Global distribution and conservation status of ecologically rare mammal and bird species

Abstract

Identifying species that are both geographically restricted and functionally distinct, i.e. supporting rare traits and functions, is of prime importance given their risk of extinction and their potential contribution to ecosystem functioning. We use global species distributions and functional traits for birds and mammals to identify the ecologically rare species, understand their characteristics, and identify hotspots. We find that ecologically rare species are disproportionately represented in IUCN threatened categories, insufficiently covered by protected areas, and for some of them sensitive to current and future threats. While they are more abundant overall in countries with a low human development index, some countries with high human development index are also hotspots of ecological rarity, suggesting transboundary responsibility for their conservation. Altogether, these results state that more conservation emphasis should be given to ecological rarity given future environmental conditions and the need to sustain multiple ecosystem processes in the long-term.

Fuzzy quantification of common and rare species in ecological communities (FuzzyQ)

“…Such a framework would also be extremely valuable for conservation biology in at least three important aspects: (1) Species rarity is an important predictor of extinction risk because the impact of environmental disturbances is expected to be higher on small populations (Davies, Margules, & Lawrence, 2000) and since budgets for biodiversity conservation are limited, quantifying the rarity of species would facilitate prioritizing some over the others. (2) From a functional perspective, the role played by common and rare species in providing ecosystem services is currently under scrutiny (Leitão et al, 2016, Loiseau et al, 2020. Although intuitively it might be assumed that most of the ecosystem functionality should reside in the former, the contribution of rare species is still poorly understood and, in fact, might be substantial (Leitão et al, 2016;Violle et al, 2017;Dee et al, 2019, Loiseau et al, 2020.…”

“…(b) From a functional perspective, the role played by common and rare species in providing ecosystem services is currently under scrutiny (Leitão et al., 2016; Loiseau et al., 2020). Although intuitively it might be assumed that most of the ecosystem functionality should reside in the former, the contribution of rare species is still poorly understood and, in fact, might be substantial (Dee et al., 2019; Leitão et al., 2016; Loiseau et al., 2020; Violle et al., 2017). So assessing rarity could also be justified in terms of identifying species that provide essential ecosystem services (Dee et al., 2019; Flather & Sieg, 2007; Loiseau et al., 2020; Violle et al., 2017) or stabilize ecological communities (Calatayud et al., 2019).…”

“…Although intuitively it might be assumed that most of the ecosystem functionality should reside in the former, the contribution of rare species is still poorly understood and, in fact, might be substantial (Dee et al., 2019; Leitão et al., 2016; Loiseau et al., 2020; Violle et al., 2017). So assessing rarity could also be justified in terms of identifying species that provide essential ecosystem services (Dee et al., 2019; Flather & Sieg, 2007; Loiseau et al., 2020; Violle et al., 2017) or stabilize ecological communities (Calatayud et al., 2019). (c) Monitoring variation of commonness‐rarity patterns over time or along geographical and environmental gradients provides a simple way to obtain crucial information on ecosystem changes (McGill, 2011).…”

“…Such a framework would also be extremely valuable for conservation biology in at least three important aspects: (a) Species rarity is an important predictor of extinction risk because the impact of environmental disturbances is expected to be higher on small populations (Davies et al, 2000) and since budgets for biodiversity conservation are limited, quantifying the rarity of species would facilitate prioritizing some over the others. (b) From a functional perspective, the role played by common and rare species in providing ecosystem services is currently under scrutiny (Leitão et al, 2016;Loiseau et al, 2020).…”

“…Although intuitively it might be assumed that most of the ecosystem functionality should reside in the former, the contribution of rare species is still poorly understood and, in fact, might be substantial (Dee et al, 2019;Leitão et al, 2016;Loiseau et al, 2020;Violle et al, 2017).…”