Barn owl screech12/1/2023 ![]() ![]() Instead, they occupy a huge ‘home range’, only defending a small area around the nest or perhaps just their mate (Barn Owl Trust 2012). For a long time I believed this was a territorial call (Sorace 1987, Siverio et al 1999), but barn owls are not territorial in the usual sense. All I can say is that it is some kind of long-distance advertisement, perhaps with an aggressive or at least assertive tone. Barely a session goes by without me recording a couple of perennial screeches.ĭespite hearing perennial screeching so often, I still have no clear idea what it ‘means’. At my home near Sintra in Portugal, I like to record nocturnal migration of passerines on suitable nights, leaving my microphones out for the quieter hours from midnight to dawn. Perennial screeching is virtually the only barn owl sound that I hear during the autumn. The scratchy sounds at close range are footsteps of a scrawny cow on gravel, curious about me and apparently oblivious to the wolves Other members of its pack join in, eventually making such a din that we are hardly able to hear the barn owl’s second screech. An Arabian Wolf Canis lupus arabs begins to howl. Every few seconds, an Arabian Scops Owl Otus pamelae goes prrr and an Arabian Eagle-Owl Bubo milesi moans languidly in the distance. The neighbours, however, could hardly be more different. Although this is Arabia, the habitat is not so dramatically different from that of the bird’s European relatives, containing grassland, a few trees and some water. In April, the grass is dry but three months later it will catch the north end of the Indian Ocean monsoon. This well-vegetated wadi is a popular picnic spot during the day. In CD1-04, a male of the subspecies erlangeri is flying along a flat-bottomed valley in the Jabal Samhan range in southern Oman, giving a perennial screech about once every 40-50 seconds. Less often, either sex may also produce perennial screeches when perched at the nest. They may fly quite far during the gaps, so when a loud screech at close range catches our attention, the next one may seem surprisingly faint and distant. Barn owls give perennial screeches one at a time at long but fairly regular intervals. Individual barn owls often seem to have a fairly distinctive signature based on the amount of hiss versus whistle, how strongly their screech rises in pitch, and how abruptly it ends. The timbre is a concentrated hissing, like an espresso machine with the steam on. Rising slowly in pitch, the screech grows in volume for one to two seconds and typically ends abruptly with a pronounced upward inflection. Perennial screeching is the Common Barn Owl sound we hear most often throughout the year. At centre stage, two Common Barn Owls exchange perennial screeches, one near and one far, for reasons known only to themselves. ![]() In the lower range, fast croaks of European Tree Frogs Hyla arborea and a few slower ones of Southern Tree Frogs H meridionalis catch my attention. Crickets take possession of higher frequencies. Bit by bit as the acoustic opens up, various creatures reoccupy their niches. Finally, the scattered trees and lush meadow grass stop rustling and the air loses its turbulence. It is late March and a thunderstorm has just taken two hours to pass. In CD1-03, we are in traditional montado near Lisbon, again in Portugal, with Cork Oaks Quercus suber and Holm Oaks Q ilex scattered through meadows reserved for fighting bulls. Although predominantly a male sound, Mebs & Scherzinger (2004) claim that either sex can advertise availability with screeching if necessary. Neighbours sometimes courtship screech in long-distance duels. After mating, they use the same sound to defend the female from rivals. Lone males are among the most fanatical courtship screechers they screech to attract females (Bühler & Epple 1980). After the third screech, the male takes off and screeches in flight for another minute. In CD1-02, we are at a nest on the edge of Rosmaninhal (‘the village of lavender’) in Portugal. Sometimes a male takes off on a ‘song flight’ and his stiff, shallow wingbeats make further ripples in the sound: five little surges per second in CD1-01. Gaps between them may be of just a few seconds, making long series with hardly a break. Individual screeches rise smoothly in pitch but end fairly abruptly. It has a hoarse timbre caused by modulations in the frequency of the sound at a rate of about 50-60 per second. I only really got to know courtship screeching when I started to target Common Barn Owls specifically.Ĭourtship screeching peaks during the weeks leading up to egg-laying. I for one imagined that I was hearing mostly males, although I had no clear idea of how to tell them apart from females. While out recording other species, we would hear a few screeches in the distance which I now know to have been perennial screeches. For years, most of our encounters with barn owls took place by chance. ![]()
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