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

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.

Characteristics, Main Impacts, and Stewardship of Natural and Artificial Freshwater Environments: Consequences for Biodiversity Conservation

“…Urban Freshwater Habitats [49] Typically low biodiversity, but there are also examples of higher species richness compared with similar non-urban habitats Biodiversity decline, high extinction risk (especially strictly aquatic organisms, such as fish and mollusks), many protected areas do not cover critical areas of biodiversity Great efforts made to minimize influence of effluents, dust is a major phosphate source (especially in summer), man-made manipulation of water levels at an amplitude much greater than natural Shift from using lake water to using desalinized water as a major source of drinking water to stop the large year-to-year fluctuations in water level, non-native fish stocking ban Tropical Freshwater Habitats [52] Flood pulse, intermittent wetlands, biggest river basins, hotspot of mega-biodiversity (i.e., fishes, amphibians)…”

“…For example, where connecting people with nature [332] is a high priority, the richness of benthic macroinvertebrates may have a limited role in measuring conservation success. In such circumstances, the presence and abundance of turtles and large freshwater dependent lizards ( Figure 2R) may be good indicators of conservation success because they often utilize riparian and terrestrial habitats as well as instream habitats and are likely to be seen often by people [49]. Combining the use of such indicators with the established ones (e.g., macroinvertebrates), fish may help to tailor biological monitoring to meet the specific goals of urban conservation projects.…”

“…We also briefly explore what can be done to protect or restore these ecosystems. We thus aim at addressing the multiplicity of still and running freshwater environments, from headwaters down to large rivers and lakes (papers published in the VSI are cited in the following): groundwater and dependent ecosystems, springs and spring-fed streams [40][41][42][43][44][45], headwaters [46,47], glacial streams [48], streams, large rivers, ancient and large lakes, high-mountain lakes, oxbow lakes, reservoirs, urban freshwater habitats (fwh) [49], mires [50], small wetland ecosystems [51], Boreal and Arctic fwh, Antarctic fwh, Mediterranean fwh, tropical fwh [52], arid-climate fwh ( Table 1; the ecosystem types addressed and flagship organisms are illustrated in Figures 1 and 2).…”

Twenty‐five essential research questions to inform the protection and restoration of freshwater biodiversity

“…These opportunities require the rethinking of targets and indicators (e.g. freshwater reptiles; Turak et al, 2020) in efforts to protect and improve urban biodiversity.…”

Alligators in the big city: spatial ecology of American alligators (Alligator mississippiensis) at multiple scales across an urban landscape

“…The American alligator ( Alligator mississippiensis ) is a widely abundant, large-bodied apex predator found across the southeastern U.S. but has received minimal attention within urban areas. This is particularly surprising because alligators, and crocodilians in general, are regularly sighted within 10 km of city centers 9 . Furthermore, alligators are a well-known indicator species that have been used to track the health of other ecosystems like the Everglades due to their ability to integrate changes in habitat and water quality within their tissues and behaviors 10 .…”