Mechanics of the exceptional anuran ear

The anuran ear is frequently used for studying fundamental properties of vertebrate auditory systems. This is due to its unique anatomical features, most prominently the lack of a basilar membrane and the presence of two dedicated acoustic end organs, the basilar papilla and the amphibian papilla. Our current anatomical and functional knowledge implies that three distinct regions can be identified within these two organs. The basilar papilla functions as a single auditory filter. The low-frequency portion of the amphibian papilla is an electrically tuned, tonotopically organized auditory end organ. The high-frequency portion of the amphibian papilla is mechanically tuned and tonotopically organized, and it emits spontaneous otoacoustic emissions. This high-frequency portion of the amphibian papilla shows a remarkable, functional resemblance to the mammalian cochlea

Polarization and ideological congruence between parties and supporters in Europe

The relationship between parties and their supporters is central to democracy and ideological representation is among the most important of these linkages. We conduct an investigation of party-supporter congruence in Europe with emphasis on the measurement of ideology and focusing on the role of party system polarization, both as a direct factor in explaining congruence and in modifying the effects of voter sophistication. Understanding this relationship depends in part on how the ideology of parties and supporters is measured. We use Poole’s Blackbox scaling to derive a measure of latent ideology from voter and expert responses to issue scale questions and compare this to a measure based on left–right perceptions. We then examine how variation in the proximity between parties ideological positions and those of their supporters is affected by the polarization of the party system and how this relationship interacts with political sophistication. With the latent ideology measure, we find that polarization decreases party-supporter congruence but increases the effects of respondent education level on congruence. However, we do not find these relationships using the left–right perceptual measure. Our findings underscore important differences between perceptions of left–right labels and the ideological constraint underlying issue positions

Diet alters species recognition in juvenile toads

Whether environmental effects during juvenile development can alter the ontogeny of adult mating behaviour remains largely unexplored. We evaluated the effect of diet on the early expression of conspecific recognition in spadefoot toads, Spea bombifrons. We found that juvenile toads display phonotaxis behaviour six weeks post-metamorphosis. However, preference for conspecifics versus heterospecifics emerged later and was diet dependent. Thus, the environment can affect the early development of species recognition in a way that might alter adult behaviour. Evaluating such effects is important for understanding variation in hybridization between species and the nature of species boundaries