Air temperature influence on the nesting period beginning in birds of prey in the “Roev ruchey” park

The purpose of the study is to identify, under controlled artificial conditions, the influence of calendar dates and surface air temperature on the beginning of nesting. The results of the study expand and clarify ideas about the influence of abiotic factors on various aspects of nesting of thirteen species of birds of prey, and may also entail some changes in the management of birds in order to correct reproductive functions. During long-term observations of reproductive pairs of birds of prey, data were collected on the timing of the start of nesting and accompanying weather conditions over a 13-year period. For the first time, data on the nesting time of birds of prey has been analyzed using the information theoretical method. The proposed approach allows for a quantitative assessment of the relationship (influence) of selected factors on nominal scales with consideration of the contingency structure. As a result of the analysis, the most probable period for the beginning of nesting of the entire list of species was determined to be in April. The temperature optimum for the beginning of nesting was revealed (8 °C). Pairs white-shouldered eagle (Haliaeetus pelagicus), kestrel (Falco tinnunculus) and white owl (Bubo scandiacus) are distinguished by their consistency in landing on the nest at a certain period. Landing on the nest of a black vulture (Aegypius monachus), an owl (Bubo bubo), a bearded owl (Strix nebulosa) and one of two pairs of grouse (Accipiter gentilis) is less time-bound. The results obtained reveal the heterogeneity of the response of reproductive behavior to air temperature, and therefore the influence of this factor should be given more attention in the context of obtaining offspring of birds of prey.