[Kestrel] Population trends. 21 July 2011.
Kestrels are relatively short-lived birds.
Mortality among the young birds is high - only around 20 per cent survive two years to breeding age. Those that do, will on average live for a further two and a half years, while a very few can survive well into their teens.
Starvation is the biggest cause of death, especially of juveniles during their first autumn and winter. Collisions and accidents, shooting
, poisoning and disease are other important causes of mortality
. [The usual casual defamation]
Kestrel numbers fluctuate, and are closely linked to vole numbers. The UK population was estimated at 52,000 breeding pairs for the 1988-91 Breeding Bird Atlas.
Like many other birds of prey, kestrels were persecuted heavily in the late 19th and early 20th century by gamekeepers, even though they rarely take game bird chicks. Reduced persecution during World War II allowed kestrel numbers to recover
[those evil gamekeepers again! Presumably the point of giving such prominence to the state of affairs 100 years ago]. They suffered a serious decline in late 1950s and in 1960s from effects of persistent organochlorine pesticides such as DDT and dieldrin, particularly in eastern England.
Although kestrels recovered following the withdrawal of these pesticides, the numbers started to decline again in 1980s. Kestrel numbers in England have fluctuated since the mid-1980s with no evidence of any long-term decline. Kestrel numbers in Scotland have declined markedly since the mid 1990s, the cause of which is unknown.
The kestrel is included on the Amber List of Birds of Conservation Concern due to the moderate decline of the UK breeding population and its adverse conservation status Europe-wide. The cause of the recent decline since 2005 has not been identified
[How convenient! Otherwise one might need to mention the rise in the population of larger raptors in the same habitats].
The RSPB: Kestrel: Population trends