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North West Norfolk Ringing Group Barn Owl Project. All of our team working on monitoring and ringing hold the necessary licences.

The Barn Owl Tyto Alba an Amber list species, is currently of medium conservation concern having declined between 25-49% over the previous 25 years. Since 1990 North West Norfolk Ringing Group have been active in monitoring and ringing Barn Owls in Norfolk. Gradually a network of sites has been developed mainly through contact with local farmers and landowners, many already had nest boxes installed in farm buildings or were willing for us to install a box when it was evident from the presence of pellets that owls were using a building

 The group Project on Barn Owls gained momentum in 2002 when we realised that although this enigmatic species was abundant in Norfolk, very little was known about the numbers of pairs that actually bred in the county, in addition very few were being ringed.

The mainly nocturnal nature of this species does not make them easy to monitor effectively and this is apparent when estimates of the number of breeding pairs in the county are based solely on reports and sightings. Estimates for 1994-2003 taken from the Norfolk Bird and Mammal Report are shown in the table.

 

Year

No breeding pairs

1994

19

1995

26

1996

59

1997

22

1998

32

1999

48

2000

34

2001

42

2002

43

2003

37

Source Norfolk Bird & Mammal Report

These figures do not accurately reflect the numbers of breeding Barn Owls as they under record the actual numbers. In 1985 Colin Shawyer estimated the Norfolk population to be around 190 pairs (Shawyer .C. 1987). A comparison of Shawyer’s estimate with those of the Norfolk Bird and Mammal Report might suggest that the numbers of pairs had slumped dramatically since 1985 but this is actually not the case. For example in 2003 the Group had access to over 250 potential sites and 101 were occupied, although only 71 pairs were actively breeding This does not include other possible sites in Norfolk that we were aware of but did not monitor for various reasons, or other breeding locations monitored by either nest recorders or ringers outside this Group, and yet the number of pairs reported in the Norfolk Bird and Mammal Report was just thirty-seven. Unless observers have access to breeding sites the numbers of breeding Barn Owls is unlikely to be accurately reported by casual observation alone and only a co-ordinated monitoring programme will be effective.

Between 1991 to 2001 very few Barn Owls were being ringed in Norfolk:

Year

NWNRG

Others

Norfolk Total ringed

1991

1

44

45

1992

1

48

49

1993

3

106

109

1994

2

62

64

1995

5

22

27

1996

10

91

101

1997

24

24

48

1998

29

33

62

1999

34

45

79

2000

53

33

86

2001

32

7

39

Norfolk Barn Owls ringed Annually 1991-2001

 The North West Norfolk RG Barn Owl Project began in earnest in 2002 when we began to concentrate our efforts by contacting farmers and landowners with the objective of installing nest boxes at suitable locations.

 In many instances it was obvious that Barn Owls were using some of these barns and buildings for roosting but lacked a nest site, other sites appeared promising for owls but no owls appeared to be using them. In both cases permission was obtained to install a box or boxes. During this time we came across places where a nest box already existed, but nobody was monitoring them and we got permission from the site owner or farmer to monitor these as well. We subsequently learned that many of these boxes had been installed  by the Hawk and Owl Trust or by Richard Brooks and so we contacted them and they agreed that we should monitor these boxes and ring the chicks annually.

 The number of sites grew rapidly and currently we monitor over 400 potential nest sites:

Distribution Map of Potential Barn Owl nest sites monitored by North West Norfolk Ringing Group

 

 

In 1985 Colin Shawyer estimated the Norfolk population to be about 190 breeding pairs. (Shawyer C. 1987. The Barn Owl in the British Isles – its Past, Present and Future. The Hawk Trust, London.)

 Today through collaboration with other Norfolk Ringers and exchange of information we know of at least 340 breeding pairs and this figure does not include pairs that we know of but cannot access because permission to monitor is denied or because they are breeding in an inaccessible natural site.

Nearly all Barn Owls now breed in nest boxes that have been provided for them.


Numbers of Barn Owls ringed annually in Norfolk.

Number ringed Annually

Year

NWNRG

County Total

1991

1

45

1992

1

49

1993

3

109

1994

2

64

1995

5

27

1996

10

101

1997

24

48

1998

29

62

1999

34

79

2000

53

86

2001

32

39

2002

142

294

2003

165

238

2004

215

399

2005

440

503

2006

332

626

2007

654

947

2008

289

588

2009

397

684

2010

376

689

2011

380

759

2012

404

807

2013

108

292

2014

663

1497

2015 238 517

It is well known that Barn owl breeding success is dependent on prey availability particularly the field vole but this is also linked to winter weather and in the winter/spring of 2012/2013 a protracted spell of harsh weather coupled with a shortage of food combined to cause a high mortality rate amongst Barn Owls. Consequently the adult population was severely  depleted and many adults that survived simply did not breed in 2013 and this resulted in the lowest number of Barn Owl chicks ringed for many years. In contrast 2014 was an exceptionally good year following the all time low in 2013 and North West Norfolk Ringing Group ringed our highest total ever. 


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