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1 July 2005 Population Dynamics and Social Behavior of the Mistle Thrush Turdus viscivorus During Winter
Piotr Skórka, Joanna D. Wójcik
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The density and behavior of the Mistle Thrush in Niepołomice Forest (southern Poland) and adjacent open areas were studied during winter (December—February) in 1996/97, 1998/99 and 2000/01. Mistle Thrush densities differed significantly from winter to winter, and the abundance of thrushes decreased as the season progressed. Bird density and mistletoe clump density were correlated positively. Birds held territories or congregated in flocks. The latter were sighted in the forest only during winter 1996/97, when the largest density of birds was noted. Flock size decreased progressively during that winter, but at the same time, the number of territorial birds remained stable. This suggests that by the end of the winter 1996/97 some birds from the flocks had begun to hold territories. Flocks were also seen in open areas, and displayed a preference for foraging on pastureland. Each individual territory in the forest consisted of several clumps of mistletoe on a few adjacent trees, which were defended against both conspecifics and other species such as Pyrrhula pyrrhula, Turdus merula and Dendrocopos major. The aggressive encounter rate was correlated positively with bird density but negatively with the progress of winter (the latter was correlated negatively with the berry supply). Surprisingly, it was not correlated with mistletoe clump density or temperature. During abundant berry years, the density of birds may have been so large that defending the fruit against numerous neighbors would have been energetically less profitable than communal foraging.



S. Cramp (ed.). 1988. The birds of the Western Palearctic. Vol. V. Oxford Univ. Press. Google Scholar


M. Cuadrado 1995. Territory characteristics and the attacks against intruders in migrant robins (Erithacus rubecula) wintering in the Mediterranean area. Ardeola 42: 161–166. Google Scholar


A. Ćwikowa , J. A. Lesiński 1981. [Floristic differentiation of comunities of present forest vegetation of Niepołomice Forest]. Stud. Ośr. Dok. Fizjogr. 9: 159–196. Google Scholar


A. Delestrade 1999. Foraging strategy in a social bird, the Alpine Chough: effect of variation in quantity and distribution of food. Anim. Behav. 57: 229–305. Google Scholar


B. Enokson , S. G. Nilson 1983. Territory size and population density in relation to food supply in the Nuthatch (Sitta europaea) (Aves). J. Anim. Ecol. 52: 927–935. Google Scholar


B. M. Gerard 1967. Factors affecting earthworms in pastures. J. Anim. Ecol. 36: 235–252. Google Scholar


A. Gruszczyk 1981. [Types of forest site of Niepołomice Forest]. Stud. Ośr. Dok. Fizjogr. 9: 205–219. Google Scholar


E. Hardy 1969. Mistle Thrushes and mistletoe berries. Bird Study 16: 191–192. Google Scholar


M. D. Johnson , W. T. Sherry 2001. Effect of food availability on the distribution of migratory warblers among habitats in Jamaica. J. Anim. Ecol. 70: 546–560. Google Scholar


P. Jordano 1993. Geographical ecology and variation of plantseed disperser interactions: southern Spanish junipers and frugivorous thrushes. Vegetatio 107/108: 85–104. Google Scholar


C. Kwit , D. J. Levey , C. H. Greenberg , S. F. Pearson , J. P. McCarty , S. Sargent 2004. Cold temperature increases winter fruit removal rate of a bird-dispersed shrub. Oecologia 139: 30–34. Google Scholar


D. F. Lott , D. Y. Lott 1991. Bronzy Sunbirds (Nectarina kilimensis) relax territoriality in response to internal changes. Ornis Scand. 22: 303–307. Google Scholar


E. Matthysen 1990. Nonbreeding social organization in Parus. Curr. Ornithol. 7: 209–249. Google Scholar


L. P. Morris , F. R. III Thompson . 1998. Effect of habitat and invertebrate density on abundance and foraging behavior of Brown-headed Cowbirds. Auk 115: 376–385. Google Scholar


J. P. Myers , P. G. Connors , F. A. Pitelka 1979. Territory size in wintering sanderlings: the effects of prey abundance and intruder density. Auk 96: 551–561. Google Scholar


L. Y. Pomara , R. J. Cooper , L. J. Petit 2003. Mixed-species flocking and foraging behavior of four Neotropical warblers in Panamanian shade coffee fields and forests. Auk 120: 1000–1012. Google Scholar


M. G. Salomonson , R. P. Balda 1977. Winter territoriality of Townsend's Solitaires (Myadestes townsendi) in Pinion-Juniper-Ponderosa ecotone. Condor 79: 148–161. Google Scholar


E. Simms 1978. British Thrushes. Collins, London. Google Scholar


P. Skórka , J. D. Wójcik 2003. Winter bird communities in a managed mixed oak-pine forest (Niepołomice Forest, southern Poland). Acta Zool. Cracov. 46: 29–41. Google Scholar


B. K. Snow , D. W. Snow 1984. Long-term defense of fruit by Mistle Thrushes (Turdus viscivorus). Ibis 126: 339–349. Google Scholar


B. K. Snow , D. W. Snow 1988. Birds and Berries. A study of an ecological interactions. T & AD Poyser, London. Google Scholar


J. A. Stamps , V. V. Krishnan 2001. How territorial animals compete for divisible space: a learning-based model with unequal competitors. Am. Nat. 157: 154–169. Google Scholar


P. T. Stypiński 1997. [Biology and ecology of the mistletoe (Viscum album) in Poland]. Frag. Flor. Geobot. S. Pol. Suppl. 1. Google Scholar


J. Suliński 1981. [Outline of climate, relief and groundwater conditions in Niepołomice Forest]. Stud. Ośr. Dok. Fizjogr. 9: 55–98. Google Scholar


A. Tye 1986. Economics of experimentally-induced territorial defense in a gregarious bird, the Fieldfare (Turdus pilaris). Ornis Scand. 17: 151–164. Google Scholar


H. Tyrväinen 1975. The winter irruption of the Fieldfare (Turdus pilaris) and the supply of rowan-berries. Ornis Fennica 52: 23–31. Google Scholar


D. Vallauri 1998. Parasite dynamics of Viscum album L. in Austrian black pine stands in the Saignon watershed (southwestern Alps). Ann. Sci. Forest. 55: 823–835. Google Scholar


K. Walasz (ed.). 2000. The Atlas of wintering birds in Małopolska. Małopolska Ornithol. Soc., Kraków. Google Scholar


J. Wasilewski 1990. Dynamics of the abundance and consumption of birds of prey in the Niepołomice Forest. Acta Zool. Cracov. 33: 173–213. Google Scholar


M. Wilson 1986. Avian frugivory and seed dispersal in Eastern North America. Curr. Ornithol. 3: 223–280. Google Scholar


W. Wiszniewski 1973. [Atlas of the climate of Poland]. IMiGW, Warszawa. Google Scholar


A. Zahavi 1971. The social behaviour of the White Wagtail (Motacilla alba) wintering in Israel. Ibis 113: 203–211. Google Scholar
Piotr Skórka and Joanna D. Wójcik "Population Dynamics and Social Behavior of the Mistle Thrush Turdus viscivorus During Winter," Acta Ornithologica 40(1), 35-42, (1 July 2005).
Received: 1 November 2004; Accepted: 1 May 2005; Published: 1 July 2005
aggressive behavior
flocking behavior
fruit defense
Mistle Thrush
Niepołomice Forest
Turdus viscivorus
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