Decoding the overlap: diagnostic acoustics to distinguish the endangered Magnificent Broodfrog, Pseudophryne covacevichae Ingram & Corben, 1994, from the common Montane Toadlet, Uperoleia altissima Davies et al., 1993 in northern Queensland, Australia

Abstract

Accurate species identification from passive acoustic monitoring data is critical for threatened species, particularly when vocal overlap with sympatric species risks misidentification. The Magnificent Broodfrog (Pseudophryne covacevichae), a narrowly endemic species of the Australian Wet Tropics listed as Endangered (IUCN) and Vulnerable (Australia EPBC), co-occurs and reproduces alongside the common Montane Toadlet (Uperoleia altissima), and the two species produce advertisement calls that overlap in structure and frequency. This study provides a diagnostic reference to reduce the potential risk of misidentification during acoustic analysis, particularly by those working in poorly documented areas between the Magnificent Broodfrog’s two main populations (Atherton Tablelands and Paluma Range). The advertisement and threat calls of the Magnificent Broodfrog are described in detail and compared with the advertisement call of the Montane Toadlet. Principal Component Analysis showed distinct clustering by species, and an analysis using the Multi-Response Permutation Procedure confirmed call duration contributes most strongly to species discrimination. The Magnificent Broodfrog’s advertisement call was longer, lower in frequency, and had more variation in pulse number than the Montane Toadlet’s short, repetitive call. These findings provide an applied framework to support accurate identification of the Magnificent Broodfrog from recordings and enhance the reliability of acoustic assessments for this threatened species.