Although Mindoro is so close to Luzon that, on a clear day, you can practically see its outline from some locations along the Batangas coast, it has always seemed much farther away than that. The interior is steep, traversed by rivers that don’t show up on most maps with any degree of precision, and forested in ways that the lowlands are no longer. It is a site that consistently surprises you, has more to offer than you anticipate, and defies the notion that everything fascinating has already been recorded, according to field researchers who have worked there.
When a rare or poorly monitored species is the subject of a survey endeavor, expedition teams return to Mindoro in part because of this reputation. The island is home to a significant number of endemic birds, which are species that cannot be found anywhere else on Earth. Some of these birds are still poorly understood because their preferred habitat is extremely difficult to access and even more challenging to consistently monitor. Among them is the Mindoro Imperial Pigeon. It inhabits the type of ecological region where its absence from survey records does not always imply its absence from the forest. It is large, dependent on the forest, and only occasionally reported at best.
Conversations with local hunters, farmers, and residents, whose daily movements thru the landscape give them observational knowledge that no amount of remote sensing can replicate, would be the first step in any expedition pushing into Mindoro’s remaining upland forest with the specific goal of finding signs of this pigeon. People who have been walking those routes for decades in towns on the forest border frequently have precise, in-depth knowledge about which birds are still there, where they have recently been spotted, and how the forest appears at elevations that outside researchers hardly go to. In Philippine field conservation, treating that knowledge as a major data source rather than anecdote is becoming more common, and for good cause.
Mud, steep grades, and a dense canopy that blocks out the sky within the first hundred meters of the forest edge are the physical realities of operating at elevation in Mindoro. Under that canopy, sound travels differently. For example, a pigeon call that might be detectable from a distance in open country is absorbed and deflected by the flora. As a result, acoustic surveys necessitate patience and stillness that are not usually necessary for fieldwork in more accessible terrain. A team reacts cautiously rather than enthusiastically when they hear anything typical of the target species, such as a specific wing beat pattern or a call note that corresponds with the recordings in the reference collection. In dense forests, misidentification is frequent. When feasible, the evidence is logged, recorded, and evaluated later using better tools and more time than the field permits.
This type of ground-level survey data, compiled over time and throughout several expeditions, is crucial to the IUCN’s methodology for evaluating species like the Mindoro Imperial Pigeon. A species’ conservation status cannot be changed by a single visit to the forest. However, a positive record from an area that hasn’t been surveyed before broadens the known range, influences protection priorities, and—possibly most importantly—provides local and national conservation organizations with tangible evidence to support the preservation of forest cover in a particular watershed or elevation band.
In order to increase survey coverage beyond what visiting research teams can accomplish in constrained field time, WWF Philippines and partner organizations operating in the region have made investments in community-based monitoring. In order to fill in the gaps left by the seasonal nature of most fieldwork, locals are trained to record bird observations using standardized methodologies, creating a data stream that continues between expeditions.
