We recorded and analysed the songs of ten male icterine warblers (Hippolais icterina) in České Budějovice (Czech Republic) to identify mimicry. Imitations represented 76.2 % of the total time of all songs and we detected 42 mimicked species. Barn swallow (Hirundo rustica), blackbird (Turdus merula), common kestrel (Falco tinnunculus) and fieldfare (Turdus pilaris) were the most common species imitated. Principal components analysis (PCA) detected individual variability in the species mimicked. The length of recording needed to detect 95 % of species mimicked was assessed to be 8.2 minutes.
From June to August in 2004 and 2005, we conducted the studies on spontaneous vocalization development of greater horseshoe bat, Rhinolophus ferrumequinum, in Zhi’an Village (Jilin province, Northeast China). In contrast to adult bats, infant bats of the greater horseshoe bat emitted calls characterized by multiharmonics and variable harmonic patterns. With the physical growth of infants, the dominant frequency, pulse duration and frequency of each harmonic of spontaneous calls increased, the number of harmonics decreased from 5–8 to 1–2 and dominant harmonic switched from first to the second with peak frequency increasing. Vocalizations of infant bats of the greater horseshoe bat could be categorized to those serving as precursors of echolocation sounds and those serving as isolation calls used to attract their mothers. According to observation on mother-infant reunion, the female adult bats only suckled their own babies, but not other pups in the same colony. And the mother recognized their own infants through both odor and vocal cues indicating that the isolation calls emitted by infant bats played an important role in mother-infant communication.
Vocalizations of the plaintive cuckoo (Cacomantis merulinus) and brush cuckoo (C. variolosus) were compared. Six major sound types were identified in the plaintive cuckoo, and four in the brush cuckoo. On the basis of song similarity as assessed by sonogram qualitatively and quantitatively, the grey-bellied cuckoo (C. passerinus) was considered conspecific with C. merulinus and the rusty-breasted cuckoo C. sepulcralis was considered conspecific with C. variolosus. The song similarities between C. merulinus and C. variolosus were considered homologous and derived from common ancestry.
The paper reported vocalizations of endemic Tibetan Plateau steppe sparrow, red- necked snow finch (Pyrgilauda ruficollis) by using SAS-Lab Pro. The subject similarity contrast and multivariate contrast were used to study the complexity and stability of sounds. The results indicated that songs of P. ruficollis were highly complicated with varied song types, song phrases, song syllable and combination of them. One song syllable shared by snow finches (Montifringilla nivalis henrici, M. adamsi, P. ruficollis and P. blanfordi) was selected as indicator to compare the taxonomic relationship among them. The similarity contrast and cluster analysis through SPSS were conducted to construct the similarity tree based on this shared syllable’s acoustic parameters including the highest frequency (HF), the lowest frequency (LF), the main frequency (MPF) and duration (DUR). The results revealed that the syllable similarities are accordant with taxonomic status suggested in previous studies based on morphologic, ecological and molecular analysis methods. The syllable shared by these snow finches were presumed to be homologous and derived from a common ancestry. Further studies on songs encoding phylogenetic signal of snow finches are needed.
"Fotografie 2013: Karel Burda, Pavel Hrdina, Lukáš Ptáček, Roman Sejkot ; námět a text Jitka Velková ; historický přehled a redakční spolupráce: Pavla Stuchlá"--Tiráž and Chronologický přehled