Human-Altered Tree-Based Habitats and Their Value in Conserving Bird and Bat Diversity in Northeast Luzon, The Philippines - Smallholder Tree Growing for Rural Development and Environmental Services - page 332

Chapter 16
Human-Altered Tree-Based Habitats and Their
Value in Conserving Bird and Bat Diversity
in Northeast Luzon, The Philippines
M. Van Weerd* and D.J. Snelder
Abstract This chapter discusses the conservation value of smallholder tree-based
systems for bird and bat species in the human-altered landscape of the Cagayan
Valley, Northeast Luzon. Birds and bats in village homegardens, small Gmelina
arborea plantations and uncultivated shrub-land were surveyed in 11 localities,
using 118 point counts for birds and 34 mist-net-lines for bats. A total of 1,093
individual birds were observed representing 58 resident bird species, including 11
species endemic to the Philippines, 15 forest bird species and one globally threat-
ened species. A total of 409 bats were captured belonging to 16 species, including
five endemics, five forest bat species and also one globally threatened species.
Gmelina forest plantations held slightly more forest bird species than homegardens
and surrounding shrub-land. However, the human-altered landscape fails to serve
as an alternative for closed-canopy forest habitat containing only 13 percent of
lowland forest birds, 15 percent of endemic lowland birds and eight percent of
threatened lowland birds known to occur in the region. For bats, human-altered
habitats offer slightly better conditions, containing 44 percent of all lowland bats,
42 percent of endemic bats and 29 percent of forest bats in the region. Most forest
birds and bats were restricted to a narrow zone bordering contiguous forest.
Reforestation through mono-culture Gmelina arborea plantations is of little direct
value to bird and bat conservation but it could act as a catalyst for forest recovery.
Better structured, diverse and interconnected homegardens and forest plantations
potentially have higher conservation values for birds and bats.
Keywords Biodiversity conservation, ecosystem services, endemic species, exotic
tree plantation, homegardens, off-park conservation