Freshwater Reptile Persistence and Conservation in Cities: Insights from Species Occurrence Records

Eren Turak,Megan Powell,Alex Bush,Jocelyn Dela-Cruz

doi:10.3390/w12030651

Abstract

Reptiles are rarely included in urban freshwater biodiversity monitoring and conservation. We explored the global persistence of freshwater dependent turtles, lizards, crocodilians and snakes in cities with a population greater than 100,000 using species occurrence data in online databases from a five-year period (2013–2018). We then used ecological niche models to help identify the locations of suitable habitats for three freshwater reptile species in Sydney, Australia. Our Global analysis showed that sightings of a majority of known species of crocodilians and freshwater turtles were recorded in databases within this 5-year period in contrast to about one in three freshwater lizard species and one in ten freshwater snake species and that freshwater reptiles were observed within 50 km of the center of 40% of the 3525 cities. While global databases hold substantial recent species occurrence records for some regions, they contain very little data for large parts of the world. Modelling showed that potential suitable habitat for the three freshwater species in Sydney was distributed across areas with different levels of urban development. The persistence of populations of freshwater reptiles in and around a large proportion of the world’s cities show that this group can play an important role in urban biodiversity conservation.

Highlights

The number of people living in cities is expected to reach 6.3 billion by 2050, representing an increase of 62% from 2014 [1]
For other groups the lists of freshwater species currently accepted by Freshwater Animal Diversity Assessment (FADA) (Aaike DeWever pers. comm.) was used (Table S1) to extract a global dataset of sightings of freshwater reptile species in the five-year period (2013–2018)
The recent lists of freshwater reptile species have 84 more snakes, 29 more lizards and 12 more turtles (Table 1) compared with the numbers published for FADA [7]

Summary

Introduction

The number of people living in cities is expected to reach 6.3 billion by 2050, representing an increase of 62% from 2014 [1]. The growth of urban populations between 2000 and 2030 is expected to be around 70%, while the growth of urban land cover in the same period is expected to be 200% [2]. One implication of these predictions is that biodiversity conservation in cities will play an increasingly important role in protecting and restoring earth’s biodiversity in the 21st century. Freshwater reptiles are typically dependent on components of both aquatic and terrestrial environments This could make them either more vulnerable or more resilient to a specific threat compared with strictly aquatic or strictly terrestrial species. The persistence of freshwater reptiles in cities can provide very useful information on the status of urban ecosystems

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