This paper was originally published in Conservation Biology.


Abstract: Human modification of the environment is driving declines in population size and distributional extent of much of the world’s biota. These declines extend to many of the most abundant and widespread species, where proportionally small declines can result in the loss of vast numbers of individuals, biomass, and interactions.

These losses could have major localised effects on ecological and cultural processes and services, without elevating a species’ global extinction risk. While most conservation effort is directed at species threatened with extinction in the very near‐term, the value of retaining abundance regardless of global extinction risk can readily be justified against many biodiversity or ecosystem‐service metrics, including cultural services, at scales from local to global.

Here, we characterise the challenges facing the identification of conservation priorities for widespread and abundant species, addressing the broader consequences of declines that differ in magnitude and spatial distribution, and where negative effects may be disconnected from the threat process driving declines. Conservation prioritisation for these species shares greater similarity with invasive species risk assessments than extinction risk assessments, because of the importance of local context and per capita effects of abundance on other species.

Because conservation priorities are usually focussed on preventing the extinction of threatened species, the rationale and objectives for incorporating declines in non‐threatened species must be clearly articulated, going beyond just extinction risk to encompass the range of harmful effects that are likely to be realised if declines persist or are not reversed. Research should focus on characterising the effects of the local decline in species that are globally non‐threatened across a range of ecosystem‐services, and quantifying the spatial distribution of these effects through the distribution of abundance. The conservation case for conserving abundance in non‐threatened species can be made most powerfully when the costs of losing this abundance are better understood…”

Read on and access the full paper at: Conservation Biology.