DAVAO CITY (MindaNews / 12 June 2026) — A recent genomic study has found that the Philippine eagle (Pithecophaga jefferyi), already threatened by hunting and habitat loss, has one of the lowest levels of genetic diversity recorded among birds of prey, raising concerns about the species’ ability to adapt to disease, environmental change, and other threats.
Published only in April of 2026 in the journal BMC Genomics, the study analyzed the genomes of 35 Philippine eagles under the care of the Philippine Eagle Foundation (PEF) and found that the country’s national bird has “exceptionally low” genome-wide heterozygosity, a measure commonly used by scientists to assess genetic diversity.
Dr. Cynthia Saloma, Dean of the College of Science at the University of the Philippines Diliman, and one of the researchers, said the finding places the Philippine eagle among the most genetically vulnerable raptors studied so far and highlights the need to consider genetics in future conservation efforts.
“Genetic diversity means having a wide mix of genes in a species,” Saloma told MindaNews. “Having a diverse set of genes across the population makes it possible for the species to adapt to changing environments, resist emerging diseases, and avoid the dangerous physical defects often associated with inbreeding.”
The study also suggests that the eagle’s population decline may have begun long before modern deforestation became widespread in the Philippines.
According to Saloma, demographic history analyses point to a long history of population decline: “One possibility is that many years ago, rising sea levels broke up larger land areas, one probably consisting of Mindanao, Samar, Leyte, and other neighboring islands, leaving eagle populations fragmented and isolated,” she said.
“Another possibility is that when early human groups migrated to the Philippines,” she continued, “hunting increased and people competed with the eagle for prey, gradually reducing food availability and stability for eagle populations.”
While the exact causes remain uncertain, the findings indicate that the species was already facing challenges before habitat destruction emerged as its primary threat.
Today, only about 400 breeding pairs of Philippine eagles are believed to remain in the wild. Low genetic diversity is expected in such a small population; however, Saloma warned that “for the continued survival of the Philippine eagle in our forests, a healthy eagle population should ideally have as diverse a set of genes as possible.”
Low genetic diversity reduces the species’ natural safeguards against disease, environmental change, and harmful mutations.
“Given that hunting and habitat loss already threaten the Philippine eagle, our findings on their low genetic diversity only make these ongoing threats significantly more dangerous,” Saloma said.
The study was conducted in correspondence with the PEF, which provided access to the sampled birds. Saloma said they have already presented their findings to the foundation and noted that continued genomic initiatives have been incorporated into the Philippine Eagle Species Action Plan for 2026-2036.
Although Saloma declined to prescribe specific breeding or reintroduction strategies, they expressed hope that the findings could help guide decisions on pairing and releasing eagles, as well as improve understanding of the genetic health of both wild and captive populations.
Looking ahead, the researchers said one important question is whether Philippine eagles from Luzon and other islands are genetically distinct from those in Mindanao, where most of the study’s samples originated. Such a study would require additional sampling from the species’ remaining populations.
For ordinary Filipinos, the message is simple, Saloma said: “If the eagle struggles, it signalscbigger risks for our forests and for us as Filipinos who depend on them. By protecting theveagle, we are protecting our own future.”
“The Philippine eagle’s genetic pool is very shallow, which means it’s more vulnerable to disease and environmental change,” she said. “By protecting the eagle, we are protecting our own future.”
For their part, Saloma and her team are already building on their findings. She revealed that a follow-up study, now under peer review in an international journal, examines the relationship between where wild-rescued Philippine eagles are found and how closely related they are genetically.
She said the study could provide additional guidance for the PEF’s conservation decisions and species management programs.
Each new study adds another piece to the puzzle of how best to protect the country’s national bird. And as scientists continue to probe the genetic history of the Philippine eagle, the growing body of research will contribute towards safeguarding it for generations to come. (Bea Gatmaytan/MindaNews)
