WI - Cormorant Research Group The Bulletin - No. 3, December 1998 Original papers

Do Pygmy Cormorants Phalacrocorax pygmaeus breed in Dalmacia (Croatia)?

Milan Vogrin

Hotinjska cesta 108, SL 2312 Orehova vas, Slovenia

Pygmy Cormorants Phalacrocorax pygmaeus belong to the category of nearly threatened bird species (Collar et al. 1994). According to the classification of Tucker & Heath (1994), it actually is a vulnerable species, of which the population is mainly concentrated in Europe. Within the Balkan Peninsula, it regularly breeds in Albania, Greece and Macedonia (Cramp & Simmons 1977). In this short note I present a summer observation of Pygmy Cormorants on Vrana Lake at the Adriatic coast of Dalmacia (Croatia), possibly indicative of breeding.

Vrana Lake covers about 3000 ha with which it is the largest natural lake of Croatia. Most of the lake’s shoreline is overgrown with Reed Phragmites australis stands, particularly in the northeastern part, where a small 30 ha ornithological reserve is situated. Vrana Lake is placed among the important bird areas (Grimmett & Jones 1989, Mikuska 1992). In the regularly flooded areas the dominant vegetation consists of Juncus spp. In the surroundings many fields are irrigated with water from the lake. Other parts of the lake’s shores are covered by garrigue vegetation, in which the commonest plant species are Juniperus oxycedrus, Paliurus australis, degraded Quercus ilex, Q. pubescens, Carpinus orientalis and Robus spp.

At least five Pygmy Cormorants were observed on 13 August 1996 along the southern part of Vrana Lake and at least two of them were adult birds in full summer plumage. They were seen alongside Coots Fulica atra. This was probably the first report of this species on the lake. In the past, Pygmy Cormorants were reported to have bred in Dalmacia in the last century in the mouth of the river Neretva (Reiser 1939 in Matvejev & Vasic 1973). Nowadays the Neretva river mouth is completely deteriorated because of human influences (Mikuska 1990). More recent reports of Pygmy Cormorants in Dalmacia in the present century are very scarce (Krpan 1980).

The ornithofauna of Vrana Lake and surroundings in northern Dalmacia has up to now rather poorly been investigated and only fragmentary descriptions are found in the literature (e.g. Krpan 1980, Sere 1981, Lukac 1986, Lissak 1990, Mikuska & Mikuska 1992, Stipcevic 1992, Mikuska & Mikuska 1993). None of these authors have ever mentioned the presence of Pygmy Cormorants on Vrana Lake. The possibility that the Pygmy Cormorants observed have actually bred on Vrana Lake cannot be excluded and further field work here and in the vicinity is necessary to make sure. Nonetheless, since Pygmy Cormorants are known to start autumn migration from August onwards (Cramp & Simmons 1977), it is also possible that the observation at Vrana Lake referred to migrant birds.

At the same occasion I also observed up to four Shags Phalacrocorax aristotelis feeding on Vrana Lake. This seems remarkable, since Cramp & Simmons (1977) as well as Lea et al. (1996) state that this species feeds exclusively at sea.

Acknowledgements

I am grateful to Maarten Platteeuw who improved my final English version.

References

Collar, N.J., M.J. Crosby & J.A. Stattersfield 1994. Birds to watch 2: the world list of threatened birds. BirdLife International, BirdLife Conservation Series No. 4, Cambridge.

Cramp, S. & K.E.L. Simmons (eds) 1977. The birds of the Western Palearctic. Vol. 1. Oxford University Press, Oxford, London, New York.

Grimmett, R.F.A. & T.A. Jones 1989. Important bird areas in Europe. ICBP Technical Publication No. 9, Cambridge.

Krpan, M. 1980. Ornithofauna of mid Dalmacija. Larus 31/32: 97-156. [Croatian with English summary]

Lea, S.E.G., C. Daley, P.J.C. Boddington & V. Morison 1996. Diving patterns in shags and cormorants (Phalacrocorax): tests of an optimal breathing model. Ibis 138: 391-398.

Lissak, W. 1990. Beitrag zur Avifauna des Küstenlandes Kroatiens - ornithologische Beobachtungen in Norddalmatien/Jugoslawien. Larus 41/42: 165-187.

Lukac, G. 1986. Influence of severe winter on the population of Fan-tailed Warbler Cisticola juncidis at the Lake Vransko. Acrocephalus 7: 10. [Slovene with English summary]

Matvejev, S.D. & V.F. Vasic 1973. Catalogus Faunae Jugoslaviae. IV/Aves. Academia Scientiarum et Artum Slovenica, Ljubljana.

Mikuska, T. 1990. Ornithological report from delta of river Neretva on June 29th 1990. Troglodytes 3: 22-23. [Croatian with English summary]

Mikuska, T. 1992. Important bird areas campaign in Croatia. Troglodytes 5: 5-8. [Croatian with English summary]

Mikuska, J. & T. Mikuska 1993. Results of mid-winter waterfowl in Croatia during 1988. Troglodytes 6: 55-93. [Croatian with English summary]

Sere, D. 1981. Fan-tailed Warbler Cisticola juncidis breeds also in Croatia. Acrocephalus 2: 37. [Slovene]

Stipcevic, M. 1992. Black-winged Pratincole Glareola nordmanni confirmed in Croatia. Acrocephalus 13: 180-182. [Slovene with English summary]

Tucker, G.M. & M.F. Heath (eds) 1994. Birds in Europe: their conservation status. BirdLife International, BirdLife Conservation Series No. 3, Cambridge.


Milan Vogrin, Hotinjska cesta 108, SL 2312 Orehova vas, Slovenia