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Tawny Owl project

Background

Every year The Hawk Conservancy Trust can receive up to 30 wild young Tawny Owls, the bulk of which arrive during May. Our mission when this happens is to ensure that the young owls are fit to be released back into the wild when old enough. That means absolute minimal human contact. It is essential that they should retain their fear of humans and not see humans as a food provider. Chicks that are not old enough to feed themselves are placed with other owls - as closely related as we can manage - and are foster-reared. As soon as the chicks are able to feed themselves they, and those that come in at a later stage in their development, are placed into a crèche with other developing Tawny Owls until they are able to fly well and fend for themselves. They are then released into a safe area in the wild.

The Hawk Conservancy Trust firmly believes that its responsibility to the young Tawny Owls extends beyond release of the individuals back to the wild. We use post-release monitoring of individual birds to ensure that the most successful rehabilitation techniques are used. In addition to knowledge of survival rates, we also have the opportunity to research the species further and collect data on distribution, abundance and habitat selection.

The latest data from the British Trust for Ornithology suggest that Tawny Owl numbers have fallen by a third since 1994, which adds to the importance of our rehabilitation and release project.

Aims

The principal aim of our Tawny Owl project is to carry out post-release investigations in order to devise the most successful rehabilitation and release system possible for these birds. The research is divided into two components, which investigate the following areas:

Post-release research:

• Habitat preferences
• Behaviour
• Prey eaten
  

Optimum release technique:

• Time of year
• Number released
• Fostering method
• Release locations/habitats

After a three to five year period we aim to publish the results of the work, and provide valuable information that can be used as a guide to the rehabilitation of young Tawny Owls.

Pre-release organisation

In order to carry out the release programme wooded habitat was required. Four small woods, approximately 2.5km from the Trust, were highlighted as being suitable. Each wood has a different structure and therefore presents a slightly different habitat for the Tawny Owls. The woods were all contained within Fox Farm Estate. At the beginning of the project, the owner of the estate, Mr John Peacock, kindly granted permission to carry out the work on his land.

Field researchers arrive at the Trust mid-July and live in our on-site student accommodation. The first week at the Trust involves inductions on issues such as health and safety, and training in tracking techniques. The researches also familiarise themselves with the release sites, and are required to liaise with local landowners, farmers, and gamekeepers that allow access to land surrounding the release sites.

Release

Juvenile Tawny Owls are released into four woodland locations.

Each owl due for release is fitted with a tail-mounted radio-transmitter in order to track movements and check for survival. The battery life for the transmitters is guaranteed for six months, which allows the study to span the juvenile owls' natural dispersal period (September), and will indicate the owls’ success in establishing a territory. The transmitters are not permanent and are shed with the growth of new tail feathers.

The four research students are required to fulfil a variety of tasks once the juvenile owls are released. Apart from tracking the owls every morning, they are required to give two presentations to the public at the Trust. These presentations explain their role and the aims of the release programme. Throughout the programme the research team transcribe the data and look for any trends in the results.

For updates on this project, and the results from 2005-2007, please see our free online magazine, The Accipiter. 2008 will see phase two of the Tawny Owl research programme begin – check both here and in The Accipiter for updates.

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