Branta Issues > Issue №2 (1999)

Present state of Bluethroat in Odessa region

Korzukov A.I., Trifonov V.G., Koval L.K.

Material was collected in the northern part of the Odessa region (the Balta district) in 1985-1994.The earliest arrival of liluethroats to the breeding area was observed on 18.03.89, the latest – on 8.04.87. Dates of the first spring observation of Bluethroats in the north of Odessa region are the following – 6.04.85, 4.04.86, 8.04.87, 30.03.88, 18.03.89, 2.04.90,5.04.91, 7.04.92, 7.04.93, 2.04.94. Dates of the first arrival in the southern areas are – 10.06.96 (Budakski Liman) and 2.04.99 (Liman of Kuyainik, the lower reaches). Mates arrive 10-15 days earlier than females.Preferable breed ini’ habitats in Kodyma River Jlood-lands are areas overgrown with reed and mace, 30-40 metres long. Bhiethroats build their nests on the ground in sedge associations or in thick grass under tussocks. Five breeding territories were counted per I km of Jlood-lands. Distance between breeding territories is 30-450 m. Estimated average density in the flood-lands (their width is 500-600 m) is 5-6 breeding pairs per 1 km.

Nest-building behaviour was observed on 9.05.93. Birds flew up to the nest with average intervals of 30-40 seconds. Building was finished by 13 May. First egg was found in the nest on 14 May. Complete clutch of 6 eggs was laid by 18 May. Clutch was incubated by a female. Duration of uninterrupted incubation interval was 1-1.5 hours. Feeding bouts took from a few minutes to a half an hour. Chicks hatched on 30 May. Bicyclic breeding was observed in the study region.Limiting factors during the breeding period are anthropogenic influence and the weather conditions.