Biology Reference
In-Depth Information
ago because of the rapid and extensive deforestation for agricultural develop-
ment. As the climate in the northeastern region is seasonal and dry, the forest
could not recover well (WorldClimate.com). On the other hand, most of the
replies were positive from the southern region.
Hybridization between long-tailed and rhesus macaques
In general, local Thai residents do not always precisely identify the species of
macaque monkeys, especially the distinctions between rhesus and long-tailed
macaques. One reason is that rhesus macaques are called “Wok” in Thai, origin-
ating from the ancient Northern Thai or Lan Na language and it means “mon-
key” (Center for the Promotion of Arts and Culture,
2009
). Thus, irrespective of
the species, Thai people identified any macaque monkeys, especially long-tailed
macaques that were the most frequently seen, as “Wok” monkeys. In addition, in
the northern, northeastern and central regions at the latitude range of 15-20
o
N,
it has been a postulated hybrid zone between long-tailed and rhesus macaques
(Fooden,
1995
; Hamada
et al
.,
2006
; Hamada
et al
., Chapter 3). Fooden (
1964
)
and Hamada
et al
., (
2006
) proposed that hybridization is occurring between
rhesus and long-tailed macaques at the boundary areas, and this is based on tail-
length variation and body size. The work of Malaivijitnond
et al
., (
2008
) has
supported this hybridization hypothesis between Thai long-tailed and Thai rhe-
sus macaques by showing evidence of mixing during human ABO-blood group
analysis of wild-caught macaques. The morphological characters of the two
species in Thailand are difficult to distinguish. The morphological characters of
Thai rhesus macaques (i.e., tail length and body mass), are different from those
of typical (i.e., Indian and Chinese) conspecifics. The relative tail length of Thai
rhesus macaques was much longer (52.30 - 66.20 percent) than the average
values from China (35.30 percent) and India (42.50 percent), whereas the body
size was much smaller (Hamada
et al
.,
2005a
;
2006
). The bipartite pelage color
pattern of Thai rhesus macaques is also not different enough for the local people
to notice (Hamada
et al
.,
2006
). In addition, the northern long-tailed macaques
have shorter tails (<120 percent) and lighter, and yellowish pelage close to that
of rhesus macaques (Hamada
et al
.,
2006
;
2008
).
In comparison, two other macaque species that are sympatric with long-
tailed macaques in the southern region, that is, stump-tailed and pig-tailed
macaques showed extensively different morphological characters (Fooden
1975
;
1990
;
1995
), thus misidentification by the southern people was
only 17.7 percent of the questionnaires surveyed. Moreover, the southern
people are very familiar with pig-tailed macaques because they are used
for coconut-picking. Among the five species of macaques in Thailand,
