Open AccessExtinct, obscure or imaginary: The lizard species with the smallest ranges
Author(s) -
Meiri Shai,
Bauer Aaron M.,
Allison Allen,
CastroHerrera Fernando,
Chirio Laurent,
Colli Guarino,
Das Indraneil,
Doan Tiffany M.,
Glaw Frank,
Grismer Lee L.,
Hoogmoed Marinus,
Kraus Fred,
LeBreton Matthew,
Meirte Danny,
Nagy Zoltán T.,
Nogueira Cristiano de C.,
Oliver Paul,
Pauwels Olivier S. G.,
PincheiraDonoso Daniel,
Shea Glenn,
Sindaco Roberto,
Tallowin Oliver J. S.,
TorresCarvajal Omar,
Trape JeanFrancois,
Uetz Peter,
Wagner Philipp,
Wang Yuezhao,
Ziegler Thomas,
Roll Uri
Publication year - 2018
Publication title -
diversity and distributions
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.918
H-Index - 118
eISSN - 1472-4642
pISSN - 1366-9516
DOI - 10.1111/ddi.12678
Subject(s) - lizard , ecology , iucn red list , range (aeronautics) , biology , biogeography , extinction (optical mineralogy) , taxon , endemism , squamata , rare species , geography , habitat , paleontology , materials science , composite material
Aim Small geographic ranges make species especially prone to extinction from anthropogenic disturbances or natural stochastic events. We assemble and analyse a comprehensive dataset of all the world's lizard species and identify the species with the smallest ranges—those known only from their type localities. We compare them to wide‐ranging species to infer whether specific geographic regions or biological traits predispose species to have small ranges. Location Global. Methods We extensively surveyed museum collections, the primary literature and our own field records to identify all the species of lizards with a maximum linear geographic extent of <10 km. We compared their biogeography, key biological traits and threat status to those of all other lizards. Results One in seven lizards (927 of the 6,568 currently recognized species) are known only from their type localities. These include 213 species known only from a single specimen. Compared to more wide‐ranging taxa, they mostly inhabit relatively inaccessible regions at lower, mostly tropical, latitudes. Surprisingly, we found that burrowing lifestyle is a relatively unimportant driver of small range size. Geckos are especially prone to having tiny ranges, and skinks dominate lists of such species not seen for over 50 years, as well as of species known only from their holotype. Two‐thirds of these species have no IUCN assessments, and at least 20 are extinct. Main conclusions Fourteen per cent of lizard diversity is restricted to a single location, often in inaccessible regions. These species are elusive, usually poorly known and little studied. Many face severe extinction risk, but current knowledge is inadequate to properly assess this for all of them. We recommend that such species become the focus of taxonomic, ecological and survey efforts.