Biology Reference
In-Depth Information
eleven species were reported to exist in our interviews. These included slow
loris (
Nycticebus bengalensis
), pygmy loris (
Nycticebus pygmaeus
), rhesus
(
Macaca mulatta
), northern pig-tailed (
Macaca nemestrina leonina
), assa-
mese (
Macaca assamensis
), stump-tailed (
Macaca arctoides
), long-tailed
macaques (
Macaca fascicularis fascicularis
), Phayer's (
Trachypithecus
phayrei
; but see Brandon-Jones,
2004
; Roos
et al
.,
2008
for classification),
Francois' (
Trachypithecus francoisi
), and doucs (
Pygathrix nemaeus
) and the
white-cheeked or yellow-cheeked gibbons (
Nomascus leucogenys leucogenys
or
Nomascus leucogenys gabriellae
). By using the collected data, we deter-
mined the distribution of long-tailed and rhesus macaques in southern Laos.
Long-tailed macaques were reported to inhabit the region east of the Mekong
River, in the eastern and southern slopes of the Bolaven Plateau, south of
15.2˚N; south of Attapeu (left bank of the Xe Xou River); and the southern half
of the Xe Pian NPA (left panel of
Figure 3.3
). Long-tailed macaques were also
found to be distributed in the region west of the Mekong River, from 15.2˚N,
and their population is continuous with those in neighboring NE Thailand
(Malaivijitnond
et al
.,
2005
; Malaivijitnand and Hamada, 2008). Most of the
long-tailed macaque pets observed in the Khong Island were originated from
this area (
Table 3.1)
, Mounlapamok District, Champasak Province.
The population of long-tailed macaques was estimated for the two regions
of the east and west of the Mekong River on the basis of density and habitable
area. We supposed that the average population in a troop is thirty (range 10-48
in Wolfheim,
1983
) and minimum densities of troop are the same as those in
southern and northeastern Thailand (Malaivijitnond
et al
.,
2005
), which are
considered to have comparable quality of habitats with eastern and western
regions of southern Laos, respectively. The maximum density was supposed to
be ten times of the minimum.
The habitable area of the region east of the Mekong River was estimated to
be about 27,000 km
2
, and the minimum density of 0.012 individual/km
2
found
in southern Thailand was used (Malaivijitnond
et al
.,
2005
). The total popula-
tion was estimated to be between 324 and 3,240 individuals.
The total area of the region west of the Mekong River is about 15,500 km
2
.
The density of this region is supposed to be the same as that in northeastern
Thailand (Malaivijitnond
et al
.,
2005
), 0.006 individuals/km
2
. The total popu-
lation is estimated to be 93-930. Thus, the national total population of long-
tailed macaques in Laos lies within the range of 420-4,200.
Rhesus macaques appeared to be distributed across all of southern Laos
including the mountainous area in the south of Pakse (
Figure 3.3
)
, except
in areas west of the Mekong River (<15.2˚N). The recorded southern-most
locality in Laos was 14.0˚N, however, Xay Phou Kiou, a forest in the Xe
Pian NPA that is continuous to the forest in Cambodia across the border, is
