'Conserving wildlife and ancient landscape'


Registered Charity Number: 702488 

POPULATION CHANGES IN FARMLAND BIRDS – Kemerton Estate – 1998-2002    (John Clarke 2002)

Since the 1950’s there has been a steady decline in the populations of most birds using farmland. In some instances a British population is under severe threat whilst many more are giving cause for serious concern. Red Data Lists and Biodiversity Action Plans include many farmland species. 

Male Whitethroat Kestrel - Large Young

At Kemerton, early conservation work appeared to be unable to prevent local populations following national trends. However, since the mid-1990’s various changes in agricultural practices at Kemerton have apparently coincided with a reversal in fortune of several species of bird. Personal observations and comparisons with work carried out in the early 1980’s gave cause for optimism and in 1998 population-monitoring trials were started. 

Initially the trials focused primarily on two typical local species – the Skylark and the Yellowhammer – using a strict methodology to obtain an annual ‘snapshot’ population assessment. Restrictions of time and resources limited the main effort to these two species. However, it was possible to monitor additional species in a less formal, but nonetheless consistent way. Thus species such as Whitethroat and Linnet were included – and it is on these four species that this report focuses. 

In 2000 Kemerton Estate entered into a whole-farm Countryside Stewardship Agreement and as part of that scheme began implementing changes to the management of field margins and of hedgerows. These were in addition to earlier changes introduced by the farm manager since the mid-1990’s. The changes at Kemerton that may have most improved the wildlife include a general increase in the ‘volume’ of each hedgerow (height and width), stricter control of chemical drift into field margins and hedge bottoms, and the provision of rough grass margins. 

While these changes were taking place at Kemerton, since 1992 The Allington Research and Educational Trust had been monitoring similar changes taking place on their farm at Loddington. Since 1994 the British Trust for Ornithology has been monitoring farmland bird populations on a regional and national basis. 

In 2000 Kemerton Conservation Trust, as part of a much farm-wide monitoring scheme included monitoring populations of the four ‘target’ bird species. Kemerton’s results could then be compared with trends identified locally by Loddington and nationally by the BTO. Close comparison of the local populations would not be practical: varying agricultural practices and differing amounts of available wildlife habitat would be affecting population numbers. 

Although the methodologies used by Kemerton, Loddington and the BTO differ considerably, so long as each is consistent then the various trends can be compared. 

Trends recorded

1. Linnet

BTO    Shows 19% decline over 7 years
Loddington Shows 150% increase over 10 years
Kemerton Shows 216% increase over 5 years   

2. Skylark

BTO    Shows 19% decline over 7 years
Loddington Shows 3% increase over 10 years
Kemerton Shows 83% increase over 5 years   

3. Whitethroat

BTO    Shows 25% decline over 7 years
Loddington Shows 80% increase over 10 years
Kemerton Shows 69% increase over 5 years   

4. Yellowhammer

BTO    Shows 13% decline over 7 years
Loddington Shows 5% increase over 10 years
Kemerton Shows 300% increase over 5 years   


  • For three of the species Kemerton appears to have reversed the national decline - and for the fourth species has far exceeded the national figure for increase
  • For all species Loddington has either reversed or considerably reduced the national declines (Like Kemerton, Loddington has been implementing changes aimed at improving the conservation value of various farmland habitats)
  • From the Kemerton results and from personal comments received from Loddington staff, it would appear that these significant gains for wildlife have been achieved as a result of comparatively small changes in agricultural practices.