The Lincolnshire Bird Club

Whilst birdwatching this morning on my local patch(Torksey area) I noted a Common Buzzard in a large, ploughed field. It's interest were 2 Brown Hares and it attacked them on 6 occasions (from the ground). The hares were not unduly perturbed and merely moved to another part of the field. The raptor eventually took flight after being continually harassed by 2 Carrion Crows.

Now, were the hares too large as prey or was it having difficulty through inexperience (plumage details suggested a young bird)?

Any comments or other suggestions?

Richard......

Any thoughts?
Richard..

this from Reif et al. (2001)

Many studies on the diet of common buzzards (hereafter buzzard) in central, eastern and western Europe and in southern Sweden have shown that they are versatile predators (Pinowski and Ryszhkowski 1962, Likhopeck 1970, Sylve´n 1978, Goszczynski and Pilatowski 1986, Jedrzejewski et al. 1994, Swann and Etheridge 1995, Graham et al. 1995, Vorisˇek et al. 1997). The basis of their diet consists of small mammals (mainly voles and mice), but in some areas, e.g. in Poland and Great Britain, also lagomorphs and birds are their main food (Jedrzejewski et al. 1994, Graham et al. 1995). Buzzards can also prey upon amphibians, reptiles, insects and earthworms (Cramp 1983). Periodic (cyclic) population fluctuations of voles and small game do not usually occur in central, eastern and western Europe and in southern Sweden (Hansson and Henttonen 1985, Angelstam et al. 1985) where diet composition of buzzards has mainly been studied. To our best knowledge, the diet composition of buzzards in areas of northern Europe with cyclic fluctuations of voles and small game has only been studied in southern Finland (Suomus 1952) and southern Norway (Spidsø and Sela°s 1988), but in these studies the densities of voles and small game were not simultaneously estimated in the field.

Juvenile hares were the most frequent prey group in the diet of buzzards by weight. Brown hares are common in the farmland and mountain hares in the edges of farmland and forests which are the preferred hunting habitats of buzzards. Most leverets taken by buzzards were relatively small (on average 0.5 kg) compared, for example, to the size of the leverets killed by the goshawk (mean weight 1.5 kg; Tornberg unpubl.).

In this instance the Hares were probably able to judge that fact they are too large to be seriously threatened by the Buzzard, and did not therefore take any serious evasive action. Despite the fact that Common Buzzards and Goshawks are of a similar size, the latter can kill much larger prey (including Common Buzzards) on account of its different strike technique - thrusting the pelvis forward at the last minute (Goslow 1971 http://elibrary.unm.edu/sora/Auk/v088n0 ... -p0827.pdf).

Alex

Vitali Reif, Risto Tornberg, Sven Jungell and Erkki Korpimaki 2001. Diet variation of common buzzards in Finland supports the
alternative prey hypothesis. ECOGRAPHY 24: 267–274.

_________________
Dr Alexander C. Lees
Lecturer in tropical ecology
Manchester Metropolitan University

Lab Associate
Cornell Lab of Ornithology,
Cornell University

http://www.freewebs.com/alexlees/index.htm
@Alexander_Lees

Hi Alex,

Many thanks for an interesting and informative reply.

Regards.......Richard..