Abstract

This paper analyzes the factors that determine the timing of the spring arrival of passerine birds in the nesting area, i.e., the Lower Ob Region. For the period 1971–2015, a reliable negative trend to an arrival shift to earlier dates for seven out of 16 species, an unreliable shift for six species, and a positive trend for three species were found. Using cluster analysis, three groups of species with similar arrival dynamics were identified. The temperature in the study area at the beginning of the arrival of all species increased with the approach to the end of the period analyzed (1971–2015) in parallel with the growing spring average monthly temperatures. Significant correlations of the starting dates of bird arrival with spring air temperatures (mainly in May), dates of ice passage along the Ob River, and the length of the migration route of the species were revealed. The relationship of the starting date of arrival in most species with the average daily air temperature directly on the day of arrival is weakly expressed. Thus, the main factors affecting the arrival dates are the average monthly spring air temperatures, primarily in May. The North Atlantic Oscillation Global Weather Index (NAO) is much less significant.

中文翻译：

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决定Ob森林苔原中Passformformes到达时间的因素的层次

摘要

本文分析了决定雀巢鸟春季在巢区（下鄂贝地区）的时间的因素。在1971-2015年期间，发现了可靠的负趋势，即16种物种中有7种到达较早日期的到来日期较早，有6种物种的变化不可靠，而3种物种则呈上升趋势。使用聚类分析，确定了具有相似到达动态的三类物种。随着进入分析期末（1971-2015年）的临近，所有物种抵达开始时研究区域的温度都与春季平均每月温度的升高平行。鸟类到达起始日期与春季气温（主要是5月），沿鄂毕河的冰过日期，并揭示了该物种的迁移路径的长度。多数物种到来的开始日期与到来当天的平均每日气温之间的关系很弱。因此，影响到达日期的主要因素是春季的平均每月气温，主要是五月。北大西洋涛动全球天气指数（NAO）的影响要小得多。