Vocal Mimicry Of Long-tailed Shrike(Lanius Schach)

The long-tailed shrike (Lanius schach), which belongs to Laniidae Passeriformes, is widely distributed in the Middle East, South and South East Asia, as well as the Southern part of China. There are 4 subspecies in China. As other Lanius shrikes, long-tailed shrikes are fierce bird and impale some of their prey in larders. They have harsh calls and pleasant songs which include lots of vocal mimicries. Most of Lanius shrikes have been classified. Their ecophysiology and migration pattern have been researched with the various kinds of advanced technology.The studies of bird sound tend to make great progress with the development of technology. The vocal organs of birds have been studied ages ago. Chinese researchers have completed fundamental research on the vocal structure of many kinds of birds while foreign researchers place emphasis on the mechanism of vocal learning. More attention is paid on the functions and meanings of the vocal mimicry besides discussions on its mechanism, which raised many hypotheses. However, most hypotheses still cannot give the reasonable explanation for the function and meaning of vocal mimicry.Lacks of relative researches have been done on long-tailed shrike's excellent vocal mimicry. This paper is aimed to study the vocal mimicry of long-tailed shrike from July 2009 to June 2010 to understand its ability of vocal mimicry from various respects. We want to study the mimicry tendency of long-tailed shrike, explore the regular pattern of mimicry and possible relationship between the mimicry and behavior, finally to propose the other potential hypothesis and supposition.The study shows that the long-tailed shrike sings all the year round, while the frequency varies with the change of season. The population in the researching area will migrate in spring and autumn according to the banding result.There were 108 species of birds found during the studying period in local area. Most of these birds are residents, summer visitors and winter birds. Whether the birds have more chance to be mimicked depends on their population. Larger population means their repertoires stand bigger chance and higher frequency to be mimicked by the long-tailed shrikes. Because the breeding birds and wintering birds occupy the main body of the bird community, therefore most mimicked birds are residents, summer visitors and winter birds. There are 54 species of birds mimicked by the long-tailed shrike and no significant differences between the two color type, schach and fuscatus.72% of mimicked birds are of Passeriformes, which is about 36% of the bird species in studying area and the number of song bird species in all the mimicked birds is bigger than other groups.The mimicry sounds of two color types of long-tailed shrikes have significant differences on the main peak frequency, high frequency and low frequency. They tend to mimic the sound of shorter time and fewer notes and are able to do the mimicry according to the original sounds'frequency, time interval and the number of syllables of other birds. The mimicry sound and the originals are of significant relationship and have similar frequency distribution with rhythm and tone color. However, they are not exactly the same sound.Other sounds of birds, animals and manmade sounds are included in the mimicries of long-tailed shrikes, which is able to reflect the features of its habitat. The animal species found in the mimicry can be considered as the reference of the biodiversity of the local area. The mimicked environment indicator species may be used to verify the habitat change in one aspect.The study of long-tailed shrike in this paper is still in exploring stage. Here we'd like to take the long-tailed shrike as an example of vocal mimicry birds to collect the basic acoustical data. We are not able to know the exact meaning and function of the mimicry by long-tailed shrike by observation. We haven't been able to prove the relevant mimicry hypothesis, and make new explanation of it at the current stage. All these questions remained are worth to design experiment for further research and from more various angles.