A very successful year 2012 for Barn Owls in the Müllerthal region
By Mikis Bastian and Marie Kayser
The Barn Owls is probably one of our best-known owls here in Luxembourg. Almost everyone knows the species or has at least heard about it. Given its mid-night peak of activity and its lifestyle which is completely relying on stealth, it is not surprising that the Barn Owl also continues to be one of our most elusive species.
The chances to actually see Barn Owls have probably never been better than this year. The relatively mild winter 2011/12 and the large quantities of acorns produced by Common Beech saw an explosion in mouse populations throughout the country in early spring. This in turn, created ideal conditions for most raptors and owls, which rely on rodents and other small mammals as a main staple of their diet and for feeding their chicks. Despite the relatively wet and cold summer, almost all owl species had an exceptionally successful breeding season in 2012.
44 barn owl chicks ringed in 2012 in the Müllerthal region alone
In the Müllerthal region, the local section of natur&ëmwelt carried out a small project to determine the size of the local breeding population of barn owls and found that nests contained almost 6 chicks on average (for first broods). In addition, half of the breeding couples went on to carry out a second incubation, which on average contained 3 young: the smaller number of chicks in the second brood probably resulted from a reduced food availability at this time of the year (some nests still had chicks as late as mid-October). Further adding to the success of 2012 was the fact that juvenile mortality – often a severe limiting factor for Barn Owls – was very low: from the time of hatching until fledging, only three owls did not survive (less than 7% overall). Of those, one was killed by an Eagle-Owl near the nest box. Overall, a total of 44 juvenile Barn Owls were ringed in the Müllerthal region and its immediate surroundings.
Threatened Barn Owls
While dramatic populations crashes are possible and not uncommon (mostly as a result of severe weather conditions, esp. in winter with prolonged periods of snow), Barn Owl populations have plummeted over the last couple of decades. The loss of breeding places (modern architecture leaves no room for wildlife, fencing off of church towers and barns to prevent pigeons from breeding, lack of tolerance from home owners) certainly plays a crucial role in this development, while the loss of the species' traditional habitat does the rest. In the latter case, it is often the combination of an intensified agriculture and the destruction of the owl's typical foraging grounds (orchards, hedgerows, extensively grazed grasslands) through the current building boom which have proven to be particularly devastating. The species' susceptibility to collisions with oncoming traffic is yet another cause that inflicts a substantial toll every year.
Stepping up the efforts to help Barn Owls
The project in the Müllerthal region provided strong clues for the fact that the lack of breeding places contributes significantly to the species' demise here in Luxembourg: an artificial nest box in a barn in Beidweiler (near Junglinster) which was accidentally closed during renovation works was "re-occupied" by an owl couple only a few days after the box was opened again. That very couple managed to successfully rear 7 chicks, showing that Barn Owls in Luxembourg could fare much better if provided with the right support measures.
To permanently safeguard the persistence of this species, which has become so reliant on human settlements and farming practices, we need to make sure that barn owls continue to find enough breeding places in our villages and settlements. Should you be interested in supporting this project either with a small donation or by putting up a nest box in your home, please contact the Centrale ornithologique (through mail: firstname.lastname@example.org or by phone.: 29 04 04 – 308) or get directly in touch with your local section of natur&ëmwelt.
The "House of Nature" at Kockelscheuer also has a complete exhibit about all our local owl species in Luxembourg. These are available for school projects or public awareness events.
We would like to thank the local "Müllerthal Section" of natur&ëmwelt and all participants for making this project possible. Our very special thanks go to all owners of nest boxes who were very keen on participating, allowing us to access the boxes and providing us with very detailed additional information. This project would not have been possible without your help!