 Amphibian populations in the beginning stages of decline often exude a number of signs , which may potentially be used to identify at @-@ risk segments in conservation efforts . One such sign is developmental instability , which has been proven as evidence of environmental stress . This environmental stress can potentially raise susceptibility to diseases such as chytridiomycosis , and thus lead to amphibian declines . In a study conducted in Queensland , Australia , for example , populations of two amphibian species , Litoria nannotis and Litoria genimaculata , were found to exhibit far greater levels of limb asymmetry in pre @-@ decline years than in control years , the latter of which preceded die offs by an average of 16 years . Learning to identify such signals in the critical period before population declines occur might greatly improve conservation efforts . 
