The Trust's work - the Westmoor Barn Owl Scheme
PDF Documents are used throughout this site. Click here to get Adobe Reader to be able to view these documents.
Westmoor Barn Owl Scheme
In late February 2009, the Barn Owl Trust launched their latest Barn Owl Scheme aimed at increasing Barn Owl populations in parts of West Devon. This was made possible thanks to significant funding from Biffaward and the Devon Bird Watching & Preservation Society. Dartmoor National Park, Devon County Council and West Devon Borough Council have also contributed. This Scheme follows on from successful Schemes carried out in other Devon Districts including East Devon, North Devon, South Hams and Teignbridge between 1997 and 2003. All of the Schemes saw an increase in Barn Owl numbers upon completion; it is hoped the same success will befall this Scheme. Originally, the Scheme was to run for 18 months but due to a few unforeseen problems along the way, it overran by 2 months, finally coming to an end October 2010.
Reasons for the Scheme
The Westmoor Scheme focussed on the area between West Dartmoor and the River Tamar (see map below), as it was the only area to have shown a significant decline in Barn Owl numbers between the last two County surveys. The number of nest records fell from 16 in 1993 to only 2 in 2003, a decline of 87.5%. This was in marked contrast to the rest of Devon, where numbers went up by an estimated 42% to between 350-470 pairs (250-350 pairs estimated in 1993). Good news for the County but not for West Devon.
Barn Owl population fluctuations are inherently linked to nesting success, which itself is ultimately controlled by food availability; starvation is the main cause of mortality in Barn Owls. Therefore, food supply exerts the greatest influence over Barn Owl populations. Food availability in turn, is largely controlled by the quality and amount of foraging habitat. The main prey item of British Barn Owls is the Field Vole Microtus agrestis, which make their tunnel systems in the litter or thatch layer of dead grass. Therefore, areas of intensively grazed pasture are virtual deserts to Barn Owls; arable landscapes are marginally better until harvest-time, as are hay meadows. However, intensively grazed pasture with headlands, margins and field corners left to become rough grassland are much improved for Barn Owls.
There is more information on this topic in the Barn Owl Conservation Handbook
Westmoor boundary map (Googlemaps ©2009)
Our aims and how we hopefully acheived them!
Obviously our aim was to increase Barn Owl numbers in West Devon between the A38 and the A30. We hope to achieved this by working with farmers and landowners in order to have improve habitat for Barn Owls and by erecting nestboxes in appropriate places.
At 23 sites (covering 69 locations in total), the Scheme applied a full package of conservation measures, which included erecting up to 3 nestboxes, giving advice about improving habitat, providing advice on safer rodenticide use and installing floats in water troughs. The 23 sites were chosen on the basis of whether nesting had occurred since the Devon county survey in 1993. The 1993 Devon county survey found 16 nesting sites but by the 2003 Devon county survey this had decreased to 2 nesting sites. We weren't able to include all 16 of these historic nesting sites in the Scheme but we did find new location where nesting had occured since the 2003 county survey and the 2006 Westmoor survey. If we could improve foraging habitat and provide various nesting opportunities then hopefully we could secure all these nesting sites for the future.
In addition, we erected nestboxes at 50 sites that either already had Barn Owls around but no suitable nesting places, or had great habitat but no Barn Owls as yet; the provision of a nestbox may encourage any dispersing juvenile Barn Owls to take up residence!
Furthermore, we offered free advisory visits to 50 sites; this included providing advice on improving habitat, on making permanent provision for Barn Owls in an outbuilding or loft space, on the use of safer alternatives to second generation rodenticides or indeed any other aspect of Barn Owl conservation.
If, during the course of the Westmoor Scheme we happened upon an area of outstanding Barn Owl habitat that had no trees or buildings in the vicinity, we had allocated money from the Biffaward funding for the erection of a Polebox. We found such a location near the Tamar Valley and with the help of Western Power Distribution, we erected a 'des res' for Barn Owls atop a disused electricity pole.
Progress to date
The Westmoor Barn Owl Scheme has finally come to an end - two months later than scheduled due to Maxine and Stuart having sustained an injured wrist and an injured back respectively. Neither occurred in the line of duty though! The Scheme started back in February 2009 and has seen 125 nestboxes erected throughout the southern half of West Devon.
Since the Scheme commenced in early 2009 we have carried out:
191 identification visits;
50 advisory visits;
62 nest-boxing visits;
Stage 1 visits covering 69 locations;
Stage 2 visits covering 69 locations;
Stage 3 visits covering 69 locations.
Altogether we have erected 102 indoor nestboxes, 22 tree nestboxes and 1 polebox - a grand total of 125 more potential Barn Owl homes in the West Devon countryside. Hopefully, this will go some way to achieving the 13% increase in the Devon Barn Owl population by 2012, set out in Objective 2 of the Barn Owl Species Action Plan.
Although it is still too early to be sure what impact the Scheme has had on the Barn Owl population in the Westmoor area, the early signs are encouraging. We have found Barn Owl pellets in many of the boxes we have put up, and it is always nice when a box we erected is used by Barn Owls. We all like our work to be appreciated!
During the course of the Scheme, we have returned to the 23 main sites several times to monitor those nestboxes, 46 in total. However, we have not been able to check any of the other 79 nestboxes that have been erected as part of the Scheme. We are hoping to secure funding that will enable us to check all 125 of the nestboxes that have been erected after the 2011 breeding season. This will give us some idea of the effect the Scheme has had.