Strigiformes

In this literature review, I examined 475 publications with information on the global diet of the Long-eared Owl Asio otus. Data within 312 publications were entered into a database, and quantitative diet data were available from 194 of these publications. The composite data set identified 477 different prey: 180 mammal, 191 bird, 15 reptile, 7 amphibian, and 1 fish species, and 83 invertebrate groupings. In 798 prey lists reflecting 813 033 prey items, small mammals accounted for 93.3% and birds for 6.4% of the vertebrate prey. Prey ranged from 1–500 g, with the vast majority of prey consisting of species ≤50 g. Twenty-three species predominate the prey in at least one species list. Diet composition at the family level was similar in different regions, but considerable differences were shown at the species level.

In diurnal bird species, individuals breeding at high latitudes have larger broods than at lower latitudes, which has been linked to differences in the daily time available for foraging. However, it remains unclear how latitude is linked with parental investment in nocturnal species. Here, we investigate nestling provisioning rates of male Tengmalm's owls in two populations at different latitudes (Czech Republic 50 °N; Finland 63 °N) with the help of cameras integrated into nest boxes. Clutch sizes were smaller in the Czech population (CZ: 5.1 ± 0.1; FIN: 6.6 ± 0.1), but given the higher nestling mortality in the Finnish population, the number of fledglings did not differ between the two populations (CZ: 3.5 ± 0.3; FIN: 3.9 ± 0.2). Nestling provisioning patterns varied within days, over the reproductive season and between the two sites. Males delivered most food at dusk and dawn, having peak delivery rates at sun angles of -11° to -15° at both sites, and males increased the prey...

The Striped Owl (Pseudoscops clamator) has a wide geographic distribution despite that there is scarce information on its reproductive
biology. In this study, we present the first published nesting records of P. clamator for Colombia. We provide data on its nesting habits
and reproductive biology from observations between April and May 2013 of a nest found in a plantation of Eucalyptus globulus in
Cajicá, Cundinamarca, Colombia. The ground nest is similar to those described from Argentina, Brazil, and Suriname; with a clutch
of two where only one chick survived and left the nest after 25-30 days. We found in the owl diet, Brazilian guinea pig (Cavia aperea)
and Eared Dove (Zenaida auriculata). Little is known about other species predated by the Striped Owl or whether this species has
more than one reproductive cycle in the Bogotá highland plateau. Future studies should further examine these aspects to assess the
possibilities for expansion of P. clamator in the Bogotá highland plateau.
RESUMEN
El búho rayado (Pseudoscops clamator) tiene amplia distribución geográfica, y a pesar de ello la información sobre su biología
reproductiva es dispersa. En este estudio presentamos el primer registro de nido de P. clamator para Colombia. Brindamos datos
sobre su anidación y reproducción, basados en observaciones de un nido encontrado en una plantación de Eucalyptus globulus entre
abril y mayo de 2013 en Cajicá, Cundinamarca, Colombia. El nido encontrado sobre el suelo es similar a otros previamente descritos
en Argentina, Brasil y Surinam, con una nidada de dos individuos, donde sólo sobrevivió un polluelo que dejó el nido luego de 25
a 30 días de nacido. Encontramos en la dieta del búho, curíes (Cavia aperea) y paloma sabanera (Zenaida auriculaya). Poco se conoce
sobre otras especies que son depredadas por el búho rayado o si esta especie presenta más de un ciclo reproductivo al año en la
Sabana de Bogotá. Estos aspectos deben ser examinados en futuros estudios para evaluar las posibilidades de expansión de P.
clamator en la Sabana de Bogotá.

We describe a new species of masked-owl from the lower montane forestof Seram, one of the largest islands in the Moluccasof eastern Indonesia, for which we propose the name Tyto almae (Seram Masked-Owl), sp. nov. Molecular (mitochondrial cyt-b) differences show that Tyto sororcula of Buru and Tanimbar is closely related to T. novaehollandiae of Australia and New Guinea (~1% uncorrected pairwise distance), and that Tyto almae of Seram differs by ~3% (uncorrected pairwise distance) from both of them. These differences are further corroborated by morphology and colouration. Although a photograph from Seram published in 1987 had already established the presence of a Tyto owl on the island, ours represents the first specimen of this species. The bird was mist-netted in wet, mossy lower montane forest at an elevation of 1,350 m. No further observations of the owl were made during four weeks of fieldwork in Seram.

Previous studies have revealed that the response of prey species to predatory risk comprised either freezing (when the prey remained immobile), or fleeing (when it ran frantically in order to remove itself from the vicinity of the predator). Other studies, however, have suggested that the prey will adjust its behavior to risk level. The present study was designed to follow the attacks of a barn owl (Tyto alba) on common spiny mice (Acomys cahirinus) and social voles (Microtus socialis guntherei), in order to reveal the correspondence between the behavior of the owl, the risk level at each phase of the owl's attack, and the defensive behavior of the rodents. Spiny mice dramatically increased the traveled distance upon the appearance of the owl, and kept moving during its attack while taking long trajectories of locomotion. Defensive response in voles dichotomized: in some voles traveled distance dropped when the owl appeared, reaching zero during its attack. In other voles, trave...

The avian retinothalamofugal pathway reaches the telencephalon in an area known as visual wulst. A close functional analogy between this area and the early visual cortex of mammals has been established in owls. The goal of the present study was to assess quantitatively ...

The barn owl (Tyto alba) is capable of capturing prey by passive hearing alone, guided by a topographic map of auditory space in the external nucleus of its inferior colliculus. The neurons of this auditory space map have discrete spatial receptive fields that result from the computation of interaural differences in the level (ILD) and time-of-arrival (ITD) of sounds. Below we review the synthesis of the spatial receptive fields from the frequency-specific ITDs and ILDs to which the neurons are tuned, concentrating on recent studies exploiting virtual auditory space techniques to analyze the contribution of ILD. We then compared the owl’s spatial discrimination, assessed behaviorally, with that of its space map neurons. Spatial discrimination was assessed using a novel paradigm involving the pupillary dilation response (PDR), and neuronal acuity was assessed by measuring the changes in firing rate resulting from changes in source location, scaled to the variance. This signal-detection-based approach revealed that the change in the position of the neural image on this map best explains the spatial discrimination measured using the PDR. We compare this result to recent studies in mammalian systems.