Figure 1.
(A) A cane toad Rhinella marina on leaf litter beside a Green Treefrog Litoria caerulea on a fallen branch in the Northern Territory. (B) A Magnificent Treefrog (L. splendida) on a rock outcrop in the Kimberley, Western Australia. (C) Habitat in the Adelaide River floodplain and adjacent monsoon forest (in the background), in Fogg Dam Conservation Reserve, Northern Territory. (D) Woodlands and limestone escarpments surrounding Lake Argyle in the Kimberley region, Western Australia.
Figure 2.
Diurnal substrates used by the three anurans in NT and WA.
Cane toads (Rhinella marina = black bars), Green Treefrogs (Litoria caerulea = light grey bars), and Magnificent Treefrogs (L. splendida = dark grey bars) were sampled in natural and anthropogenically disturbed environments. Data for radio-tracked animals were included as only one record per period per individual.
Figure 3.
Nocturnal substrates used by the three anurans in NT and WA.
Cane toads (Rhinella marina = black bars), Green Treefrogs (Litoria caerulea = light grey bars), and Magnificent Treefrogs (L. splendida = dark grey bars) were sampled in natural and anthropogenically disturbed environments. For radio-tracked animals, only a single record per tracking period was included for each individual.
Figure 4.
Height above ground of substrate used by the three anurans in NT and WA.
Cane toads (R. marina) = RM, green tree frogs (L. caerulea) = LC, and magnificent tree frogs (L. splendida) = LS. Circles represent averages and bars are standard errors. Data for both study areas and environments are pooled together.
Figure 5.
Ordination plot of microhabitat used by the three anurans in NT and WA.
The plot shows the first two axes of a Nonmetric Multidimensional Scale analysis for microhabitat use of Rhinella marina (black circles), Litoria caerulea (triangles) and L. splendida (squares). Solid black lines connect all microhabitats used by R. marina with the centroid of all observations for the species. Hatched grey lines and hatched black lines connect microhabitats used by L. caerulea and by L. splendida, with the respective centroids for each species.
Table 1.
Pianka Index of microhabitat overlap among invasive cane toads Rhinella marina (RM), and native frogs Litoria caerulea (LC) and L. splendida (LS) in Australia.
Table 2.
Percentage of encounters of nearest neighbours according to species in the two studied areas.
Figure 6.
Proportion of encounters of pairs of nearest neighbor species within radio-tracked anurans.
caerulea = Litoria caerulea, marina = Rhinella marina, splendida = L. splendida. The panels show data for diurnal habitats in the Northern Territory (a) and Western Australia (b), and for nocturnal habitats in the Northern Territory (c) and Western Australia (d). Graphs show mean values and associated standard errors. Nearest-neighbour pairs that contain two different species are shown in stippled format.
Figure 7.
Average distance to the nearest neighbor of anurans.
Data show patterns according to the pair of species involved, study site, and occurrence of breeding activity in frogs, at (a) night for surveyed frogs and (b) by day and night for radio-tracked frogs. Bars are standard errors. R = Rhinella marina, C = Litoria caerulea, S = Litoria splendida.