The Candaba Swamp in Central Luzon is a vast complex of
freshwater ponds, swamps and marshes with surrounding areas of seasonally
flooded grassland, arable land and palm savanna on a vast alluvial flood
plain. The entire area is usually flooded in the wet season, but most of it
dries out during the dry season (late November to April) and is converted
into rice fields and plantations of water melons. It is an important area
for agricultural and fisheries production, water for irrigation, and natural
This marshland is an extremely
important staging and wintering area for ducks, especially in October and
November when the swamp regularly supports thousands of birds. The two most abundant
migratory species in the area are Anas
luzonica and A. querquedula. A. acuta is
common, and Dendrocygna arcuata, Anas _orphyri, A.
clypeata, Aythya ferina and A.
fuligula occur in significant numbers. The reed-beds at Candaba
and in the surrounding areas are one of the few known wintering areas of the
Speckled Reed Warbler Acrocephalus
sorghophilus, a very local species which breeds in northeastern China.
The marshes support breeding populations of several Rallidae, notably Rallus
zorquatus and Porphyrio_orphyria,
and some ducks may breed. In all, about 60 species of birds use the marsh
for feeding and roosting.
The main area for waterfowl is an impoundment of about 300 ha, with a
mixture of open shallow water, small islands, and rafts of floating
vegetation, adjacent to the Pampanga River about 9 km north of Baliuag. The impoundment is used as a fish pond
during the rainy season, and then drained in January or February to be used
for agriculture. Candaba Swamp acts as a natural flood retention basin
holding wet season overflow from the Maasim, San Miguel, Garlang, Bulu and
Penaranda Rivers, and draining into the Pampanga River. The natural
retention capacity is estimated at approximately 1.5 billion cubic metres.
Candaba Swamp continues to be drained or converted to wet agriculture
severely limiting habitat for waterfowls. Others have been converted into
fishponds causing the vegetation cover to be patchy. Siltation is apparent
but can be controlled by ensuring that the upland vegetation cover is
adequate especially in the Sierra Madre Range. Although a small portion of the swamp had been declared
as a Bird Sanctuary and has become a popular site for bird watching, there
is a need to establish some overall protection (strategies) and to manage
water levels in order to maintain the services derived from this wetland.