Electronic Scientific Paper Archive

Journal information

Mongolian journal of Biological sciences

Price: Free

Add to cart

Data for Waterbirds at Buyr Nuur (Eastern Mongolia)

Oleg A. Goroshko
Daursky State Nature Biosphere Reserve, Russia, e-mail: root@tasey.chita.ru and goroshko@cinr.chita.su

Introduction

Information about birds of Buyr-Nuur Lake is very limited. This lake is located on the Mongolian- Chinese state border. During 19-20 July 2003 we
made bird observations using a vehicle, binoculars (x8) and telescope (x35). We observed about 70% of the Mongolian part of the shore. Besides the territory closely adjoining the state border, we observed the lowest part of the valley near the mouth of the Khalkhin-Gol river. We also observed
about 400 m along the river. The lake has almost fresh water and the water plant Potamogeton crispus grows there in large amounts. During our visit P. crispus had long stems up to 3 meters. The mouth of the Khalkhin-Gol river is covered by dense and high willow bushes and reeds. Great Cormorant Phalacrocorax carbo, which nests on the bushes, is a very numerous breeding species at the mouth of the Khalkhin-Gol river. Chicks were big and about half of them were able to fly during our visit. Therefore we counted both adults and juveniles. At noon on 20 July the density of cormorants in the mouth was about 1200 birds (1000-1400) per each 100 m of the river valley. We estimated that about 30,000-96,000 cormorants
were located in the mouth in total. During this day we recorded a huge flock (about 20,000-25,000 individuals) of feeding cormorants at the southern part of the lake and thousands of birds on all other parts of the lake that we were unable to count because of the large distance). Our observations
are not a complete census, but a very approximate estimation of the total number of cormorants at Buyr-Nuur is about 50,000-160,000 birds. Bittern Ixobrychus sp. We recorded two single adult birds flying over the mouth but we were unable to determine the species. Grey Heron Ardea cinerea are numerous breeding birds at the mouth. They nested mainly on the bushes. An approximate estimation of the total number (adults and juveniles) at Buyr-Nuur is about 3,000-20,000 birds. Purple Heron Ardea purpurea. We recorded 3 single adult birds at the mouth and found one nest (located on a bush) with 3 big chicks. It is the first
record of breeding of this species at Buyr-Nuur L.
Great Egret Egretta alba. We recorded 2 single
adult birds at the mouth and found one nest (located
on a bush) with 4 big chicks. It is the first record of
breeding of this species at Buyr-Nuur.
Greylag Goose Anser anser. 190 non-breeding
adults were counted at the southern and southwestern
parts of Buyr-Nuur. 53% of them were
moulting flight feathers. Moulting birds fed on the
water near P. crispus, non moulting fed in the grass
meadows near the lake. Greylag Geese did not make
mixed flocks with Swan Geese but comprised
single-species flocks of 20-70 individuals.
Swan Goose Anser cygnoides. Moulting Swan
Geese gathered in huge flocks at the south-western
part of Buyr-Nuur mainly near the big spit (N 47
41; E 117 36). The biggest flock recorded there
comprised about 23,600 birds. We made 4 counts
of this flock during 19-20 July. Breeding families
and small groups of moulting non-breeding birds
were distributed along the entire shore. Breeding
geese were most numerous near the mouth of the
Khalkhin-Gol river. All moulting and breeding
geese were located on the water 10-300 m from
the shore and were opportune for counting. We
counted 29,056 non-breeding geese, 46 breeding
adults and 108 goslings. The total estimated number
is about 29,800 birds (28,470-31,960). The
estimation is very cautious and probably
understated. Almost all (more than 99.9%) of Swan
Geese at the lake were moulting flight feathers and
were unable to fly. They fed on leaves of P. crispus.
The number of Swan Geese at Buyr-Nuur
comprises more than half of the world population
estimated at 50,000-60,000 birds (Wetlands
International 2002). The high number of moulting
Swan Geese at Buyr-Nuur is not typical and is
probably related to the very bad forage conditions
on the main part of the Daurian steppe territory in
2003 (Goroshko 2003).
Whooper Swan Cygnus cygnus. 168 nonbreeding
adults were counted at the south-western
part of Buyr-Nuur. All were moulting and flocked
together with moulting non-breeding Swan Geese near the big spit and were opportune for counting.
Swans fed on the water near P. crispus.
Ducks were rare on Buyr-Nuur. At the mouth
of the Khalkhin-Gol river we recorded 5 Mallards
Anas platyrhynchos and 4 Wigeon Anas penelope.
Ruddy Shelduck Tadorna ferruginea were absent
on Buyr-Nuur, but 100 birds were recorded at a
small salty lake located close to Buyr-Nuur. At the
same site 70 Common Shelduck Tadorna tadorna
were seen. On the shore of Buyr-Nuur we also
recorded 2 Demoiselle Crane Anthropoides virgo,
2 Black-winged Stilt Himantopus himantopus, 1
Common Greenshank Tringa nebularia, 8 Spotted
Redshank Tringa erythropus, 5 Black-tailed
Godwit Limosa limosa, about 800 Black-headed
Gull Larus ridibundus, about 200 Yellow-legged
Gull Larus cachinnans, about 300 White-winged
tern Chlidonias leucopterus, 32 Caspian Tern
Hydroprogne caspia, about 60 Common Tern
Sterna hirundo and 8 Little Tern Sterna albifrons.
All of these species were non-breeding, except for
Sterna hirundo which may be breeding.
Buyr-Nuur is a very important site for birds
especially for the globally threatened Swan Goose.
There are no islands on Buyr-Nuur and so all of
the geese are forced to roost and rest on the lake
shores. Therefore the geese are very susceptible to
disturbance. It is very important to protect Buyr-
Nuur and limit human activity there.

Reference

  1. Wetlands International. 2002. Waterfowl Population Estimates – Third Edition. Wetlands International Global Series No. 12, Wageningen, The Netherlands, 226 pp.
  2. Goroshko O.A. 2003. 2003 – extremely unfavourable year for Swan Geese in Dauria trans-boundary region (Russia and Mongolia). - 2003 International Anatidae Symposium in East Asia & Siberia Region. Proceedings. Seosan, Korea: 83-92.