Sleeping site fidelity in three neotropical species of herpetofauna

A animal species studied to date have shown sleep or sleep-like behaviour (Tobler, 2000). Sleep aids in a variety of processes including recovery of cellular and endocrine systems through to learning, memory and energy conservation (Mignot, 2008; Libourel & Herrel, 2016). At the same time, periods of sleep could present risks as an animal may be exposed to predation while inactive (Amlaner & Ball, 1983). Regardless of its functions, sleep is among the most prominent of animal behaviours and as such is likely to be a behaviour that responds dynamically and adaptively to different environmental variables (Tobler, 2000). Sleeping site selection must play an important role in obtaining the benefits of sleep while avoiding predation (Amlaner & Ball, 1983). It is likely influenced by microhabitat preferences, the need for protection from predators or exposure, and remaining within territories to avoid competition (Christian et al., 1984; Clark & Gillingham, 1990). Thus, once selected, a sleeping site may be maintained through days, weeks, or longer, to retain these benefits over time (González-Zamora et al., 2015). However, to date studies of sleeping site preferences or site fidelity have focused mainly on endotherms (mammals and birds) rather than ectotherms such as reptiles, amphibians, fishes or invertebrates (Amlaner & Ball, 1983; Campbell & Tobler, 1984; Christian et al., 1984; Clark & Gillingham, 1990; Hartse, 1994). In reptiles specifically, sleeping sites have been recorded widely in anoles, including some Amazonian species such as Anolis punctatus, Anolis trachyderma and Anolis transversalis. However, there is far less information for other reptiles and amphibians (Clark & Gillingham, 1990; Vitt et al., 2002; Vitt et al., 2003a; Vitt et al., 2003b; Poche et al., 2005). Here we report sleep site fidelity for two species of lizard Enyalioides laticeps (Guichenot, 1855) and Anolis fuscoauratus D’Orbigny, 1937 and one amphibian species, the toad Rhinella margaritifera (Laurenti, 1768). To gather data, we undertook day and night-time visual encounter surveys between June and August 2019 in the camping area of the Sani Reserve, Sucumbíos, Ecuador (0° 26’ 18.47” S, 76° 16’ 45.11” W). The habitat in the Sani Reserve is a mixture of mostly terra firme forest, igapó (blackwater flooded forest) and varzea (white water flooded forest) with the Challuacocha lagoon and its surrounding reeds and grasses located around the reserve’s ecolodge (Hollamby, 2010). Six trails were surveyed on separate days on a rotational basis. During these surveys we first recorded E. laticeps and R. margaritifera sleeping on 10th July, and recorded them again on 17th July. Sleeping was determined through behavioural indicators such as closed eyes upon our arrival, lack of escape behaviour, or time of observation outside the reported diel activity pattern. In the camp, we recorded an individual A. fuscoauratus that was returning to sleep in the same site from the 19th July. We placed flagging tape a few metres from the sleeping sites of E. laticeps and R. margaritifera as a warning so that we could approach slowly when nearby while also not drawing attention to the specific site. We then visited these flagged sites daily from 24th July 2019 to 4th August 2019 and the A. fuscoauratus site (in camp) from 19th July to 4th August 2019. We did not visit the any of the sites on Mondays, as we were not in the reserve. We were unable to reach the E. laticeps and R. margaritifera sites on the 1st and 3rd of August due to bad weather, but we could still observe A. fuscoauratus as this was within the camp. During each visit we recorded the presence or absence of the individuals at the sites. To characterise the microhabitats used for sleeping, we photographed each location (Fig. 2A, 3A, 4A) and in each case measured the height from the ground and distance from the trail where applicable. The animals were not captured so morphometric data was not collected. Based on their size, all three individuals were considered to be adults and each had unique colour patterns that allowed us to confidently recognise the same individual on successive occasions.