Distribution and Habitat
Population and Distribution
Geocrinia vitellina is confined to a 6.3 km2 area east of the Leeuwin-Naturaliste Ridge in the extreme s.w. of WA (Tyler 1997). Only six populations of G. vitellina are known (Roberts et al. 1999). Population estimates are available for Spearwood North and South from 1992 to 1998 (Driscoll 1998, 1999; Roberts et al. 1999) and Geo Ck from 1993 to 1994 (Driscoll 1998, 1999). Estimates of calling males for the three locations varied between approximately 30 and 160 individuals (Driscoll 1998, 1999; Roberts et al. 1999). Populations at Spearwood varied in size over the survey period with no obvious cause of decline or increase at either site (Roberts et al. 1999). In 1994 the maximum total number of adults of the species was estimated at 2,230 frogs (Wardell-Johnson et al. 1995 in Roberts et al. 1999). Habitat
Geocrinia vitellina is wholly distributed within SF (Tyler 1997). However, most of the species range has been recommended for gazettal as a Nature Reserve as part of the Regional Forest Agreement.
Wardell-Johnson and Roberts (1993) described the biogeographic barriers separating the distributions of four allopatric species from the Geocrinia rosea complex. Both G. alba and G. vitellina occur in permanently moist sites in relatively dry and seasonal climatic zones and their distributions are separated by 9 km of lateritic uplands and narrow valleys (Wardell-Johnson & Roberts 1993). Geocrinia vitellina occupies six unconnected and undisturbed areas of riparian vegetation at an elevation of 120 m in broad u-shaped valleys where there is marked topographic relief (Tyler 1997). The species is abundant at seepages but rare on the valley floor (Tyler et al. 1994).