Threatened butterflies
of central Nepal
B. Khanal ¹, M.K. Chalise ² &
G.S. Solanki ³
¹ Natural History
Museum, Manju Shree Bazaar, Swayambu,Kathamandu 44620, Nepal
² Central Department of
Zoology, Tribhuvan University, Kirtipur,
Kathmandu 44618, Nepal
³ Department of Zoology,
Mizoram University, Tanhril Campus, Aizawl, Mizoram 796004, India
1 baya2000@live.com, 2 mukesh57@hotmail.com, 3 gssolanki02@yahoo.co.in
(corresponding author)
doi: http://dx.doi.org/10.11609/JoTT.o2825.4612-5 | ZooBank: urn:lsid:zoobank.org:pub:100E053D-1C22-4CDD-8E1D-AB26DD89BA6A
Editor: Peter Smetacek,
Nature Research & Adventure in the Himalaya, Nainital,
India. Date of
publication: 26 July 2013 (online & print)
Manuscript details: Ms #
o2825 | Received 08 June 2011 | Final received 20 June 2013 | Finally accepted
02 July 2013
Citation: Khanal,
B., M.K. Chalise & G.S. Solanki (2013). Threatened
butterflies of central Nepal. Journal of Threatened Taxa 5(11):
4612–4615; http://dx.doi.org/10.11609/JoTT.o2825.4612-5
Copyright: © Khanalet al. 2013. Creative Commons Attribution 3.0 Unported License. JoTTallows unrestricted use of this article in any medium, reproduction and
distribution by providing adequate credit to the authors and the source of
publication.
Funding: None.
Competing Interest: None.
For figure, table -- click here
In Nepal, the area above
3000m is occupied mostly by palearcticbutterflies while the temperate, subtropical and tropical species are
sequentially distributed below this altitude. The temperate zone has many micro-habitats to offer to different butterflies.
The central
districts, namely, Kathmandu, Bhaktapur, and Lalitpur are dominated by evergreen broad-leaved mixed
forests between 1800–2400 m. The evergreen Oak (Quercus) forest covers the area above 2000m (DMP
1969). Conifers like Pinus roxburghiiand Pinus wallichianaalso occur in these districts. Besides Schima wallichii, Castanopsis indica and Alnus nepalensiscan be observed in wet ravines. Other flora observed here are Ilex doniana,Zizyphus incurva,Leucodeptrum canum,Myrica esculenta,Myrsine semiserrata and Rhododendron arboreum.
The central region of Nepal
was once forested (Upreti & Ghimire1982). These hills and valleys are
now cultivated and very little forest is left (Chalise2010). Some forested areas of this
region are incorporated into the protected area network like the Langtang National Park and Nagarjun-ShivapuriNational Park. The Langtang National Park lies at
32km north of Kathmandu City while the latter is located close to this city
with its northern boundary to the Nuwakot District. Teinopalpus imperialis,Papilio krishna, Diagora nicevillei, Troides aeacus etc. are the notable species found in the
Kathmandu Valley. The southern part
of the valley, extending from Godavari (1360m) to PhulchowkiMountain (2734m) is a species -rich area where more than 150 species of
butterflies, mostly forest dwelling species, are found (Smith 1989). The recent loss of trees in these
forests has left the hills virtually bare except for a few areas between
2660–2715 m. These changes in the natural habitat have had a negative
impact on the butterflies of the region. Therefore, an attempt has been made
here to identify the threats imposed on some rare butterfly species of this
region.
Material and Methods: The present study was carried
out in the central part of Nepal which includes three
districts—Kathmandu, Bhaktapur, and Lalitpur (Fig. 1). The base-line study consisted of direct observations made during
2004–2009 and comparison is made with the present study conducted during
2010–2011 in the three mentioned districts. A butterfly net was used for capturing
insects. Data sheets and field
guides as well as an altimeter and a diary were used in the field.
The peak diversity of
butterflies was observed during May to August. Talbot (1939, 1947), Smith (1989) and Khanal & Smith (1997) were consulted for
identification. Capture and release
method was adopted to identify species in the field. Habitat alteration was assessed minutely
in relation to perceived threat factors. The species records mentioned in the National Red Data Book of Nepal
(NRDB 1995) and the field data resulted from the study made in the central
districts in 2004 to 2011, are considered for the current status of the
species.
Results: The interesting findings of
this study are mentioned in Table 1. Four species of butterflies were found at low density and therefore, are
considered at high risk. These
species are restricted to narrow distributional ranges in all the three
districts. These species are Teinopalpus imperialis, Papilio krishna, Meandrusa lachinus,and Euripus consimilis. Other species surveyed
in this study are under declining state as shown by the field
studies conducted in 2004–2011.
Discussion and Conclusion: The human population in the
central part of Nepal is rising rapidly (CBS 2003). Tourist inflow is also comparatively
high in this region. Some areas of
the central districts are included in the protected area network, except the
Godavari and Phulchoki forests where a rich diversity
of butterflies, with several rare and endemic species and subspecies are found. Study based on field surveys
from 2004 to 2011 has indicated that 19 species are now under very low density
in their known habitats. Shrinkage of habitats due to construction of roads and
establishment of quarry industry are, therefore, imposing severe impacts on the
species like Chrysozephyrus disparatus interpositas, Thermozephyrus ataxus,Maneca bhotea,Pamela dudgeoni dudgeoni Celastrina hersilia vipia, Neptis manasa Neptis nycteus, Phaedyma aspasia kathmandia, Euthalia dudu Diagora nicevillei, Lethe latiaris hige, and Satarupa zulla. None of these species have been reported
in other parts of the country except the central districts considered for this
study.
Teinopalpus imperialis, Meandrusa lachinus, Papilio krishna, and Maneca bhotea dwell
in forests, being usually found on mountain tops where vegetation like Quercus semicarpifolia,Michelia sp., Rhododendron arboreum and Daphne bholuaare found. Meandrusa lachinus has a very narrow range along the
Himalaya from Uttarakhand to Arunachal Pradesh and
the mountains of Laos and China.
The probable factors imposing
severe impacts on the above mentioned species are:
(1) Forest clearing for
governmental activities and tourism, which has a negative impact on populations
of these butterflies in Kathmandu Valley.
(2) Daphne bholua, a host plant of Teinopalpus imperialis, is used in the paper industry and has
been extensively harvested in these areas. These factors have caused the
butterfly species mentioned above to be included in the “endangered” category (Smith
1989).
Pamela dudgeoni, Neptis manasa, N. nycteus,Phaedyma aspasia,Diagora persimilis,D. nicevillii are restricted to forest
habitats close to streams, where vegetation like Quercus semecarpifolia, Alnus nepalensis, Celtis tetranda and Schima wallichii are found.
(3) Streams in Godavari
forest have now dried up presumably due to the impact of marble quarrying,
which has been going on in the area for the last several years.
(4) Celtis tetranda, the host plant of Diagora persimilis is lopped for fodder.
(5) Diagora nicevillei, an endangered nymphalid,
is probably one of the rarest butterflies in the world
(Smith 1990). Furthermore, the only
known Himalayan population is confined to a small pocket in Godavari forest and
the area has now been reduced due to stone quarrying and deforestation.
(6) Other threats perceived
elsewhere for D. nicevillei include grazing,
mining, unsustainable uses of biological resources, urbanization, tourism and
illegal trade (Khanna & Kumar 2001). This species is given protection under
Schedule I (Part - IV) of the Indian Wildlife (Protection) Act, 1972 (Singh
& Singh 2002). In the National
Red Data Book of Nepal it has been included in the endangered category (NRDB
1995). This species has five
subspecies known so far which includes D.n.nicevillei Moore from Chambato western Nepal; D.n. nigra Morishita from the Kathmandu Valley; jermyni Druce from the Tons
Valley, India; ouvrardi Watkins from
northwestern Yunnan, southeastern Tibet, China and magna Omoto & Funahashi from Vietnam.
(7) Tajuria luculentus, Celastrina hersilia and Euthalia duda are found from 1730–1880 m in mixed
forest of Alnus nepalensisand Quercus semicarpifolia (DMP 1969). In Nagarjun, a large forest area has been cleared to build monasteries
and roads.
(8) The marble mining at
Godavari has destroyed a large portion of the habitat of many rare and
endangered species including Teinopalpus imperialis, Papilio krishna, Phaedyma aspasiaand Euthalia duda.Chalise (1978) in his study at Godavari found that
nine species of nymphalids were becoming increasingly
rare.
(10) The habitat of Amblopala avidienain Nagarjun forest is threatened mainly due to the
broadening of roads and building of monasteries.
(11) Lethe latiaris, which inhabits shady Quercus-Alnus forest at 1670m is impacted mostly due
to road construction, picnickers and herb collectors. Godavari forest is notorious for these
ecological malpractices.
Euripus consimilis occurs sparingly at
1370–1400 m; its host plant, Trema orientalis, is an uncommon tree at low elevation and it
may be commoner in the belt below 1000m elevation. The population of Satarupa zulla, which also occurs at the same elevation asEuripus consimilis but in Alnus-Quercusforest which is also declining due to increasing anthropogenic activities in
this part. The status of many
species is changing mainly due to habitat degradation. Only two species, Troides aeacus and Troides helena have been listed
in CITES Appendix II (Khanal et al. 2010).
Nepal Red Data Book (1995) incorporated 142 species of butterflies under
different threat categories.
The continued habitat
degradation and pressure on natural resources is adversely affecting butterfly
populations outside the protected area network. There is a need for discovering,
assessing and taking steps for long term conservation
initiatives for endangered butterfly taxa, especially involving the local
community and government.
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