Habitat type and density influence vocal signal design in satin bowerbirds

Abstract

Summary1. This study provided a thorough test of the acoustic adaptation hypothesis using a within-species comparison of call structure involving a wide range of habitat types, an objective measure of habitat density and direct measures of habitat-related attenuation. 2. The structure of the bower advertisement call of the satin bowerbird was measured in 16 populations from throughout the species' range and related to the habitat type and density at each site. Transmission of white noise, pure tones and different bowerbird dialects was measured in five of six habitat types inhabited by satin bowerbirds. 3. Bowerbird advertisement call structure converged in similar habitats but diverged among different habitats; this pattern was apparent at both continent-wide and local geographical scales. Bowerbirds' call structures differed with changes in habitat density, consistent with the acoustic adaptation hypothesis. Lower frequencies and less frequency modulation were utilized in denser habitats such as rainforest and higher frequencies and more frequency modulation were used in the more open eucalypt-dominated habitats. 4. The white noise and pure tone transmission measurements indicated that different habitats varied in their sound transmission properties in a manner consistent with the observed variation in satin bowerbird vocalizations. 5. There was no effect of geographical proximity of recording locations, nor was there the predicted inverse relationship between frequency and body size. 6. These findings indicate that the transmission qualities of different habitats have had a major influence on variation in vocal phenotypes in this species. In addition, previously published molecular data for this species suggest that there is no effect of genetic relatedness on call similarity among satin bowerbird populations.

Spectral characteristics of intense mew calls in cat species of the genus Felis (Mammalia: Carnivora: Felidae)

“…Morton 1975;Waser and Waser 1977;Wallschläger 1981Wallschläger , 1985Brown and Waser 1988;Wiley 1991;Brown and Gomez 1992;Brown et al 1995;Daniel and Blumstein 1998;Slabbekoorn and Smith 2002;Ryan and Kime 2003;Saunders and Slotow 2004;Blumstein and Turner 2005;Boncoraglio and Saino 2007). Data on diverse vertebrate taxa support this hypothesis (Morton 1975;Gish and Morton 1981;Wallschläger 1980Wallschläger , 1982Wallschläger , 1985Wallschläger and Nikolskij 1985;Masters 1991;Saunders and Slotow 2004;Slabbekoorn 2004;Seddon 2005;Nicholls and Goldizen 2006;Tubaro and Lijtmaer 2006), while in other taxa it is only supported weakly (Blumstein and Turner 2005;Boncoraglio and Saino 2007) or is not supported (Daniel and Blumstein 1998;Kime et al 2000;Saunders and Slotow 2004). In all types of natural habitat, the height of the signal source and that of the receiver are important factors in acoustic communication (Kime et al 2000;Slabbekoorn 2004), although the relative importance of the elevation above ground may be different for sender and receiver (Mathevon et al 2005).…”

Imitating the neighbours: vocal dialect matching in a mimic–model system

“…Previous work on the advertisement song of the satin bowerbird (Nicholls & Goldizen 2006) has shown that the geographical variation in bowerbird song reflects the acoustic properties of their local habitats. However, the variation apparent among populations in this study is independent of the effect of habitat acoustics, since all recordings of both species were obtained in similar rainforest habitats with similar acoustic properties.…”

“…Many of the model species whose songs are incorporated into the lyrebird display show geographical variation in song structure. For example, the advertisement song of the satin bowerbird (Ptilonorhynchus violaceus) is known to vary in structure among populations throughout its range along the east coast of Australia (Tack et al 2005;Nicholls & Goldizen 2006), and is a common feature in lyrebird mimicry.…”

Human language diversity and the acoustic adaptation hypthesis

“…Hunter & Krebs (1979) examined songs of great tit (parus major) populations in widely dispersed sites from Morocco and Iran to Spain, Norway and the U. K. and found that birds inhabiting denser forest environments had songs with a lower maximum frequency, narrower frequency range and fewer notes per phrase than birds inhabiting more open woodland or hedgerows. Nicholls & Goldizen (2006) studied satin bowerbird (Ptilonorhynchus violaceus, Figure 2) populations along the east coast of Queensland, Australia, and found significant effects of variation in local habitat on song structure: "Lower frequencies and less frequency modulation were utilized in denser habitats such as rainforest, and higher frequencies and more frequency modulation were used in the more open eucalyptdominated habitats." Within-species effects have also been reported, inter alia, by Wasserman (1979), Anderson & Connor (1985), and Tubaro & Segura (1994).…”