Romuald Mikusek
Ornis Polonica 2019, 60: 1–15
https://doi.org/10.12657/ornis.2019.1.0
Abstract: Caches, or places where food is scatter hoarded for a short time, play a crucial role in winter for the Eurasian Pygmy Owls Glaucidium passerinum. Observations carried out in the Stołowe Mountains (SW Poland) at 25 broods in 1997–2006 indicate that they are important also outside the breeding season. A total of 183 caches, where owls deposited single prey items, were analysed. Food was hoarded near nest holes, almost exclusively by females, at the height of 0–30 m above the ground (mean 13 m) and at the distance of 3–70 m (mean 27.5 m) from the nest hole, mainly on spruce branches and tops of broken tree trunks. Females hoarded and retrieved prey items mostly at sunrise and sunset, which coincided with the timing of food delivery by males. Out of 191 prey items passed by males to females, 40% were stored in caches. Prey items were stored on average for 38 hours. A total of 29 aggressive encounters within a breeding pair were recorded, including 26 (90%) attacks of females against males. The author hypothesises that a strong aggression of a female towards a male near a nest hole is associated with a defence of stored food items.
Keywords: cache, catching place, Eurasian Pygmy Owl, female’s aggression towards the male, food, Strigidae, Strigiformes
