Hosmer's Frog  |  

Cophixalus hosmeri

Status: Critically Endangered on the EPBC Act list

The Rattling Nursery Frog is a small species of frog (snout-to-vent length of males to 14 mm, females to 17 mm), belonging to the family Microhylidae. It is the lightest of Australian Cophixalus with mean adult mass of 0.27 g. The most consistent morphological character for distinguishing it from other Cophixalus species of similar size is its relatively short hind legs. The Rattling Nursery Frog is grey-brown above with obscure darker flecks and blotches, the most consistent being a chevron-shaped mark between the shoulders and a streak behind the eye. The throat, chest and sometimes abdomen are dark grey with paler Cophixalus hosmeri (Rattling Nursery Frog) Conservation Advice Page 2 of 10 stippling or the abdomen and thighs are sometimes yellowish. The skin is smooth to slightly granular above and smooth below. The male call is a rapidly pulsed tap with some variation occurring between individuals within sites but all of the various calls are of considerably higher frequency than other Australian Cophixalus species. The eggs are relatively large and are laid in very moist soil or more recently have been found in the axils of palms. The tadpole develops inside the egg and when it has completed metamorphosis it hatches from the egg as a fully formed froglet.

Government evidence of impact of climate change:

Expand all Close all
  • Australian Government, Conservation Advice, Cophixalus hosmeri

    Threats Threats to the Rattling Nursery Frog include climate change; habitat degradation and introduced species.
    Climate change modelling carried out by Williams and Hilbert (2006) suggests that five Cophixalus species (including C. hosmeri) would lose more than 50 percent of their core habitat with a 1 oC increase in temperature.
    Therefore the impacts of climate change are thought to be the greatest threat to the survival of these microhylid frogs (Williams 2007).
    The Rattling Nursery Frog was ranked second on the list of the 20 most vulnerable vertebrate species to climate change in the Wet tropics (Williams Hilbert 2006).
    Changes in hydrology and other effects of climate change (e.g. reduction in food supply) may also alter the susceptibility of frogs to disease; but these impacts are likely to be variable among species and sites (DoEE 2016). 2.0 Habitat loss and degradation 2.1 Clearing; Known Feral pigs are responsible for habitat damage trampling; potential and potentially cause adult frog mortality fragmentation; (Richards et al. 1993). altered hydrology 3.0 Invasive species 3.1 Yellow Crazy Known Yellow crazy ants spray formic acid to Ants potential subdue prey; which causes burns and (Anoplolepis irritates the skin and eyes of animals.
    The IUCN Guidelines (2017) indicate that subpopulations such as these; located at the same altitudes in identical habitat on geographically similar mountains should be interpreted as a single location for the species because they may be affected by the same most serious plausible threat in this case climate change.
    A continuing decline in area of occupancy and area; extent and or quality of habitat; and therefore number of mature individuals; may be inferred based on climate change (Shoo 2005 Williams et al. 2003 Williams and Hilbert 2006).
    Distribution weather events modelling for this species suggests a e.g. cyclones; population reduction of greater than 40 if droughts temperatures increase by 1 oC (Shoo 2005).