DATA ON NOCTURNAL ACTIVITY OF DAREVSKIA RUDIS (BEDRIAGA, 1886) (SAURIA: LACERTIDAE) IN CENTRAL BLACK SEA REGION, TURKEY

Interactions between the environment and internal regulation drive the biophysiological dynamics of lizards. Although diurnal lizards are usually heliothermic, they can sometimes be active in the absence of sunlight. Here, we report, for the first time, a case of nocturnal behavior (aided by the artificial light) in the spiny-tailed lizard - Darevskia rudis (Bedriaga, 1886) – a species that normally exhibits diurnal activity.


Introduction
Interactions between the internal rhythms and the environment shape the activity patterns of lizards (Underwood 1992). Unlike geckos that exhibit crepuscular lifestyle, the Lacertid lizards are considered to be strictly heliothermic and therefore are thought to be only active during the day. A range of behaviours of these ectotherms, including locomotion, feeding and reproduction, depend on environmental conditions, (Angilletta et al. 2004;Meiri et al. 2013). Ambient temperature is an important factor determining these processed (Pontes-da Silva et al. 2018). Thus, any change in these conditions may cause unusual behaviors.

Material and Methods
Individuals were observed during herpetological surveys in July and August 2014. First observation was recorded on the 12th July 2014 at 00:20 a.m. We observed two male and two female Spiny-tailed lizard, Darevskia rudis, active and foraging at night on the walls of the Historical Sinop Prison, Turkey (36T 677448 E, 4654818 N; 15 m asl). The air temperature was 25 º C, recorded by AccuWeather Superior Accuracy™ on the first night. Since that time, this activity pattern was recorded continuously until the end of August 2014. The ambient air temperatures varied in a narrow range (mean temperature: 26.4 º C) during these night surveys. The walls were illuminated by the powerful long-range field scanning projectors (approximately 1000W each). The walls were built from ashlar blocks (in the 13 th century) and were covered with infrequent grassy vegetation. Under these conditions, the 2x250 (red lines) and 1x150 (green line) meter transects along the prison walls were set up in the east-west direction, and surveyed by at least three observers ( Figure 1).

Results & Discussion
The mean number of active lizards per a single night observation period was 14.5 (min 12, max 17 in different nights). Both adult and juvenile individuals were observed displaying the following major behaviors: leaving the shelter (a), active movement (b), foraging (c), fronting to artificial light source (d) and feeding (e) (Figure 2 a-e).
Darevskia rudis is often found in urbanized areas (Sevgili et al. 2016). Previous studies demonstrated strong correlation between the lizards' body and the ambient temperatures, as well as capability of altering their metabolic processes or energy assimilation levels (Nowakowski et al. 2018).
Avoidance of very high daytime temperatures, generation of heat from the light projectors and attraction of insects towards the projectors might be the reasons for a switch from the diurnal towards nocturnal activity in these lizards. The stone wall can reach an extreme temperature of up to 46ºC in the daytime. We speculate that it may be a major driving force underlying the alteration in behavior. Secondly, although the lizards' body temperatures have not been recorded, the powerful projector can serve as an external heat source for keeping their body temperature in thermal safety margins (TSM) and so allowing mobility. Moreover, nocturnal behavior might help to avoid predation more easily, by escaping to the nonilluminated parts of the wall. Finally, the projectors attract insects, providing foraging opportunities (Perry et al. 2008 Anatolia has been well studied under many herpetological surveys (Baran et al. 1992;Tok & Çiçek 2014;Afsar et al. 2016;Kumlutaş et al. 2017). Although most of them are related to faunistic records, phylogeography or similar issues, there was a recent interest in studying the unusual behavioural strategies in reptiles (Kurnaz et al. 2016;Koç et al. 2018). Thus, our findings will add to the studies of biophysiological dynamics in the Lacertid lizards: This nocturnal activity strategy of a diurnal lizard has been observed in-situ in the absence of any manipulation by the observers. A combination of temperature and other above mentioned factors might cause such unusual behavior (Vidan et al. 2017). This is the first documentation of the nocturnal activity in D. rudis. The artificial light in urban zone created a new specific ecological niche, exploited by D. rudis.
Further research that will address an in-situ thermal comparison of obligate diurnal and this nocturnal population might be a good point to understand the thermal alterations in D. rudis. More generally, it would make a valuable contribution to understand the activity patterns of Eurasian poikilothermic organisms.