Herpetology Notes, volume 10: 133-135 (2017) (published online on 10 March 2017)

Observations of an opportunistic feeding strategy in flat-tailed house ( platyurus) living in buildings

Robbie Weterings1,*

House geckos (Hemidactylus spp.) are voracious In order to get clear images I served rice on a blue plate insectivorous that feed on large numbers of that was placed on top of the bin. Figure 1 shows how daily. Several of this genus live inside buildings H. platyurus approaches a bin and snatches some boiled in close proximity to people where they forage near rice. On another occasion I observed the same species artificial lights, feeding on those insects that are feeding on cucumber and fried egg. attracted to light (Perry et al., 2008). This makes these Hemidactylus species are generally thought to be species excellent subjects for behavioral studies and strict insectivorous (see above), however here I show dietary analysis. Indeed, many studies have investigated that some species also feed on vegetal food items. Both the diets of geckos belonging to the genus Hemidactylus Hemidactylus platyurus and H. frenatus are often found and found that diets of these species mainly consist of with close association with humans. The opportunistic insects such as Lepidoptera, Diptera but often also feeding strategy reported here may help to explain their contain other arthropods such as Arachinidae (Tyler abundance in urban areas and their success as colonizer 1961; Ramires and Fraguas 2004; Rocha and Anjos and invasive species throughout the world (Carranza and 2007; Diaz Perez et al., 2012; Tkaczenko et al., 2014). Arnold 2006). The abundance of insects inside buildings Most of these studies suggest that house geckos are can show high variation and might not always be strict insectivores, which is not any different for the flat- sufficient for house geckos. Feeding on other foods such tailed house (Hemidactylus platyurus). as rice, fruits and egg may aid survival during periods of During the period between March 2013 to December low abundance. Similar opportunistic behavior in 2016, I often observed house geckos (both Hemidactylus urban settings has been reported for other gecko species frenatus and H. platyurus) foraging in garbage-bins such as the Malagasy day gecko ( modesta and on diner-tables in Kamphaeng Phet and Minburi, leiogaster). This species was observed feeding on honey Thailand and Malinau, Indonesia. I first assumed these and artificial sugars inside homes (Gardner and Jasper geckos were feeding on insects, such as house-flies, fruit- 2015). However, unlike the genus Hemidactylus, the flies or ants, that were attracted to leftovers. However, I genus Phelsuma contains many species that also feed never actually witnessed the geckos preying on insects at in natural situations on fruits and nectar (Murphy and these specific locations. The geckos always disappeared Myers 1996; Minnaar et al., 2013; Taylor and Gardner quickly when I tried to observe them. However, I 2014). observed several times that fruits like papaya were eaten It is unclear to what level vegetal food items play a by something, which I initially thought must have been role for Hemidactylus species in natural situations, rats. It was later when I realized that it could have been because few dietary analysis have reported the presence house geckos. In order to confirm this suspicion I placed of food items other than insects or other arthropods. a camera near the garbage-bin in an attempt to capture One study on H. mabouia reported the presence of one of the geckos feeding on non-insect foods (Fig. 1). vegetal material, but this was considered to be ingested accidentally (Iturriaga and Marrero 2013). Two reasons why non-insect food-items could be overlooked in dietary analysis are because they are often much harder to identify from stomach content or feces than insects 1 Cat Drop Foundation, Drachten, Netherlands and feeding behavior is often studied at locations were * Corresponding author e-mail: [email protected] geckos are actively feeding on insects. 134 Robbie Weterings

Figure 1. Hemidactylus platyurus feeding on rice from a bin in Malinau, North Kalimantan, Indonesia on 11 December 2016. First H. platyurus approaches the boiled rice (A-C), then it snatches some rice grains (D-F) and finally it handles the rice and swallows it (G-I).

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Accepted by Jiri Smid