Tuesday, January 17, 2012

Great Grey Shrike /Stor Tornskade

Flora and Fauna
Lanius excubitor

foto Ormstrup 7. January 2011, stig bachmann nielsen, Naturplan.dk

I saw the Great Grey Shrike on a field near Ormstrup manor in the Viborg district, where it was sitting in a treetop. The owner of the manor has plant belts of  hardwood in his large fields. The trees are not yet taller than 2-3 meters, but the project has already given results. Birds are quick to discover new places. It's a fine place for birds now and later, and we saw both the Great Grey Shrike and a Common Buzzard in the top of one of the new trees. This is really a good thing. Last time we were out - it was in the Odder district -  I told you about the landlord at Åkær manor, who had cut down the hedgerows, so the tractors could work close to the edge of the field - and I was sad, because it was a destruction of important habitats for the birds. But  something good has happened  here. The birds have achieved some good new places in this area, and  Ormstrup Manor should have some praise for this project.  

The Great Grey Shrike /Stor Tornskade is a spectacular, longtailed bird, the size of a thrush. The scientific name  of the Great Grey Shrike literally means "sentinel butcher": Lanius is the Latin term for a butcher, while excubitor is Latin for a watchman or sentinel. This refers to the birds' two most conspicuous behaviours – storing food animals by impaling them on thorns, or the barbs of barbed wire and using exposed tree-tops or poles to watch the surrounding area for possible prey.

The keen eye of the watchful "sentinel" misses nothing that moves. It will drop down in a light glide for terrestriel prey or swoop hawk-like on a flying insect. Small birds are sometimes caught in flight too, usually by approaching them from below and behind and seizing their feet with the beak. If no prey ventures out in the open, Great Grey Shrikes will rummage through the undergrowth or sit near to hiding places and flash their white wing and tail markings to scare small animals into coming out. It will sometimes mimic songbirds to entice them to come within striking distance. Occasionally, animals as large as a young ermines, bats, and salamanders, and even fish, are killed and eaten by the Great Grey Shrike.

Male and female are similar in plumage with a grey crown and back, weith black wings, black eye mask and white wing bands. 
The Great Grey Shrike breeds in parts of Europe and eastwards in a broad belt through Asia to the Pacific coast. Furthermore it is found in North America (where it is known as the Northern Shrike) and Central America. The breeding population in the western part of South Europe was recently divided as separate species: Southern Great Shrike/Lanius meridionalis with 7 various races, like L. m. meridionalis from the Iberic peninsula and L. m pallidirostris, which belongs to the Asian steppes and was seen a few times in Denmark.

Great Grey Shrike breeds in Denmark especially in open heath and bog areas with a spread growth. This nature type is in Denmark mainly found in Jutland, and there is only registration of breeding pairs from this region. Good breeding places are military exercize areas, which are kept open by nature management, like in Karup, Holstebro, Borris and Oksbøl. In the winter season the Danish breeding population of Great Grey Shrike is supplemented by birds from the North, who establish themselves and defend permanent winter territories in the country. Based on studies in the winter 2003/2004 it is estimated that the Danish winter population of the Great Grey Shrike is 350-450 birds. The largest winter presence is in Ribe and Ringkøbing district and in Frederiksborg district (Sjælland). 

The Great Grey Shrike is carnivorous, with rodents making up over half its diet. In summer the food is large insects, amphibians, lizards, mice and little birds, while the winter food especially is mice and little birds. The population size in Scandinavia follows quite closely the size of the rodent population, and there were more overwintering Great Shrikes in Denmark in each 3.-5. year, when the rodent population was in top. 
 Like the Red-backed Shrike the Great Shrike is stockpiling in times with food surplus. They are storing food by impaling it on thorns.

Great Grey Shrike came supposedly to Denmark from the south in the late 1800s. The first breeding find was registered in 1927. The Danish population of Great Shrike topped in the 1940s, but declined down to 30-50 pairs in the 1970s. The population probably never exceeded 100 breeding pairs. In the latest years was a slight increase to 13 breeding pairs in 2003, while the previous 5 years were only registered between 2 and 6 pairs. (There is only registered breeding pairs in the middle part of West Jutland). The mid European population of Great Grey Shrike was generally declining, this might be due to destruction of biotopes, especially overgrowth of the open heath areas.

Source: Fugle og Natur, Dansk Ornitologisk Forening ; Danmarks fugle og Natur; Naturpark maribo-søerne
Source: A few notes about food from wikipedia.

photo Great Grey Shrike, Ormstrup, Viborg district 7 January 2011: stig bachmann nielsen, Naturplan.dk

From wikipedia:
Altogether, the Great Grey Shrike is common and widespread and not considered a threatened species by the IUCN . Wherever it occurs, its numbers are usually many hundreds or even thousands per country. Its stronghold is the region around Sweden, where at least almost 20,000, perhaps as many as 50,000 were believed to live in the late 20th century. However, in some countries it is not robustly established; in Estonia only a few hundred are found, with less than 200 in Belgium and some more or less than 100 in Latvia and Lithuania, respectively. The few dozen in the Netherlands and the 10 birds or so in Denmark might disappear because of a few years of adverse circumstances. By contrast, in Luxembourg plentiful high-quality habitat is found; though the number of Great Grey Shrikes in this tiny country is necessarily limited, the average population density there is 25 times as high as in Lithuania.


Wanda..... said...

I can remember reading of the 'butcher' bird, maybe here on your blog at one time. Birds really are quick to find things. The Shrike reminds me of our mockingbird with it's long tail.

Thyra said...

Hej Wanda, I think the resemblance to the mocking bird is mentioned somewhere, maybe on wiki. I did not know before that this little bird was such a robber. It's my son who knows and finds the birds! I'm just a follower!!
Your bird-photos in your post yesterday are so wonderful, Wanda, I love that red cardinal and the little wren!
Grethe ´)