Conservation status

Nine species of shrikes have the unhappy privilege of being on the list of the globally threatened species, including six bush-shrikes, two helmet-shrikes, and one true shrike. They all live in sub-Saharan Africa, where they are still poorly known and have a very small range. Another common characteristic is that they almost all, including the Lanius shrike, live in forest habitats. The possible exception is the recently discovered Bulo Berti boubou; the only known individual was trapped in acacia shrub. All these birds have habitats that face deforestation for the benefit of various types of agriculture.

Population estimates must be taken with extreme caution. It is assumed that the Bulo Berti boubou population totals fewer than 50 pairs in the only area where it is known in Somalia. The Gabela bush-shrike (Laniarius amboimensis) and the orange-breasted bush-shrike (L. brauni) both live in tiny areas in western Angola and have populations that are thought to be between 250 and 1,000 pairs. The Mt. Kupé bush-shrike and the green-breasted bush-shrike (Malaconotus gladiator) are mainly confined to western Cameroon; the latter species also has a tiny population in eastern Nigeria. They are respectively thought to have populations numbering between 50 and 250 pairs and between 2,500 and 10,000 pairs. The population of the Uluguru bush-shrike (Malaconotus alius), endemic to the mountains of the same name in eastern Tanzania, benefited from a detailed survey in 2000. The results were rather encouraging, as about 1,200 pairs were located, thus doubling previous estimates. The two helmet-shrikes on the Red List are the Endangered Gabela helmet-shrike (Prionops gabela) with 1,000-2,500 pairs in western Angola, and the Vulnerable yellow-crested helmet-shrike (Prionops alberti) with 2,50010,000 pairs in the east of the Democratic Republic of Congo. The Sâo Tomé fiscal is endemic to the island of the same name, which lies in the gulf of Guinea, 160 mi (255 km) off the coast of Gabon. It is the only true shrike on the IUCN

A loggerhead shrike (Lanius ludovicianus) has its lizard prey impaled on a barbed wire fence in California. Shrikes may stash their prey by impaling it on fences or thorned branches. (Photo by Maslowski. Photo Researchers, Inc. Reproduced by permission.)

Red List. It is judged to be Critically Endangered with perhaps fewer than 50 pairs; other estimates, however, give a few hundred pairs.

Another five species are classified as Near Threatened. Three are in Africa: two bush-shrikes and one helmet-shrike; two are in Asia: one Lanius shrike and the Bornean bristle-head.

Almost all the species mentioned above are confronted with a major problem: deforestation. That is, however, not the general cause explaining the present worrying decline of Lanius shrikes in North America and Europe; on the contrary, these semi-open habitat species have certainly benefited from the clearance of forests. They have adapted extremely well to "untidy" open landscapes associated with low-intensity farming. A strong association exists between them and the lifestyle based around cultivation and domestic stock. The golden age for many such shrikes has, however, come to an end with the industrialization of agriculture. Large-scale production techniques have involved a high level of mechanization and an increase in field size. This has led to the disappearance of large areas of non-productive habitats, such as hedgerows, bushes, isolated trees, ponds, marshes, banks, ditches and even of grassy paths, which are favored by shrikes. Widespread use of pesticides has reduced their food resources.

Was this article helpful?

0 0

Post a comment