How to make a common species rare: A case against conservation complacency

Ongoing unraveling of a continental fauna: Decline and extinction of Australian mammals since European settlement

“…However, these foundations for biodiversity conservation are clearly not sufficient for maintaining the Australian mammal fauna. Although the reserve system provides fundamental conservation security for at least some other biodiversity groups (106), many of Australia's conservation reserveseven some of the largest and highest profile reserves-have lost or are rapidly losing some of their mammal species (21,22). Furthermore, although the environmental legislation is arguably effective against some acute factors (such as broadscale land clearing, and localized development that may affect threatened species) and has led to the cessation of exploitation of marine mammals, it has proven to be largely ineffective against the insidious and pervasive threats that are responsible for most of the decline in Australia's terrestrial mammals (notably introduced predators and changed fire regimes).…”

“…Although the information base is constrained by the very limited amount of monitoring, most threatened and Near Threatened Australian land mammal species are continuing to decline (7), with some monitoring programs indicating population reductions of >90% in multiple species over the last two decades, even in large conservation reserves (21)(22)(23). With retrospective assessment of conservation status, the review concluded that 55 terrestrial mammal taxa now have a worsened conservation status than they had in 1992 and only a small minority of species is doing better than 20 y ago (Fig.…”

An Evaluation of Butterfly Gardens for Restoring Habitat for the Monarch Butterfly (Lepidoptera: Danaidae)

“…These examples of the rapid and unanticipated loss of common species illustrate how complacency towards species with large population sizes can have disastrous consequences when timely action is not undertaken to safeguard their populations (Lindenmayer et al 2011). As a further example, recent failure to act quickly on evidence of rapid population decline led to the extinction of a bat in Australia, the Christmas Island pipistrelle (Pipistrellus murrayi), which was a common species as recently as 1984 (Martin et al 2012, p. 275).…”

Continental-level biodiversity collapse

“…However, at the same time, the treedwelling marsupial greater glider (Petauroides volans) (Fig. 1B) became regionally extinct and others, including the common ringtail possum (Pesudocheirus peregrinus), are in steep decline (4). Such "ecological surprises" underscore the critical need for careful monitoring of management interventions, including feral predator control.…”