Sea Turtles, Volunteers and Visitors

Sea Turtle Conservation Program: October Update

We’ve completed another month of the sea turtle conservation program on the Osa Peninsula, Costa Rica and we’re getting close to the end of the nesting season. After 4 months of tireless work by our field coordinators, field assistants and volunteers, we have registered a total of 1233 sea turtle nests, between Piro and Carate (Fig. 1). As I mentioned earlier, for logistical reasons, we cannot gather daily information from all beaches and visits to Rio Oro beach have been very limited, so this number of sea turtle nests should be considered a minimum; i.e., the actual number of sea turtle nests on these beaches is higher than reported here.

Figure 1. Total nests registered, according to month, beach and species. CM: Chelonia mydas agassizii, DC: Demochelys coriacea, EL: Eretmochelys imbricata, LO: Lepidochelys olivacea

Of these 1233 recorded nests, we know that at least 242 (20%) were predated. Of predated nests, 43% were by humans, while the remaining 57% were predated by dogs, pigs, crabs and other animals. We can reasonably estimate that approximately 10,600 eggs have been illegally removed between Piro and Carate for human consumption (assuming that each nest had 100 eggs and they were all taken).

If we focus on the Olive Ridley sea turtles (Lepidochelys olivacea), the most common sea turtle species on the Osa Peninsula, not taking into account the Rio Oro data, as the data that we have doesn’t appear to be representative of the real situation, we can see that during the 2010 season, Carate beach is where we find the greatest amount of illegal harvesting of eggs (Fig 2). Throughout the season, more than 50% of reported predation is caused by humans, a situation that hasn’t occurred on Piro and Pejeperro beaches.

Figure 2. Percentage of Olive Ridley sea turtle nests predated by humans and other animals according to month and beach.

Remember that you can help us save sea turtles that visit the southern part of the Osa Peninsula in several ways: 1) tell others about our project and the importance of protecting sea turtles, 2) by volunteering with sea turtles or 3) by making a donation to support our sea turtle program or the other conservation work that Friends of the Osa does on the Osa Peninsula.

Science and Research, Sea Turtles

Let´s have a bad joke!

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

What turtle has the best eye sight?

A SEE TURTLE!

And that´s why it´s so important that we make sure on night patrols that we spot the ladies before they spot us…the last thing we want to do is scare them back to the sea. A good turtle detective just doesn´t do that. An Olive Ridley could have swum thousands of miles to get to this specific beach  which is why here at Friends of the Osa we do what we can to ensure we have minimal impact on beach patrols- especially at night. Females can be deterred from nesting and the hatchlings’ important journey to the sea can be disrupted just by the presence of white lights. For this reason, we only use red light on the beach. Sea turtles, like many other reptiles, don´t actually have the color red within their visual spectrum so it means we can work safe in the knowledge that they don´t feel like a criminal fleeing from the scene of a crime!

Volunteering with sea turtles on the Osa Peninsula, Costa Rica

We´ve just said goodbye to the lovely Brandy and Nick who were volunteering  with us for 2 weeks, staying at Finca Exotica in Carate. Their second day it was unnecessary to use ANY  artificial light to spot a turtle as on an afternoon stroll to the lagoon at around 3:30pm, we  discovered a solitary uptrack and on the top…an Olive Ridley covering a nest! It was a beautiful day anyway so this just completely topped it off. Most sea turtles come up during the night to lay their eggs as they feel it´s safer but this individual obviously had other ideas! It was a real treat to see her in natural light.

Of course, night patrols aren´t always a walk in the park.  We are in the peak of the rainy season, and it’s not uncommon for there to be times when the rain has penetrated every ounce of clothing, sand has made its way into every crevice you never thought possible and throughout the patrol, one can´t help but feel like you’re on the losing side in World War III against the elusive sand flea. But the second you catch a glimpse of a turtle, watching each egg drop into the nest she created ever so carefully, we are reminded of how much energy has been invested in this process and just how vital our efforts are to protect nesting sea turtles. Our efforts here on the Osa seem so small- but nest by nest, day by day, the data we gather can be interpreted and contributed to the global effort for sea turtle conservation, and together we can make a difference.  Besides, who wouldn´t care to swap the office for this?

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!

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.

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!

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, Community Outreach

Ornithological Union of Costa Rica Conference

Karen Leavelle presenting the Yellow-billed Cotinga spatial distribution project

The Costa Rican Ornithological Union’s second annual conference was held July 28 – 30th 2010 in the school of biology at the University of Costa Rica in the capital of San Jose.  The conference was dedicated to Daniel Janzen and his pioneering work in the field of conservation and reforestation in Costa Rica over the last several decades.  Attendees present represented national and international organizations working hard at avian science and conservation throughout the country coming together to share common interests in the more than 830 resident and migrant bird species found in this tropical landscape.

Friends of the Osa’s avian ecologist Karen Leavelle was in attendance to present a poster outlining the upcoming Yellow-billed Cotinga radio telemetry project slated to begin at the end of this year.  Also in attendance were Liz Jones and Abraham Gallo to present their findings from a two year study looking at the current distribution of the Yellow-billed Cotinga, Black-cheeked Ant-Tanager and the Mangrove Hummingbird all of which are endemic species considered to be endangered by BirdLife International.  This project was supported by Friends of the Osa, the American Bird Conservancy and the Evergreen Foundation producing vital information highlighting the conservation status of each species and the importance of the rainforest and mangrove habitats to species survival remaining on the Osa Peninsula and surrounding areas.

Elizabeth Jones presenting Yellow-billed Cotinga project results

The Yellow-billed Cotinga project was born out of Liz and Abrahams results on the species current distribution.  This project will focus on tracking Cotingas throughout the Osa Peninsula in order to determine the spatial and temporal distribution of a population of Cotingas from the Rincon area.  Essentially this project will show temporal habitat use and the spatial movements of the birds between feeding, nesting and roosting areas.  Information gained will indicate forested areas in need of protection for this species and others that also depend on the same habitats for their survival.  Keep your eye for more information on this project as its December date approaches.

The conference itself and Friends of the Osa’s participation proved to be important as a manner of disseminating information to a national and international ornithological audience on project results, upcoming studies and our role on the Osa Peninsula in avian science and conservation.

Science and Research

The OBC and studies into microhabitat preferences of focal group taxa

By: Zia Mehrabi, University of Oxford.

The Osa Biodiversity Center (OBC) provided a brilliant opportunity for biological research at an accessible location bordering Corcovado National Park (CNP). CNP represents the largest remaining tract of tropical lowland forest left standing on the pacific coast of Central America. The Osa Peninsula is phytogeographically unusual with high floral species diversity of an estimated 500 species of woody plants and exhibits high primate abundances as well as being home to charismatic large felids such as puma and jaguar.  The work undertaken at the OBC during April 2010 primarily aimed to clarify insights into the microhabitat preferences of particular dung beetles (Coleoptera: Scarabaeidae: Scarabaeinae) identified in earlier study investigating the fidelity of ecological methods used for inventorying insect functional groups at Sirena Biological Station (CNP) during the months of July and August 2009.  In order to efficiently and cost effectively map diversity it is widely recognised that the use of indicator groups is necessary. The sensitivity of Dung Beetles to light, soil type, moisture, temperature, leaf litter, structural complexity, vegetative cover, and resource type are widely recognized, advocating their utility as an indicator of the influence of abiotic environmental parameters on patterns of diversity in tropical ecosystems on a global scale. In order to map spatio-temporal distributions of biological organisms it is important to measure habitat variables on the scale at which they influence the taxa studied. If the habitat is not defined from the perspective of the organism then inference made from data reporting environmental influences on distribution of populations may be inaccurate.  The material generated during the study at the OBC will be identified at the Oxford University Museum of Natural History. It is an exciting prospect that the work at OBC may back earlier work that has identified a microhabitat preference of dung beetles on trap placement, work that potentially has serious implications for sampling methodologies currently employed in comparative ecological work which  aims to report the influence of deforestation and habitat degradation on tropical biodiversity.

All photography by Zia Mehrabi on night walks at OBC during April 2010

The accommodation facilities at the OBC are superb, with comfortable beds, clean running water and delicious food. Furthermore the staff are extremely friendly and helpful, facilitating communication with the local community and achievement of research objectives. In addition, accessibility from the nearby town of Puerto Jimenez and contact via satellite connection ensure ease of logistics. There is a nicely set out trail system that provides some great tracks for night walks where a plethora of insects , arachnids and reptiles may be easily observed and photographed. Overall I was very happy in the time I spent at the OBC and would recommend it to other researchers wishing to explore this interesting region of the world.