Coral restoration, citizen science and partners in the Osa

Blogpost by Sawyer Judge

“Was your coral scouting successful?” I hear a lovely British accent come calling from the stairs. Two dogs come bounding down the stairs to the beach as Harvey is helping us out of the boat. The owner of the accent, Susan, makes her way towards us. “How was the boat ride, loves? Come refresh with some juice in the kitchen. It’s cas juice! Fresh made!”

There are six of us visiting the Saladero EcoLodge that Harvey and Susan call home. Harvey and Susan are long-time partners of Osa Conservation, and they’re housing us for a night while we look for sites for the new coral restoration project that our Citizen Science Director, Luis Vargas, is directing. RFA and photographer Eleanor Flatt and I, a donor-retention and administration intern, are accompanying him to document the project. Also with us are members of the National Institute of Learning (INA) – a project partner. We’ve just finished with the work of scouting out some good sites for the project. Harvey is very knowledgeable of the area, and it turns out that the best place to install an underwater coral nursery may actually be right off the coast of Saladero itself!

Picture of the scenery around Saladero EcoLodge

Picture of the scenery around Saladero EcoLodge

We’re glad the coral restoration will take place at Saladero for a number of reasons. The property is nestled in the lush, bay-side rain forest around Golfo Dulce, and it’s a picture perfect example of how conservation and ecotourism live in harmony. Over a pleasant lunch of open-faced tortilla pill-ups, garnished with Harvey’s home-made hot sauce, I learn a little more about the scope of their work.

Some coral found in Golfo Dulce

Some coral found in Golfo Dulce

When Harvey decided that his homeland of Florida wasn’t hot enough for his liking, he and Susan purchased the 480 acres of lowland tropical forest where Saladero rests. They’ve conserved not only the surrounding bay, but enough primary forest for three extensive trails and a mangrove system. Saladero acts as a base for ecotourists, birdwatchers, researchers, and the national park service when monitoring illegal poaching and fishing activity. Much of their conservation work, however, happens in conjunction with Osa Conservation. Camera traps on their trails aid in collecting data on big cats and other mammals as part of our Biological Monitoring Program, and Harvey and Susan conduct quarterly samples of macro-invertebrates to monitor their river health for Rios Saludables. Now they’re excited to welcome our Marine Education and coral restoration efforts as well.

After lunch, Harvey gives us a tour of the property. His background is in carpentry, so the functionality and design of the space is very important. Saladero has everything from a space for students to set up tents and cook outdoors to up-most accommodation for “glamping.” Harvey even got the permits to build some of it himself. The property runs on hydro-electric and solar-electric energy systems. They even have a solar-heated shower. In addition to the facilities themselves, the botanical and agricultural projects they run are impressive to say the least. Walking through the grounds, we help ourselves to the delicious fruits of overflowing mimon and mangosteen trees. We smell the blossoms of the Ylang-ylang tree, the oil of which perfumes Channel No. 5, and we learn about the incredible medicinal properties of the bitter ash tree. Harvey and Susan strive to cook with the ingredients they grow. They even ferment their pineapple into a lovely vinegar, and sometimes make their own chocolate.

Sunset seen from Saladero EcoLodge

Sunset seen from Saladero EcoLodge

After the tour, Eleanor and I borrow paddle boards from the shack and enjoy the sunset, floating on the calm sea. Like magic, we saw sting rays jump from the water and even a group of dolphins before we head back to shore for dinner. Dinner is wood-fired pizza – Harvey’s specialty since he built the wood-fired oven 6 years ago – and traditional coconut ice cream. Susan explains that they often try to incorporate local custom into nature education and experience at Saladero, and their employees contribute a lot to the customs Saladero adopts. “We’re a family here,” says Susan, her eyes sparkling through her purple, wide-rimmed glasses.

Osa Conservation is lucky to have partners like Harvey and Susan at Saladero. Their hospitality extends not only to visitors, but to our conservation programs. They’re hosts for humans and nature alike, and experts at conserving a little piece of paradise.

Marine Conservation, Sea Turtles

Building a Sea Turtle Hatchery

Blogpost written by Marina Garrido, Sea Turtle Volunteer

As a sea turtle volunteer, I have spent the last few weeks here in the Osa constructing the turtle hatchery for the upcoming nesting season. Each year, the hatchery is moved to a new location along the beach in order to relocate nests in an area with “clean” sand which was not used in the previous nesting season.  The process is long and tough and requires many hours and many hands, but the end product is so rewarding that the work is well worth it.

We begin the project by moving barriers from the old hatchery to the site of the new one. The barriers are made of bamboo, which protects the hatchery and the nests inside from the large high tide waves of the Pacific Ocean.

Photo by Manuel Sanchez, group builds up the outer walls of the hatchery

Photo by Manuel Sanchez, volunteers help build the outer walls of the hatchery

Next we begin the important step of sifting the sand one meter down (about the depth of a sea turtle nest). This step is important for removing debris and obstacles from the sand where new nests will be relocated. Sifting of the sand is the longest, most labor intensive, process in the creation of a new hatchery. Once all of the sand has been sifted and placed in the new hatchery location, it is time to make the surface flat and compact again.

The next step is to fill hundreds of sacs with sand in order to reinforce the outer barrier of the hatchery fence, which provides protection of the sea turtle nests against predators. Predators of sea turtle nests include dogs,  coatis, vultures and more.


Photo by Manuel Sanchez, Sandbags line the outside of the hatchery for reinforcement

Photo by Manuel Sanchez, Sandbags line the outside of the hatchery for reinforcement


We then build the structure using newly cut recycled bamboo and cover it with nets to further protect it from predators. The final step is to section off the inside of the hatchery into a grid system which allows us to identify every nest inside. These codes from the grid system make it easier for us to track and predict when the nests will hatch.

Photo by Manuel Sanchez, Closing up sandbags to keep the structure sturdy

Photo by Manuel Sanchez, Closing up sandbags to keep the structure sturdy

As you can see, building and maintaining the hatchery each season is hard work. Thankfully, we have the help of volunteers and school groups that come to help move the process along. It is fun work done along a beautiful beach! Not to mention, we get fresh coconut water during our breaks!


Photo by Manuel Sanchez, Group from Colegio Puerto Jimenez joins Osa to build the hatchery

Photo by Manuel Sanchez, Group from Colegio Puerto Jimenez joins Osa Conservation to build the hatchery


Special thanks to Colegio Puerto Jimenez for their help in building the hatchery. To learn more about how you can get involved with our Sea Turtle Volunteer Program, please check out this link below:

Saving Sea Turtles

Sustainable agriculture

What’s the Deal with Sustainable Agriculture?

Blogpost written by Mollie Carroll, Intern

Most of us never think past the walls of the grocery store when it comes to our food. And, we definitely don’t often go as far as to think about the practices used to produce it. Yet, in an ever modernizing world, we should stop for a moment to question what really goes into making the food that we eat every day and ask ourselves, “What’s the deal with sustainable agriculture?”

In the United States, the amount of farms has drastically decreased as yield from industrial farms skyrockets. The goal of modern industrial agriculture is to increase output produced while also decreasing costs. The main issue with industrial agriculture stems from the negative externalities created when companies are focused on this goal.

A negative externality means that the cost shown on the price tag of food we buy does not represent the true cost to society. These added social costs include things like health risks and environmental problems. The false sense of price causes people to consume more than the socially efficient levels of outcome. Basically, we are lured into over consumption, and nothing acts as a deterrent from buying products that have negative health and environmental effects.

For now, we will focus solely on the environmental effects of industrial agriculture, and there are plenty.

Photo by Rob James

Photo by Rob James Garden Beds Without Pesticides

First, fertilizer use has increased dramatically in recent years, but the products are no more efficient. Only around 1/3 of the nitrogen in fertilizer gets absorbed leaving the rest to enter our runoff. Among other things, excess nitrogen in runoff creates dead zones in waterways.

Dead zones are areas in which oxygen is depleted and nutrient rich water allows for algae blooms. This causes not only asphyxiation of marine life, but can also impact reproduction and longevity of wildlife.

Pesticides cause similar issues with their inefficiency. Only about .1% of pesticides reach their target species! That means 99.9% of the pesticides we use cause unwanted damage. Chlorpyrifos, for example, is used on bananas grown in monocultures. While the amount of the pesticide found in the bananas is often low, communities and ecosystems around the farms exhibit extremely high levels of the chemical.  This damage includes disrupting delicate predator-prey balances. Pests (the prey) often recover much faster from population declines caused by pesticides than predators such as birds. Pesticides also are a suspected major cause in the decline of honeybees because they weaken their immune system and disrupt reproduction.

Photo by Rob James

Photo by Rob James Wild Pepper Growing Without Pesticides

Some of the increase in pesticide use can be attributed to the reliance on monocultures. When breeders attempt to make disease resistant crops under time constraints, they often cross breed plants isolating one resistant trait instead of the complex web of traits that is the cause of a species disease resistance. Because of this, diseases are able to evolve at a faster rate exacerbating the need for new varieties of plants and pesticide use. Monocultures intensify this need creating a vicious cycle.

Today, we rely on monocultures mainly to feed our livestock; 66% of grain production in the United States goes directly to livestock. The same amount of land, when used to plant legumes, can produce ten times the amount of protein.

Meat can also be tricky to produce.  One common inefficiency of meat production is the exorbitant amount of water it requires- almost 100 times the grain equivalent in protein.

Photo by Rob James

Photo by Rob James Commitment to Sustainable Animal Husbandry Practices

Water use in industrial agriculture is becoming an increasingly threatening problem. Around two-thirds of water worldwide goes directly to agriculture leading to the rapid depletion of aquifers. Similarly, the EPA states that 70% of stream and river pollution in the United States comes directly from agriculture.

This list includes just some of the many effects of industrial agriculture that harm our environment and make promoting sustainable agriculture more important every day. But what exactly is sustainable agriculture?

Sustainable agriculture is the production of food using practices that protect the environment and may even promote benefits such as increased biodiversity.

Photo By Max Villalobos Bird's Nest Found Among Crops on Wildlife Friendly Farm

Photo By Max Villalobos Bird’s Nest Found Among Crops on Wildlife Friendly Farm

At Osa Conservation’s wildlife-friendly farm, we make conscious decisions to ensure the sustainability of our farming practices.

One major sustainable practice that we implement is growing native crops that support the local ecosystem. Planting a large variety of local crops helps suppress weeds, which then reduces the need for harmful pesticides. It also means that crops can thrive in local soil without the use of fertilizers.

Keeping the farm substance-free is especially important because of the integration of crops and livestock. This practice is said to reduce soil degradation because manure from livestock continuously stimulates soil fertility. Further, integrating crops and livestock ensures that no failed harvests or crops go to waste. This not only means happy animals, but happy farmers too!

Photo by Rob James

Photo by Rob James

Another important task of our sustainable farming is to carefully care for our soil. Among other techniques, Osa Conservation uses reduced tilling methods, such as through the use of compost and biochar. Not only does biochar contribute to carbon sequestration, but it helps transform agriculture waste into soil.

It is hard not to support sustainable farming when you consider the differences in the environmental impact. At Osa Conservation, we are incredibly proud of our wildlife-friendly farm, and not just because our food is delicious!

If you’re looking for a once in a lifetime opproutunity to be a part of the sustainable agriculture movement, come volunteer with our program in the Osa. Learn more about it here!

Sustainable Farm Research Field Assistant

Sea Turtles

Every Day is Sea Turtle Day Here in the Osa

Blogpost written by Marina Garrido, Sea Turtle Volunteer


World Sea Turtle Day was just last week and the sea turtle team at Osa Conservation was super excited. Why? Because to us, it is not just a day, but a day in which we hope the whole world can remember and think about, even if just for a moment, these amazing animals.

Sea turtles are one of the most ancient animals alive. They belong to the family Quelonidae, which  also encompasses terrestrial turtles. One interesting fact about sea turtles, is that unlike the terrestrial turtles, they cannot hide their bodies inside their shells.

Photo by Marina Garrido, baby sea turtles journey back to the ocean

Photo by Marina Garrido, baby sea turtles journey back to the ocean

Currently, there are seven sea turtle species swimming in the seas and oceans. Costa Rica is home to four of these species including: the Olive ridley, the Pacific Green turtle, the Hawksbill and the Leatherback. All four of them can be found in the Osa Peninsula!

All sea turtle species are considered highly endangered. Here in Osa Conservation, we are conserving and protecting sea turtles to make a change. How do we do it? We patrol two beaches every day, looking for turtle tracks. If we find a nest, we move it to the hatchery in order to protect it. Thanks to the hatchery we can control the nests and study them to improve the success of the hatchlings. For example, one of the things we control is the temperature of the nests. Why? The sea turtles are reptiles and therefore the temperature surrounding the nest determines gender. Females are born on high temperatures and males on low temperatures. Unfortunately, the temperatures have increased in the past few years due to climate change, and so, more females are being born than males.

Photo by Marina Garrido, volunteers observe a nesting female at night

Photo by Marina Garrido, volunteers observe a nesting female at night

We have been very successful in protecting the turtles thanks to the help of everyone that comes to volunteer. Last year we set around 15,000 hatchlings free. Still we need a lot of help from all of you! Below you can find a little list of things you can do to help the sea turtles:

  • Do not throw any trash into the ocean.
  • Clean the beaches as you walk and close to where you spend time.
  • Reuse and Recycle.
  • Use reusable fabric bags instead of plastic bags.
Photo by Marina Garrido, Sea turtle volunteers release hatchlings back to the ocean

Photo by Marina Garrido, Sea turtle volunteers release hatchlings into the ocean








The Unexpected Values of Vanilla

Blogpost written by Lesley Mould, Intern

Since vanilla is so popular, it was surprising to learn how challenging it is to grow it in the wild! Vanilla is one of the many rare and distinct plants that can be found in the Osa. The uniqueness of the vanilla plant is fascinating, and its potential to both reforest and spur regional development is heartening in a field that can often be cynical.  As an intern in Osa Conservation’s Washington, D.C. office with a strong interest in botany, I find the traits and characteristics of the vanilla plant incredibly enticing.


A brief history of Vanilla

Vanilla is the most popular flavoring in the world, the second most expensive, and an incredibly time- and labor-intensive crop. In the 17th century, factories to manufacture the vanilla flavor began to emerge throughout Europe. Vanilla became a common commercial crop in 1841 after Edmond Albius discovered an effective method for hand pollination. This is still the dominant harvesting methodology today.

Photo by Osa Conservation

Photo by Osa Conservation

Fast Facts about Vanilla

The vanilla grown in Costa Rica is a Vanilla planifolia. The vanilla vine grows on a host tree, and if unattended, can grow up to 30 meters and reach the tops of forests. The vanilla bean is the fruit of the Vanilla orchid, and is the only edible fruit of the 25,000 orchid species native to Central America and the surrounding regions. The vanilla flower only blooms for 24 hours, and if it is not pollinated, the plant dies and the beans cannot be used. There are over 50 species of vanilla, but only a few of them are used for flavoring.

Vanilla must be grown in a moist, tropical climate between 75 and 85 degrees Fahrenheit, and between 10 and 20 degrees north and south of the Equator. It is impossible to grow the same vanilla vine in the more than one country because of soil and climate variances, so each growing region produces vanilla with a slightly different flavor.

Photo by Osa Conservation

Photo by Osa Conservation

Vanilla Pollination

Manual pollination of the vanilla plant is done with a very small stick and takes a great amount of time and precision. Fertilization by a native species is incredibly rare—so rare, in fact, that scientists are unsure of exactly which species are pollinators. It has been suggested that the Melipona bee is a vanilla pollinator, but its small size makes is an unlikely candidate.


Photo by Osa Conservation

Vanilla Conservation

Conservation of the vanilla plant is of paramount importance. Its labor-intensive cultivation, niche growing environment, short life-cycle, and extraordinarily high demand place a great deal of pressure on vanilla crops. That is why Osa Conservation is excited to help further this conservation research! An exciting project is under development, so stay tuned for more information on what is happening in the field as Osa Conservation works towards gaining a better understanding of the role of vanilla in the rainforest.

Osa Conservation’s BioStation is the perfect place to conduct further research on the vanilla plant and its pollination. We have several vanilla plants, both wild and domesticated, that researchers can observe and study, and maybe even use to find new solutions to the problems of deforestation, regional underdevelopment, and vanilla shortage!


Why the Osa is Impossible to Forget

Blogpost written by Robert Baker, Volunteer

Hi, my name is Bob Baker. For the past 10 years, my wife Lindsay and I have come to the Osa Peninsula for two weeks every March. We come to enjoy what National Geographic calls the “most biologically intense place on earth.” We typically stay in vacation rentals in the Cabo Matapalo area which is about 18km south of Puerto Jimenez at the tip of the peninsula. Last March (2016), we arranged to visit Osa Conservation’s biological station and during our visit,  Manuel Sanchez (Sea Turtle Program Coordinator) asked if we would like to join him on a sea turtle beach patrol one evening. Joining Manuel, and rescuing and releasing 17 baby Green sea turtles to the ocean was such an amazing experience that I decided to become a sea turtle volunteer with the program again this past March for a week.

Photo by Bob Baker

Photo by Bob Baker

On the first day, we met for an orientation session and learned that our duties would begin at 5:00am the next morning when Manuel, our supervisor, would meet us at the dining station. From there we started our hike to Piro beach and began our first sea turtle patrol.

Beach patrols as a sea turtle volunteer involve walking, paying attention and more walking. Manuel taught us that there are primarily 2 species of sea turtles that visit this beach, as well as Pejeperro beach, for nesting purposes. These are the Olive Ridley (Lepidochelys olivacea) and the Green sea turtle (Chelonia mydas). Leatherback sea turtles (Dermochelys coriacea) and Hawksbill sea turtles (Eretmochelys imbricata) also occasionally visit these beaches. We even got to see a Leatherback nest during our stint. Manuel taught us about the different species and how to identify them. For example, Olive Ridley sea turtles leave asymmetrical, or alternating, tracks. On the other hand, Green turtles leave wider, symmetrical tracks due to their size.

Photo by Manuel Sanchez

Photo by Manuel Sanchez

On this first morning, we recovered approximately 100 Green sea turtle eggs and carried them to the hatchery. The hatchery is a covered area within the vegetation just off the beach. Careful to maintain the same dimensions as the original nest, we dug a hole in the hatchery compound placed the eggs in the new “nest,” We then removed about 25 Green sea turtle hatchlings from another nest and watched them make their small journey to the waiting ocean. Fantastic!

The next morning, we were up at 3:30am to patrol the longer Pejeperro beach. We found Green and Olive Ridley tracks and a few new nests. We did not remove the eggs  from their nests on this beach due to lesser rates of poaching and predation.

Photo by Manuel Sanchez

Photo by Manuel Sanchez

During my week as a sea turtle volunteer, I saw other wildlife including Fiery-Billed aracaris, baby Green iguanas, a Red-eyed tree frog, Yellow-headed caracaras, Squirrel monkeys and a Common potoo. Although we did not see them, we used our skills to determine that other species were nearby.  Manuel, Delaney and I hiked to a camera trap and found an amazing photo of a jaguar. This jaguar had been in front of this camera the previous evening. Manuel was so excited because it was the second jaguar they had seen and documented recently. We also encountered Puma “scratchings” on the trail to the camera trap location.

Photo by Manuel Sanchez

Photo by Manuel Sanchez

Later in the week, alone on the Ajo trail I came upon a herd of approximately 50 White-lipped peccaries. At first, I thought they were the more common Collared peccaries. However,  Osa Conservation’s Andy Whitworth later corrected me and explained that Collared Peccaries travel in small groups (usually no more than 10-20). White-lipped Peccaries travel in herds from anywhere between 50-300 individuals.  After showing Manuel my photos he confirmed they were of the white-lipped variety. The abundance of peccaries, one of the jaguar’s natural prey, further explain the jaguar in the vicinity.

Photo by Manuel Sanchez

Photo by Manuel Sanchez

On my last full day, I went out on 2 patrols (Piro at 3:30am and Pejeperro at 8pm), transferred 137 Olive Ridley eggs to the hatchery, hiked the Ajo and Tangara trails, visited 2 camera traps and  hiked to the Sunset rocks to watch another beautiful Pacific Ocean sunset. The next morning, I went on my last sea turtle patrol with Manuel and Marina (a new research assistant). Tired from the night before, we doggedly walked the beach. We ended up transferring 93 Olive Ridley eggs to the hatchery, a great way to end my sea turtle volunteer experience. A big thanks to Manuel, Alejandra, Karla, Rachael and Andy for their support and making this a wonderful life experience. Cheers!


A botanical walk for all 5 senses

Blogpost written by Marina Garrido, Research Field Assistant

A few days ago, part of the staff and some researchers went for a walk with Osa Conservation’s botanist, Reinaldo Aguilar, from the biological station to the wildlife-friendly farm. All along the way, Reinaldo showed everyone different kinds of plants that grow in the Osa Peninsula, and shared his knowledge about the flora. We all had a lot of fun and enjoyed each plant we saw with all five senses. Since the staff is comprised of both Spanish and English speakers, we got to learn the plant names in both languages. Now, we want to share everything we learned with all of you.


We started by learning about the Bromelia, from the family Bromeliaceae. The flower blooms during the night, and signals the plant to begin growing a new branch. Once the flower has been pollinated by bats and the flower is ready to become a fruit, some of the petals are eaten by crabs. We also learned that palm trees are characteristic of the primary forest, eventhough some species, like the royal palm, can be found in different habitats.


Along the way, we met some capuchin monkeys eating the fruits of a tree called Cow tongue, or Lengua de vaca (Liconia argentia). It is not uncommon to see capuchin monkeys, spider monkeys, and white-nosed coatis snacking on the fruit of this native tree on a morning walk around the station.


Once we were inside the wildlife-friendly farm, Reinaldo introduced us to the marvelous Anacardiaceae family. Within this family, there are some of  Osa’s tastiest fruits: mangos, jocotes, pistachios, and cashews. The genus Pistacia used to have its own family, but was recently added to the Anacardiaceae family. One of the defining characteristics of this family is the resin canals visible on the pith of the plants.


We had some fun with our confusion between the Guava and Inga trees. The Guava tree is called Guayaba in Spanish (Psidium guajaba). Its leaves are opposite and simple, and the flowers are white and very smelly. Its sweet fruit is a favorite of many monkeys and the leaves possess glands that excrete oil to protect themselves from larvae. When backlit, these glands look like tiny cells surrounding the leaf. On the other hand, a species of the Inga tree is called Guaba in Spanish (Inga edulis).  Its fruit grows in a pod, which can easily be opened by hand. The seeds are found inside the pod along with the characteristic white pulp. These fruits can be found all around the peninsula and are a sweet and delicious snack for every wanderer in the Osa.

An additional tree that we all enjoyed was the Pochote tree (Bombacopsis quinata). This tree is common on the Pacific coast of Costa Rica. Its thorns cover the entire trunk and its white flowers turn red once they fall. These two unique characteristics make this tree quite easy to identify. Its leaves are edible and, according to some of our assistants, very tasty!


Celebrating Biodiversity!

Blogpost written by Eleanor Flatt, Biodiversity Research Field Assistant


In the Osa, “biodiversity” is an  understatement…

In the human world, we select people to represent our countries, our towns, our villages, our communities; it is similar in the animal kingdom. A flagship species is an ambassador for a specific habitat and normally conservation of that species or the area they inhabit has benefits for other species. Here in the Osa Peninsula, we are home to a staggering 2.5% of the planets biodiversity, living on a mere 0.00000085% of the earth’s total surface area. Now that’s impressive! This biodiversity includes many iconic, endemic, and endangered species, which are ecologically important to this region. Here are 7 of the most interesting and exciting examples you might find during your visit to the Osa.


Yellow-bellied sea snake (Pelamis platurus)

Photo by www.golfodulce.org/pelamis-en.html

Photo by www.golfodulce.org/pelamis-en.html

This beautiful yellow-bellied sea snake can be found in the temperate waters of the Golfo Dulce. Its physiological adaptations allows this species to become boat-like, with a tapered belly similar to the keel of a boat providing stability in water, along with a flattened and broadened tail, which performs like a paddle for swimming…this is the Michael Phelps of the snake world!



Yellow-Billed Cotinga (Carpodectes antoniae)

Photo by Glen Bartley

Photo by Glen Bartley

The Yellow-billed cotinga is an endangered bird whose small population occupies only a tiny area. There are estimated to be 250-999 individuals, and only 150-700 of them are mature. They occur in mangroves, lowland forest, scrub, and occasionally in isolated trees in nearby clearings. After completing a radio-tracking study to understand their habitat uses for breeding and feeding, Osa Conservation is now focusing on protecting this land through the creation of a reserve.



Mangrove Humming bird (Amazilia boucardi)

Photo by Nick Hawkins

Photo by Nick Hawkins

Mangrove hummingbirds are another vital species in the mangrove habitat. They feed mainly on the flowers of the tea mangrove and are the only birds that have adapted to collect nectar with a specialized tongue. Their diet of carbohydrate-rich sugar nectar is necessary to support the hummingbird’s significant energy demands, as their wings beat 200 times per second. They will feed on between 1,000 and 2,000 flowers each day, allowing the tea-mangrove flowers to maintain high pollination rates. We are in the midst of starting a new project to protect the mangrove habitats here in the Osa.



The White Lipped Peccaries (Tayassu pecari)


Populations of White-lipped peccaries are decreasing due to hunting and habitat degradation and fragmentation. Consequently, this species is now listed as vulnerable. Records indicate that they can form groups of as few as 5 to as many as 200 individuals. In conjunction with the wildcat program, Osa Conservation will be radio-collaring and  monitoring the  peccary population, as they are essential prey for large cat populations.



Green Turtle (Chelonia mydas)

Manuel Sanchez

Photo by Manuel Sanchez

Green turtles, listed as endangered by the ICUN, are one of the many sea turtle species that come to nest here. It is hypothesised that the hatchlings leave the nesting beach and begin an oceanic phase by floating passively in major current systems, which serve as developmental grounds, after several years. They then proceed to seagrass and algae-rich areas where they forage until maturity. In the Osa, we have the Golfo Dulce, which is rich in these foods, and we monitor Playa Peje Perro, which is considered an important beach because  of its high population of nesting female green sea turtles.



The Spider Monkey (Ateles geoffroyi)

Photo by Manuel Sanchez

Photo by Manuel Sanchez

Spider monkeys are energetic and agile movers found high in the canopy. Recorded as endangered on the IUCN Red list due to hunting, pet trafficking and habitat fragmentation, spider monkeys are in dire need of protection. Osa Conservation works hard to protect their areas of habitat, including important corridor routes surrounding national parks, and restore other aspects of their habitat. Spider monkeys are typically found in groups of 20-30 individuals, but often split up during the day to forage. In the evening, they all return to a specific “sleeping tree” to be together as a big family.



Golfo Dulce Poison Dart Frog (Phyllobates vittatus)

Photo by Manuel Sanchez

Photo by Manuel Sanchez

The Golfo Dulce poison dart frog is yet another species affected by habitat fragmentation and degradation, both of which have caused it to become endangered. As an endemic species here in the Osa (meaning it is only found in this region), this species is all the more special! Females deposit eggs on leaves above the ground, then the males carry the hatched larvae to small pools where they complete their development – a true team effort.


These are just a few of the many wonderful and magnificent species you can find here in the Osa Peninsula that we are working to conserve by protecting and restoring their habitats.  These are just a few of the amazing species we can appreciate as we celebrate World Biodiversity Day!










Celebrating Endangered Species Day! Endemic and Endangered: Stories of a frog and a tanager.

Blogpost written by Alejandra Rojas, Naturalist Guide and Avian Program Coordinator


     black-cheeked-ant-tanager-_low-qualityPhoto 1:  The endemic & endangered Golfodulcean Poison-arrow Frog  and Black-cheeked Ant Tanager (Photo credit: Manuel Sanchez Mendoza)


What does a Golfodulcean Poison-arrow Frog and a Black-cheeked Ant-tanager have in common?

Not only are they endemic to the Osa Peninsula in Costa Rica, but they are also endangered – a term used to describe when there are so few individuals surviving that the species is at risk of no longer existing in the wild.  There are many reasons that could drive a species to this status, including: habitat loss, illegal pet trade, introduction of exotic species, diseases, illegal hunting or overfishing.


Why does the Osa have so many endemic species?

Because of its geological formation where it evolved as an island before merging with the Costa Rica mainland (nearly 2 million years ago), the Osa Peninsula harbors a high level of endemic species. Endemic species are those which are found exclusively in one location in the world. This endemism, together with the immense concentration of life forms found in this region, is the reason why the Osa is globally known as a biodiversity hotspot and has such an important conservation value.


Why are these endemic species endangered?

Although the Golfodulcean Poison-arrow Frog and the Black-cheeked Ant-tanager can be found in areas close to the Osa Peninsula, populations are isolated, and in the case of the frogs, are considered a rarity. According to the IUCN Red List of Threatened Species (2017) both species are endangered because of their small distribution range, confined to protected areas, where logging and continuously habitat loss around these areas  are the major threats to both species nowadays. In the case of the frog, water pollution due to gold mining in the Osa is also a huge threat.


What is it like to experience these endemic & endangered species?

If you have never had the chance to explore nature in the Osa and see these animals, I invite you to go on an imaginary hike: It´s 5:15 am and we embrace an early morning hike into the rainforest. Binoculars in hand, a nice flute-like sound indulge our senses: it is the Black-cheeked Ant-tanager, but we have not seen it yet. This bird performs this particular song only in the early morning, sometimes accompanied by the howler monkeys´ chorus.

Time passes and a chatter-like sound captures our attention. Should we look up to the canopy? No, we better focus in the understory, where this species inhabit. As all tanagers, the Black-cheeked Ant-tanager fly in family groups and forage in the lower levels of the forest in search of small arthropods and fruits- a behavior that makes them important for controlling defoliating arthropods and also for dispersing seeds. Wait! Be careful with these bunch of army ants passing through the trail; let´s find a good place to enjoy the show:  the Black-cheeked Ant-tanagers are following the “ant swarm” with a mixed flock. We watch for 10 minutes until they disappear in the vegetation, following the path of the ants.

Photo 2: Black-cheeked Ant Tanager (Photo credit: Manuel Sanchez Mendoza)

As we keep walking in the rainforest another sound captures our attention:  the Golfodulcean Poison-arrow frog-  a diurnal species (active both day and night).  We can hear two calls but they are far away; maybe if we move towards a creek we can find them. Indeed, as we approach a small creek, we spot two males calling together on top of a log! These frogs are very territorial and we are witnessing a territorial display. Their colors (known in biology as aposematic coloration) are warning us that they are highly toxic. Continuing our walk along the creek, we find another male, but this time carrying tiny larvae on his back. He will soon deposit them in the water for their next life stage. Our hike concludes and we are thrilled to have successfully found these two endangered species that can only be seen in the Osa.

Photo 3:  The endemic & endangered Golfodulcean Poison-arrow Frog (Photo credit: Manuel Sanchez Mendoz

Why are endangered species important?

Experiencing nature is one way we can understand the importance of protecting endangered species. Each species, endangered or not, has a role to play in the greater ecosystem, whether by dispersing seeds, controlling other species, or by directly helping other species maintain the ecosystem health. These two endemic species- the Golfodulcean Poison-arrow Frog and the Black-cheeked Ant-tanager- are also important because they act as umbrella species. This means that if we protect their habitat we are also protecting the habitat of other important species, including other endangered animals and plants as the Jaguar (Panthera onca), the Scarlet macaw (Ara macao) and the Nazareno or Purpleheart (Peltogyne purpurea) found in the Osa.

Is it too late? Not yet!

Do we still have time to save the Golfodulcean Poison-arrow Frog and the Black-cheeked Ant-tanager? Yes, but we need ongoing efforts to conserve the vital ecosystems that support these animals and the surrounding biodiversity. Because these species are restricted to protected areas and they know no political boundaries, it is even more important to prioritize the buffer areas, forest patches and biological corridors that connect their habitat and are the last stronghold for their survival.

Please help Osa Conservation continue to save these amazing species and so much more! 100% of your donations goes toward helping conserve the habitats and ecosystems on which these species and so many more rely! You can visit our page here to make a donation or visit here to learn about visiting the Osa and seeing these incredible creatures for yourself! Every effort counts!


Celebrating Migratory Birds! Migratory birds, wetlands and people in the Osa Peninsula

Blogpost written by Alejandra Rojas, Naturalist Guide and Avian Program Coordinator

Every year, thousands of birds around the world start a long journey that is fundamental to their survival: migration. Each species has its particularity: they fly in flocks or by their own, during the day or the night, they rest or they fly restless, large distances or short distances. Despite their different migration strategies, all of these birds have something in common: they face challenges to survive their “flyway” – a term used to describe the route regularly used by large numbers of migrating birds.

One of the biggest threats to many migratory birds is habitat loss along the flyway due to fragmentation, pollution and human development. Wetlands, in particular, are especially fragile and important areas for a high diversity of migratory birds. Unfortunately, wetlands are also among the most endangered ecosystems worldwide, largely due to loss of forest coverage.



Wetlands, such as mangroves, are one of the most productive ecosystems in the world. They provide key ecosystem services such as water storage, nutrients production, protection against storms, stabilization of coastal areas, purification of water and retention of sediments. Humans also obtain other benefits directly from wetlands, such as fishing, aquaculture and tourism opportunities that provide an economic income for local communities.

Indeed, there is a special connection between birds and mangroves! Because of  their sensitivity to environmental changes and the impacts on their flyway habitats, migratory birds are important biological indicators that help us understand the ecological health of an area and can help inform conservation planning.

The Osa Peninsula has large extensions of mangroves, riparian forests and estuarine lagoons that act as a temporary home for aquatic birds that visit Costa Rica during their migration and stop sites. Ducks (Anatidae), herons and egrets (Ardeidae), plovers and sandpipers (Scolopacidae and Charadriidae), terns and gulls (Lariidae) and warblers (Parulidae) are between the most commonly seen migrants in the mangroves.



Conservation efforts like those of Osa Conservation, which include the restoration of wetlands, help ensure the sustainable restoration of migratory bird habitat on which so many species rely. Through education and local awareness efforts, Osa Conservation encourages the involvement of local communities to help mitigate the negative impacts of human activities and to share the message of the importance of migratory birds and their habitat.  Conserving wetlands for migratory birds is crucial for their survival and ours: Their Future is our Future.