Cyclicity of long-term dynamics of reproductive parameters in the tree sparrow Passer montanus

The spectral analysis of the multi-year (1984–2005) dynamics of reproductive parameters in the population of Tree Sparrow Passer montanus was carried out in the vicinity of Lake Chany (Baraba forest-steppe). In this species the inter-annual dynamics cycling of the average size of clutches and eggs was revealed. The dominant clutch size cycle of the Tree Sparrow is 11 years. This species may adapt to the cycles of the air temperature dynamics similar in time during the second and third decades of May, when the most pairs begin to reproduce. Since the sparrows fledge mostly with insects, an abundance of which depends on thermal environment, such adjustment provides a higher productivity of individuals and populations in general. Less expressed 3–4-year cycles of clutch size, most likely, are caused by the intra-population reasons. The average seasonal fecundity of the Tree Sparrow depends on the ratio between the first and second clutches. The proportion of second clutches varies with the periodicity of three-year and 12-year (multiple of three). Perhaps this is due to the three-year dynamics of the age structure, as the majority of Tree Sparrow yearling are monocyclic. Rhythm spectra of long-term changes in the linear dimensions and volume of eggs of the Tree Sparrow are very similar. The most powerful cycle lasts approximately 7-year, but there are 3-and 2-year periodic components less expressed on power. Probably the of egg dimensions cycling is determined by a variety of external and intra-population factors (food supply, age distribution of the population, timing and duration of their breeding season). References Vengerov P. D. Jekologicheskie zakonomernosti izmenchivosti i korreljacii morfologicheskih struktur ptic (Ecological regularities of variability and correlation of morphological structures of birds). Voronezh: Publishing house of Voronezh state University, 2001. 248 pp. Erdakov L. N. Biologicheskie ritmy i printsipy sinkhronizatsii v ekologicheskikh sistemakh (khronoekologiya) (Chronoecology: Biological Rhythms and Principles of Synchronization in Biological Systems). Tomsk: Tomsk. Gos. Univ., 1991. 216 pp. Klimov S. M. Jekologo-jevoljucionnye aspekty izmenchivosti oomorfologicheskih pokazatelej ptic (Ecologo-evolutionary aspects of the oomorphological parameters in birds). Lipetsk: Lipetsk State Pedagogical University Press, 2003. 208 pp. Lack, D. The Natural Regulation of Animal Numbers, Oxford, 1954. Translated under the title Chislennost' zhivotnykh i ee regulyatsiya v prirode, Moscow: Inostrannaya Literatura, 1957. 404 pp. Marple Jr. S. L. Digital spectral analysis with applications, New Jersey: Prentice Hall, 1987. Translated under the title Cifrovoj spektral'nyj analiz i ego prilozhenija, Moscow: “Mir” 1990. 584 pp. Martynyuk V. S., Vladimirskij B. M.Temuryants N. A. Biologicheskie ritmy i jelektromagnitnye polja sredy obitanija (Biological rhythms and electromagnetic fields environment) // Geophysical Processes and Biosphere. 2006. Vol. 5. No. 1. P. 5-23. Mänd R. Vnutripopuljacionnaja izmenchivost' ptich'ih jaic (Intrapopulation variation of avian eggs). Tallin: “Valgus”. 1988. 192 pp. Payevsky V. A. Demografija ptic (Avian Demography). Leningrad: “Nauka” Press, 1985. 285 pp. Pul'siruyushchee ozero Chany (The Pulsating Lake Chany), Leningrad: “Nauka” Press, 1982. 304 pp. Taranyuk M. I. Issledovanie ciklichnosti klimata i monitoring atmosfernyh processov na territorii jugo-vostoka Zapadnoj Sibiri (Analysis of climate cyclicity and monitoring of atmospheric processes in the southeast of Western Siberia), Cand. Sci. (Geogr.) Dissertation, Tomsk: Publishing house of Tomsk state University, 2000. 116 pp. Chernyshov V. M. Population ecology of the Tree Sparrow (Passer montanus) in the South of Western Siberia // Birds of Siberia: fauna, communities and populations structure and dynamics / Ed. L. G. Vartapetov. - Moscow: KMK Scientific Press Ltd, 2011. (Proceedings of the Institute of Systematics and Ecology of An