70 Monitoring Threatened Species and Ecological Communities
as threatened: for most species there is insufficient data on population trends to
provide the evidence required for listing. Because most reptile species are not
formally listed as threatened, they are accorded little priority for monitoring (or
other conservation actions). The lack of, or limited, monitoring for most
threatened reptile species is a major impediment to conservation recovery: without
adequate monitoring, the impacts of threats are poorly resolved, the effectiveness
of management responses is not evaluated (and there is insufficient evidence to
guide improvement in management), and information is insufficient to
appropriately revise conservation status. In some cases, the lack of adequate
monitoring may mean that precipitous declines are not detected and hence
managers may lose critical opportunities to prevent extinctions.
Introduction
The Australian reptile fauna is very distinctive, with >90% of species endemic to
Australia (Chapman 2009), but poorly resolved. By global standards, there is a very
high ongoing rate of description of new species (Meiri 2016) – for example, the
number of recognised Australian reptile species increased by almost 90% over the
30-year period from 1974 to 2013 (Cogger 2014). Furthermore, the conservation
status of only ca. 15% of Australian reptile species has been formally assessed by
the IUCN (Meiri and Chapple 2016).
Although this chapter focuses on listed threatened species, it is pertinent to
recognise also that – with some notable exceptions (How 1998) – there is relatively
little long-term monitoring of Australian reptiles generally. As a consequence, for
most reptile species there is little population trend data available from which
conservation status can be assessed. In part ref lecting this very incomplete
knowledge base, the proportion of Australian reptile species that are formally
listed as threatened is relatively low (6.7%) (Walsh et al. 2012; Meiri and Chapple
2016). This chapter considers the 69 reptile taxa listed as threatened nationally
under the Environment Protection and Biodiversity Conservation Act 1999 (EPBC
Act) (56 species and four subspecies) or listed globally by the IUCN (44 species) (as
at December 2016). This set comprises six marine turtles, seven freshwater turtles,
43 lizards, 10 terrestrial snakes and three sea snakes.
Many of Australia’s threatened reptile species are so poorly known and
difficult to detect that monitoring is currently unfeasible and a relatively low
priority relative to other research and management needs. Examples include the
brigalow scaly-foot Paradelma orientalis (Kutt et al. 2003), and the Christmas
Island blind snake Ramphotyphlops exocoeti for which there have been only six
records since 1910 and for which no reliable detection method has been developed
(Maple et al. 2012). There is also the notable case of the Pedra Branca skink
Niveoscincus palfreymani, for which monitoring is currently untenable because it is