Genetic analysis reveals the costs of peri-urban development for the endangered grassland earless dragon

Genetic diversity and structure of the threatened striped legless lizard, Delma impar: management implications for the species and a translocated population

“…Of the 154 striped legless lizards analysed from six Canberra populations in this study, we observed relatively high levels of genetic diversity (mean A = 11.5, mean A R = 8.9, mean H E = 0.80) as compared to other threatened reptiles that co-occur in these grassland habitats. For example, similar diversity measures (mean A = 8.8 and 14.8, mean A R = 8.4 and 11.7 and mean H E = 0.81 and 0.84) were observed in two separate studies of the endangered grassland earless dragon (Tympanocryptis pinguicolla) (Hoehn et al 2013;Carlson et al 2016), and in the closely related pink-tailed worm-lizard (Aprasia parapulchella) (mean A = 4.9 and H E = 0.52) (Knopp and Sarre 2012), which are both grassland specialists that inhabit native grasslands of the Australian Capital Territory (which includes the Canberra region). Levels of diversity were also comparable in the Australian Alpine Skink (Pseudemoia cryodroma) (mean A = 10.9, mean A R = 8.5 and mean H E = 0.71; Haines et al 2017) and the mountain log skink (Pseudemoia entrecasteauxii) (mean A = 12.2 and mean H E = 0.85; Stapely et al 2003) and in several more distantly related species such as the northern grass lizard (Takydromus septentrionalis) (Guo et al 2015), the "fire-specialist" lizards Amphibolorus norrisi, Ctenotus atlas, and Nephrurus stellatus (Smith et al 2011), the arboreal geckos Oedura reticulata and Gehyra variegata (Hoehn et al 2007), the Australian scincid lizards Tiliqua rugosa and T. adelaidensus (Gardner et al 2008) and the limbless lizard (Anniella alexanderae) (Wogan et al 2015), where observed diversity measures ranged from A = 7.8 to 16.4 and H E = 0.77 to 0.90.…”

A roadmap for urban evolutionary ecology

“…Ensuring the resilience of urban populations requires large population sizes to maintain sufficient genetic variation for natural selection to act upon (Sgrò et al, ). Consequently, to facilitate movement between populations and promote the maintenance of genetic diversity and long‐term persistence of populations, the authors recommended the protection, rehabilitation, and connection of the lizard's grassland habitats (Hoehn et al, ). Large, diverse populations can also be achieved through strategies such as building and conserving sufficiently large parks, curbing urban sprawl, and creating dispersal corridors between populations, potentially along existing roadways and railways (Haddad, ), as well as riparian zones (Edge et al, ).…”

“…To achieve this outcome, it will be necessary for urban scientists to redefine how they study urban ecosystems and communicate their findings to help decision-makers incorporate evolutionary insights into practice. For example, highways severely limit the dispersal of an endangered Australian lizard, Tympanocryptis pinguicolla Mitchell (earless dragon), which has resulted in the isolation and genetic differentiation of remnant populations, and declines in abundance (Hoehn, Dimond, Osborne, & Sarre, 2013). Ensuring the resilience of urban populations requires large population sizes to maintain sufficient genetic variation for natural selection to act upon (Sgrò et al, 2010).…”

Taxonomy and conservation of grassland earless dragons: new species and an assessment of the first possible extinction of a reptile on mainland Australia

“…The population sizes at several of those sites have declined since surveys began and the lizards have become undetectable in some places [43]. The populations that remain are heavily fragmented by roads, airports and other infrastructure forming genetically discrete populations in most cases [44]. A major population distributional disjunction that may pre-date the European settlement of Canberra occurs to the north and south of the Molonglo River which splits Canberra.…”