Littlejohn’s Tree Frog is a medium-sized frog from the Family Hylidae (“tree frogs”). Females are larger than males, having a snout-to-vent length (SVL) to 72 mm, while males reach 56 mm SVL. The dorsal surface is mostly smooth and light grey, grey-brown, or warm dark brown. The ventral surface is granular and white or cream in colour. Distinctive bright orange-red markings are present on the inner and hind surfaces of the legs. A broad vertebral band extends from behind the eyes and down the back, which is sometimes longitudinally dissected by a pale line. In light grey specimens, the vertebral band is barely visible. Some specimens have scattered darker patches or mottling, especially over the sides. The head is broader than it is long, and the snout is rounded and slightly upturned. A skin fold is present above a distinct brown tympanum. A dark stripe extends from the tip of the snout to the eye, broadens over the tympanum, and terminates at the shoulder. The eyes are large and golden. The legs are moderate to long. The fingers and toes are long with moderately expanded discs. The fingers have distinct basal webbing between the third and fourth fingers, and the toes are almost fully webbed with less webbing between the first and second toes.
Littlejohn's Tree Frog, Heath Frog |
Status: Endangered on the EPBC Act list
Government evidence of impact of climate change:
Australian Government, Conservation Advice, Litoria littlejohni
Habitat has also been degraded by climate change (including increased severity and frequency of bushfires and drought) and visitors to National Parks.
Mortality Trend unknown associated with Bd erodes the capacity of the population to Extent across the entire sustain loss of recruitment associated with drought and reduces range resilience to climate change (Scheele et al. 2016).
Climate change Increased severity Status current Climate change is expected to cause a pronounced increase in and frequency of extinction risk for frog species over the coming century (Hagger Confidence known heatwaves and et al. 2013 Pearson et al. 2014).
Climate projections for change to Consequence severe south eastern Australia include reduced rainfall; increased precipitation average temperatures; and more frequent droughts.
Climate change is expected to impact frog recruitment by reducing the availability and altering the seasonality of breeding sites (Lemckert and Penman 2012 DEPI 2014 Lowe et al. 2015).
This sort of event is increasingly likely to reoccur as a result of climate change.
A continuing decline in EOO; AOO; extent and or quality of habitat (and therefore number of locations or subpopulations); and number of mature individuals may be inferred based on the ongoing threats to Littlejohn s Tree Frog; in particular disease (Bd); habitat loss; and climate change (see Criterion 1); thereby meeting subcriterion (b)(i;ii;iii;iv;v).
Increased intensity Status current Localised extinction of frogs has been observed through bushfire and frequency of events.
They are unable to Confidence known bushfire flee and have a low tolerance of extreme temperatures and Consequence severe desiccation (Gillespie et al. 2016).
An analysis by a team from the National Environmental Science Program (NESP) Threatened Species Recovery (TSR) Hub showed that 21 of the distribution of Littlejohn s Tree Frog was affected by these fires (with 9 burnt in high to very high severity fire); and the estimated proportional population change for this species from pre fire levels to one year after the fire was an overall decline of 11 from pre fire levels; but that the decline could be as large as 26 (bound of 80 confidence limits).
The fires 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 Littlejohn s Tree Frogs after the fire was estimated to be 6 percent lower than it would have been had the 2019 20 fire not occurred (Legge et al. 2021).
The number of locations; based on altered fire regimes as the most serious plausible threat; is estimated as three; meeting the threshold for listing as Endangered under subcriterion (a) (see Table 2).
Adding to a loss of forest habitat; the availability of breeding sites; particularly ephemeral ponds; was likely reduced during recent extreme drought events.