4166 measurements of wing length in Reed Warblers were made during 9 breeding and pre-migratory periods in Central Poland. In the studied population there was significant differentiation in the wing length among seasons in adult and juvenile birds. Multiple regression and path analysis showed that weather factors (temperature and precipitation) during the breeding period determine the long-term variation in the wing length in both adult and young birds. Changes in wing length were explained by natural selection and habitat selection. In breeding and pre-migratory periods, temperature and precipitation influence in food availability, and thus affect optimisation of energetic expenses on feeding. It was revealed that long-winged individuals are best adapted to cold and rainy conditions, the short-winged ones, to warm and dry summers. The weather conditions obtaining when the birds arrive at the breeding grounds could be linked to differentiation in availability of optimal places for establishing territories, thereby influencing cempetition for breeding territories and the effectiveness of their occupation by morphometrically different birds.
REFERENCES
D. J. Aidley
,
R. Wilkinson
1987. The annual cycle of six Acrocephalus warblers in a Nigerian reed-bed. Bird Study 34: 226–234. Google Scholar
A. Anselin
,
E Meire
1989. Habitat selection of Sedge Warbler Acrocephalus schoenobaenus (Linne, 1758) and Reed Warbler A. scirpaceus (Hermann, 1804) in small reedbeds. Annls. Soc. r. zool. Belg. 119: 121–136. Google Scholar
R. T. Barrett
,
M. Peterz
,
R. W. Furness
,
J. Durinck
1989. The variability of biometric measurements. & Ring. Migr. 10:13–16. Google Scholar
C. J. Bibby
,
D. K. Thomas
1985. Breeding and diets of the Reed Warbler at a rich and a poor site. Bird Study 32: 19–31. Google Scholar
P. T. Boag
,
P. R. Grant
1981. Intense natural selection in population of Darwin's finches (Geospizinae) in the Galapagos. Science 214: 82–85. Google Scholar
M. Borowiec
1983. [Study on colour ringed breeding population of Reed Warblers (Acrocephalus scirpaceus) at Milicz fish-ponds]. Dolina Baryczy 2: 1–10. Google Scholar
M. Borowiec
,
E. Dąbrowska
1991. [Nesting ecology of Reed Warbler Acrocephalus scirpaceus (nest material, nest size and nest distribution)]. Ptaki Ślaska 8: 26–39. Google Scholar
D. M. Bryant
1978. Environmental influences on growth and survival of nestling house martins Delichon urbica. Ibis 120: 271–283. Google Scholar
D. M. Bryant
,
K. R. Westerterp
1982. Evidence for individual differences in foraging efficiency amongst breeding birds: a study of house martins Delichon urbica using the doubly labelled water technique. Ibis 124: 187–192. Google Scholar
D. M. Bryant
,
K. R. Westerterp
1983. Short term variability in energy turnover by breeding House Martins Delichon urbica: a study using doubly-labeled water (D2O18). J. Anim. Ecol. 52: 525–543. Google Scholar
P. Busse
1976. The spring migration of birds at the east part of Polish Baltic coast. Acta zool. cracov. 21: 121–261. Google Scholar
P. Busse
1983. Biometrical standards in the Operation Baltic work. Ring 10: 125–138. Google Scholar
C. Bussmann
1979. Ökologische Sonderung der Rohrsänger Südfrankreichs aufgrund von Nahrungsstudien. Vogelwarte 30: 84–101. Google Scholar
A. M. Cardenas
,
J. A. Torres
,
C. Bach
1983. [A comparative study of the alimentary diet of Acrocephalus arundinaceus and A.scirpaceus in Zonar pond]. Ardeola 30: 33–44. Google Scholar
C. K. Catchpole
1972. A comparative study of territory in the Reed Warbler (Acrocephalus scirpaceus) and Sedge Warbler (Acrocephalus schoenobaenus). J. Zool. 166: 213–231. Google Scholar
E. Cowley
1979. Sand Martin population trends in Britain, 1965–1978. Bird Study 26: 113–116. Google Scholar
N. B. Davies
,
R. E. Green
1976. The development and ecological significance of feeding techniques in the Reed Warbler (Acrocephalus scirpaceus). Anim. Behav. 24: 213–229. Google Scholar
A. A. Dhondt
,
R. Eyckerman
,
J. Huble
1979. Will great tits become little tits? Biol. J. Linn. Soc. 11: 289–294. Google Scholar
A. Dyrcz
1979. Die Nestlingsnahrung bei Drossel- und Teichrohrsänger an den Teichen bei Milicz in Polen und zwei Seen in der Westschweiz. Orn. Beob. 76: 305–316. Google Scholar
G. Erlinger
1986. Die Rohrsänger der Hagenauer Bucht. Teil 2: Der Teichrohsänger. Ökol. 8: 19–24. Google Scholar
A. O. Ettinger
,
J. R. King
1980. Time and energy budgets of the Willow Flycatcher (Empidonax traillii) during the breeding season. Auk 97: 533–546. Google Scholar
P. Ewins
1985. Variation of Black Guillemot wing lengths postmortem and between measurers. Ring. & Migr. 6:115–117. Google Scholar
J. C. Finlay
1971. Breeding biology of purple martins at the northern limit of their range. Wilson Bull. 83: 255–269. Google Scholar
R. C. Fleischer
,
R. F. Johnston
1982. Natural selection on body size and proportions in house sparrows. Nature 298: 747–749. Google Scholar
R. C. Fleischer
,
R. F. Johnston
1984. The relationships between winter climate and selection on body size of house sparrows. Can. J. Zool. 62: 405–410. Google Scholar
R. C. Fleischer
,
S. I. Rothstein
1988. Known secondary contact and rapid gene flow among subspecies and dialects in the brown-headed cowbird. Evolution 42: 1146–1158. Google Scholar
P. R. Grant
1986. Ecology and evolution of Darwin's Finches. Princeton University Press, Princeton, New Jersey. Google Scholar
P. R. Grant
1991. Natural selection and Darvin's Finches. Scient. Amer. 4: 58–64. Google Scholar
R. E. Green
,
N. B. Davies
1972. Feeding ecology of Reed and Sedge Warblers. Wicken Fen Group Report 4: 8–14. Google Scholar
O. Hogstad
1985. Annual variation in mean body size of a brambling Fringilla montifringilla population. Ornis Fenn. 62: 13–18. Google Scholar
A. Järvinen
,
J. Ylimaunu
1986. Growth of nestling Pied Flycatcher Ficedula hypoleuca in northern Lapland. Ornis Fenn. 63: 17–25. Google Scholar
R. F. Johnston
,
R. K. Selander
1973. Variation, adaptation and evolution in the North American house sparrow. In:
S. C. Kendeigh
,
J. Pinowski
(eds.).
Productivity, population dynamics and systematics of granivorous birds. PWN, Warszawa, pp. 301–324. Google Scholar
G. Jones
1987. Selection against large size in the sand martin Riparia riparia during a dramatic population crash. Ibis 129: 274–280. Google Scholar
S. C. Kendeigh
1941. Length of day and energy requirements for gonadal development and egg laying in birds. Ecology 22: 237–248. Google Scholar
A. Król
1984. [Foraging ground division between sexes during feeding nestlings in Reed Warbler (Acrocephalus scirpaceus)]. Dolina Baryczy 3: 48–53. Google Scholar
S. Kuzniak
1991. Breeding ecology of the Red-Backed Shrike Lanius collurio in the Wielkopolska region (Western Poland). Acta orn. 26: 67–84. Google Scholar
B. Leisler
1981. Die ökologische Einnischung der mitteleuropäischen Rohrsänger (Acrocephalus, Sylviinae). I. Habitattrennung. Vogelwarte 31: 45–74. Google Scholar
H. R. Lindman
1992. Analysis of variance in experimental design. Springer-Verlag, New York Inc. Google Scholar
B. K. McNab
1980. Food habits, energetics, and the population biology of mammals. Am. Nat. 116: 106–124. Google Scholar
B. K. McNab
1988. Food habits and the basal rate of metabolism in birds. Oecologia 77: 343–349. Google Scholar
J. J. Nowakowski
,
K. Lewandowski
1995. [Diet of birds from genus Acrocephalus, Locustella, and Reed Buntings Emberiza schoeniclus in coldness and rainy period]. Mat. XVI Zjazdu Pol. Tow. Zool., Łódź, p. 120. Google Scholar
M. Orell
1983. Nestling growth in the Great Tit Parus major and Willow Tit P. montanus. Ornis Fenn. 60: 65–82. Google Scholar
C. M. Perrins
1965. Population fluctuations and clutch size in the Great Tit, Parus major. J. Anim. Ecol. 34: 601–647. Google Scholar
A. Pikulski
1986. [Breeding biology and ecology of Savi's Warbler (Locustella luscinioides) at Milicz fish-ponds (preliminary report)]. Ptaki Śląska 4: 2–39. Google Scholar
T. D. Price
,
P. R. Grant
1984. Life history traits and natural selection for small body size in a population of Darwin's finches. Evolution 38: 483–494. Google Scholar
D. Schluter
,
J. M. Smith
1986. Natural selection on beck and body size in the song sparrow. Evolution 40: 221–231. Google Scholar
K. Schmidt-Nielsen
1991. Scaling. Why is animal size so important? Cambridge Univ. Press. Google Scholar
K. Schulze-Hagen
,
H. Flinks
1989. Nestlingsnahrung von Sumpfrohrsängern Acrocephalus P. alustris. Vogelwelt 110: 112–125. Google Scholar
K. Schulze-Hagen
,
G. Sennert
1990. Teich- und Sumpfrohrsänger Acrocephalus scirpaceus, A. palustris in gemeinsamem Habitat: Zeitliche und räumliche Trennung. Vogelwarte 5: 215–230. Google Scholar
T. B. Smith
1990. Natural selection on bill characters in the two bill morphs of the Africal Finch Pyrenestes ostrinus.Evolution 44: 832–842. Google Scholar
R. Sokal
,
J. Rohlf
1981. Biometry. Second Edition. W. H. Freeman and Company, San Francisco. Google Scholar
R. F. Stocek
1986. Spring weather and local movements of Tree Swallows, Tachycineta bicolor.
Can. Field Nat. 100: 134–136. Google Scholar
P. D. Sturkie
1965. Avian physiology. Cornell University Press, Ithaca, New York. Google Scholar
J. Taillandier
1990. Premieres données sur la dynamique d'une population de rosserolle effarvatte (Acrocephalus scirpaceus) en Marais Salant de Guérande (Loire-Atlantique). Alauda 58: 21–28. Google Scholar
V. A. Tucker
1973. Bird metabolism during flight: evaluation of a theory. J. Exp. Biol. 58: 689–709. Google Scholar
A. Turner
1984. Nesting and feeding habits of brown-chested martins in relation to weather conditions. Condor 86: 30–35. Google Scholar
K. R. Westerterp
,
D. M. Bryant
1984. Energetics of free existence in swallows and martins (Hirundinidae) during breeding: a comparative study using doubly labeled water. Oecologia 62: 376–381. Google Scholar
J. B. Williams
1988. Field metabolism of tree swallows during the breeding season. Auk 105: 706–714. Google Scholar
W. Winkel
1981. Zur Populationsentwicklung von fünf MeisenArten (Parus spp.) in einem Lärchen-Versuchsgebiet von und nach dem strengen Winter 1978-79. Vogelwelt 102: 41–47. Google Scholar
Z. Wojciechowski
1992. [The attempt of explanation the longterm variability in metric traits of Swallow (Hirundo rustica)]. PhD thesis, University of Lodz, 115 pp. Google Scholar
J. H. Van Balen
1967. The significance of variations in body weight and wing length in the Great Tit, Parus major. Ardea 55: 1–59. Google Scholar
Balen J. H. Van
1980. Population fluctuations of the Great Tit and feeding conditions in winter. Ardea 68: 143–164. Google Scholar
