Migrations and Wintering of the Kestrel (Falco tinnunculus) in Poland

Abstract

In Poland, the Kestrel is an uncommon bird during the winter time. It rarely winters in the eastern part of the country; however, the reported numbers of regular wintering cases increase towards the southwest. The aims of this study were: to analyse the wintering area of Kestrels nesting in Poland, to compare distances covered by the birds migrating for the first time in their life to their movements in the following years, and to determine the origin of Kestrels wintering in Poland. The material for the analysis comprised 171 recoveries of the birds ringed in Poland or recorded in Poland but ringed abroad within the years 1931-2001. Out of 48 adult Kestrels ringed or recovered during both migration periods (autumn and spring), the great majority were recorded in Poland; only 2 birds were found as adult ones in France and 1 in Ukraine. We obtained 32 recoveries of Kestrels ringed in Poland as chicks or as individuals in their first year of life and recorded again during their first migration season (autumn-spring). Five of them were recorded outside the country. In Poland, there were reported 94 Kestrels that had been ringed abroad. Those birds came from Finland, Sweden, Norway, Germany, Denmark, Slovakia, the Czech Republic and Ukraine. These data show that mainly Kestrels nesting in the north of the continent migrate across Poland and some of them winter here as well. A great majority of recoveries referred to Kestrels ringed in Finland. These birds also came to Poland from Germany and from the areas located to the southwest of Poland.

Settlement Phenotypes: Social Selection and Immigration in a Common Kestrel Population

“…Longer tails usually means higher costs for flight, making long trips difficult, which explains why migratory birds tend to have shorter tails (Balmford et al, 1993;Thomas and Balmford, 1995). The natal and reproductive dispersal distances found in kestrels are not very long (<200 km; Terraube et al, 2015), but in general kestrels travel long distances after fledging and in premigratory and migratory periods (Adriaensen et al, 1997;Śliwa et al, 2009;Village, 1990;Holte et al, 2016). Kestrels are also migrants in southern Europe, traveling to Africa during the winter, as observed in our population, where at least three individuals born in our population were found dead during the winter in Mauritania and Morocco.…”

Population genetic structure of the European kestrel Falco tinnunculus in Central Poland

“…This pattern could be an outcome of our sampling scheme: samples from Łódź were collected during a single season separated by 4 years from the season in which the majority of samples from Warsaw were collected. The mean lifespan of kestrels, based on ringing data, was assessed to be 1.3-1.9 years, but for birds in the second year of life, it increases to 2.9 years (reviewed in Śliwa and Rejt 2006). Most kestrels breed for the first time in their first year of life (Village 1990(Village , 1998.…”

“…In rural regions, tree-based nests have been systematically disappearing over the last few decades. Similarly, observation data suggest that the number of kestrels in many rural areas seems to have decreased in the last decades (Śliwa and Rejt 2006), whereas they appear to become increasingly abundant in cities. It is not clear whether this patchy distribution, caused mainly by gathering within urban areas during breeding season, affects the population genetic structure of the species.…”

“…In Warsaw, European kestrels produce 4.4-5.4 successfully reared offspring per breeding pair-slightly higher than rural populations (about four successfully reared offspring per breeding pair). The mortality rate of the offspring of urban birds is about 50% in the first year and increases in subsequent seasons (review in Śliwa and Rejt 2006). In Warsaw, bulk of prey is composed by mammals (mostly voles "Microtus" sp).…”

“…Other prey groups were significantly less numerous-birds composed about 12% of prey; reptiles less than 4% (e.g. Śliwa and Rejt 2006).…”