Does urbanization influence the diet of a large snake?

Abstract

Urbanization facilitates synanthropic species such as rodents, which benefit the diets of many predators in cities. We investigated how urbanization affects the feeding ecology of dugites Pseudonaja affinis, a common elapid snake in south-west Western Australia. We predicted that urban snakes: 1) more frequently contain prey and eat larger meals, 2) eat proportionally more non-native prey, 3) eat a lower diversity of prey species, and 4) are relatively heavier, than non-urban dugites. We analyzed the diet of 453 specimens obtained from the Western Australian Museum and opportunistic road-kill collections. Correcting for size, sex, season, and temporal biases, we tested whether location influenced diet for our 4 predictions. Body size was a strong predictor of diet (larger snakes had larger prey present, a greater number of prey items, and a greater diversity of prey). We identified potential collection biases: urban dugites were relatively smaller (snout-vent length) than non-urban specimens, and females were relatively lighter than males. Accounting for these effects, urban snakes were less likely to have prey present in their stomachs and were relatively lighter than non-urban snakes. Other urban-adapted carnivores appear to benefit from urbanization through increased food supplementation, but we found the opposite of this: urban dugites were less likely to contain a meal, and their meals were smaller, indicating they did not make greater use of synanthropic species than was evident for non-urban snakes. In contrast to other carnivores, snakes do not appear to fit a consistent directional pattern for size differences between urban and non-urban populations.

Hits Close to Home: Repeated Persecution of King Cobras (Ophiophagus hannah) in Northeastern Thailand

“…Human predisposition to kill snakes adds additional sources of mortality for snakes occupying human-dominated areas (Akani et al., 2002; Bailey, Campa, Harrison, & Bissell, 2011; Meek, 2012; Pandey et al., 2016; Shankar, Singh, Ganesh, & Whitaker, 2013; P. B. Whitaker & Shine, 2000; Wolfe, Bateman, & Fleming, 2017).…”

“…King cobras have multiple life history traits that increase vulnerability to extinction, including large body size, higher trophic position, restricted diet, and slower maturation (Böhm et al., 2016; Stuart et al., 2012; Todd, Nowakowski, Rose, & Price, 2017; Wolfe et al., 2017). Conservation strategies, such as snake relocation, are proving problematic and frequently unsuccessful, leading to aberrant behaviors and lower survival rates (Butler, Malone, & Clemann, 2005; Devan-Song et al., 2016; Dodd & Seigel, 1991; Fry, 2018; Germano et al., 2015; Plummer & Mills, 2000).…”

Investigating the role of urbanisation, wetlands and climatic conditions in nematode parasitism in a large Australian elapid snake

“…; Jones, 1978, 1980). Mainland tiger snakes feed heavily on frogs (Aubret et al, 2006; Shine, 1987a and Table 2) whereas dugites prefer reptiles and mammals (Shine, 1989; Wolfe et al, 2018) and thus are not exposed to infection. Additionally, tiger snakes introduced from WA mainland to Carnac Island, WA, a desert island without frogs, are exempt of nematodes (Aubret, 2005).…”

Snakes on an urban plain: Temporal patterns of snake activity and human–snake conflict in Darwin, Australia

“…Despite being home to many dangerously venomous snakes, including urban adapted species such as tiger snakes (Notechis scutatus; Lettoof et al 2020), brown snakes (Pseudonaja spp. ; Wolfe et al 2018) and red-bellied black snakes (Pseudechis porphyriacus; Shine & Koenig 2001), there are relatively few human fatalities from snake envenomation in Australia (between one and four deaths occur each year; Isbister 2006). Australia's low snake bite fatality rate is likely due to low human population densities, safe agricultural work standards, and exceptional first aid and medical standards (Isbister 2006).…”