The Biodiversity of Davao’s Watersheds

April 24th, 2016 by

DAVAO CITY – In the olden days, Bagobos living in Davao’s watersheds look to the limokun, the white-eared brown Philippine dove, for omens. In indigenous folklore, the limokun is believed to be a spirit messenger, a harbinger of doom or fortune. For Filipino ornithologists, however, the limokun occupies a more mundane status, albeit a very important one, since the dove is a Philippine endemic, which means that it can be found only here in Philippine watersheds.

However, like most endemic species, the limokun’s survival is at stake since its habitat, which is found in lowland dipterocarp forests along the watershed, is fast vanishing due to various threats. In 2012, watershed advocacy group Interface Development Interventions, Inc. (IDIS) commissioned wildlife biologists from the Philippine Eagle Foundation (PEF) to conduct a biodiversity assessment on two of Davao’s important watersheds, the Talomo-Lipadas (TL) and Panigan-Tamugan (PT) watersheds, which are the current and future sources of the city’s drinking water.

“The watersheds, essentially, are a center for endemism.”, said PEF Conservation Director Jayson Ibanez who said that his team was able to document 171 vertebrate species, mostly endemic, which are living in the dipterocarp forests found in the lowland areas. 28 of these species are categorized as threatened and near threatened, according to the International Union for the Conservation of Nature (IUCN).

Along with the Philippine eagle, the list includes the Tarictic hornbill, the rare Mindanao montane racquet tail, the Mindanao scops forest owl, the Mindanao fruit bat, the Philippine flying lemur and the Philippine pygmy squirrel.

“With such richness in biodiversity, Dabawenyos should all the more do everything they can to protect the watersheds.”, said IDIS Executive Director Ann Fuertes.

“If we continue to be complacent in our efforts, such richness will soon be gone or depleted. We haven’t even begun to study the entirety of Davao’s watersheds. There could be more plants and animals which have not been taxonomically identified yet and still may hold valuable medicinal or ecological value.”, she said.

She also pointed out the importance of a rich biodiversity especially in helping mitigate the effects of climate change. “It keeps the environment in natural balance, making it more resilient and adaptable to external stresses. It also keeps the pest population in check.”, she added.

But according to Fuertes, unregulated development in the watersheds are destroying the forest habitats which are essential to the survival of these threatened species. She pointed out the data compiled in the report which showed the increasing number of banana and pineapple plantations and farms which are slowly encroaching watershed conservation areas.

The report recommended, among other suggestions, to fast-track the ground survey and delineation of conservation areas in the watershed. It also recommended that the city come up with “an effective monitoring system and enforcement mechanism to stop the expansion of monocrop plantations in environmentally critical areas of the watershed.”

But while this may seem to be too late – since, as Ybanez pointed out, that out of the many dipterocarp forests that Davao used to have, only the Malagos forest survived- such interventions will do more in the long run.

“If our goal for conservation is essentially to save as many representative habitats as possible, then from the perspective of reforestation, the dipterocarp forests are a priority.”, he said. (Misael Paranial/EDGE DAVAO, Special Supplement)