water conditions. Thus, P. bibronii males make nesting sites in areas that are moist and are likely to flood to initiate hatching. P. bibronii eggs hatch in response to partial pressure of oxygen in the surroundings. Eggs develop in burrows that are buried under vegetation or leaf litters. The atmospheric oxygen reaches the eggs through small tunnels and oxygen pressure remains stable until eggs are mature. Eggs reach maturation after 39 days of age and if they are flooded at this point they will be ready to hatch. Once the nest is flooded with water the partial pressure of oxygen in the nest decreases as the oxygen consumption of the embryos increases. The low partial pressure of oxygen triggers the hatching of the egg and the tadpoles are released. If partial pressure of oxygen never decreases due to delayed flooding, development of the egg stalls. Conservation efforts P. bibronii are widespread throughout Queensland, Australia. The Flora and Fauna Guarantee Act of 1988 designated the species as threatened and the International Union for Conservation of Nature (IUCN) designated the frog as Least concern. Increasing drought in the Australian grasslands has caused a decrease in frog populations overall. The drought has caused once lush paddocks to turn to barren fields, creating fewer places for the P. bibronii to burrow. There has been increasing habitat loss for these frogs causing a significant decline in the population. However, P. bibronii populations are enduring and can still be heard in the woodlands during mating season. Tracking these frogs is also very difficult as they are very secretive and cryptic, thus it is hard to get an accurate population count of the species. On February 7, 2004, wildfires burned down many natural areas in the Melbourne area. This fire burned down many natural habitats of P. bibronii causing a steep decline in their population levels in disturbed habitats. The impact of these fires is thought to have affected the mortality rates of adult frogs, amount of territory for breeding, and overall habitat loss. Efforts have been made to track changes in P. bibronii population size before and after the fires, but the lack of pre-fire data has made it hard to make any conclusions about the effects of the fire on the population. Sources Anstis, M. 2002. Tadpoles of South-eastern Australia. Reed New Holland: Sydney. Robinson, M. 2002. A Field Guide to Frogs of Australia. Australian