Falling vulture numbers in the Americas could have serious implications for public health and ecosystems, new research has found.

A first-of-its-kind study conducted at Osa Conservation, in the Osa Peninsula, Costa Rica has revealed that pig carcasses take twice as long to decompose if vultures are not present to provide their rapid recycling services.

Notably, other scavengers do not fill the void left by the absence of the birds, except for flies, whose numbers were seen to double with the reduced competition.

The study, published in Ecology and Evolution, and led by scientists in the Centre for Ecology and Conservation at the University of Exeter, Cornwall, and OSA Conservation in Costa Rica, shines a light on the underappreciated role played by vultures. It also raises questions and concerns about the potential impact of increased fly populations on the environment and human health.

“This research underlines the unique and irreplaceable role that vultures play as nature’s ‘clean up crew’,” says Julia Grootaers, co-author and Behavioural Ecologist at the University. “Unloved and unappreciated – even to the point of persecution – the importance of vultures is stark when you remove them from an ecosystem. These apex scavengers have specialised and highly acidic digestive systems that can destroy many of the pathogens found in carrion, thus mitigating the spread of disease from carcasses to other wildlife, livestock and humans.”

The research team placed domestic pig carcasses within 500m of each other, in both forest and grassland areas, over a series of tests spanning the wet and dry seasons. Half of the carcasses were secured but left open to all scavengers, while the remainder were placed inside a cage with netting, making them inaccessible to larger animals. And at each site, the researchers installed cameras and insect traps to record animal presence and monitor the number of flies and dung beetles.

Studying the footage, the team identified Black Vultures, Turkey Vultures and King Vultures at 15 of the 16 carcass sites, with few signs of other potential scavenging species such as pumas, ocelots, caiman, or coyotes. And when they measured the rates of decomposition, they found that the carcasses open to vultures lost an average of 9.5kg of mass each day, compared with just 4.8kg for those that were placed in the cages.

The researchers also recorded a near doubling of the number of flies at those sites where vultures were excluded, but no discernible variation in the numbers of dung beetles.

“Our results demonstrate that intact scavenger communities, with vultures, invertebrate and microbial decomposers, efficiently decompose carcasses at double the rate compared to when it is insects and microbes alone,” said Dr Chris Beirne, Director of Wildlife Programs at Osa Conservation. “And it’s apparent that in Costa Rica, other large vertebrate scavengers do not drive decomposition in the food chain – and that is consistent with what we see in other regions, including Kenya and northern Spain.”

The researchers say that the increased amount of time it takes for carcasses to decompose when vultures are not present enables flies to reproduce and for their larvae to reach maturity.  This, they say, increases the likelihood that they might become vectors for diseases such as botulism, anthrax, e-coli and Salmonella.

“While dramatic vulture declines have already been documented across Africa, Asia, and Europe, this study raises concerns about the overlooked vulnerability of their American counterparts,” adds Greta Hernandez, of Universidad de Panamá. “And the findings highlight the urgent need for deeper research into vulture population trends in the Americas, the critical ecosystem services they provide, and the conservation action needed to safeguard these silent stewards of the environment.”

Vulture exclusion halves large carcass decomposition rates and doubles fly abundance is published in the latest edition of Ecology and Evolution.

(Español Abajo)

In Southern Costa Rica, the AmistOsa landscape supports the largest lowland tropical rainforest on Central America’s Pacific slope. Comprising protected areas and working agricultural landscapes, AmistOsa boasts unparalleled levels of endemicity and rarity with over 400 species of birds, 140 mammals, and 500 tree species described so far. The region encompasses cloud forest mountaintops, archaic tropical lowland rainforest, Central America’s largest mangrove system, and the unparalleled seascape of the Cocos-Galapagos swim way, making it a biological hotspot on which the planet depends. 

Here, Osa Conservation works with a network of farmers and community members to create resilient agricultural landscapes that will simultaneously create more sustainable livelihoods for local farmers, sequester carbon at scale, and ensure as many wildlife species as possible survive climate change. Our goal is to build climate resilience for people and nature at scale.

A Tropical Blueprint for Sustainability

The AmistOsa region, a vital ecological corridor in southern Costa Rica, faces critical challenges due to climate change and biodiversity loss. Our goal is to reverse these trends by integrating sustainable farming practices with conservation through agriculture, demonstrating how tropical farming landscapes can coexist with thriving ecosystems.

Over the next three years, the grant from Walmart Foundation will help us: 

• Farmer Empowerment: Partner with 350 farmers in the AmistOsa Restoration Network to implement tailored regenerative farming plans that boost productivity and sustainability.
• Financial Incentives: Establish biodiverse agricultural areas as priority zones for Costa Rica’s REDD+ (reducing emissions from deforestation and forest degradation in developing countries) scheme to financially incentivize farmers to restore and protect forests and water systems.
• Restoration at Scale: Rehabilitate 270 hectares of degraded land and improve management of over 1,800 hectares through silvopastoral systems, riparian restoration, and agroforestry.
• Enhanced Biodiversity: Plant 300,000 native trees from over 300 native species to promote biodiversity and ecosystem health.
• Water Security: Protect and restore riparian zones to enhance water access and quality for an estimated 102,000 vulnerable community members.
• Build climate resilience: Foster sustainable farming techniques that improve soil health, increase crop diversity, and enhance livelihoods.

Scalable Impact: Publish open-access reports and host workshops to share restoration and financial schemes, demonstrating how reinvestments in locally led initiatives can achieve better impacts for people and nature.

Building Resilience for People and Nature
This work builds on Osa Conservation’s legacy of integrating conservation and community development. Osa Conservation has been on the ground in this region for over two decades. We have planted over one million trees and engaged thousands of community members in restoring vital ecosystems. Regenerative agriculture holds immense potential to address the dual crises of climate change and biodiversity loss. By improving soil health, reducing water consumption, and integrating conservation with farming, this project will strengthen local livelihoods and improve economic stability. 

Making it Possible

Osa Conservation is grateful for our supporters who help make this work possible. This year, Osa Conservation secured funding from the Walmart Foundation to scale our innovative Farms for Nature project. This initiative aims to establish a model for regenerative agriculture that can inspire similar efforts across tropical regions globally.

Join Us in Shaping a Sustainable Future

As we work to transform tropical agriculture, we invite partners, stakeholders, and advocates to learn from and build upon this project. Together, we can create a global movement toward regenerative practices that prioritize both people and nature.

Stay updated on this journey at Osa Conservation or learn more about the Walmart Foundation at Walmart.org.

This is a new chapter in tropical restoration—one that aims to have a lasting impact on ecosystems and communities across the tropics.

Avanzando la Agricultura Regenerativa en Costa Rica

El apoyo de la Fundación Walmart impulsa la ampliación de los impactos de conservación.

En el sur de Costa Rica, el paisaje AmistOsa resguarda el bosque tropical de tierras bajas más grande de la vertiente pacífica de Centroamérica. Compuesto por áreas protegidas y paisajes agrícolas productivos, AmistOsa alberga niveles incomparables de endemismo y rareza, con más de 400 especies de aves, 140 especies de mamíferos y 500 especies de árboles registradas hasta ahora. La región incluye cimas de bosques nubosos, selvas tropicales antiguas, el sistema de manglares más grande de Centroamérica y el corredor marino Cocos-Galápagos, lo que la convierte en un punto crítico de biodiversidad del cual depende el planeta entero.

Aquí, Conservación Osa trabaja con una red de agricultores y miembros de la comunidad para crear paisajes agrícolas resilientes, que al mismo tiempo generen medios de vida sostenibles para los agricultores locales, capturen carbono a gran escala y aseguren la supervivencia del mayor número posible de especies frente al cambio climático. Nuestro objetivo es construir resiliencia climática para las personas y la naturaleza a gran escala.

Un Modelo Tropical para la Sostenibilidad

La región AmistOsa, un corredor ecológico vital en el sur de Costa Rica, enfrenta desafíos críticos debido al cambio climático y la pérdida de biodiversidad. Nuestro objetivo es revertir estas tendencias integrando prácticas agrícolas sostenibles con la conservación a través de la agricultura, demostrando cómo los paisajes agrícolas tropicales pueden coexistir con ecosistemas prósperos.

Durante los próximos tres años, el financiamiento de la Fundación Walmart nos permitirá:

• Empoderar a agricultores: trabajar con 350 agricultores de la Red de Restauración AmistOsa para implementar planes personalizados de agricultura regenerativa que aumenten la productividad y sostenibilidad.
• Ofrecer incentivos financieros: establecer áreas agrícolas biodiversas como zonas prioritarias para el esquema REDD+ de Costa Rica (Reducción de Emisiones por Deforestación y Degradación de los Bosques), generando incentivos para restaurar y proteger bosques y sistemas de agua.
• Restaurar a gran escala: rehabilitar 270 hectáreas de tierras degradadas y mejorar la gestión de más de 1,800 hectáreas mediante sistemas silvopastoriles, restauración de corredores ribereños y agroforestería.
• Mejorar la biodiversidad: plantar 300,000 árboles nativos de más de 300 especies, promoviendo la biodiversidad y la salud de los ecosistemas.
• Fortalecer la seguridad hídrica: proteger y restaurar zonas ribereñas para mejorar el acceso y la calidad del agua para aproximadamente 102,000 miembros de comunidades vulnerables.
• Construir resiliencia climática: fomentar técnicas agrícolas sostenibles que mejoren la salud de la tierra, aumenten la diversidad de cultivos y fortalezcan los medios de vida.
• Multiplicar el impacto: publicar informes de acceso libre y organizar talleres para compartir prácticas de restauración y esquemas financieros, demostrando cómo las inversiones en iniciativas locales pueden lograr mejores resultados para las personas y la naturaleza.

Construyendo Resiliencia para las Personas y la Naturaleza

Este trabajo se basa en el legado de Conservación Osa de integrar conservación y desarrollo comunitario. Conservación Osa ha trabajado en esta región durante más de dos décadas, plantando más de un millón de árboles y colaborando con miles de miembros de la comunidad en la restauración de ecosistemas vitales.

La agricultura regenerativa tiene un enorme potencial para enfrentar la doble crisis del cambio climático y la pérdida de biodiversidad. Al mejorar la salud de la tierra, reducir el consumo de agua e integrar conservación con agricultura, este proyecto fortalecerá los medios de vida locales y mejorará la estabilidad económica.

Haciendo Posible este Esfuerzo

Conservación Osa agradece a nuestros aliados y patrocinadores, cuyo apoyo hace posible este trabajo. Este año, Conservación Osa ha asegurado un importante financiamiento de la Fundación Walmart para ampliar nuestro innovador proyecto Fincas para la Naturaleza. Esta iniciativa busca establecer un modelo de agricultura regenerativa que pueda inspirar esfuerzos similares en otras regiones tropicales del mundo.

Únase a la Construcción de un Futuro Sostenible

Mientras trabajamos para transformar la agricultura tropical, invitamos a aliados y defensores de la conservación a aprender y colaborar con nosotros. Juntos, podemos crear un movimiento global hacia prácticas regenerativas que prioricen tanto a las personas como a la naturaleza.

Mantente al tanto de este proyecto en Conservación Osa, o conoce más sobre la Fundación Walmart en Walmart.org.

Este es un nuevo capítulo en la restauración tropical, con el potencial de dejar un impacto duradero en los ecosistemas y comunidades de los trópicos.

Contributions by Guido Saborío Rodríguez, Dr. Carolina Pinto, and Yvonne Kemp

Introduction

World Rewilding Day marks a pivotal moment in conservation, emphasizing the restoration of natural habitats and the reintroduction of key species to recover ecosystem services provided by nature. Among the most promising efforts is Rewilding Costa Rica, by reintroducing the White-Lipped Peccary (WLP) in locations where it has disappeared in the South Pacific. The Osa region is a testament to the country’s remarkable recovery from extensive deforestation back to a beacon of biodiversity.¹

The Osa Peninsula: A Conservation Success Story²

Once a victim of rampant logging, Costa Rica’s Osa Peninsula has undergone a dramatic transformation. From a low of 21% forest cover in 1987, concerted efforts by the government and local communities have increased Costa Rica´s forest cover up to 59.4% by 2020. Today, the Peninsula is a complex mosaic of dense forests, critical habitat for the WLP and other spectacular species such as tapirs and jaguars, interrupted by productive farmlands. This turnaround is a powerful example of how dedicated conservation initiatives can repair and restore natural ecosystems. But there is much more work to be done to connect the forest habitats and its wildlife populations amidst the fragmented landscape in the South Pacific of Costa Rica.

Focusing on the White-Lipped Peccary for Rewilding

The decline of the WLP, a species integral to the forest ecosystem for its key role in seed dispersal and soil health, and as prey for apex predators like jaguars, mirrors the broader challenges of habitat fragmentation. Osa Conservation’s innovative rewilding project focuses on enhancing the ongoing restoration effort to create forest corridors through reconnecting fragmented habitats, and actively bringing back WLP to key areas in the landscape in order to maintain and promote healthy populations of wildlife and tropical forest.

Osa Conservation is preparing to embark on a project to safeguard the peninsula’s biodiversity through active rewilding efforts. By building forest corridors, and establishing new populations in areas where WLP used to be 30 years ago, we aim to recover the previous distribution and guarantee its safe migration; and through this, establish a model for similar conservation efforts across Latin America. The initiative involves meticulous planning together with the local Government (MINAE-ACOSA) for the capture and relocation of WLPs, ensuring their successful adaptation and long-term survival in the habitats where they will be reintroduced.

A Vision for the Future: Beyond the Peccary

The project’s ambition extends beyond the WLP. Dubbed “Climate Adaptation Lifeboats,” this comprehensive strategy integrates science, community involvement, and government support to create resilient ecosystems capable of withstanding the pressures of climate change and biodiversity loss. It presents a beacon of hope and a replicable model for global biodiversity conservation.

Community Engagement and the Path Forward

The engagement of local communities is vital to the success of rewilding efforts. In towns like Rancho Quemado, the WLP has become a symbol of ecological resilience and local pride, showcasing the positive impact of shifting from exploitative practices to conservation-minded stewardship. Osa Conservation’s participation in local festivals and educational programs highlights the importance of community support in achieving long-term conservation goals.

Conclusion

The Rewilding Costa Rica project, which firstly aims to recover the White-Lipped Peccaries’ historical distribution in the South Pacific of Costa Rica, is more than a conservation project; it is a testament to the potential for human-led initiatives to restore natural balance and biodiversity. As World Rewilding Day approaches, it serves as a reminder of the global importance of such efforts and the need for continued support and engagement from the global community. Through donations, volunteering, land protection, or responsible tourism, everyone has a role to play in supporting the rewilding initiatives that are crucial for our planet’s future.

Support Rewilding Efforts

To contribute to these vital conservation efforts, consider supporting Osa Conservation. Every action, big or small, helps pave the way toward a more biodiverse and sustainable future.

1. https://www.researchgate.net/publication/362334565_Nearshore_marine_biodiversity_of_Osa_Peninsula_Costa_Rica_Where_the_ocean_meets_the_rainforest ︎
2.  Updated from FRA 2020 Report for Costa Rica https://www.sirefor.go.cr/pdfs/publicaciones/FRA-FAO_2020-COSTA_RICA.pdf ︎

Es de las especies más raras, de las más preciosas piedras, y de los minerales más valiosos que buscamos. Los Naturalistas poseen estos tesoros raros pues sabemos que tienen un valor excepcional. Ellos se han diferenciado del resto y de lo común, se han adaptado y especializado para llenar un nicho que nada más podría. Marvin López Morales era uno de esos tesoros. 

A Marvin le importaba, más que a nadie que he conocido, los árboles y plantas de su hogar, la península de Osa, donde nació, creció, se formó y adaptó a su ambiente, y aplicó su habilidad única e incomparable al desafío más apremiante de nuestros tiempos – salvar una parte de nuestro planeta. 

Conocí a Marvin hace 6 años cuando él trabajaba como botánico de campo para unos de los más prominentes equipos de ciencia del mundo. Brooke Osborne me dijo, “no lo habríamos logrado sin Marvin”. Él sabía mejor que nadie de la flora – y no fue difícil para ellos entrenar a una mente tan inquisitiva y apasionada en cómo llevar a cabo complejos experimentos bioquímicos para entender procesos de intercambios de gases de las plantas en el bosque lluvioso de la Osa. Él se sentaba en nuestro antiguo laboratorio a realizar experimentos que iban más allá de mi comprensión. Pero cuando preguntaba, él elocuentemente explicaba los experimentos y técnicas para que yo pudiera entender. Cada vez que traía una semilla, fruta o rama, Marvin casi inmediatamente podía decirme el género e incluso la especie. Rápidamente me di cuenta de la verdadera joya que había encontrado. 

Conservación Osa necesitaba un programa dedicado a proteger y restaurar esos árboles raros y amenazados de la región – y el talento para construir ese programa estaba justo bajo nuestras narices. Por lo que este año contratamos a Marvin. Él y la botánica peruana Ruthmery Pilco, comenzaron a trabajar juntos para construir el programa que no solo plantaría decenas de miles de árboles para restaurar bosques a través de la región, sino también para dar un enfoque especial a las especies más raras y amenazadas. Algunas son tan raras que están enfrentando rápidamente el riesgo de extinción. Éstas eran las que Marvin más atesoraba y cuidaba. 

Nosotros tres, este año somos coautores de una publicación científica que detalla la recuperación debido a esfuerzos de conservación de la especie – Pleodendron costaricense. Pero fue la pasión de Marvin y determinación lo que llevó a descubrir como este árbol podría ser salvado de su inminente destino. Ruthmery me dijo, “No conseguimos que ninguna de las semillas germinará pues algo las está destruyendo. Marvin estaba tan frustrado que se sentó por días en la casa de germinación intentando entender qué era lo que pasaba – y nada- y las semillas continuaban siendo destruidas. Entonces, una noche entera en el vivero pasó solo con una linterna. Finalmente, descubrió a las culpables. Las cucarachas, comiéndose sus preciosas semillas. Intentó matarlas con trampas de cerveza. Me llamó, riéndose, para decirme que era la primera vez que él había comprado cerveza en el supermercado – no para él, sino para que las cucarachas murieran felices. Incluso eso, no paró a las cucarachas. Y así, al día siguiente él construyó un encierro especial para mantener a los tortuosos bichos lejos de sus semillas. Semanas después, los primeros brotes de las diminutas semillas aparecieron – sus primeros bebés Pleodendron. Así es como Marvin llamaba a todas sus plantitas – especialmente a aquellas que salvaba de la extinción. 

Ruthmery me dijo en otra ocasión… “Marvin me llamó una mañana a decir que ha estado despierto desde el amanecer pretendiendo ser un colibrí y que pronto tendría muchos hijos”. Ruth estaba confundida… y Marvin comenzó a reírse. “Una vez que paró de reírse, él explicó que las plantas de vainilla con las que estaban trabajando no eran polinizadas naturalmente – y entonces fue temprano esa mañana a polinizar todas, el mismo”. ¡Un padre orgulloso claramente!

Marco Hidalgo recientemente recordó el momento que comprendió el verdadero talento naturalista de Marvin. Ellos habían ido a un evento en Bahía Drake, en donde tenían un taller con guías locales, y cualquier persona interesada en los árboles raros de la península de Osa. Marco fue como guía y facilitador, ya que conocía a Marvin desde que era un niño, y ahora un compañero de Conservación Osa. Marco dijo que al finalizar el entrenamiento de Marvin, uno de los guías locales más expertos vino donde Marco y lo llevó a un lado… “¡Wow! Este muchacho realmente sabe de lo que habla. Y él es de la península. Eso me hace muy orgulloso”. Los verdaderos naturalistas no obtienen esto de los libros. Casi cada fin de semana yo veía a Marvin publicar acerca de descubrimientos de algún lugar de la península, siempre colectando, siempre aprendiendo, constantemente compartiendo – eternamente explorando. 

Finalmente, Ruthmery me dijo que, durante una de nuestras ceremonias de dedicación de árboles, Marvin se acercó y susurró a ella, “Tengo los ojos puestos en un árbol en el sendero Tangara. Un día quiero uno de esos árboles gigantes de Ajo (Caryocar costaricense) para mí”. Cuando Ruth caminó con Marvin a ver ese árbol, ella se acercó al mismo… “No lo toques Ruth” él bromeó, sonriendo dijo “Es mío”. 

Y así debe ser. Todos los que conocimos a Marvin sentimos el dolor de su fallecimiento la semana pasada. Y mientras este nunca se irá, tomaremos consuelo de las semillas que Marvin ha sembrado. Junto con las decenas de miles de árboles que él ayudó a replantar, y las semillas que han crecido dentro de nosotros – inspirados a mirar, tocar, oler, aprender y cuidar la naturaleza. Un verdadero tesoro, un hábil naturalista, y una persona ejemplar. Todos aquellos que quieran rendir homenaje a Marvin y su árbol siempre serán bienvenidos a visitar el sendero Tangara en Conservación Osa – pero deben pagar un tributo – naturalizar los bosques que los rodea, así como Marvin lo hizo.

English Translation

It’s the rarest of species, the most precious of gemstones, and the most valuable minerals that we seek. Naturalists covet these rare treasures because we know that they hold some exceptional quality. They’ve differentiated from all that is common around them – adapted and specialized to fill a niche that nothing else possibly could. Marvin López Morales was one such treasure.

Marvin cared more than anyone I know about the trees and plant life of his home – the Osa Peninsula, where he was born, raised, became formed and adapted to his environment, and applied his unique and unparalleled skillset to the most pressing challenge of our time – saving a piece of our planet.

I first met Marvin six years ago when he was working as a field botanist for some of the most prominent international science teams from around the world. And Brooke Osborne told me, “We couldn’t have done it without Marvin”. He knew the flora best – and it wasn’t hard for them to train such a sharp and passionate mind how to carry out complex biochemical experiments to understand gas exchange processes of the plants from Osa’s rainforest. He would sit in our old lab conducting experiments which were beyond my comprehension. But when I inquired, he would eloquently explain the experiments and techniques so that I might understand. Every time I brought a seed, fruit, or branch from my hike to work, Marvin could almost immediately tell me the Genus, if not the species. I quickly realized I had encountered a true gemstone. 

Osa Conservation needed a program to protect and restore the rare and threatened trees of the region – and the talent to build such a program was right under our noses. So, we hired Marvin that year. Marvin and Peruvian botanist Ruthmery Pillco began working together to build a program that would not only go on to plant 10’s of thousands of trees to restore rainforest throughout the region, but that also gave focus to the rarest and most threatened species. Some are so rare that they are fast facing the risk of extinction. It was these that Marvin treasured and cared for the most.

The three of us co-authored a scientific paper this year detailing the conservation recovery of one such species – Pleodendron costaricense. But it was Marvin’s passion and determination that ultimately discovered how this tree could be saved from its imminent fate. Ruthmery told me, “We couldn’t get any of the seeds to germinate because something was destroying them. Marvin was so frustrated that he sat for days in the germination house trying to see what was happening – but nothing did – and the seeds continued to be destroyed. So, one evening he spent the whole night in the nursery, alone with a flashlight. Finally, he discovered the culprits. Cockroaches – eating all of his precious seeds. He tried to kill them with beer traps. He called me, laughing hard, to tell me that this was the first time he had ever bought beer from the supermarket – not for himself, but for a cockroach to die happy. Even that didn’t stop the cockroaches. And so, the next day he built a special enclosure to keep the devious bugs away from his seeds. Weeks later his first little sprouts appeared from the tiny seeds – his first ever Pleodendron babies”. That is how Marvin referred to all his seedlings – especially those he was saving from extinction.

Ruthmery told me on another occasion… “Marvin called me one morning to say that he had been up since dawn pretending to be a hummingbird and would soon have many children.” Ruth was confused… and Marvin began to chuckle. “Once he’d quit laughing, he explained that the vanilla plants that we were working with weren’t being pollinated naturally – and so he went along early that morning to pollinate them all himself.” A proud father indeed!

Marco Hidalgo recently recounted the moment he realized the depths of Marvin’s true naturalist talent. They had gone to an event in Drake’s Bay, where Marvin was to deliver a workshop to local guides, and anyone interested, about the rare trees of the Osa Peninsula. Marco went along to help facilitate, having known Marvin since he was a young boy, and now a teammate with Osa Conservation. Marco said that right after Marvin’s training concluded, one of the most knowledgeable local guides came over to Marco and pulled him aside…. “Wow! That young guy really does know his stuff. And he’s a local from Osa. That makes me so proud.” True naturalists don’t get this from books. Almost every weekend I would see Marvin’s media posts where he was discovering some remote corner of the peninsula, always collecting, ever learning, constantly sharing – eternally exploring.

Finally Ruthmery told me that during one of our recent tree dedication ceremonies, Marvin leaned over and whispered to her, “I have my eye on a tree on Tangara trail. One day I want one of these Giant Ajo trees (Caryocar costaricense) for myself.” When Ruth walked with Marvin to see the tree, she stepped forward and reached out… “Don’t touch it Ruth” he joked, smiling. “It’s mine.” 

And so it shall be. All of us who have known Marvin felt the pain of his passing last week. And while it will never completely leave, we will take solace from the seeds that Marvin has sown. Both the literal 10’s of thousands of trees in the forests he helped replant, and the seeds he sowed inside of us – inspired to look, touch, smell, learn and care for nature. A true treasure, a skilled naturalist, and an exemplary person. All who want to pay homage to Marvin and his tree will always be welcome to visit the Tangara trail at Osa Conservation – but you must pay tribute – to naturalise the forest that surrounds you, like Marvin did.

THIS DEDICATION WAS WRITTEN BY OSA CONSERVATION EXECUTIVE DIRECTOR, DR. ANDY WHITWORTH.  TO SEE MORE ON MARVIN AND HIS LEGACY, CLICK HERE.

Photo credit, Dr. Andy Whitworth & Lucy Kleiner

Photo by Brandon André Güell

It was about 06:00 after night-long heavy rains ended a short dry spell, and already you could hear a deafening chorus of creatures gathering at the pond. Though sleepless and mosquito-ridden, we trudged chest-deep through the murky swamp waters with notebook and camera in hand to reach the source of the chaos. That’s when we saw it: One of the largest aggregations of treefrogs likely ever to be witnessed.

Tens of thousands of adult gliding treefrogs (Agalychnis spurrelli) literally poured over each other in attempt to breed and lay eggs. And for two Costa Rican tropical biologists and herpetologists, this rare biblical magnitude of frogs was like heaven on earth. This is Costa Rica. This is Osa. This is “Shampoo Pond”.

Since 2015, I have been studying how frog embryos use environmental cues to change their behavior. My current Ph.D. research in the Osa aims to understand how specific reproductive strategies interact with both environmental cues and development to affect embryo behavior and survival. For these gliding treefrogs, tens of thousands of reproducing adult frogs mean hundreds of thousands of frog eggs and embryos. And in this species, embryos are left alone to fend for themselves after they are laid. That means this event leaves behind a massive all you can eat frog-egg buffet for hungry predators

Why have a massive population lay their helpless eggs all at once in one location? That’s a great question, and it’s one I hope to answer!

In some cases, an overwhelming amount of prey can function as an antipredator adaptation if, for example, the overabundance of frog eggs decreases the probability of any one egg’s chance of being eaten. Basically, it can serve as a form of “safety in numbers”. This is known as predator swamping (or predator satiation). Shampoo Pond offers a pristine ecosystem where this hypothesis can be tested using these treefrogs.

In 2018, with the assistance of Katherine González, a Costa Rican tropical biologist, we conducted initial egg clutch monitoring studies in the hopes of determining whether this reproductive strategy has any impact on offspring survival. But this system has even more to it!

If undisturbed, gliding treefrog embryos develop and hatch into the pond as tadpoles in 6 days. But with so many threats, many wouldn’t survive that long.

How can frog heaven get any more interesting, you say? Well, what makes these treefrogs particularly interesting is their ability to respond to threats by hatching prematurely!

That’s right! These embryos can hatch almost 40% early to escape the jaws of a hungry predator like snakes, wasps, and even monkeys! However, many of them don’t hatch early, and thus will die during predator attacks. We know the embryos have the ability to hatch early, but sometimes they don’t. Why?!

In addition to predation, these embryos are susceptible to desiccation, fungal infection, and flooding. These threats provide unique cues, which the embryos use to inform their decision of when best to hatch. This is called environmentally cued hatching, and it’s presumable a very adaptive embryo behavior— it increases their survival and fitness. But for the gliding treefrog, this behavior may not be as plastic or adaptive as in other species. Here in the Osa, another focus of my research is understanding the mechanisms which cause these embryos to hatch or not to hatch in these contexts at different developmental stages.

Our work has only begun at Shampoo Pond, and we hope that it will elucidate the conservation importance of this fragile ecosystem and its inhabitants, particularly amidst the current anthropogenic environmental changes in Neotropical rainforests.

In 2021, Disney recognized a cohort of 15 Disney Conservation Heroes across 13 countries who “demonstrated incredible commitment to working with their communities to care for wildlife and habitats,” Martin said. “From individuals who protected their own land as nature reserves to those who found innovative ways to support wildlife while honoring cultural traditions, these Heroes have each taken risks, shown courage, and contributed to an inspiring global story of hope for the future,” Martin added.

Below are descriptions of Osa Conservation’s nominees for the esteemed award.

A trilingual field biologist and exceptional leader, Ruthmery is a Quecha woman working in conservation throughout the Americas. Her work has focused upon the magnificent Andean spectacled bear, as well as rare plant conservation on the Osa Peninsula. Hailing from a small farm in Peru bordered by the Andean highlands, Ruthmery has dedicated her life to protecting wildlife and rainforests. Ruthmery is leading an effort to restore and rewild landscapes, where the Andean bear is currently threatened by habitat loss and human-wildlife conflict. Her work doesn’t stop in Peru either — in Costa Rica, Ruthmery’s botanical expertise and program leadership has helped her team prevent the extinction of a rare and critically endangered plant species. The plant, belonging to the cinnamon family, has only been known to science since 1998. Ruthmery’s team has delicately worked to collect seeds found from the four remaining mature plants left in the wild. These precious seeds are then propagated and planted with the aim of replanting them in the wild. Ruthmery is currently active in efforts to protect plants of the Osa Peninsula.

Yolanda Rodriguez is an active conservation leader working from her small community of Rancho Quemado on the Osa Peninsula. Yolanda is an entrepreneur and community activist, where she started her own family business raising native butterflies while teaching local communities and tourists alike about the importance of the environment. She is a member of several community committees working to promote education, natural resource protection and increase the accessibility of nature to those with disabilities. Yolanda was a leader in the Rancho Quemado Community Biological Monitoring Group, heading a project that monitored and protected local peccary populations from hunting and habitat loss. She has raised awareness surrounding this vulnerable species through community events, such as the first White-lipped Peccary Festival held in 2019. Yolanda was also active in supporting the first annual Peccary Brigade, which brought community members together to spend 24 days tracking migrating peccary herds of over 100 individuals, work critical for informing conservation strategies.

Videos linked here

On Saturday, April 30th, over 400 community members — or “Rainforest Heroes — from across southern Costa Rica convened to honor and celebrate outstanding leaders in conservation. Those honored are profoundly dedicated to the protection of the Osa Peninsula’s unique biodiversity.

“Each hero celebrated today shares a common goal: to protect the beautiful, wild home we share, the Osa Peninsula,” said Manuel Ramirez, co-founder of local NGO Osa Conservation and long-time local of Southern Costa Rica. “The heroes are here to receive the recognition they deserve for all of their marvelous, tireless work.”

These conservation heroes represent a wide breadth of backgrounds, ages, and identities, yet share a common mission: fighting for the protection of one of Earth’s greatest wilderness areas. The rainforest heroes have carried out the goal of conservation with a wide array of innovative strategies from sustainable farming, to coral and mangrove restoration, to species and land protection.

“It is incredible to be celebrated in front of so many. We are surrounded by people who fight day after day to conserve and protect the Osa Peninsula, an incredibly special place that we all call home,” said Dionisio (Nito) Paniagua upon receiving his recognition. Paniagua, an eco-tour guide and volunteer ranger, was crowned a “Rainforest Hero” for his dedication to the preservation of biodiversity. “I know that here, in this crowd, there are a ton of Rainforest Heroes who will soon be where I am now.”

Five short documentaries detailing each hero’s successes premiered at the event, all of which are now available on Osa Conservation’s YouTube channel.

“It was one of the most emotional, exciting days of my life,” said Socorro Avila, a leader active in coral reef restoration and local recycling efforts. “Never in my life did I imagine the celebration would be this beautiful.”

The celebration also included cultural dancing led by local youth groups, sales at the local farmer’s market, handmade crafts, and various activities such as bouncy houses and face painting. Additionally, the event featured environmental-centered booths, including one that donated 350 rare and native tree saplings to event-goers. Over a dozen local NGOs, local organizations, and government agencies worked in tandem to honor the conservation heroes alongside hundreds of attendees.

“Each of these heroes is an excellent example for future generations,” said Ramirez.

The family Paniagua Villalta, creators of a small sustainable farm to table operation known as Aviva Organic, were among those awarded at the celebration. The family runs the operation from their home in the Talamanca mountains. “Being named a Rainforest Hero is a great honor, and an immense responsibility,” said Xiomara Villalta. 

“I am so honored to be part of this place, part of these communities,” said Nito Paniagua “with these people who love our home and fight to protect it.” 

For more information:

Lucy Kleiner

Communications Coordinator 

lucykleiner@osaconservation.org

• On February 18, National Geographic Pristine Seas premieres a feature documentary “OSA: Exploring the Blue Corcovado,” showcasing highly pristine and valuable marine ecosystems off the coast of Southern Costa Rica.
• The currently unprotected marine ecosystem is a vital habitat for sea turtles, hammerhead sharks, humpback whales, spinner dolphins, and an array of other marine species.
• The team, comprised of researchers and filmmakers, published findings that underscore the importance of protecting the ecosystem, which they claim “would benefit the rich biodiversity of this part of the country as well as replenishing nearby overexploited important fisheries resources.”
• Artisanal fishers in the area also support the Corcovado Marine Protected Area.
• Media package here – Photo credit: Enric Sala, National Geographic Pristine Seas

National Geographic Pristine Seas premiered a documentary film highlighting Osa Peninsula’s (Costa Rica) stunning marine biodiversity. The film, made in 2019 during a 4 week long intensive National Geographic expedition, includes awe-inspiring visuals of marine life adjacent to Corcovado National Park. The team, comprised of scientists, local marine experts, and researchers from the University of Costa Rica concluded thorough their research that this nearshore habitat, understudied historically, needs further protection.

“We have seen it in hundreds of marine reserves around the world… When an area is protected, marine life recovers spectacularly,” says Dr. Enric Sala, National Geographic Explorer in Residence and executive director of the National Geographic Pristine Seas project. “But not only is marine life protected, but local communities also benefit with better jobs, with higher income through ecotourism.”

The species-teeming marine ecosystems bordering Corcovado National Park are included in a broader corridor of Marine Protected Areas that include Cocos Island National Park, the Galápagos Marine Reserve, Coiba National Park, and Malpelo Fauna and Flora Sanctuary. “Here, a much larger area should be created, an area that connects the Osa Peninsula,” says Dr. Jorge Cortés, a researcher at the Center for Research in Marine Sciences. Expanding Corcovado’s Marine Protected Area is critical to linking marine ecosystems, marine-coastal habitat connectivity that becomes more vital as climate change increasingly pressures these biomes. Establishing continuity between Corcovado’s awe-inspiring marine wonders and other Marine Protected Areas will also ensure species of vulnerable marine megafauna such as sea turtles, hammerhead sharks, and humpback whales have the ability to traverse highly important marine corridors.

Artisanal fishers in the area, too, express their discontent with a lack of protection for Corcovado’s marine ecosystems. “In 10 years, if it continues as it stands right now … to be honest, we won’t have fish here” says Edwin Artavia, a fisher from the La Palma Community on the Osa Peninsula. Witnessing the decline of fish stocks and sizes firsthand, these locals advocate for conservation action to protect the areas off the coast of Corcovado National Park. “What is needed is a strong union among everyone with a vision for the future,” stated José Moya, a local fisher of the Artisanal Fishers Association of Golfito, Puntarenitas Island.

The vast Corcovado National Park, comprised of 40,000 hectares of land, is already a well-known tourist destination famous for its unique biodiversity. Creating a Marine Protected Area is a crucial next step to protecting this wildlife-rich region, ensuring that key marine breeding habitats are protected for a wide array of shark species, rays, turtles, whales, dolphins, and commercial species foundational to the area’s blue economy and sustainable development to thrive. Economic growth from protected marine ecosystem will manifest in three primary ways:

1) Bolster the government’s tourism and boost Corcovado’s already-renowned brand to encompass coastal communities and marine tourism, synthesizing terrestrial and ocean conservation

2) Ensuring protected areas for marine life, which will allow fish stocks to replenish and larger fish to seep into the region’s fishing communities

3) Heightening the sustainability of ecotourism beyond the park, as sportfishing and similar coastal tourism activities will reap the benefits of replenished fish stocks and larger fish.

Costa Rica serves as a global leader in conservation, and the establishment of additional protections for Corcovado’s marine ecosystems presents a unique opportunity to bring the country’s environmental achievements to the next level. Protecting the ecosystems and biodiversity of both Corcovado’s terrestrial and marine biomes would provide immense ecological and social benefit to the Osa Peninsula region.

Watch the documentary premiere February 18 on the National Geographic channel at 8 p.m. in Costa Rica (9 p.m. Eastern).

NGPS trailer: https://drive.google.com/file/d/1Ulh4VxV1N2eBpWOqGbcTdYHdnywj9Bmg/viewImages: https://www.dropbox.com/sh/gr3aluruxrc5bkd/AABcU6wYotA5trkF2Zc4uRmVa?dl=0  Photo credit: Enric Sala, National Geographic Pristine Seas