Nocturnal birds of prey in captivity: a study in the owl Strix virgata (Strigidae)

Objective. To observe the behavior, hormonal patterns, and welfare in captive mottled owl Strix virgata (Strigidae). Materials and methods. The study was conducted at environmental management units (UMA) in Xalapa, Mexico, on six owls: two females in one enclosure, one male and one female in another, all without public exhibition and with environmental enrichment, and two isolated owls, kept caged or perched, with daytime public exhibition. Behaviors were monitored in each pair or individual during 120 hours of filming (60 h during the day and 60 h at night). Concentrations of fecal metabolites of corticosterone, estradiol, and progesterone were measured, and welfare was assessed with observational indicators and surveys. Results. The paired owls showed normal behaviors and excellent welfare (95.5%), while the isolated individuals showed undesirable behaviors and regular welfare (51.4%). Of 24 behaviors considered in an ethogram, 11 were observed repeatedly in all specimens. The isolated birds had higher agonistic, feeding, and individual activity (p<0.001) than the paired birds, although it did not result in lower levels of corticosterone (p=0.09) nor estrogens (p=0.29) in females, only in progesterone (p=0.001). Conclusions. In captive mottled owls, daytime exhibition and inadequate facilities promote the presence of undesirable behaviors that can affect their welfare. Therefore, the use of enrichment measures, such as larger enclosures, feeding at night, and pair housing (female and male, or two females) should be considered to reduce the negative effects of captivity and increase their welfare.