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Despite its prevalence across bird taxa, avian vocal mimicry remains a poorly studied field of animal behaviour. In order to advance our understanding of the function of avian vocal mimicry, the field requires that the range of vocal mimicry in birds is described. The Tawny Lark (or Sykes's Lark, Galerida deva) is endemic to central and western India. Recent work on other Galerida larks has found that the mimetic vocalisations match the biodiversity of their acoustic environment, thereby conferring a significant novel function in study of individual mimetic variation linked to biodiversity. Here, we provide a detailed account of the variety of mimetic sounds produced by the Tawny Lark. We also describe acoustic and peer-based analyses that gauge the accuracy of the mimicry. By providing a detailed description of mimicry, we provide a basis for future study of the function of mimicry in this species. [ABSTRACT FROM AUTHOR]

Taxonomic descriptions of new anuran species are published with high frequency in the recent systematics literature. In contrast, there are fewer detailed quantitative descriptions of the vocalizations of these new species. Here, we describe the vocalizations of a recently described shrub frog, Pseudophilautus kani (Anura: Rhacophoridae; Biju and Bossuyt 2009) endemic to the Western Ghats region of India. We recorded two distinct, pulsatile call types that could be distinguished by their temporal and spectral properties as well as their mode of production. Type 1 calls (creek) were short (≈85 ms), consisted of about six or seven pulses (92 pulses/s) and had a spectrum with a single frequency peak at about 3.5 kHz. By comparison, Type 2 calls (ta-ta-ta-ta) were typically longer (≈ 320 ms), contained fewer pulses (4-5) produced at much lower rates (12 pulses/s) and had broadband spectra with multiple frequency peaks, two of which were consistently present at about 2.3 and 4.6kHz. Video analyses indicated that males produced pulses in Type 1 calls using a single, continuous contraction of the trunk musculature, whereas pulses of Type 2 calls were produced with separate muscle contractions. In both call types, spectral properties were significantly negatively related with body length and body mass. The pulse rate and pulse period of Type 2 calls were also related to body size. No call properties were correlated with body condition. Patterns of individual variation in call properties were generally consistent with those described for other anurans. [ABSTRACT FROM AUTHOR]

This study has two goals: empirically, it accounts for variation found in the use of ethnically-marked variants among British-born Asians; methodologically, it assesses the variationist approach against a repertoire approach. In Part I, analysis of one Punjabi-derived phonetic trait, examined in interview data only, suggests that younger women shift to exclusive use of the British prestige variant. Part II expands the analysis to four variables and to broader speech repertoires for four individuals. The repertoire analysis shows the conclusions in Part I to be inaccurate, and instead reveals: (1) retention of Punjabi traits by young women in the home domain; (2) two types of repertoire - flexible and fused; (3) a gendered reversal in repertoire type over time; and (4) a network diversity basis for these differences. Unlike the initial variationist analysis, the use of repertoire analysis and a new Network Diversity Index leads to the discovery of a shift among lower-middle-class British Asians from traditional Punjabi to urban British social structures. [ABSTRACT FROM AUTHOR]