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Aim: Conservation has recently shifted to include behavioural or cultural diversity, adding substantial value to conservation efforts. Habitat loss and fragmentation can deplete diversity in learnt behaviours such as bird song by reducing the availability of song tutors, yet these impacts are poorly understood. Vocal mimicry may be particularly sensitive to habitat loss and fragmentation through the resulting reduction in both heterospecific models and conspecific tutors. Here we examine the relationship between habitat availability and both mimetic repertoire size and song composition in male Albert's lyrebirds (Menura alberti), a near‐threatened species renowned for its remarkable mimetic abilities. Location: Eastern Australia. Methods: We calculated repertoire size and composition from recordings of male Albert's lyrebirds from throughout the species' range. We estimated patch size and local habitat availability using a species distribution model and remotely sensed vegetation types. We assessed the local model species assemblage through species distribution models and automated acoustic detectors. Results: Individual males in smaller habitat patches, or in areas with a lower proportion of suitable habitat, mimicked fewer model species and fewer vocalization types. However, they mimicked comparatively more vocalizations from each model species than individuals in larger patches or with more intact habitats. All model species were likely to occur in most study sites, suggesting that repertoires are not driven by the availability of model species. Main Conclusions: Our results suggest that mimetic repertoire sizes are influenced by habitat availability through the number of lyrebird tutors. Further, individuals in disturbed habitats may partially compensate for mimicking fewer species by mimicking more vocalizations from each species. This study supports the hypothesis that cultural diversity may be impoverished by habitat loss and fragmentation in a similar way to genetic diversity. Variation in song diversity may therefore indicate population health and highlight populations in particular need of conservation action. [ABSTRACT FROM AUTHOR]

Geographic variation in bird song has received much attention in evolutionary studies, yet few consider components within songs that may be subject to different constraints and follow different evolutionary trajectories. Here, we quantify patterns of geographic variation in the socially transmitted "whistle" song of Albert's lyrebirds (Menura alberti), an oscine passerine renowned for its remarkable vocal abilities. Albert's lyrebirds are confined to narrow stretches of suitable habitat in Australia, allowing us to map likely paths of cultural transmission using a species distribution model and least cost paths. We use quantitative methods to divide the songs into three components present in all study populations: the introductory elements, the song body, and the final element. We compare geographic separation between populations with variation in these components as well as the full song. All populations were distinguishable by song, and songs varied according to the geographic distance between populations. However, within songs, only the introductory elements and song body could be used to distinguish among populations. The song body and final element changed with distance, but the introductory elements varied independently of geographic separation. These differing geographic patterns of within‐song variation are unexpected, given that the whistle song components are always produced in the same sequence and may be perceived as a temporally discrete unit. Knowledge of such spatial patterns of within‐song variation enables further work to determine possible selective pressures and constraints acting on each song component and provides spatially explicit targets for preserving cultural diversity. As such, our study highlights the importance for science and conservation of investigating spatial patterns within seemingly discrete behavioral traits at multiple levels of organization. [ABSTRACT FROM AUTHOR]