Two species of freshwater turtle coexist in the Bellinger River: Elseya georgesi is common but limited to the Bellinger River, whereas Emydura macquarii is widespread but rare in the Bellinger River. The Bellinger River population of E. macquarii has been proposed as a distinct subspecies, so it may be endangered. Survivorship, fecundity, growth, size and age were determined for El. georgesi and the finite rate of increase (λ) was estimated by a life-table analysis using mark–recapture data from surveys between 1988 and 2004. These parameters were compared with those of well studied populations of E. macquarii to assess whether modelling the demographic parameters of El. georgesi could serve as a surrogate for estimating the influences of these demographic parameters on λ in the Bellinger River population of E. macquarii. We estimated that ~4500 El. georgesi inhabit the study area and, despite a size distribution strongly biased towards large individuals, the population is increasing (λ = 1.15) in the best-case scenario, or slightly decreasing (λ = 0.96) in the worst-case scenario. Comparing El. georgesi with E. macquarii from the Bellinger River and elsewhere suggests that E. macquarii grows faster, attains greater maximum size, has a greater clutch size and a higher fecundity than El. georgesi. Hence, El. georgesi does not serve as a good surrogate to determine demographic influences on λ in E. macquarii.

in New Zealand, introduced mammals, especially rats, have been considered a primary factor in the extinction of amphibians. Leiopelma hochstetteri is a riparian frog, and is the most widespread of the surviving species of native frogs in New Zealand. at present, all populations of this frog species coexist with introduced mammals, which in some cases have been subject to pest-management operations without monitoring the potential benefits or damage to the frogs. We investigated the influence of a 7-year rat management operation on frog abundance in the Waitakere Ranges, New Zealand. We identified which habitat characteristics had significant influence on frog abundance; confirmed that the study areas represented similar habitats both inside and outside the pest-managed area, and finally evaluated the effects of the pest-management activities. frog abundance was positively correlated with percentage area covered by boulders and percentage area covered by water. Since the study sites were similar in terms of those variables, we could make a reliable comparison of frog abundance in relation to pest management. Presence/absence of pest-management operations did not have any significant effect on frog abundance. Size-frequency distribution data suggest that there has been recruitment of young frogs both inside and outside pest-management areas in the past 7 years.

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Leiopelma hochstetteri is the most widespread and abundant endemic frog species in New Zealand, although it now survives only in spatially fragmented populations throughout the North Island of New Zealand and the Great Barrier Island of northeastern New Zealand. The species is known to occur in wet areas adjacent to shaded streams in forested catchments; however, no quantitative ecological data exist to enable characterisation of its habitat. In the present study, novel data on the current distribution and habitat requirements of this species are reported for 1 population in the Waitakere Ranges, northwestern New Zealand, which is considered as a conservation management unit for the species. Frogs were found within most streams surveyed (68.2%). Statistical modelling demonstrates that frogs most likely occur in small, erosive streams with coarse substrates and cold waters, surrounded by mature or undisturbed riparian vegetation. Anthropogenic activities such as clearing or logging are identified as threats to this frog species.