Margareta Lakušić

Reptiles rely on behavioural thermoregulation to maintain optimal body temperature (Tb), essential for many physiological functions. However, thermal biology remains poorly studied in many snake species, including the Caspian whipsnake (Dolichophis caspius, Gmelin, 1789). This study examined the thermal biology of the Caspian whipsnake under natural and laboratory conditions. In the field, we investigated the influence of sex, age category, season, time of day, air temperature, detection status, feeding status, and shedding phase on Tb. Under controlled conditions, we assessed preferred Tb variation and its relationship to active thermoregulation. In the field, Tb was significantly affected by sex, season, time of day, air temperature, feeding status, and shedding phase, but not age category, body size or detection status. Males had lower Tb than females and snakes with food in their stomachs exhibited higher Tb. Tb increased from March to June and from morning to afternoon, and air temperature had a positive effect on Tb. In the laboratory, mean Tb (24.5 ± 4.9 °C) was lower than in the field (26.9 ± 5.2 °C) and was significantly associated with body posture and terrarium part, indicating active behavioural thermoregulation. In the laboratory, males had lower Tb than females, and juveniles had lower Tb than adults. The lower thermal preference suggests a cooler thermal niche than many colubrids, potentially increasing their susceptibility to climate warming. However, the broad Tb variation and behavioural thermoregulation indicate some flexibility in responding to environmental changes. These findings highlight the role of behavioural thermoregulation in snake thermal responses to environmental variation.

We present the updated distribution of batracho-and herpetofauna in southern and south-eastern Serbia, based on literature and new field records for 16 amphibian and 22 reptile species. In these two biogeographic regions, already recognized as biodiversity hotspots, we discovered two new amphibian species with limited distribution: Hyla orientalis and Pelobates balcanicus. Also, one species (Triturus ivanbureshi) has restricted distribution, while one (Bombina bombina) is rare. Four reptile species have limited distributions and six are rare in these regions. The presence of hybrid zones and the influence of the Mediterranean climate make southern and south-eastern Serbia areas of great importance and the target for future ecological and conservation studies in Serbia.

The prerogative of animal welfare science includes wild species and ecological studies. Yet, guidance enshrined in legislation is narrowly derived from studies involving laboratory rodents; legitimacy for non-mammalian free-ranging species is thus debatable. The European directive 2010/63/EU illustrates this problem. It includes this key statement: “Practices not likely to cause pain, suffering, distress or lasting harm equivalent to, or higher than, that caused by the introduction of a needle…” which determines if the directive shall apply. Protocols involving surgery clearly fall within the scope of the directive: procedures are scrutinized, investigators and technicians must be qualified and various agreements are required (e.g. issued by an ethical committee). By contrast, non-invasive procedures, like mark-recapture population studies, merely need a permit from wildlife authorities (at least in most countries). Yet, blood sampling that implies the introduction of a needle—one of the most common practices in animals—could shift any study on the constraining-side of the directive, on the grounds that puncture impacts individuals more severely than capture. We examined the validity of the needle-threshold using the stress response of free-ranging snakes. Our results based on physiological markers show that blood sampling does not add any stress to that triggered by capture, and thus questions the usefulness of the needle-threshold to gauge welfare in wild animals. The specificities of studying wild species should be considered to redress captivity biased animal welfare policy.

In the most recent comprehensive distribution of vipers in the western and central Balkans, 210 precise records (146 UTM cells) for all three species of vipers (Vipera ammodytes, V. berus, and V. ursinii) were presented for Serbia. During the past eight years, extensive field investigations within the ongoing conservation projects in our country (e.g. Ecological Networks and Natura 2000), significantly increased the number of faunistic records, which urged the need for publishing the updated distribution of all three species of vipers in Serbia. We collected a total of 770 records of vipers in Serbia, of which literature data constitute 49.4% (n = 380) and unpublished field data made as much as 50.6% (n = 390) of the records. As expected, V. ammodytes was the best-represented species, accounting for 614 records (79.8%), followed by V. berus with 145 records (18.8%), and V. ursinii with 11 records (1.4%). Results of the present study showed that in our country there are three areas crucially important for the diversity of vipers, with all three species present: Koritnik Mt. and Žljeb Mt. in Metohija, as well as Mokra Gora Mt. in south-western Serbia. We also found 25 10×10 km UTM squares with sympatry of two species of vipers. The designation of areas of special importance for vipers (e.g. Mokra Gora Mt., Dukat Mt., Besna kobila Mt., Kamena Gora Mt.) should be one of the priority actions for improvement of their conservation statuses in our country.