Nestled on Costa Rica’s northern Caribbean coast, Pacuare Reserve—a conservation area stewarded by Ecology Project International—is well-known for protecting sea turtles. However, there’s much more happening here. This biodiverse paradise, bordered by winding canals on one side and the Caribbean Sea on the other, offers a unique setting for studying everything from terrestrial mammals and primates to the elusive agami heron (Agamia agami).
Beyond its well-known turtle conservation work, Pacuare Reserve is also home to three long-term research projects focused on primates, terrestrial mammals (including felines and their prey), and the agami heron. Since September 2023, Wildlife Monitoring Technician Lola Crassard has been leading these efforts, trekking through the jungle to gather vital data.
“We work with species on the IUCN Red List, like jaguars and agami herons, as well as three primate species facing population declines,” Crassard explains. “If we don’t protect them, they could disappear. Our research here can serve as a model for conservation elsewhere.”
Primate Research
Pacuare Reserve is home to three charismatic monkey species: Geoffroy's spider monkey (Ateles geoffroyi), the mantled howler monkey (Alouatta palliata), and the white-throated capuchin (Cebus imitator). All three face major threats from habitat loss, hunting, and the illegal wildlife trade, with the spider monkey listed as Endangered and the other two as Vulnerable.
Researchers use two main approaches: direct group recognition and line-transect distance sampling. Field surveys track species presence, group size, age and sex composition, and movement patterns via GPS data.
Early findings estimate population densities of 13 individuals/km² for spider monkeys, 16 individuals/km² for capuchins, and 8 individuals/km² for howler monkeys. Researchers have also identified 9 howler monkey troops, 5 spider monkey troops, and 8 white-throated capuchin troops. Understanding where and how these monkeys live helps drive smarter conservation efforts.
Camera Trap Research on Terrestrial Mammals
Since 2014, Pacuare Reserve has used camera traps to keep tabs on terrestrial mammals, originally to study jaguar (Panthera onca) predation on green sea turtles (Chelonia mydas). Over time, this expanded into a larger project examining mammal population trends and predator-prey relationships.
Cameras are placed throughout various habitats, from dense forests to lagoons and trails. The footage is analyzed via Zooniverse, a citizen science platform where volunteers help identify species.
Between March and August 2024, camera traps captured 2,461 videos, with 25% showing animal activity. Over four years, researchers have documented 25 mammal species, including jaguars, ocelots (Leopardus pardalis), lowland pacas (Cuniculus paca), and red brocket deer (Mazama americana).
Jaguar sightings peak between June and October, aligning with turtle nesting season and the arrival of agami herons. With six to eight jaguars identified, it's clear that Pacuare Reserve plays a role in a broader regional wildlife corridor, emphasizing the need for cross-boundary conservation efforts.
You can help monitor large mammals, birds, and other animals of Pacuare Reserve by checking out our videos on Zooniverse - click here.
Agami Heron Research
The agami heron is one of the most mysterious birds around, and Pacuare Reserve is its only known nesting site in Central America. These secretive birds nest between May and September in a lagoon within the Reserve, making it a critical location for understanding their breeding success and habitat requirements.
Researchers conduct systematic nest counts and observe colony activity through direct monitoring and camera traps. In 2024, 68 nests were recorded, with approximately 130 adult herons at the peak of nesting season. The average egg incubation period lasted 21 days, with a 55% hatching success rate. However, predation and environmental factors, like extreme temperatures, took a toll on chick survival. Conservation actions include habitat management and the removal of invasive aquatic plants that could impact the herons’ food supply or expose them to more predators.
All findings are shared with the IUCN agami heron Working Group, contributing to global conservation strategies.
Student Engagement in Research
Pacuare Reserve isn’t just about research—it’s also about education. Visiting student groups, often through Ecology Project International (EPI), get hands-on experience in conservation. They attend workshops on research methods and help collect field data. Thanks to the Zooniverse platform, students can even participate remotely by identifying species from camera trap footage.
A Living Laboratory for Conservation
Pacuare Reserve is an active, living research station where scientists, conservationists, and students collaborate to better understand and protect Costa Rica’s unique wildlife. Long-term studies on primates, terrestrial mammals, and agami herons provide essential data while also inspiring the next generation of conservationists.
“We focus on at-risk species because they’re essential to the ecosystem,” Crassard explains. “Jaguars, as top predators, keep other species in check, while monkeys help regenerate the forest by dispersing seeds. A healthy ecosystem depends on this balance and diversity.”
Through rigorous research and immersive learning opportunities, Pacuare Reserve is shaping both the future of biodiversity protection and the environmental leaders of tomorrow. These ongoing efforts highlight the importance of safeguarding Costa Rica’s rich and fragile ecosystems for generations to come.