Na Hang Nature Reserve, Tat Ke Sector - Frontier-publications.co.uk

Na Hang Nature Reserve, Tat Ke Sector 1997
The differences in numbers records of owls, hornbills, woodpeckers and pittas reflects
the more disturbed nature of the forest in the Tat Ke sector. In the previous phase
these groups were all found in primary forest which was more widespread, and less
affected by human utilisation and disturbance, than was the forest in this sector.
Other differences reflect the predominantly higher altitude of much of Tat Ke's forest,
and variation in the migrant species recorded over the period of each phase.
10.4.2 Range extensions and altitude reductions
Eight records indicate 'range extensions' of species, and 8 records indicate 'altitude
reductions' from species ranges and typical altitude distributions recorded by King et
al. (1975).
Most of the species for which 'altitude reductions' were recorded had also been
observed at low altitudes in the previous SEE winter survey for Na Hang, when it was
suggested that seasonal migration between habitats at different elevations could
account for the observations (Hill and Kemp, 1996). The presence of individuals
outside their recognised altitude limits in different seasons suggests that some species
at least are normally resident at these altitudes.
10.4.3 Evidence of breeding
Evidence of breeding was recorded for 10 species, and juveniles of another 11 species
were seen. The most significant of these records was that juveniles of 3 of the
internationally 'near-threatened' species were observed: Urocissa whiteheadi (Whitewinged
Magpie), Alcippe rufogularis (Rufous-throated Fulvetta), and Cochoa viridis
(Green Cochoa), which suggests that they breed within the reserve.
10.4.4 Biodiversity value of the reserve
Na Hang Nature Reserve is of major importance nationally and internationally for the
conservation of birds. The two study periods in Tat Ke and Ban Bung have recorded
15 species of internationally scare birds (although most of these fall into the 'nearthreatened'
group, not in imminent danger of extinction) and a further 4 species
endangered within Vietnam (see Appendix 7c for full list). The reserve should be
managed for its bird conservation value in addition to the protection it gives to the
monkeys. There need be little conflict between management for bird and mammal
conservation, as both would benefit from a reduction in human use of forest resources.
Frontier-Vietnam Environment Research Report 9 38