-f / Survey of Bird PopulAtion in Narayani River ~asin Lowland, Nepal d , - Narayan Pd. Dhakal .. Submitted to: Orintal Bird Club, V.K. I I r TABLE OF CONTENTS Acknowledgments Introduction 1 Objectives 2 Study Area 2 Methods 10 Results and Discussion 12 Conclusion and Rconunendations 21· literature Cited 22 ACKNOWLEDGMENTS First and foremost, I would like to thank 0riental Bird Club (OBC~, UK, for .providing financial support to conduct this study. Special thanks are due to Melanie Heath of OBC for providing suggestions and relevant literature. The team members Ramesh Chaudhari and Rajendra Ada.hik2!i (local nature guides), and Kapil PokhrcJ (NCRTC) were very much helpful througho J.t the study period. Finally, 1 would like to extend my sin. . ;crc thanks ., . to Dr. Shant R. JnaW;:ll! for his critical conunents on this report. Ivhs. Sarita Jnaw~ helped to edit the final draft. I i t I INTRODUCTION In Nepal, a vast net wQirk of mOlmtain streams come together to r'onn the Nar. .y ani river basins. The Kali Gandaki, Trisuli and Marsyangdi, all being. gU;cier fed, are the main tributaries. The Nara)<.:u river system is the third largest river syster of Nepal after Sapta IS Koshi in the east and Kamali in the west. Eventually converging witn Ganges river in India and emptying in the Bay of Bengal the Narayani river meets the Gangetic plain below the gorge of Siwalik foOl. hills. The semi tropical Narayani basin fan out in alluvial braided channels that provide habitat for nwnerous local and resident bird species. Lack of proper management systems, illegal capture and hWlting, degradation and loss of forests for agricultural fixpansion, fuel \'Iood, fodder and timber collection along the river banks for ever increasing population of the country are U:e m~ threats of bird conselVation in :Nepal. Water birds inhabiting the Narayani river basin are also threatened from the ffects of conversion of fo~est land into agricultural land along the river course. About 60 km long st·~tch of Narayani river along the western bOWldary of the Royal Chitwan National Park provides a relatively secured refuge for watr;;r birds since it is well protected through pa.: l rules and reguiatil.lIlS as clearly stated iD the National Park Act 1973. Despite the stri;;~ protection measures the bird populations in this section are affected by local communitieE :nhabiting along the western bank. A comprehensive management system, regular monitoring of the bird population, use of local paIticepatory approach in conselVation and cons~lVation awarem:ss among local residents an.: needed to ensure long tenn survival of the water birds in the Narayani river basin. Thiu study snould be an important contributio:l to better Wlderstanding of water birds of Narayani river and also provides basic infonnation necessary for conservation of avifauna (·f this area. OBJECTIVES The main objectives of the present study w('''''' t('~ 1. prepare a check list of bird species in the 58.9 km long stretch 01 Narayani river thahJnDS the western boundary of the RCNP. 2. detennine frequenc)" density and diversity of water birds in the study area STUDY AREA General Location The Royal ChitwanN1tional Park (84020' E and 27030' N) is Nepd's first national park gazetted in 1973. The park iBlocated in the sUbtropical lowland, Terai, in the Chitwan District, roughly 60 miles from Kathmandu (Fig. 1). The park lies between Rapti River, ·,,1:&'" ... which demarcate:: the northern bOilIldary from an intensively cultivated fann lands, and Indo-Nepal border in the south. Narayani river delineates the western boundary while in the east the park is bmmded by forests and cultivated lands. Climate The climate is subtrop~Gal with a swnmer monsoon from mid JWIC 10 late Seph.:mber and a relatively dry wint. .. r St·lSOn. The mean temperatw-e reaches a ma."( mum of about 3 7 0 in May. Rainfall pattern i~ wUmodal. The mean annual rainfall is ahout 2500 mm, 95% of which fall between Ma.}' and September (rvIishra 1982). 2 --------_. .. _---•.. -•.... -. E P A V o I 4 8 , . ! , r." ,/ \, '. 1_-- ~ ~ R " [." "o~ C:~. l°'-o*\-'"\., AT l' '\.,~ ~,~ ' ' ./ \, II , .' -,. """ .' " .. ./' • J , ".. '-,,,, p ' l. '"\.''''. N' "'. ~ Figure 1. :Map of the RCNP sho~!lg the location of the Narayani River.! Drainage and Hydrology . The park consists of thr~e main river systems: Rapti in the north, Reu in the middle and Narayani in the west. The Chwia hills bisect the park with its northe.ffi face draining into the Rapti, the southern aspect fonn the catchment of the Reu river. The Someswor ridge and the Dawme lill forms the· soutllern catchment and both drain into the Narayani. Both the Rapti and Rew flow westwards and converge at Khoria Mohan near Tiger Tops from where they drain into the Narayani. The Narayani then meanders southwards through a narrow gorge between Cte Someswor and the Dawme hills for about 25 km wttil it reaches to Nepal-India border where it is dammed near Tribenighat. Narayani originates in the high Himalaya and finally drains into the Bay of Bengal after joining the Ganges in India. The flood plain along the northern sector of the park in the Rapti valley .".re interspersed with a few oxbow lakes and 8v'amps which contain water even during the dly season. Vegetation Three major vegetation types have be(,,'n studied in Chitwan (Lauric 1978). They include sal and riverine for .;st,and grassland. Sal forest consists of monotypic stand of sal (Shorea robusta) and covers about 70% of the park area. The homogenous sal forest is occasionally associated with a few other tree species including Terminalia tomenlosa, Dalbergia latifolia and Bahunia spp. Themeda arundinesia is the important grass species fowtd in the sal forest. Riverine forest occupies an area of about 7% along the water cow Jes and islands in both Rapti and Narayani n lees. Bombax ceiba, Trewia nudif/ora, .Aia //otus philippinensis, Butea monosperma, Bahunia spp. and Careya arborea are the mo:,t conunon tree species. Associated wtder story shrubs (Murraya koinigii, Ca//icarpa macrnphy//a, Clerodendron viscosum, Colebrook..·tl oppositijolia) and various types of climbers (Acacia conicinna, 4 Bridelia stipuJaria, Stipharia joponica awl :;nospora sinensis) ar~ also common in the . riverine forest. Grasses Me sparse except in clearings and at the fore:::t edges. Grasslands extend alOllt the water courses, mainly on bolh n~w ami old tloodplains. The important grass species ~ncludc Saccharum spontaneum, S. bengulei.c.:is, S. arundinaceum, Narenga porphyrocomc~, Themeda spp., Phragmitis /carica and lmp ..: ,·uta Gylindi"ica. Royal Chitwan Natiomu. Park contains sueh endangered species as Rhinuc.:erm unit:Ul'ms, Penthara tigris, PJananista gangeticus. Among otilcrs, Panlhe;u pardus, .Melursus ursinus, Bos gaurus, Axis axis, A. pOrCll1US, Cervus unicolOl Jvfuntiacus muntjak, J Gavialis gangaticus a/id Crocodilus paJustris :u:e also important fauna Jound in the park. Besides, above 450 spr;cies of .both terrestrial and aquatic avifawv.l are recorded in tile park. Bengal florican, giant hornbill, iesser florican, black stork and white stork are among . ' .. the endangered bird spt;.:;ies recorded in the park. OthCf commqn avit"auna include peafow~ redjungle fow~ different species of egre~,~, ~ .. ;ron.s, kingfishers, fly:.:.aichers, woodpecken:~·. .' mynas, drongos,Wagk"Jj.ui, geese, ducks, cormorants, wabblers and b;!blers. Intensive Study Area The intensive study wru. carried out in a 58.9 km long stretch of the Narayani river that fonns the western boUl.rlary of the Royal Chitwan National Park eii:. 2). The 58.9 km long study area was d~vjded into 5 sections and extends from Kuja.w in the north to the Tribeni barrage in the south to encompass a total area of ca 98 sq. k.':l1. The river forks and diverges to form a ~ of channels and islands, majority of which art! densely vegetation. 5 Nl 0-,' .~ c;::::)\::) ~ ~ '" o, . 5 10 IS' '~ Figure 2. :Map .of 58.9 km long main study area in the Narayani River~ - - In general, the vegetation in the Islands consists of khair-sissoo, brest and floodplain grasslands. The khair-sissoo forest is domir.ated by Acacia catechu and Dalbergia sissoo. and floodplain grassL"'.o,d by tall grass species, mainly Saccharum spontaneum. huportant fauna in this section of the Narayani include a large nwnber of water birds, endangered species of crocodiles, Gengetic dolphin, Indian ottel', and above 25 species of fishes. Description of Sectiof;}s Section I Section I of the swvey area extends from Kujauli to Laukhani check post and measures a total length of ca 10 km. Near Bhendabari (little north of Kujauli where Tuborg Beer Factory is located), Nal.'ayani blfurcates into two main channels fonning a large island and joins few hoodred meters down stream. The islaud is densely vogetated consisting of a dense khair-sissoo for~t encircled by a narrow strip of tall grassland a~f)ng tht; edges. Khair Acacia catechu and sissoo Dalbergia sissoo are the dominant trel;; species fOood in the island forest. Bombaxiceiba, Ehretia laevis and Sigizium cuminiiarc among the ilSsociated tree species commonly found in the island. Similarly, Murraya koenigii, Callicarpa macrophylla and Colebrookla oppositijoiia are among the common under story shrub species. Saccharum spuntaneum and I mperala cylmdricu are lht; two important grass species found in the gussland. i Of the two channels, the southern channel with minirnwn human interfenmce provides a secured resting and fet 'aing ground for the water birds. The bird p<}',>ulations inh..lbiting the northern channel that flows through Pithauli village suffer from a nwnber of human activities including laundry and illegal fishing. Besides, a number of village kids attempting .. to kill birds were also ',een frequently in the northern bank. Furthermore, cAttle grazing"in a 7