Caching, Cannibalism and Carrion-Feeding: A Review of Multiple Opportunistic Feeding Strategies Employed by Owls in Their Survival
Heimo Mikkola,
Alan Sieradzki
Opportunistic feeding strategies, including cannibalism, carrion-eating, food hoarding, food sharing,
and kleptoparasitism, are all important aspects of predator ecology. Food caching behaviour in owls
has evolved to reduce the risk of starvation. Cannibalism in owls comprises five forms: siblicide, filicide,
non-parental infanticide, conspecific strife, and conspecific scavenging. Scavenging is a behaviour in
which animals consume carrion, sometimes via kleptoparasitism, whereby an individual actively steals
procured food. Food sharing among siblings is a very little-known interaction among owl nestlings.
In this review, we document 21 owl species recorded as engaging in cannibalism, 25 known to scavenge
carrion, 30 reported to practise food caching of excess food, and 8 species that have been observed
engaging in kleptoparasitism to gain or lose captured prey.
Thus far, many of our observations are based on second-hand information derived from pellet analysis
and occasional nest and field visits. A more comprehensive understanding of opportunistic feeding
behaviours is required to assess their prevalence and to accurately interpret dietary data from previous
studies. Modern nest filming using camera trap systems should help determine how frequently these
opportunistic feeding strategies occur and under what circumstances they are used in the wild.
