Great Grey Shrike
The Great Grey Shrike has gained the moniker the Butcher Bird for its rather macabre practice of impaling its prey on thorn bushes…
Find out why this bird has earned the nickname ‘Butcher Bird’
Iwhile think I was about 10 years old when I first saw a Great Grey Shrike. my memory may be a bit vague about my age, it isn’t about the bird. I can still see it in my mind’s eye as if it were yesterday; sitting atop a small battered pine tree surrounded by a sea of heather. The bird looked impressive enough, but when someone said it was also known as the Butcher Bird, and that it impaled its prey items on thorns, my childhood imagination roared into life and the bird became forever fixed in my memory. We don’t get many Great Grey Shrikes wintering with us in Britain, but we always get some, scattered across the country from mid-september until the end of March (sometimes staying even later). These are birds not to be missed, so, if you have one near you, make sure you get to see it this month. Great Grey Shrikes are conspicuous birds, so if there is one wintering in your area, the likelihood is that people will know about it. Speaking and networking with other local birders, be it in a hide or on the internet, is a great way to find out what birds are about. The Great Grey Shrike is the largest shrike found in Europe. It breeds across the northern half of the continent, with those in the most northerly climes, such as Scandinavia, migrating in the winter. A handful of these migrating birds come to Britain, choosing to winter in a variety of habitats including heathland, moorland, young forestry plantations and coastal areas. Even in winter, the shrike is territorial and will often return to the same wintering site year after year. So, if a site has held a shrike in the past, it is definitely worth checking again. These are medium-sized passerines, with a distinctive long tail and a rather plump (some say chunky!) body. The head, with
its black eye mask contrasting with soft grey above and white below, is also very noticeable, even at a distance. This head is topped off with a short, powerfullooking bill that ends in a fine hooked tip. The wings are black with white flashes in them and the long-rounded tail is also black with white sides. It is an eye-catching bird! While wintering birds can be found in a variety of habitats in a variety of places, the one common factor to them all is that the sites are open with several perch points dotted about. Great Grey Shrikes like to sit up on these perches, sometimes only a metre or so in height, from where they can scan around them, looking for potential food. Fence posts, scrubby trees, telegraph poles and even overhead wires can all serve as shrike perches, so make sure that you check these out when looking for your wintering shrike. The Great Grey Shrike is a predator, a look at the small but still fearsome bill is enough to tell you that! They eat a wide variety of food, everything from beetles to small birds are taken, with perhaps their favourite food being small mammals, such as voles and mice. Small prey can be devoured on the spot, but larger prey can present a bit of a problem, they need to be broken up in to small easy-to-swallow portions. Raptors, such as the Sparrowhawk, have the same problem and use their feet and talons to tightly grip they prey, while tearing at it with their bill.
Thorny situation
Shrikes have the bill for this, but they don’t have the feet. Instead they use the thorns on trees such as the Hawthorn and the spikes of barbed wire to hold their prey items fast. It may seem gruesome to us, but the shrike’s habit of impaling its prey on to a thorn or a wire is a great example of problem-solving in nature. With the item secure, the bird can easily tear it into small portions. But not all prey items are eaten straightaway, some are stored on these thorns and wires, creating larders for the bird to use when the weather turns bad and prey becomes scarce. It is this habit of using spikes, either natural or manmade, to store and process its prey that has led to the Great Grey Shrike acquiring the nickname of Butcher Bird (a name that is also used for other shrike species). But there is more to this butchery behaviour than meets the eye. Studies have shown that when feeding on invertebrates such as crickets and some beetles, the shrikes will always leave these items impaled in their larders for several days. Many crickets and some beetles
THE GREAT GREY SHRIKE IS A PREDATOR, A LOOK AT THE SMALL BUT STILL FEARSOME BILL IS ENOUGH TO TELL YOU THAT!
produce a chemical that makes them distasteful to predators, it is believed that the shrikes have learnt to recognise these species and it is these that they leave impaled for longer. After a few days, the chemical starts to wear off, allowing the Shrike to feed on them. Further studies on this behaviour have also thrown up an intriguing possibility that appears to show that shrikes ‘understand’ the value of food nutrition. Allowing the prey item to dry out improves its nutritional value, but this has long been thought to be an incidental effect of the shrike’s behaviour and not the cause of it. But it has recently been discovered that the bird could be deliberately drying the food to improve its nutritional value. When trying to solicit a mating from a female, a male shrike will often offer the female food as an enticement and studies show that the male will select a dried piece of food for this, rather than a freshly caught item. More studies are needed, but this behaviour seems to imply that the male (and the female) recognise the ‘higher value’ of the dried item. The site I saw my first ever Great Grey Shrike on all those years ago is by no means a regular haunt of the species, yet it left a very memorable impression on my young mind. This month is a great time to go looking for your very own memory!