The ‘Pearl Owls’ of Hungary.


Hungarian Pearl Owl - Tyto alba gutatta

When is a Barn Owl not a Barn Owl?  Tony Jones travelled to Hungary to find out.

Precariously balanced on an ancient oak beam, I steal a glance towards the ground, some 30 metres below. The nest box seems to be getting heavier by the second and the wind is whistling unnervingly around the bell tower, heightening my sense of vulnerability and exposure. All I can think is: “Don’t fall… don’t fall… don’t fall… for goodness sake… don’t fall!”

I’m half way through a six week placement with the Barn Owl Foundation of Hungary, working alongside three other conservation trainees and volunteers from Ambios, a Devon based organisation which places trainees and volunteers with conservation projects around the world. Under the watchful eye of Akos, the Foundation’s Director, our goal is to support his crusade to save the European Barn Owl.  Although my conservation experience is predominantly reptile orientated, I couldn’t resist this opportunity to broaden my horizons.

So, at the sharp end of this conservation crusade, you find me 30 metres above the ground, placing Barn Owl nesting boxes into church bell towers. I have never thought of conservation initiatives as such an adrenaline rush!

Barn Owls in Hungary are not the same as Barn Owls in Britain; in fact, they are not even called Barn Owls. European Barn Owls are a different sub species to the British variety and have a Hungarian common name that translates as Pearl Owl. Although closely related, the two sub species differ in several ways. Most obvious is the difference in plumage, as the European owls generally lack the striking white frontage displayed by their British cousins. There are several differences in their natural history, too.

The reason I’m in a bell tower is simple. For centuries church towers have been a haven for birds, usually pigeons, Jackdaws and Kestrels, but Barn Owls too will often choose a corner of a tower as a nesting site. Before the invention of barns and bell towers, Barn Owls would utilise the hollow chambers inside old dead trees as nest sites. Modern woodland management methods where old trees are routinely felled forced the owls to substitute with barns and towers.

The early 80s saw the Barn Owl population in Hungary fall sharply following the introduction of automated bell ringing systems to many churches. Unfortunately these automated systems were very delicate and broke down easily under a bombardment of pigeon droppings. In order to preserve the equipment, church caretakers took to sealing up the towers to prevent fouling by pigeons, which also unwittingly sealed up the access to the Barn Owls’ preferred nesting sites.

The Foundation is taking steps to get bell towers opened up again to allow access for the owls. Ideally, they would protect the bell and the equipment below with a platform barrier. However, as Akos told us on our first day at Barn Owl HQ: “Unfortunately this is an expensive and intrusive process and we simply don’t have the funds or the time to implement it. Instead we concentrate on plan B. This is to place nest boxes just inside a window so that the owls can get into the box, but have no access to the rest of the tower. This solves the problem of nest site availability, but it has its drawbacks.

“Fledgling owls will often need a few attempts before they master the art of flying. Inside the bell towers the youngsters could make short clumsy flights between beams and ledges until they learn to fly properly. Without access to these ‘practice perches’, fledglings will sometimes end up on the ground where they face danger from predators and road traffic.

“It’s an unavoidable hazard. Our goal is to install as many of these nest boxes as possible to increase the total of successes. We’re playing a numbers game.”

Barn Owls in Britain have suffered a similar decline in the number of available nesting sites due to the recent trend to convert barns into homes. New planning guidance from governmental advisory body, Natural England, suggests that all barn conversions in the UK should make provision to accommodate nesting Barn Owls, regardless of whether or not a survey finds Barn Owl activity. Such legislation in Hungary would have less of an effect as Hungarian owls utilise barns less frequently, preferring more elevated nest sites. This must be why the common name ‘Barn Owl’ never stuck in Hungary. Akos tells me that their choice of nest site is an attempt to avoid mammalian predators in the form of Beech Martins and Sand Martins that take chicks and eggs from nests at lower levels.

Despite their differences, both UK and Hungarian Barn Owls are finding 21st century life tough. Modern land management practices, new technologies and the change of use of many of the buildings traditionally used as nest sites, are all taking a toll on owl populations. There have been several studies in Hungary conducted in tandem with the UK Barn Owl Trust. Radio tracking is being conducted simultaneously in both Hungary and Britain to compare seasonal and environmental data in a quest to understand more about Barn Owl ecology.   Initial analysis suggests that UK Barn Owls appear to have a much wider hunting range than their Hungarian counterparts and researchers think this could be due to subtle dietary differences. Pellet analysis from British Barn Owls reveal a taste for the field vole (Microstus agrestis) which makes its home in small areas of habitat that are distributed across a wide area, whereas Hungarian owls can dine on the more abundant common vole (Microtus arvalis) that does not occur in the UK.

Modern agricultural and land management practices can often be detrimental to wildlife, and particularly to birds.  It is impossible to turn back the clock and revert to outdated methods, but the teams in Hungary and in Britain are working hard to find ways for today’s humans to live in harmony with today’s barn owls.  Re-establishing suitable nesting sites and campaigning to maintain suitable feeding habitats are key to achieving this balance, and, according to the results of the latest Hungarian survey, it appears that Akos is winning!

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TAGGING A BARN OWL

The Barn Owls we tracked in Hungary for our research were tagged in 2009 by Ambios volunteers and David Ramsden, Director of the UK Barn Owl Trust, and they were caught using a most ingenious method.

“We had previously set up a nest box with a sliding trap door suspended by a very long string that went all the way from the box entrance to the bottom of the church tower”, says David. “Having caught the nesting female in the afternoon, our next aim was to catch the male as he made his first delivery of food that evening. The plan required four volunteers, several torches, a pair of scissors and various lengths of string.”

The team knew that capturing the male would be difficult as he would be making his appearance during the hours of darkness and that anything unexpected would likely frighten him off.  “The plan was to drop the trap door by cutting the string at the bottom of the tower” said David, “Inside the church, standing in the darkness, the person springing the trap could see neither the nest box nor the bird flying in. We needed a way of signalling the precise moment to make the cut and so the silent string system was devised.

David and the volunteers were stationed at strategic points around the churchyard to watch for the male’s arrival, with one volunteer stationed at the base of tower to spring the trap. Unfortunately there wasn’t a clear line of sight from the watchers to the tower.   This problem was overcome by using yet another volunteer. From David, the signal string ran across the graveyard and was lashed to the ‘volunteer’ who in turn held another length of sting that ran past the church and into the tower where the trap tripper waited, armed with a pair of scissors. Should they spot the male arriving, a sharp tug on the line would alert the volunteer to pull the second line to alert the trapper who would cut the cord and spring the trap.

As darkness fell the volunteers waited poised stock still and silent as the tension mounted.  The stakes were high.  The team had just three days in which to trap and radio tag the pair before David had to return to the UK.  As the only person licenced to tag the owls David,s input was vital to the mission.

“We all knew that we probably had only one chance.” he says. “A spooked owl may avoid the nest for a while and should that have happened valuable funds, many man hours and everyone’s time and effort would have been wasted.  Waiting for the male to make an appearance was unbearably tense.  Suddenly we all heard a Barn Owl screech nearby and within moments the male was perched just outside the nestbox. After a pause he entered the box, we counted to ten, The volunteer felt a sharp tug on the line tied to his ankle, he quickly tugged on the second string to alert the trap man and the door dropped.  It was so dark we couldn’t be certain that we’d caught him until we climbed the church tower and peered in the nest box. Success! The female who’d been wearing her radio tag for six hours was sitting perfectly on her nest and the male was easily captured.

Both the male and female had been tagged, weighed measured and released in less than twenty minutes and each continued to go about their routines as normal.  In addition to providing valuable radio tracking data, the pair successfully fledged five young.

Thanks to

David Ramsden at The Barn Owl Trust

www.barnowltrust.org.uk

Akos Klein at the Hungarian Barn Owl Foundation

www.gyongybagoly.hu/index.php/englishunion-jackjpg

Simon Roper at Ambios

www.ambios.net

Published: Bird Watching Magazine. January 2010

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~ by Tony's Desk on March 4, 2010.

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