all well and good but it is the sea turtles we are here for and they´ve proved not to fail with appearances. Olive Ridley are commonly sighted here with Green´s following second, but in the last month we´ve also had a handful of the critically endangered Leatherback and Hawksbill coming up onto our beaches – amazing! Due to the incubation period of some Olive Ridley nests being 45 days we are also starting to see more and more hatchlings appear too. For anyone who has been in the right place at the right time, you´ll know how incredibly cute these youngsters are! Sadly only 1 in 1000 makes it to adulthood which is why it´s so important that we use all of our best efforts to do what we can. One of our protected nests just hatched yesterday morning and we caught a straggler on her way to her new home, the sea. Fingers crossed she will be one of the females returning to the beach in the future to continue the cycle.

Picture by Carlos García.

Baby sea turtle making its way to sea

We would like to take this opportunity to say a HUGE thank you to all of the fantastic volunteers we´ve already had come and help us in our conservation efforts this year. This is a critical time in the history of sea turtles and with the help of volunteers we as humans really can save them from extinction. Please don´t standby whilst the last of these majestic creatures disappears.  Come get involved and make a difference too!

Birds

Birder's Challenge

Riverside Wren nest by Cheryl Chip & Jim Tamarack

For those of you who may remember, I posted a feature on the Riverside Wren (Thryothorus semibadius) back in April.  It was one of my first postings for the then new Friends of the Osa’s blog The Osa Chronicles and a few of you commented on both the nature history and photography by Gianfranco Gomez.

One of the species ecological behaviors I wrote about was of reproduction and nesting.  When I spoke about the nest of the Riverside Wren this is what I said:  “Nests are bulky globe structures with a roof and a vestibule (so to speak) not only used for raising young but also for sleeping at night any time of the year by either one individual or as many as possibly 3.  This species can be found nesting from December to August, nine months out of the year!”

Not long after this posting some friends and residents of the Osa Peninsula Jim Tamarack & Cheryl Chip saw the posting and sent me this photo they took of a Riverside Wren roosting in its nest at night near their home.  This photograph was taken in the month of December, but it also could have been taken any time of the year.

Riverside Wren at Drake Bay

Now, the position of this bird has had many of us puzzled for some time so I am inviting commentary from you all.  It looks like the bird is camouflaging itself in the nest, but how?  The Riverside Wren has barred black-and-white stripes only on the breast and belly while the back is solid rufous.   It’s as if it were laying on its back.  Are there two birds here?  Is this the Riverside Wren?

OK birders, its time to chime in.  I am waiting for your opinions and comments.

Science and Research, Sea Turtles

Sea Turtle Conservation Program Piro-Carate: August Update

Last month I shared with you the total data for in situ nests, nest predation and false crawls for the month of July, and mentioned that these data were not adjusted for sampling effort. By sampling effort, I mean the amount of time and / or distance that was invested on each beach to get the data. For example, we monitor 2 km of Piro beach and 4.5 km of Pejeperro beach.  So, it isn’t the same to walk Piro beach and find two turtles as it is to walk Pejeperro beach and find two turtles – the distances covered are very different.  To compare these two values, we must express them in proportion to the distance traveled, i.e. density of turtles per kilometer. In this case, that would be: Piro: 2 / 2 = 1 and Pejeperro: 2 / 4.5 = 0.44.

Sea Turtle Conservation Results through August 2010

Figure 1. Density of sea turtle visits during the months of July and August on the beaches of Piro-Carate, Osa Peninsula 2010.

By calculating the July and August data in this way, taking the sampling effort on each beach into account, we get the results shown in Figure 1. As you can see, Rio Oro is the beach with the highest density of in situ nests, nest predation and false crawls, followed by Pejeperro. From this graph, we can also see that the density of depredated nests on Rio Oro beach is very similar to the density of in situ nests, which is obviously worrying. In the coming days, I will conduct a preliminary analysis of predation in conjunction with Courtney Thomas, one of our assistants, who is using her participation in this project as part of her studies at Evergreen State College.

I would also like to take advantage of this note to thank Mr. Eliecer Villalta and Mr. Geinor Barquero, from MINAET’s Department of Control and Protection, for their support in recent weeks. Their presence, along with other peers in the area, had an immediate effect in reducing poaching of turtle eggs. I hope we can continue to coordinate this type of support throughout the rest of the season.

Remember that you can help us to protect sea turtles that visit the southern part of the Osa Peninsula in several ways: 1) telling others about our project and the importance of protecting sea turtles, 2) participating in our sea turtle volunteer program and 3) by making a donation to help fund the continuation of the Sea Turtle Conservation Program.

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.