New Study Identifies Where Philippine Eagles Can Thrive Again in Leyte: GIS-based research maps more than 10,000 hectares of possible release sites for future eagle reintroduction
- 2 days ago
- 7 min read
DAVAO CITY, Philippines - A new scientific study has identified more than 10,000 hectares of possible release sites for Philippine Eagles in Leyte. The findings provide an important guide for future efforts to bring the country's national bird back to one of the islands where it once lived.
The study, titled “Identifying Suitable Release Sites for Philippine Eagles in Leyte for Aiding Reintroduction Using GIS-based multi-criteria Decision-making,” was published in the Philippine Journal of Science. It used Geographic Information Systems, or GIS, to map areas in Leyte that may be suitable for future Philippine Eagle releases.
The researchers identified about 10,320 hectares of suitable release areas in the Anonang-Lobi Mountain Range and Mt. Nacolod Key Biodiversity Areas. Of this total, around 9,554 hectares were classified as the most suitable areas because they are farther from human settlements and meet important habitat and safety conditions.
These areas include forest landscapes connected to parts of Ormoc City, Baybay City, Kananga, Burauen, Silago, Mahaplag, Sogod, and Javier.
The study supports the Philippine Eagle Reintroduction Program, a partnership among the Department of Environment and Natural Resources, the Philippine Eagle Foundation, local government units, universities, conservation partners, and local communities.
“Successful reintroduction starts with good science,” said Dr. Jayson C. Ibañez, Director for Operations of the Philippine Eagle Foundation and co-author of the study. “This research helps us identify where future Philippine Eagles can be safely acclimatized and soft-released into the wild. By identifying suitable hack sites, we can improve the chances that released birds will adapt to their new environment and eventually establish territories in Leyte’s forests.”
Why Leyte matters
Leyte was once part of the natural range of the Philippine Eagle. Over time, however, its eagle population appears to have declined substantially because of long-term habitat loss from deforestation, combined with possible hunting pressure and other human-related threats.
By the time Super Typhoon Yolanda struck Leyte in 2013, the island’s eagle population may already have been very small and vulnerable. The severe damage caused by the typhoon likely added further pressure to a population that was already struggling to survive. While the exact causes and sequence of the population’s disappearance remain difficult to determine, the combined effects of forest loss, human pressure, and a major natural disaster may have contributed to the decimation of Leyte’s remaining Philippine Eagles.
In 2024, the Philippine Eagle Foundation and its partners released the first two Philippine Eagles in Leyte under the country’s pioneering eagle reintroduction program. In 2025, three more eagles were released. These five eagles represent the first of several planned release batches involving a total of 16 eagles, with the long-term goal of establishing a self-sustaining population of six breeding pairs within the Anonang-Lobi Mountain Range.
The new study provides additional scientific guidance for these future releases by helping identify areas where eagles may have better chances of survival.
Mapping safer release areas
The study used GIS, expert input, habitat data, and spatial analysis to locate areas that meet important conditions for Philippine Eagle release.
The researchers considered several factors, including forest habitat, terrain, distance from settlements, human disturbance, roads, and possible power line risks. They also looked at possible access points, including areas that could support helicopter transport during eagle release operations.
The study identified two main categories of release areas. “Suitable” areas are at least 150 meters away from human settlements but may need stronger monitoring and community engagement. “Most suitable” areas are more than 500 meters away from settlements and are expected to have lower levels of human disturbance.
For lead author and BS Geodetic Engineering student Demi Julianna L. Gentiles, the study shows how mapping and geospatial science can support real conservation work.
“This research showed us and my student co-authors how GIS, mapping, and spatial analysis can help solve real conservation challenges,” Gentiles said. “It also taught us that conservation is a collaborative effort involving students, scientists, conservation practitioners, government agencies, and local communities working toward a common goal.”
According to Dr. Alexis Richard C. Claridades of the Department of Geodetic Engineering, University of the Philippines Diliman, mentor to the student authors, and corresponding author of the study, the research shows the value of using science to guide conservation decisions.
“Conservation works best when it is guided by evidence,” Claridades said. “GIS and spatial analysis allow us to identify locations that offer the best opportunities for species recovery. These tools help conservation organizations and government agencies make informed decisions and direct resources to areas where they can have the greatest impact.”
Science, partnerships, and local action
The Philippine Eagle Foundation said the study highlights the growing role of universities and technical experts in conservation.
“One of the most important developments in conservation today is the growing contribution of academia,” said Dennis I. Salvador, Executive Director of the Philippine Eagle Foundation. “Studies such as this provide the scientific foundation for conservation action. Through our network of academic partners and experts, the Philippine Eagle Foundation is able to support the DENR’s mandate of protecting biodiversity with sound science.”
Salvador said that restoring Philippine Eagles to Leyte will require long-term cooperation.
“No single organization can save the Philippine Eagle alone,” he said. “Conservation requires the combined efforts of government agencies, universities, local communities, conservation groups, and the private sector. This study is a good example of how partnerships can generate the knowledge needed to guide conservation action.”
The findings have also encouraged local governments whose forests were identified as possible eagle release landscapes.
“We are delighted to learn that the forests of Javier were identified among the areas capable of supporting future Philippine Eagle releases,” said Javier Mayor Michael Dragon Javier. “Even before the study was published, its findings inspired our municipality to express its willingness to host a future eagle release and commit local government resources to help make it happen.”
Mayor Javier said eagle conservation also supports the protection of forests that people depend on.
“Conserving forests for Philippine Eagles also mean protecting our watersheds, preserving biodiversity, and maintaining carbon sinks that help address climate change,” he said. “The people of Javier depend on healthy forests for water, livelihoods, and quality of life.”
A guide for conservation planning
The study is expected to help guide conservation planning across Leyte’s remaining forests.
“This study is both timely and highly relevant to ongoing conservation planning efforts in Leyte,” said Dr. Arturo Salazar, Regional Executive Director of DENR Region VIII. “As DENR and its partners consider which forest areas should be prioritized for protection and conservation, this research provides valuable scientific information that can help guide those decisions.”
Salazar said the findings can support stronger protection of important forest areas.
“The study helps us understand which forest areas are most important for Philippine Eagle recovery and biodiversity conservation,” he said. “This information can become an important basis for setting aside conservation zones, strengthening habitat protection measures, and supporting future protected area initiatives.”
He added that protecting eagle habitat also benefits people.
“When we protect landscapes important for the Philippine Eagle, we are also protecting watersheds, biodiversity, and ecosystem services that communities depend on,” Salazar said. “Science-based studies such as this help ensure that conservation investments and policy decisions are directed to areas where they can have the greatest long-term impact.”
Next steps
The researchers said the mapped release sites should still be checked on the ground. Field validation will help confirm actual forest conditions, identify possible threats, and improve future release planning.
The study also noted that some threats, such as small power lines, are difficult to map completely using available data. Future work can improve the analysis by adding more detailed field information, verified power line maps, nesting habitat checks, and local community assessments.
For the Philippine Eagle Foundation and its partners, the study provides another important step toward restoring Philippine Eagles in Leyte.
As one of the world’s rarest birds of prey, the Philippine Eagle continues to face threats from habitat loss and human activities. But with science-based planning, strong partnerships, and support from local communities, Leyte may once again become home to a thriving population of Philippine Eagles.
About the Study
The study, “Identifying Suitable Release Sites for Philippine Eagles in Leyte for Aiding Reintroduction Using GIS-based multi-criteria Decision-making,” was authored by Demi Julianna L. Gentiles, Khalil C. Torneros, Julia Clarice Uy, Jayson C. Ibañez, Denver Jerk T. Lodrico, and Alexis Richard C. Claridades. It was published in the Philippine Journal of Science.
About the Philippine Eagle Foundation
The Philippine Eagle Foundation (PEF) is a non-profit organization dedicated to conserving the critically endangered Philippine Eagle and its habitat. Founded in 1987, PEF focuses on research, conservation breeding, community-based initiatives, and education programs to protect the species and promote environmental sustainability. Based in Davao City, the foundation operates the Philippine Eagle Center, which serves as a conservation breeding facility, education hub, and research institution. PEF collaborates with various stakeholders, including indigenous communities, government agencies, and private sector partners, to ensure the survival of the Philippine Eagle and the preservation of the country’s rich biodiversity.
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