Richmond Range Sphagnum Frog  |  

Philoria richmondensis

Status: Endangered on the EPBC Act list

The Richmond Mountain Frog is a small, squat, pear-shaped frog endemic to north-east New South Wales (NSW). Males and females are similarly sized with a snout-to-vent length (SVL) of 28 mm for males and 27 mm for females. The skin is smooth with the occasional low ridge or tubercle on the dorsal surface. Like other Philoria species, individuals are variable in colour and pattern. The dorsal surface is bronzy-brown to orange, with an irregular blackish band that runs across the lower back. Smaller dark blotches or spots are sometimes present and aligned on either side of the vertebral line as well as posteriorly on the flanks. The ventral surface is dirty-white to yellow or pale orange. Faint to conspicuous irregular cross-bars are sometimes present on the upper surface of the limbs. The under surface of the legs, feet, and hands are dark. The head is approximately one quarter of the SVL and wider than it is long. The snout is bluntly rounded in profile. A supratympanic fold is present, and the tympanum is hidden or indistinct. A narrow dark-brown band runs from the snout to the eye, then widens, and continues as a broad, dark stripe from the eye, through the ear, to the base of the shoulder. The eyes are prominent with a horizontal pupil, and the iris is golden above and brown below. The hind-limbs are short. The fingers and toes are long, slender, cylindrical, and unwebbed. Breeding males have a poorly developed nuptial pad on the first finger, and females have spatula-shaped first and second fingers. The description of the adult is drawn from Knowles et al. 2004; Cogger
2014; and Anstis 2017. Tadpoles are small, growing to 19 mm in total length. The body is very small (5.5 mm) and oval, with the abdomen wider than it is deep. At later stages, the body turns darker with increased grey pigmentation, but the intestinal mass remains visible. The snout is rounded. The eyes are lateral in earlier stages, dorso-lateral later. The oral disc edges are slightly keratinised. The fins
are clear with numerous blood vessels. The dorsal fin begins from just onto the body. Both the dorsal and ventral fins are shallow along the length of the tail with the tail-tip broadly rounded.

Government evidence of impact of climate change:

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  • Australian Government, Conservation Advice, Philoria richmondensis

    Threat factor Threat type Evidence base and status Climate Change Increased Known current Climate change is expected to cause a pronounced temperature increase in extinction risk for frog species over the intensity frequency coming century; with terrestrial breeding and change to frogs identified as some of the most vulnerable taxa precipitation patterns (Hero et al. 2005 Lemckert Penman 2012 Hagger et al. 2013 Pearson et al. 2014 Lopez 2016).
    Climate projections for eastern Australia include reduced rainfall; increased average temperatures; and more frequent droughts.
    Despite this protection; impacts from climate change have been observed.
    Increased Known current Climate projections for eastern Australia of higher intensity frequency of temperatures and change to rainfall patterns will bushfire increase the scale; frequency and intensity of wildfires in the region (CSIRO 2007 CSIRO Bureau of Meteorology 2015).
    This sort of event is increasingly likely to reoccur as a result of climate change.
    In addition; an anticipated decline in the amount of montane rainforest habitat is predicted under moderate (RCP6.0) and extreme (RCP8.5) climate change scenarios (Lopez 2016).
    There is no evidence of Bd related declines for the species and its disappearance from historical sites is thought to be related to climate change (drought) rather than disease.
    Threats; in particular climate change; are likely to have resulted in a population decline in the Richmond Mountain Frog.
    Climate change has the greatest impact at higher elevations; which are home to the largest concentration of threatened anuran species (41 percent); with terrestrial breeding frogs identified as some of the most vulnerable taxa (Hero Morrison 2004 Hero et al. 2005 Lemckert Penman 2012 Hagger et al. 2013 Pearson et al. 2014 Lopez 2016).
    The species small and fragmented range; habitat specialisation of bogs and soaks; together with small clutch sizes and slow growth rates; increase its susceptible to perturbations under climate change.
    In particular; the small population size (see Criterion 3); already high degree of subpopulation isolation (Knowles et al. 2004 Willacy et al. 2015 OEH 2019); and the low dispersal ability (and associated poor recolonisation potential) of the species (Newell 2018); reduces the likelihood of recovery from extreme events associated with climate change (as identified in Criterion 1).
    Climate change is already thought to have impacted the population.
    The Richmond Mountain Frog population is projected to continue to decline based on the ongoing threats to the population; most notably climate change; which is already thought to have impacted the population (as identified in Criterion 1).
    Information and research priorities Understand the potential influence of climate change on the long term survival prospects of the species; due to altered temperatures; rainfall patterns; bushfires; environmental stressors; and diseases.
    An analysis by a team from the National Environmental Science Program (NESP) Threatened Species Recovery (TSR) Hub showed that 8 of the distribution of the Richmond Mountain Frog was affected by these fires (with 3 burnt in high to very high severity fire); and the estimated proportional population change for this species from pre fire levels to 1 year after the fire was an overall decline of 6 from pre fire levels; but that the decline could be as large as 20 (bound of 80 confidence limits) (Legge et al. 2021).
    The 2019 20 bushfires may have accelerated any population decline; through direct mortality and the unfavourable post fire conditions (loss of shelter; increased susceptibility to predators; and loss of prey); as well as a reduction in future recruitment (egg and tadpole death and breeding site degradation).
    A structured expert elicitation process was used to estimate the proportional population change for this species from pre fire levels to immediately after the fire and then out to three generations after the fire; when exposed to fires of varying severity.
    For comparison; experts also estimated the population change over time in the absence of fire by three generations; the overall population of the Richmond Mountain Frog after the fire was estimated to be three percent lower than it would have been had the 2019 20 fires not occurred (Legge et al. 2021).
    Field studies during the 2020 21 breeding season found evidence of the impact of the 2019 20 bushfires; as well as drought conditions prevailing before the fires.