The Little Owl was successfully introduced into Britain during the 1880's. The species rapidly dispersed throughout England, Wales and Southern Scotland until the 1930's. After which point, there were reports of severe declines in southern and central England. It is believed that the decline was due to a series of harsh winters and pesticide poisoning during the 1950's and 1960's. The Little Owl is now classified as native to Britain however it's breeding status means that it is infrequently the focus of research.
In 2008, Emily Joachim started a PhD at the University of Reading, researching the effects of agriculture on the ecology of the Little Owl in Britain. This project involves researching various aspects of this species including population dynamics, both locally and nationally, juvenile dispersal behaviour, diet and feeding behaviour. Natural Research has funded Passive Integrated Transponder (PIT) equipment to aid with researching feeding behaviour of the species.
The Little Owl is a lowland farmland bird and it's diet consists of invertebrates, small mammals and birds, all of which are sensitive to agricultural change. The Little Owls feeding behaviour and diet is therefore influenced by changes in landuse and agricultural practices. This species is also a crepuscular species, hunting primarily at dawn and dusk apart from during the breeding session when foraging during the day is sometimes possible depending on the supply and demain of the food.
The combination of PIT tag equipment and nest cameras have been employed to examine the feeding behaviours of the Little Owl, this allows a number of things. Firstly, nest site attendance during the breeding season, secondly male and female provisioning rates throughout the breeding season, thirdly peaks in feeding rates during a 24 hour period and finally variations in prey items returned to nest site.
During May 2009, PIT tag data logger were fitted at the entrances of 2 Little Owl nest sites in Wiltshire (Salisbury Plain). Three pairs of Little Owls were PIT tags, which were attached to their tarsus using small plastic bird ring. A PIT tag is a glass encased microchip with its own unique 10 character alphanumeric radio frequency code. The unique code is transmitted to a data logger everytime it is in range of the PIT tag scanner.
The equipment was made available th this project during May 2009, which meant the Little Owls were tagged when the female was about the lay eggs. The PIT tag kits were kept running throughout the the breeding season. Here is the results of the 2009 monitoring:
In 2010, nest box cameras were fitted to 4 nest sites in March and monitored throughout the breeding season. The results of the montioring are still being correlated. It is hoped that in 2011 more nest box cameras and PIT tags will be deployed in Oxfordshire.
Photo: V. Cartwright