Screech Owls Disappear From Vancouver Region
Western screech owls, once commonly observed in forests throughout British Columbia's lower mainland, had disappeared from 22 sites by 2002.
Pacific Spirit Park used to be the best spot in Vancouver for seeing or hearing screech owls.
The last time the little, tuft-eared birds were detected there was in 1999. Other parks in Surrey, Burnaby, Langley, North Delta, Vancouver and Tsawwassen have also lost their screech owls.
Coinciding with the vanishing screech owls is an influx of barred owls. They were first noticed in 1966 at Surrey, and breeding barred owls were first documented 20 years later in Langley. Screech owls persisted longest in smaller forest patches of less than 30 ha, areas smaller than a barred owl's home range. The evidence points to predation by barred owls as being responsible for the decline in screech owls.
Fragmented forests are where screech owls are most vulnerable to being eliminated by the larger barred owls. Once gone, lengthy distances between forest patches prevent more screech owls from moving in. Birders expect the small owls to persist in southwestern BC in habitat suitable for screech owls but not barred owls, such as plantations of young coniferous trees.
Kyle Elliott. 2006. Declining Numbers of Western Screech-owl in the Lower Mainland of British Columbia. British Columbia Birds. 14: 2-11.