Scientific Journal of the BirdLife Hungary

A Magyar Madártani és Természetvédelmi Egyesület tudományos folyóirata

Ornis Hungarica. vol.17-18. (2009) p.1-11.

Breeding ecology and population decline of the crested lark Galerida cristata in Warsaw, Poland
G. Lesiński

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Kivonat:

The crested lark Galerida cristata inhabited almost exclusively open areas in the outskirts of new settlements of Warsaw in the years 1980-2006. The highest density of the species (0.11 pairs/km2) in the entire city (494 km2) was recorded in 1986, and locally (a plot of 2.6 km2) – 5.7 pairs/km2 in 1980. Breeding period lasted from April 12th (the first egg) to July 31st (the last fledgeling) with broods most intensively initiated in May. There were usually 4-5 eggs per brood, rarely 3 (mean 4.36±0.60 SD). The mean number of eggs in the first brood was 4.47±0.64 eggs, in the first repeated brood – 4.17±0.98 eggs and in the second brood – 4.09±0.70 eggs. Most pairs (71%) performed the second brood. Reproductive success of the population of 17 pairs studied in 1980 was 3.47 fledgelings leaving the nest per nesting pair (nearly 40% of broods were destroyed).
Breeding losses resulted mostly from human activity and intensive rainfalls. Population of G. cristata in Warsaw was characterized by a great dynamics. None of the 17 pairs living on the plot of 2.6 km2 in 1980 remained in 1987 due to the management of new settlements. The species strongly regressed throughout the city: 53 pairs were found in 1986 but only 2 in 2002, one pair in 2003-2005, with a total extinction in 2006. One of probable reasons for this decline could be the development of populations of corvid predators – mainly Pica pica (its density has increased near 20 times) and Corvus cornix in peripheral Warsaw.