Volume 46• Number 4 • 2005

203 Abundance, distribution and breeding ecology of the Penduline Tit Remiz pendulinus
      in the Milicz Fishponds.
      Beata Czyż

Abstract: In 2002-2004 the abundance, distribution and breeding ecology of the Penduline Tit Remiz pendulinus were investigated in the Stawno fishponds complex within the "Milicz Fishponds" reserve. In the area of 1200 ha, 68, 65 and 50 pairs bred consecutively in particular seasons of the study period. The greatest number of the species nests were situated on the ponds Słoneczny Górny and Gadzinowy. Nests were mostly built in willow and birch trees in the period from early April till the beginning of July, an average nest height equalling 3.9 m. The nests located above the solid ground hanged, on average, higher than those over water or wet ground. In the studied population the median date of nest building commencement fell on 9th May. The first young fledged on the turn of May. The mean clutch size amounted to 4.9 eggs. The broods incubated by the female were, on average, larger than those incubated by the male and deserted; 46.2% of broods were successful and 53.8% lost. The main reason behind the brood loss was nest desertion even before starting the incubation process (69.4% of all losses). Predation was responsible for 9.4% of all losses on broods.

213 Breeding phenology of the Red-breasted Flycatcher Ficedula parva in the Białowieża
      Forest.
      Cezary Mitrus, Beata Soćko, Marta Dołegowska, Piotr Zozula

Abstract: The breeding phenology of the Red-breasted Flycatcher was investigated in 2000-2004 under natural conditions of the Białowieża National Park on three study plots and along main forest paths. The first males arrived between 29th April and 7th May. The phenology of 63 broods was monitored. The earliest first-egg laying was observed on 5th May 2001 , the latest on 12th June 2002 . The majority of females (68%) commenced the breeding season between 18th May and 3rd June. The earliest hatching was recorded on 29th May and the latest on 29th June. Most nestlings (64%) appeared between 7th and 22nd June. Fledging started from 11th June and the latest was observed on 11th July. Most of the fledglings left the nests between 17th June and 2nd July. The earlier brood commencement observed in Białowieża can be a result of several reasons: phenological data from other European regions are often based on irregular observations and small samples, and much of this information is several tens of years old. Many years' obervations of some European bird species indicate that climate warming can be responsible for considerably earlier egg-laying timing.

221 Nesting of the Shelduck Tadorna tadorna in Western Pomerania in 2004.
      Zbigniew Kajzer, Łukasz Ławicki

Abstract: In the season of 2004, 58-67 Shelduck breeding pairs were recorded at 23 localities within Western Pomerania . The species was most abundant in the lower Odra River valley and Szczecin Lagoon region. The most important sites included a gravel-pit in Bielinek (7 p.) and the flood waters of Kostrzyneckie Rozlewisko (6-7 p.) within the former area, and the Świna River delta (6 p.), sedimentation tanks of the Chemical Plant in Police (5-6 p.) and the bay of Zalew Kamieński (3-5 p.) in the latter. Shelducks were encountered in four habitat types; the greatest number of pairs in the river valley (42%), on lagoons and lakes (31%), the remaining part of the population at sites of anthropogenic origin such as sedimentation tanks at industrial plants and gravel-pits. At least 1/6 of the breeding pairs observed were recorded to have bred successfully, with ca 8 nestlings (N=10) per successful pair. Western Pomerania constitutes the most significant breeding ground of the Shelduck in Poland . In the last dozen or so years a clear decline in the species abundance occurred in the Szczecin Lagoon region but, simultaneously, dynamic development of the population inhabiting the lower Odra River was noted.

231 Lead contents in tissues and feathers of the Black-headed Gulls Larus ridibundus
      breeding on the Mietkowski Reservoir.
      Grzegorz Orłowski, Ryszard Polechoński, Wojciech Dobicki, Zbigniew Zawada

Abstract: An analysis of lead (Pb) content in six types of tissue (pectoral muscle, liver, kidneys, lungs, femur, cerebrum) and feathers of the Black-headed Gull Larus ridibundus breeding on the Mietkowski Reservoir (an area of 980 ha, Lower Silesia), based on samples taken from 14 individuals (9 adults and 5 fledglings), showed the highest concentrations of this metal in the brain tissue of fledglings having the smallest body mass (83.00 and 55.20 mg g-1 Pb dry weight). The ratio of minimum to maximum lead concentrations in brain tissue was 1:6.82 in fledglings and 1:1.42 in adults. In general, of all analyzed tissues, statistically significant differences in mean lead concentrations (± SD) between fledglings and adult birds (P=0.03) were noted only for bones (fledglings:17.61 ± 6.35 vs. adults: 56.06 ± 31.48 mg g-1 dry weight). The bones of adult birds were characterized by very high diversification of the lead content (extreme values: 28.60 and 121.88 mg g-1 dry weight). In fledglings, increased contents of the metal were found in lungs (fledglings: 13.14 ± 2.40 vs. adults: 11.24 ± 1.04 mg g-1 dry weight) and feathers (fledglings: 10.40 ± 5.36 vs. adults: 8.22 ± 2.43 mg g-1 dry weight). The level of lead contamination of Black-headed Gulls from the Mietkowski Reservoir was decidedly lower when compared with the population inhabiting the strongly industrialized region of Upper Silesia .

Overviews

241 Further changes in the taxonomy of Polish birds.
      Tadeusz Stawarczyk

Summary: The latest decisions of the BOURC and German taxonomists concerning changes in avian taxonomy have inspired the Polish Avifaunistic Commission to introduce analogous modifications with regard to species noted in the national checklist. The changes pertain to both species splitting and the generic names.

Notes

244 Settlement of the Raba River basin by the Goosander Mergus merganser.
      Łukasz Kajtoch, Agata Piestrzyńska-Kajtoch

Summary: A study of the distribution and abundance of a new population of the Goosander was conducted in the Raba River basin (south-eastern Poland ) in 2000-2005. In particular years, the number of pairs ranged between 4 and 16. The decrease in the number of breeding pairs recorded for 2002-2004 was caused by cutting of forests and regulation of the river bed. The Goosander populated also the Dobczycki Reservoir and the Stradomka, Tarnawka and Krzyworzeka River valleys in the Wiśnicki Foothill, forming the first population in the Polish Carpathian Mts. In 2005 the total abundance of this species was estimated at 20-24 pairs. It probably breeds in burrows and in beech forests, and is likely to spread into other river valleys of the Carpathian Foothills in the future.

247 First record of nest parasitism by the Cockoo Cuculus canorus on the Red-breasted Flycatcher
      Ficedula parva.
      Cezary Mitrus, Beata Soćko

Summary: On 28th May 2005 , during a control of an earlier observed nest of the Red-breasted Flycatcher, two eggs were found inside, one of which typical of the species and the other considerably larger and differently coloured. The nest was situated at a height of 1.8 m, behind detached bark of an enormous live lime tree. During a control on 3rd June, five eggs of the Red-breasted Flycatcher and one of the Cockoo were found in the nest. A subsequent visit, on 6th June, revealed that the nest content had been destroyed by a predator. This was the only case of nest parasitism among the 122 nests of this flycatcher controlled in 2000-2005 in the Białowieża National Park . The Red-breasted Flycatcher had not been known before as a host to whose nest the Cockoo can dump its eggs.

250 Mystery bird 41: Mediterranean Gull Larus melanocephalus.
     Jan Lontkowski

Announcements

252 Avifaunistic Commission Special Communiqué

Summary: This paper regards an extraordinary case of an observer who after many years of activity turned out to be dishonest, and therefore the whole of his output has to be considered unreliable. The Commission lists 104 revised and invalidated records, in that number the Cetti's Warbler only record which has been removed from the national checklist.

Reports

255 10th International Grouse Symposium IUCN, 26.-30.09.2005, Luchon , France.
      Dorota Zawadzka

256 Results of bird ringing at the Turawski Reservoir in 2000-2004.
     Adam Wojciechowski, Grzegorz Hebda

Summary: Waders and passerines ringing was conducted using 25-40 walk-in traps and up to 10 mist nets at Turawski Reservoir, Opole district. In total, 5814 birds of 64 species were ringed, including 3536 waders of 18 species and 2278 Non-Charadrii of 44 species. The main species trapped were: the Wood Sandpiper Tringa glareola, Common Snipe Gallinago gallinago and Common Sandpiper Actitis hypoleucos. Twenty-four ringing recoveries were obtained, concernig mainly the Common Snipe from France .

260 Results of bird ringing at the Siemianówka Reservoir in 2002-2004.
      Michał Polakowski

Summary: Ringing was conducted during the spring and autumn migration in 2002-2004 at Siemianowka Reservoir , NE Poland . Birds were trapped with 29-61 mist nets and up to 3 walk-in traps. In total, 16,853 birds belonging to 121 species were ringed. The dominant species were: the Robin Erithacus rubecula, Chiffchaff Phylloscopus collybita, Sedge Warbler Acrocephalus schoenobaenus, Great Tit Parus major and Blackcap Sylvia atricapilla. Among the trapped birds, the following are worth mentioning: 11 Citrine Wagtails Motacilla citreola and a Pallas's Warbler Phylloscopus proregulus. Fourteen recoveries were obtained.