Effects of ambient temperature during the nestling stage on a stress indicator in nestling pied flycatchers Ficedula hypoleuca

Long-term and short-term changes in ambient temperature can cause stress in birds, leading to changes in the level of hematological parameters. The H:L ratio (heterophil-to-lymphocyte ratio) is a hematological index that allows for the assessment of the stress induced by environmental changes, including weather conditions. In this paper, we examined the influence of temperatures and the sum of precipitation on the health of nestling pied flycatchers (Ficedula hypoleuca) by using the H:L ratio reflecting the body’s response to stress. All examined temperature indicators influenced the H:L ratio, yet the average value of daily minimum temperature during the first 12 days of nestling life had the strongest influence, maximum temperature had the weakest effect, while precipitation had no significant influence. Our research indicates that even a small increase in temperature caused a stress reaction in nestling pied flycatchers, which was reflected by an increase in the H:L ratio. The increase in the stress index (H:L ratio) was probably a result of poor weather conditions (precipitation, low temperature), which prevented the adult birds from actively foraging and properly feeding the nestlings.

Use of landmarks for nest site choice and small-scale navigation to the nest in birds

Nest sites of animals are often concealed to keep vulnerable offspring from being detected by predators. Parents may use landmarks near the nest to relocate it quickly. We allowed blue tits (Cyanistes caeruleus) to choose between two nest boxes fixed on the same tree with either none, the same, or different white painted markings. Surprisingly, the female brought material to both boxes and sometimes laid eggs in both. In a second experiment, we let pied flycatchers (Ficedula hypoleuca) and great tits (Parus major) become familiar with a marking on the initial nest box and then let them choose between two new nest boxes erected on different, nearby trees. Neither species preferred the box with the matching mark. In nature, the birds may locate the correct entrance of a cavity using other landmarks near the nest opening, like branches and the height of the cavity opening above the ground.

Additions to the list of bird species in the Shushensky Bor National Park

This work includes additions to the existing annotated list of birds of the Shushensky Bor National Park, given in the book by ornithologist S.Yu. Petrov and senior state inspector S.V. Chumakov Birds of the Shushensky Bor National Park, published in 2020 in an electronic form. The paper provides general data on the avifauna of the national park, as well as the results of recent studies as of early 2021. The paper provides information on the sightings of 11 bird species that were not previously recorded in the park as a whole: Ptyonoprogne rupestris (Scopoli, 1769); Turdus merula (Linnaeus, 1758); Monticola saxatilis (Linnaeus, 1766); Ficedula hypoleuca (Pallas, 1764) аnd on individual cluster sites Mountain forestry: Podiceps cristatus (Linnaeus, 1758); Crex crex (Linnaeus, 1758); Charadrius dubius (Scopoli, 1786); Turdus obscurus J.F. Gmelin, 1789; Turdus iliacus (Linnaeus, 1766) and Perovsky forestry: Lanius borealis [excubitor] (Vieillot, 1807); Chloris chloris (Linnaeus, 1758), indicating the nature of their stay and biotopic distribution. The paper is illustrated with photographs taken on the territory of both clusters of the national park by employees of the Shushensky Bor National Park and by local birdwatchers.