The influence of the pine marten (Martes martes) on the nesting of birds in artificial nests in north-eastern Ukraine

Abstract

Passerines are the most threatened by predators during the nesting period. According to the results of visual observa-tions conducted during 2019−2021 in forests of north-eastern Ukraine, a high proportion of bird nests destructed by the pine marten (Martes martes) in artificial nest boxes was revealed. The impact of the predator was assessed ac-cording to the following signs: the front wall of the nest box fell off, the bird’s nest was destroyed and torn, traces of claws on the front wall of the nest box, fragments of feathers and bones of the bird found nearby. In the pine forest of the Hetmansky National Nature Park near Kamenka village, the share of destroyed by the pine marten nests increased during 2019−2021 from 15.6% to 36.0% and 45.2%, respectively. In a forest of the Homilshansky Lisy National Nature Park near Zadonetske village, the largest share of nests ruined by the forest marten was 51.1% in 2020 and 33.3% in 2021. Cases of predation predominated in net boxes with nests of Parus major in the third dec-ade of May (21.05−31.05)—15.9% (n = 47) in the Homilshansky Lisy National Nature Park; F. albicollis in the first decade of June (01.06−10.06)—19.1% (n = 43) in the Hetmansky National Nature Park near Kamenka village. In general, the results indicate an increase in the destruction of nests in nest boxes by the pine marten in the first dec-ade of June (01.06−10.06) and in the first or second decade of July (01.07−20.07) for most bird species, including Parus major, Ficedula albicollis, Phoenicurus phoenicurus, Ficedula hypoleuca, and Erithacus rubecula. At the end of the third decade of February and during March, an inspection of nest boxes showed that a large number of adults of Parus major spend the night in the nest boxes. At the same time, in 2021, their share was 15% (n = 100), of which 10% became victims to the forest marten in the Homilshansky Lisy National Nature Park near Zadonetske village. In the territory of Hetmansky National Nature Park near Kamenka village, in 2020, Parus major was also the main victim of the pine marten, with a share of 5.0% (n = 120). Among the adult birds in the nest boxes that did not form breeding pairs or of which, eventually, the male or female died, the inspection of nest boxes also revealed cases of predation by the pine marten.