Table 1.
A comparison of models incorporating likely detection covariates.
Fig 1.
A comparison of the distance histograms and fitted detection functions between cues (right), and between body sizes (left).
The arrow in (e) indicates the apparent deficit in audio detections at short distances resulting from the prioritisation of visual cues for accuracy of distance estimation during surveys.
Fig 2.
The distribution of estimated Effective Strip Width (ESW) 95% confidence intervals across all species examined, ranked in order of their estimated ESW from Distance analysis.
An inset histogram shows the distribution of ESWs across all species, overlaid with with the probability density function for this distribution.
Fig 3.
Estimated Effective Strip-widths plotted against log(body mass) for each of the 52 species compared here.
See text for regression results. The shaded area shows 95% confidence intervals for the model including all species. Labelled points indicate species outlying to this trend: above the line two species with distinctive and penetrating calls CURR = (Pied Currawong (Strepera graculina), SFD = Superb Fruit-dove (Ptilinopus superbus). Below the line two species which rarely or only softly call (ABT = Australian Brush Turkey (Alectura lathami), TPIG = Topknot Pigeon (Lopholaimus antarcticus), one species more difficult to separate from congeners by call alone (ASW = Atherton Scrubwren (Sericornis keri), and one species more likely to call when close to the observer ((per. obs.) YTSW = Yellow-throated Scrubwren (Sericornis citreogularis)).
Table 2.
Results of overall and per-species analyses of the effects of each factor covariate on ESW.
Fig 4.
Left: Box-plots showing the relative effect of each covariate, expressed as the proportion of total ESW. Right: Biplots of each species showing the distribution of shifts in ESW. An “x” indicates those species with non-overlapping 95% confidence intervals (see text for details of species). Solid lines are linear regressions of the relationship, with 95% confidence intervals shaded.