Tag Archives: evolution

Rock Refugia

Patrick Couper is Curator of Reptiles and Amphibians at Queensland Museum and has an active interest in the taxonomy, ecology and conservation of Queensland’s diverse reptile fauna.

Patrick Couper

A major focus of Patrick’s research has been the discovery and description of leaf-tailed geckos that live in the rainforests of eastern Australia. Leaf-tails, which have a long rainforest ancestry, often have strong associations with rocky outcrops. Rocky areas have provided a safe haven for these animals through past periods of climate change. Patrick and Conrad Hoskin (James Cook University, Townsville) have termed such areas, lithorefugia. (Refugia are areas where special environmental conditions have enabled a species or a community of species to survive despite their extinction from surrounding areas.)

Leaf-tailed Gecko, Orraya occultus, from a boulder-strewn creek line in NE Qld

Layered rocky areas are well-buffered from fire and provide cool, moist, stable conditions. These conditions are similar to those found in rainforests.

Black Mountain near Cooktown- typical boulder habitat

The Australian continent was once blanketed with extensive rainforests but as conditions became increasingly arid, these forests contracted to smaller pockets like the remnants now found in coastal Queensland and NSW. As the forests contacted so did their faunas and some rainforest animals retreated to, and survived in, rocky landscapes, many of which are now well isolated from modern rainforests.

During this time, many species became extinct but others survived in these rocky landscapes and produced new species. Recent DNA studies show that many of these rock-dwellers have strong genetic ties to modern rainforest animals. The lithorefugia story is important for understanding the evolutionary processes that shaped Australia’s rainforests and their associated faunas.

There are many examples of rainforest animals that survived in rocky areas. Rainforest snail, spiders, tail-less whip scorpions, and microhylid frogs, such as the Black Mountain Boulder Frog are some examples. There are even mammals that have undergone a shift from rainforest to rock. For instance, the Rock Ringtail Possum that is found in rocky parts of the Kimberley region (WA) and Arnhem Land (NT) has genetic and behavioural characteristics similar to the Green Ringtail Possum, a species now found only in the high altitude rainforests of NE Queensland.

Black Mountain Boulder Frog, Cophixalus saxatilis

The above discussion is relevant to Unit 2 (Change and Survival) of the draft Senior Biology Curriculum. For example, in the Science Understanding strand of this unit is the topic: Evolution of Australian flora and fauna, including

  • significant events in Australia’s geological history and their effect on the evolution of a unique flora and fauna
  • the effect of change in past climates on Australia’s flora and fauna

Species adapt to different conditions as habitats and climates change. To learn more about how climate change has affected the evolution of different animal groups, investigate the online learning resource, Dinosaurs, Climate Change and Biodiversity which contains many teacher and student resources.

To learn more about the work that Patrick does, visit his Biography page.

You can investigate leaf-tailed geckos and other amazing reptiles, by visiting the Reptile section on Queensland Museum’s website.