Farming alongside apex predators

Blogpost written by Eleanor Flatt, Restoration and Biodiversity Research Field Assistant

Many intensely biodiverse tropical rainforests are not only inhabited by wonderful wildlife but also by people who call it their home. In these areas, farms offer opportunity to grow crops or maintain livestock in order to provide income for their families. In an ideal world, these two landscapes would be separated and conflicts would not exist. However, located where the rainforest meets farm, there is a matrix where the flora and fauna interact and where human-wildlife conflicts can occur.

steam rolling

In the Osa, we witnessed first-hand this fascinating matrix between farm and wildlife when we recently heard that a goat had been killed by a predator on our farm. Interestingly though, when we arrived at the farm we found that not only one goat had been killed but two! But by what?

To investigate this, we set up a camera trap near each goat, hoping the predator would return to collect their kill. As day turned to night, we used the lights on our phones to check the final camera and navigate through the field back to the car. As we were approaching the car, we looked up and found two big beady eyes shining at us – IT WAS A PUMA!  This was my very first sighting of a puma and we were only a couple of meters away! Laying down, the puma observed us as we observed him while we walked past. We quickly hopped into the truck as he got up and headed towards the goat. We watched as the puma approached the goat and dragged away the carcass to enjoy the dinner alone. What a very exciting experience for us to watch!

Photo taken from our camera trap

Photo of the puma taken by our camera trap

Yet, this young male puma wasn’t the only visitors to the goats. Through our camera traps, we were able to observe a common opossum, yellow headed caracara, black vulture and the magnificent king vulture – all feasting on these recently killed meals.

Photo of King Vulture taken by our camera trap

Photo of King Vulture taken by our camera trap

Observing this very real and natural event brought mixed emotions. While it was a sad loss for the farm, it was such an important wildlife interaction to witness. Seeing this first hand, brought to light the challenges facing farmers in  areas where they are trying to co-exist with important apex predators.

Predation of livestock by a wild cat is a monetary loss for a farmer that could mean not being able to provide food for the family. This challenge of farming alongside apex predators in a rainforest system is not only found in Costa Rica, but globally. Unfortunately, this type of human-wildlife conflict can often result in the killing of these apex predators to protect one’s farm.

Osa Conservations strives to build a balance between healthy ecological systems with sustainable practices. Our wildlife-friendly farm offers opportunities to see not only how to grow sustainably, but also within the context of the greater ecosystem through agroforestry and rewilding. Yet, as we can see, farming alongside apex predators is no easy feat. As we continue to use the farm, we look for opportunities to better understand these challenges and to find solutions for tropical farming.



Passionflowers and Butterflies: A love-hate relationship

Blogpost by Ruthmery Pillco Huarcaya, Biodiversity & Conservation Projects Coordinator and Botanical Assistant

After a long but successful morning collecting specimens for the botanical garden we headed back to the station, excitement and rumbling stomachs in tow. Suddenly, one small plant close to the trail caught my eye. I curiously approached it, going in for a closer look. What was it? I called over our botanical assistant Marvin to pick his brain. Immediately he smiled with happiness and enthusiastically screamed: “It is a passiflora, collection number 11 for the botanical garden and a potential new species of passiflora for the Osa Region!”

A flower of a passiflora vine

A flower of a passiflora vine

Passifloras are vines commonly called passionflowers. While some of them are purely grown for ornamental purpose, others are grown for their edible fruits (passion fruits, granadillas, etc.). Many tropical rainforest insects and plants have had a long love-hate relationship. I am fascinated by plant-animal interactions, and passifloras are a splendid example of coevolution and intelligence. This species of passiflora has an unfriendly relationship with heliconius butterflies, who lay their eggs on the leaves of passionflower vines, which eventually hatch into hungry leaf-eating caterpillars. Passifloras try to protect themselves with a range of defenses.

A passiflora mimicking the presence of butterfly eggs

Passifloras mimicking the presence of butterfly eggs

One example is that the passifloras contain a chemical defense, they produce cyanide present in the stem and leaves. However, heliconius butterflies have acquired the ability to integrate this poison and even use it to defend against their own predators. Another strategy is that the passifloras will perform mimicry by copying leaf shapes of other plants that are not hosts of the heliconius butterfly eggs. Through this form of camouflage there is a chance that they can avoid, or at least reduce the possibility, of being preyed upon by these hungry caterpillars. This passiflora method is to grow structures on the leaves to look like butterfly eggs. Since the female heliconius butterflies are extremely careful when selecting sites to lay their eggs, if the leaf appears to be occupied, the butterflies will move away and continue searching for a different place to lay the eggs.

A passiflora with glandular trichomes

A passiflora with glandular trichomes

Some passifloras also have glandular structures, which secrete sticky and smelly substances that trap small caterpillars to prevent them from munching on their leaves. Additionally, the passifloras will also receive help from other organisms by producing nectar to attract ants who will then pick off young heliconius caterpillars. In return, the ants are rewarded with sugar (a great example of a mutualistic relationship!).

Who knows how the heliconius butterflies will evolve to overcome these defense tactics! Meanwhile, we will continue searching for more species of passiflora native to the Osa Peninsula, learning more about this interesting plant and how it interacts with flora and fauna.

A picture of Ruth

A picture of Ruth, the author


A breeding frenzy of gliding tree frogs!

Blog written by Abigail Fields, Osa Conservation DC Intern

Imagine hundreds of tiny green and yellow masses moving all around on a leaf. They shift up and down, sashaying side to side, stepping on top of one another as they move in different directions. Small, light green buds can be seen around the masses as well. No, these aren’t bugs, but actually an army of gliding tree frogs and their eggs.

Each year during the rainy season explosive breeding takes place, leading to these gatherings of frogs. The frogs mate and lay their eggs on long leaves that overhand a body of water. After 6-8 days, the babies, or tadpoles, hatch and fall into the water below, where they will transform and grow into adult frogs.

The gliding tree frog is a small species of frog (generally 2-3 inches in length) characterized by its changing appearance. It is light, yellow-green color during the day and a much darker green at night, so as to camouflage itself.  They have slim bodies and broad heads adorned with very large red-black eyes with reticulated eyelids (a translucent third eyelid that can be draw across the eye for moisture and protection!). Interestingly, their webbed feet allow them to glide through the air. The webbing acts as a parachute when they jump, which is why they were named the “gliding” tree frog.

Mostly, the gliding tree frog inhabits tropical and subtropical wetlands (as is necessary for laying eggs) in Colombia, Panama, Ecuador, and of course Costa Rica! They live in the tree canopies of the forests year-round until they come lower to mate by the water sources. The gliding tree frog hunt mostly bugs such as crickets, flies, and moths. When moving between trees, they use their webbed feet and powerful legs to propel themselves and glide between the branches.

Gliding Tree Frog, by Manuel Sanchez

Like most amphibious species, habitat loss, pollution, human encroachment and more are threatening them and leading to a trend in decreasing populations. They are still, however, listed as a species of “Least Concern” on the IUCN Red List, as the rate of decrease is slow. Though this is complicated by the frog’s traditional tree habitat, which makes them notoriously difficult to monitor and see. Even so, conservation efforts to protect this species, as well as the countless others threatened by climate change and habitat loss, are essential to protect their futures.

Despite being difficult to locate in the trees, the breeding frenzies are another story.  Earlier this year, Manuel Sanchez  captured an excellent video of one of the breeding frenzies that came along with the beginning of the rainy season in Costa Rica! As you can see, the frogs have no problems with personal space!


Exploring the waters with Rios Saludables

Blog by Megan Tudor, previous Sea Turtle Volunteer

The wet season in the Osa Peninsula is just that—very wet. For the past three weeks, I have been out trekking in torrential rain, both first thing in the morning and late at night, while working on the sea turtle program. I also had the opportunity to help with various other important field research tasks being carried out by the incredible team at Osa Conservation.

Megan performs a pH test from a water sample

Megan performs a pH test from a water sample

One project that I especially enjoyed helping with was the Rios Saludables program,  coordinated by Hillary Brumberg. I had fun working in the water and seemed to always be getting wet! Water quality testing here in the Osa Peninsula is incredibly important, as it affects many people in the area. The testing includes looking at the pH, alkalinity, nitrate levels, conductivity and temperature of the water.

We set off down to Piro River armed with a big box full of equipment and a homemade surber sampler (a rebar cube used to sample sections of the river with a net attracted to capture interesting river wildlife). Since it’s the rainy season, the river is currently flowing fast, so walking through and along it was a challenge in itself; one which I did not manage with dry feet! With one misstep into a deep section, the river was over my boots and soaking through my socks!

Several volunteers conduct water quality tests

Testing the different aspects of river health took about two hours, with detailed instructions to follow for the more complex tests. I looked at the pH and the nitrates while others analyzed other aspects. Good news – Our tests showed that everything was in a healthy range in this part of the river! Lastly, we used the suber sampler to gather leaves and sediment from the river bed in hopes of finding some macro-invertebrates. After combing through what we gathered in the nets in five different locations along the river, we identified a couple of species of mayfly before returning them to the water.

This experience was fascinating and gave me insight into the wider range of research taking place in the Osa Peninsula and a deeper understanding of the importance of this conservation work. I loved it!



Do you know of the white-lipped peccary?

Blog written by Juan Carlos Crus Diaz, Feline Program Coordinator

The white-lipped peccary is a species that represents the tropical forests of Latin America just as much as the jaguar or tapir; however, they are often not nearly as well known.

The white-lipped peccary (Tayassu pecari), or “chancho de monte,” has a range from Southern Mexico to Northern Argentina. They are a very important species for tropical forests because they directly benefit the regional biodiversity. When they search for worms and seeds on the ground, they move around the soil  making it possible for certain plant species to flourish. In addition, peccaries are the main prey of the jaguar, the top predator of the continent. For this reason, white-lipped peccaries are often considered one of the best indicators of ecosystem health.


Two white-lipped peccaries

Two white-lipped peccaries walking through water


Unfortunately, peccaries are threatened due to excessive hunting and loss of habitat from deforestation. They are protected by law in every country where they are found and are included in the Apendix II  of CITES (the Convention on International Trade in Endangered Species of Wild Fauna and Flora) and considered ‘Vulnerable’ in the Red List of Species from the IUCN (International Union for Conservation of Nature). In the Osa Peninsula, this species faces great hunting pressure, which has diminished their numbers so greatly in the past few years that they are currently at their lowest abundance in the last 25 years.

To combat this, Osa Conservation, in conjunction with the Costa Rican government (SINAC-ACOSA), is starting a  project to learn more about the ecology of the white-lipped peccary in order to inform and improve a conservation monitoring plan for them.

Two white-lipped peccaries

Peccaries foraging in the Osa

This project will “tag” individuals from different groups with GPS collars which will be monitored and used to generate a distribution map of the species to better understand their habitat-use and to know their real-time location. With this information, we will work with our partners to not only improve the conservation efforts of the peccaries, but also strengthen the conservation efforts for the wildcat predators that rely on them for survival.



Wildcats, like this jaguar, rely on peccaries as their main prey.


In addition, the communities located in the areas next to Corcovado National Park, where the peccaries and many other species live, will be our allies for the biological monitoring of populations of the white-lipped peccary, as well as 19 other species of terrestrial mammals, including the 5 species of wildcats found in the Osa.

Four local communities (Alto Laguna, Los Planes, Rancho Quemado and Rio Tigre) will perform biological monitoring using camera traps and tracks. Osa Conservation is excited to provide the logistic and technological support and start an environmental education project with local schools and communities. Visitors to Osa Conservation’s biological station will also have an opportunity to more more about this project during their stay.


A white-lipped peccary snout

The white-lipped peccary

We are excited to be a part of this initiative that brings conservationists, communities, scientists and governments together for a united goal to help protect the health of Osa’s ecosystems!



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