Antipredator behaviour of invasive geckos in response to chemical cues from snakes

Abstract

Antipredator behaviours and the ability to appropriately assess predation risk contribute to increased fitness. Predator avoidance can be costly; however, so we expect prey to most strongly avoid predators that pose the greatest risk (i.e., prey should show threat sensitivity). For invasive species, effectively assessing the relative risk posed by predators in the new environment may help them establish in new environments. We examined the antipredator behaviour of introduced Asian house geckos, Hemidactylus frenatus (Schlegel), by determining if they avoided shelters scented with the chemical cues of native predatory snakes (spotted pythons, Antaresia maculosa [Peters]; brown tree snakes, Boiga irregularis [Merrem]; common tree snakes, Dendrelaphis punctulata [Grey]; and carpet pythons, Morelia spilota [Lacépède]). We also tested if Asian house geckos collected from vegetation vs. anthropogenic substrates (buildings) responded differently to the chemical cues of predatory snakes. Asian house geckos did not show a generalised antipredator response, that is, they did not respond to the chemical cues of all snakes in the same way. Asian house geckos avoided the chemical cues of carpet pythons more strongly than those of other snake species, providing some support for the threat‐sensitivity hypothesis. There was no difference in the antipredator behaviour of Asian house geckos collected from buildings vs. natural vegetation, suggesting that individuals that have invaded natural habitats have not changed their antipredator behaviour compared to urban individuals. Overall, we found some evidence indicating Asian house geckos are threat‐sensitive to some Australian predacious snakes.

Recognition of reptile predator scent is innate in an endangered lizard species

“…The ability to distinguish between predators and nonpredators and risk levels have been found in reptile and primate species (Buchanan- Smith et al 1993;Stapley 2003;Lloyd et al 2009;Cisterne et al 2014;Cornelis et al 2019). The pygmy salamander (Desmognathus wrighti) could distinguish between chemical cues from a specialist snake predator and two generalist predators, namely, beetle and salamander species (Forester et al 2019).…”

“…Many taxa are known to recognise and respond to chemical stimuli from predators, including reptiles, amphibians, mammals, fish, birds, crustaceans and invertebrates (Kats and Dill 1998;Apfelbach et al 2005). Recognition of predator cues can be threat sensitive, as predicted by the threat-sensitive hypothesis, whereby prey can differentiate between predators based on the degree of threat posed (Helfman 1989;Stapley 2003;Lloyd et al 2009;Cornelis et al 2019). Alternatively, predator recognition can be generalised via avoidance of multiple species cues (Blumstein 2006;Webb et al 2009Webb et al , 2018.…”

Reaction to Novel Objects and Fecal Glucocorticoid Metabolite Levels in Two Species of Nocturnal Geckos

“…Also, in contrast to Landova et al [39], which presented the snake, we only presented the chemical cues and in a different manner to the one used in other studies with scented filtered papers [52][53][54]. However, as Cornelis et al [51] pointed out, it is unclear which method is more effective in capturing appropriate predator odors or which specific chemicals induce the antipredator behavior, and more studies in this area are needed to properly interpret these differences.…”

“…According to the threat-sensitivity hypothesis, animals should adjust their anti-predator responses according to the level of threat posed by specific predators, i.e., [49,50]. For example, it has been shown that Asian house geckos (Hemidactylus frenatus) did not respond to the chemical cues of all snakes in the same way [51] or that scincid lizards (Carlia rostralis, C. rubrigularis and C. storri) selectively avoid chemical cues from dangerous varanid predators and ignore those of the less dangerous [52]. Therefore, if our geckos could not distinguish the level of threat or even if the scent represented a threat at all, this could cause the different responses.…”

A failed predation attempt by Chrysopelea paradisi (Serpentes: Colubridae) on Hemidactylus frenatus (Squamata: Gekkonidae) in Borneo, Malaysia

“…The Paradise Flying Snake (Chrysopelea paradisi Boie, 1827) and the Spiny-tailed House Gecko (Hemidactylus frenatus Duméril and Bibron, 1836) are examples of t e first ro p. Hemidactylus frenatus occurs in southeastern Asia and has been introduced to several islands, as well as to Australia, America, and Africa (Das 2010). It is the planet's most widespread lizard, having been spread around the world following human activity (Cornelis et al 2018). This small gecko measures about 67 mm SVL.…”