Great Grey Shrike's European breeding range stretches from central France north to Norway and eastwards into Asia. The more northerly populations are migratory, while southern ones hardly move. Most breeding birds leave their territories during September and October and spend four or five months in their winter quarters. Return migration takes place largely in March and April. Most of the Scandinavian population heads south to central and western Europe, with some Norwegian birds coming to Britain, while some of the birds on their way to France and northern Spain in the autumn may be displaced to the east coast of Britain.
The Atlas of Wintering Birds in Britain and Ireland (1986) estimated the total British wintering population to be at least 150 birds, but 10 years later an analysis of records from 1986-1992 suggested an annual total of half this number, implying that there has been a substantial decline. However, recent reports on scarce migrants, which ignore wintering birds from the previous year, showed a steady 125-160 records from 1986-93, after which there was a decline to just over 50 records in 1997, and then a huge jump to 232 in 1998.
The data for this bumper year showed that 36 new birds were seen between January and May, then a huge arrival took place between late September and mid-November, amounting to a further 196 birds by the end of the year. Since then numbers have fluctuated, with as few as 58 in 2001 to as many as 157 in 2003, and about 100 of these from early October to late December.
The pattern of arrivals is similar in most years, with passage migrants starting to appear in late September but the majority in October. Some wintering birds arrive back at their regular sites early in October (the long-staying bird at Elveden, Suffolk, returned on 9 October 2005). Migration through the Northern Isles is at its height in October, usually peaking in the last week but sometimes earlier if numbers are particularly high. By the end of November most birds that are set to stay until spring have set up a wintering territory, and numbers in Britain are then fairly stable through the winter months.
Most autumn birds arrive on the eastern side of Britain, from Shetland to Kent, with the highest numbers in Yorkshire and Norfolk. Most are singletons, but there have been instances of small groups of four to 10 birds concentrated in a small area, always in October.
A comparison of migrant arrivals and numbers of wintering birds suggests that more birds winter in years when there has been a large arrival in autumn. The appearance of good numbers of migrants in Sweden has been related to high populations of small rodents during the breeding season.
Individual Great Grey Shrikes hold winter territories and will often return year after year to the same site. Birds that appear at other sites may be wandering individuals, perhaps young birds which have not yet set up a permanent territory. They winter throughout Britain, with most in England, especially in the south and east. A few birds are seen in Wales each year, while in Ireland the species is a rarity, with fewer than 25 records since 1900.
Like most shrikes, Great Grey's preferred feeding strategy is ‘wait-and-pounce’, from a prominent position on top of a bush or high tree branch. It will, however, also hunt like a Sparrowhawk, waiting in the dense cover of a bush from which it dashes out, surprising its prey. Winter prey is largely made up of small mammals and some small birds. Finches are often a target, and some birds may wait by a finch roost for supper in the evening.
Shrikes have a ‘tomial tooth’ on each side of the upper mandible, similar to that of falcons, and this may help the bird bite through its prey’s spinal cord.
In winter they will roost in conifers, and have been known to roost in company with Magpies.
How to find
Like all shrikes, Great Grey needs vantage points from which to watch for prey. Open ground with scattered bushes, especially heathland, is the preferred winter habitat, and young conifer plantations are also attractive.
While they can be very obliging and obvious, perched atop a bush or tree, they can also be infuriatingly difficult to see, sometimes concealing themselves in the edge of a bush, so patience may be needed when watching at a wintering site. They usually fly fairly low and direct, so choose a watching place where you can see a good part of the area where the bird is usually present, and try to locate any favourite perches in advance, as birds will frequently return to them. If a bird has fed recently it may not be so obvious, but shrikes do store spare food in winter, perhaps wedging a vole or small bird in the fork of a bush.
Where to look
As well as migrants arriving on the east coast, there are several long-staying and regular wintering birds which have been seen in recent years. New wintering birds are found each year, and many of their locations can be found on the various bird news websites.
Regular wintering sites are marked *.
- Lancashire: Stocks Reservoir (SD 731564)*
- Yorkshire: Spurn Point (TA 416154) and South Gare (NZ 561262)
- Derbyshire: Walton-on-Trent (SK 208168)*
- Norfolk: coast from Holme to Winterton and Santon Warren (TL 820880)
- Suffolk: Weather Heath, Elveden (TL 787776)*
- Surrey: Thursley Common (SU 900416)*
- East Sussex: Ashdown Forest (TQ 470320)*
- Hampshire: Beaulieu Road Station (SU 347063)* and Black Gutter Bottom (SU 204162)*
- Fife: Isle of May (NT 655995)
- Shetland: Fair Isle (HZ 210720)
- Conwy: Clocaenog Forest (SJ 019520)*
- Port Talbot: Mynydd Margam (SS 815895)*
Lack, P. 1986. The Atlas of Wintering Birds in Britain and Ireland. Academic Press Inc, Oxford.