Ream National Park Twelve Month Report

Methodology
Study sites
Throughout the year, four survey areas were investigated, from base camps in different parts
of the Park (Figure 1). Three or four trap-sites were studied in each area, through ten nights’
trapping of small mammals, amphibians, reptiles and butterflies. A summary of these
biodiversity sampling sites can be found in Appendix 1. Vegetation plots were also carried
out in the vicinity of these sites. In addition, turtle surveys were conducted in wetland areas
adjacent to the trap-sites and at separate locations. Estuarine bird surveys were carried out by
boat in six zones on the Prek Toep Sap estuary and nearby sea.
Fauna
Bucket Pitfall Lines
At each trap-site, three (or four) 50 m bucket pitfall lines were laid, to encompass as wide a
variety of habitats as possible. Each line comprised 11 buckets spaced at 5 m intervals (10 x
25 litre (L) buckets and one 45 L bucket in the centre of the line to trap larger animals that
could climb out of the smaller traps), linked by a 0.5 m high drift fence of plastic sheeting..
The drift fence was dug into the substrate and pegged with stakes to keep it taut and to
channel any passing animals into the buckets. Traps were checked early each morning and
late each afternoon, to minimise exposure and predation of the captured animals. Captured
animals were identified using field guides (Cox et al. 1998; Lekagul 1988; Lim & Lee 1990;
Stuart et al. 2001), and two individuals (male and female) of each species not listed as
protected by the IUCN or CITES (IUCN 2000; Phalla 2002) were taken as voucher
specimens. Species already represented by vouchers were released.
Small Mammal Traps
At each trap-site, two lines of 20 mesh traps were positioned, parallel to two of the bucket
lines, near tree roots, heavy undergrowth, logs and burrow entrances, or wired onto tree limbs
up to 2 m high. The traps were baited (with roasted coconut or banana) and set from late
afternoon each day and checked early each morning over the 10-day study period. The sex,
weight and morphometrics of the animals captured were recorded. Up to two animals (male
and female) of each species not listed as protected by the IUCN or CITES (IUCN 2000;
Phalla 2002) were taken as voucher specimens. Species already represented by vouchers
were given a unique fur-clip and released.
Turtle Traps
Freshwater turtles were caught in a variety of water-courses using 98 x 24 cm mesh traps with
1 – 2 m net extensions to enable captured turtles to swim up to breathe. Eight to ten traps
were placed, at approximately equal distances apart, in areas of shallow, flat water. Traps
were removed when heavy rainfall and fluctuating water levels put the turtles at risk of
drowning. The traps were secured to trees and/or other solid structures to prevent them being
pulled into the water by larger turtles or predators. They were baited with fish, placed in a
pierced plastic bag, fastened securely below the water line and well within the net to avoid
animals eating the bait from outside. Traps were baited and checked at 24 hour intervals. For
any turtles captured, measurements of the length and width of carapace, weight, sex and age
were recorded and the specimen’s carapace, underside and head were photographed. Turtles
were identified using Stuart et al. (2001). Vouchers of these vulnerable animals were not
taken. A numbering code was assigned to the marginal scutes of the carapace, each turtle
being given a unique mark using nips.
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