The Barn Owl colour ringing project has already provided valuable insights, including some notable sightings (see photograph) and unfortunate recoveries of birds that have perished.

The main aim of this project is to better understand Barn Owl chick dispersal, which is generally believed to be relatively limited, with most movements falling between 9 and 14 km from their natal sites. However, the first year of a Barn Owl’s life is particularly perilous, with studies indicating that around 70% of juveniles do not survive beyond their first year. Many face significant threats after dispersal, which is evident from our findings.

Summary of Results Since August 2024:

Sightings:

• • 4 sightings have been reported:

• • • Two birds were observed fledging and hunting near their nest boxes, eventually dispersing when they became proficient hunters.
    • One chick, ringed near Burton Mill Pond, was later spotted near Lavington, a 5 km journey.
    • Another Barn Owl, ringed on 21st June near Cranleigh, was seen at Beeding Brooks on 17th August, marking an impressive 40 km movement. Female ADJ, see image.

Recoveries:

• • 7 recoveries have been recorded, highlighting some of the key threats Barn Owls face:

• • • 2 road traffic accidents, both within 2 to 4 km of their natal sites, show how vulnerable young owls are to collisions, especially when hunting low over roads.
    • 2 electrocution incidents on power lines, 3 to 4 km from natal sites, further emphasize the danger of human infrastructure.
    • 3 unknown causes, with 2 of the birds later found predated. One of these, a chick ringed on 12th July near Storrington, was recovered on 11th October at Sandy Point Nature Reserve on Hayling Island, having travelled 46 km.

These incidents underscore the numerous dangers young Barn Owls face, including collision with road or rail traffic and electrocution which are the leading causes of mortality during the vulnerable first year after fledging. Other significant threats include accidental drowning in uncovered cattle troughs and the ingestion of poisoned rodents, which can lead to secondary poisoning and death.

Reporting Sightings:

As winter approaches and prey becomes scarcer, Barn Owls will likely become more active during daylight hours to compensate for the reduced availability of food. This increased daytime activity presents greater opportunities for sightings. We encourage everyone to keep an eye out for colour-ringed Barn Owls, which can be identified by a red ring with white letters on their left leg. If you spot one, please report it to us at info@sussexbarnowlgroup.org

2024 monitoring and ringing effort.

We found a slight increase in records of early broods this year with 77% of chicks ringed in the last 2 weeks of June and the first 2 weeks of July. Brood sizes were the smallest encountered from the time there has been consistency in monitoring since 2020, (viz 2.5, 3.2, 2.6, 2.5, 2.4). The wet late winter and early spring may have led to difficulty in hunting, which did not allow females to put on the weight necessary to lay larger clutches (pers obs).

However, from the 200+ boxes visited by ringers and Schedule 1 agents we found a 48% Barn Owl occupancy – the highest for 5 years.

125 boxes in total were occupied as follows:

94 by Barn Owls, 90 of which contained breeding birds. Other occupants included Stock Dove Columba Oenus, (19 boxes). Western Jackdaw Corvus Mondella (8 boxes). Common Kestrel Falco Tinnunculus (2 boxes). Tawny Owl Strix Aluco. (1 box) and Mandarin Duck Aix galericulata (1 box).

In total two hundred and twenty-four Barn Owls were ringed by Sussex Barn Owl Group, two hundred and twelve chicks and twelve adults. This was the first year the group embarked on colour ringing both adult and young Barn Owls with highly visible, unique rings with letters, this is to determine chick dispersal and adult movements, and it will be a long term meaningful project.

In August and September 4 sightings and 5 recoveries were reported to us.

A box in the upper Cuckmere contained a brood of 3 Barn Owls, 2 of which were considered to be of Dark breasted Tyto Alba guttata and Tyto Alba alba mixed parentage, although a license for DNA sampling was granted it was found the UK DNA database did not contain any guttata illustrations!

Note to all SOS members

Please be vigilant when observing Barn Owls in the field in East and West Sussex and report any colour ring sightings to info@sussexbarnowlgroup.org.

All sightings will be acknowledged.

Terry Hallahan

September 2024

Our group volunteers were treated to a rare occurrence recently, while visiting a box located in a barn at a site north of Brighton.

Inside we found four Kestrel chicks and three Barn Owl chicks co-existing in a box the size of a large tea chest!

The Kestrel chicks were approximately 22 days old, so these will fledge in five to ten days. The Barn Owl chicks were aged between 28 and 32 days and will remain in the box for a further 30 days.

All seven chicks were healthy in weight.

The Barn Owl which occurs in the UK is unmistakable with its ghostly white plumage. ‘Our’ race Tyto alba is separated into over 30 subspecies, the nearest of which is present in Central and Eastern Europe known as Tyto alba guttata, also described as the Dark Breasted Barn Owl. Very occasionally these birds wander to the UK and have been known to interbreed with our white owl.

This week we discovered a brood in a box located on private land close to the upper Cuckmere, which contained two female Dark Breasted chicks, which we believe to be from a guttata parent.

In the photos, note the comparison between Tyto alba and the chick we ringed here in Sussex