Perspective: The causes and biogeographical significance of species’ rediscovery

Richard Ladle,Steve Jennings,Maan Barua,Ana C M Malhado,Paul Jepson

doi:10.21425/f53312432

Abstract

perspective: The causes and biogeographical significance of species’ rediscovery

Highlights

Rediscoveries of putatively extinct species are of great potential interest to both conservationists and biogeographers (Crowley 2011)
Species are ‘lost’ from scientific knowledge for different reasons and, not all rediscoveries are significant for biogeographical research or conservation
Rediscoveries of species that underwent a well documented decline and disappearance – and are of greatest potential importance for both conservation and biogeographical research – appear to be poorly repre‐ sented in the literature compared to rediscovered species that were only known from a handful of mu‐ seum specimens

Summary

Introduction

Rediscoveries of putatively extinct species are of great potential interest to both conservationists and biogeographers (Crowley 2011). Biogeographers have started to use information on species rediscoveries to test theories of population decline and range collapse under anthropogenic disturbance (Fisher 2011a,b; Fisher and Blomberg 2011). One of the strongest patterns observed was that redis‐ coveries were generally made at higher elevations than the original record (excluding mountain‐top and coastally restricted species). This provides some support for the hypothesis that higher ele‐ vations can sometimes provide ecological refugia (Towns and Daugherty 1994) and fits with the fre‐ quently observed pattern of habitat destruction and population extinction progressing from low to high altitudes (Triantis et al 2010). We believe that formalizing the concept of rediscovery in this way has the poten‐ tial to create new measures of the state of knowl‐ edge of the world’s rarest species, provide a quan‐ tifiable metric to support existing endangerment categorizations, and would help to maintain the culture of biogeographical exploration that con‐ tributes to the datasets that underpin global con‐ servation target‐setting, advocacy and monitoring

Conceptual framework

Ecological factors

Rediscoveries reconsidered

Findings

Conclusions