Butterflies on the brink: identifying the Australian butterflies (Lepidoptera) most at risk of extinction

Abstract

The diversity and abundance of native invertebrates is declining globally, which could have significant consequences for ecosystem functioning. Declines are likely to be at least as severe as those observed for vertebrates, although often are difficult to quantify due to a lack of historic baseline data and limited monitoring effort. The Lepidoptera are well studied in Australia compared with other invertebrates, so we know that some species are imperilled or declining. Despite this, few butterfly taxa are explicitly listed for protection by legislation. Here we aim to identify the butterfly taxa that would most benefit from listing by determining the Australian butterflies at most immediate risk of extinction. We also identify the research and management actions needed to retain them. For 26 taxa identified by experts and various conservation schedules, we used structured expert elicitation to estimate the probability of extinction within 20 years (i.e. by 2040) and to identify key threatening processes, priority research and management needs. Collation and analysis of expert opinion indicated that one taxon, the laced fritillary (Argynnis hyperbius inconstans), is particularly imperilled, and that four taxa (Jalmenus eubulus, Jalmenus aridus, Hypochrysops piceatus and Oreisplanus munionga larana) have a moderate–high (>30%) risk of extinction by 2040. Mapped distributions of the 26 butterflies revealed that most are endemic to a single state or territory, and that many occupy narrow ranges. Inappropriate fire regimes, habitat loss and fragmentation (through agricultural practices), invasive species (mostly through habitat degradation caused by weeds and rabbits) and climate change were the most prevalent threats affecting the taxa considered. Increased resourcing and management intervention will be required to prevent these extinctions. We provide specific recommendations for averting such losses.

Red hot frogs: identifying the Australian frogs most at risk of extinction

“…We used structured expert elicitation to forecast which, and how many, Australian frog species are at imminent risk of extinction, with the aim of improving prioritisation, direction and resourcing of management aimed at preventing future extinctions. Our approach follows comparable methodology to estimate imminent extinction risk among Australian birds and mammals (Geyle et al 2018), freshwater fish (Lintermans et al 2020), terrestrial squamates (Geyle et al 2020) and butterflies (Geyle et al 2021).…”

Anonychomyrma inclinata sp. nov. (Hymenoptera: Formicidae): description, biology and interaction with the endangered bulloak jewel butterfly, Hypochrysops piceatus Kerr, Macqueen & Sands, 1969 (Lepidoptera: Lycaenidae)

“…2016) and has been assessed through an expert elicitation process as having a greater than one‐in‐three chance of extinction by 2040 (Geyle et al . 2021). The species is currently approved for assessment for listing under the Australian Government Environment Protection and Biodiversity Conservation Act 1999 and the process is due to complete in April 2022 (Australian Government 2019).…”

A national‐scale dataset for threats impacting Australia’s imperiled flora and fauna

“…Recent estimates show that one million species are now threatened with extinction (hereon “threatened”) globally and could go extinct in the next century (IPBES, 2018 ), with at least 515 terrestrial vertebrates likely to be lost within the next 20 years (Ceballos et al., 2020 ). In Australia, 25 taxa (ten birds, seven mammals, six reptiles, one butterfly, and twenty fish) are likely to become extinct within the next 20 years unless major conservation action is undertaken (“taxa” is used through the manuscript to collectively refer to species, subspecies, and important populations; Geyle, Braby, et al., 2021 ; Geyle, Tingley, et al., 2021 ; Geyle et al., 2018 ; Lintermans et al., 2020 ). This decline is driven by rapidly increasing direct and indirect pressures of human activities on species survival.…”