a partner church in the WOLDSBURN benefice
CHURCH AT KIRKBURN
SPARROW HAWKS and your Garden Birds
Robin Arundale
Having acquired a reputation over the years as someone who ‘knows summat about bods’ sooner or later the subject of Sparrowhawks ‘killing all our garden birds’ crops up in almost every conversation I have concerning birds. This is also a recurring theme of irate letters to the ‘Yorkshire Post’ and no doubt other newspapers calling for these murderous hawks to be taken off the protected list and shot to bring their numbers under control. Because of the generally negative perception people have of this bird, I thought I would take the opportunity to put the depredations of this amazing predator into perspective.
Firstly, it is only in the last ten years or so that, for the first time in living memory, we have a population of Sparrowhawks in the UK of something like the level that we would expect an environment such as ours to naturally sustain. Prior to the present day, Sparrowhawks were pursued and harried without mercy by game preserving interests from the early nineteenth century. These birds were afforded protection by the Protection of Birds Act 1954 only to succumb to the effects of the introduction of organochlorine pesticides in the early 1960’s. These pesticides were fat soluble and incredibly persistent. While compounds like aldrin and dieldrin brought about the direct mortality of the adult birds, others such as DDT reduced the thickness of Sparrowhawk eggs and led to increased breakages during incubation. This all resulted in a massive drop in the breeding population which only gradually recovered to present day levels after these chemicals had been phased out.
Firstly, it is only in the last ten years or so that, for the first time in living memory, we have a population of Sparrowhawks in the UK of something like the level that we would expect an environment such as ours to naturally sustain. Prior to the present day, Sparrowhawks were pursued and harried without mercy by game preserving interests from the early nineteenth century. These birds were afforded protection by the Protection of Birds Act 1954 only to succumb to the effects of the introduction of organochlorine pesticides in the early 1960’s. These pesticides were fat soluble and incredibly persistent. While compounds like aldrin and dieldrin brought about the direct mortality of the adult birds, others such as DDT reduced the thickness of Sparrowhawk eggs and led to increased breakages during incubation. This all resulted in a massive drop in the breeding population which only gradually recovered to present day levels after these chemicals had been phased out.
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www.churchatkirkburn,org,uk page 175 1 of 3 Sparrowhawks Robin Arundale 2007 12 November 2008