Ivelin Mollov // ZooNotes 9: 1-4 (2010)

During our study we identified 23 prey items in 12 prey categories in the trophic spectrum of Anguis fragilis with average number of prey items per stomach 2.87. The most important prey components are snails and slugs (Gastropoda) with 39.14% and beetles (Coleoptera) with 21.72%. The estimated trophic niche breadth is very high – 19.46. The Slow Worm forages primarily at dawn or twilight, and the feeding is most intensive in the summer season. It can be considered “swallowing” predator and a “polyphage” to some extend, capturing only slowly moving prey.

Ivan Telenchev,  Daniela Simeonovska-Nikolova and Venislava Spasova // North-Western Journal of Zoology 2021 17 (1): 77-81

The ability of sensing chemical cues is a common way for reptiles to recognize predators, mates and potential competitors. To characterise the model of anti-predatory behaviour of the Slow worm Anguis fragilis and the Eastern Slow worm A. colchica their response to the odour of the Nose-horned viper, Vipera ammodytes and the Balkan adder, V. berus bosniensis was studied in laboratory conditions. The experiments were carried out between May and July 2016-2017 with 10 individuals of A. colchica (5 adults and 5 juveniles) and 11 individuals of A. fragilis (6 males and 5 females, all adults). As stimuli, we used a clean swab as a control and a swab impregnated with scents from the snakes. The behavioural responses of the two slow worms to the stimuli were recorded and compared. The results showed that individuals from both A. colchica and A. fragilis recognize the odour of both potential predators – Vipera ammodytes and V. berus bosniensis. However, in A. colchica, adult individuals took a higher risk than juveniles, and in A. fragilis males took a higher risk than females, probably due to their different life strategies and functions in populations.

Beate Strøm Johansen & Geir Inge Høines // The Herpetological Bulletin 165, 2023: 24–26

There are few published accounts of slow worms Anguis fragilis swimming or bathing, and where there are reports they describe only single individuals in water.

Badziukiewicz Jakub // Folia Pomer. Univ. Technol. Stetin., Agric., Aliment., Pisc., Zootech. 2021, 360(59)3, 19–30

The paper presents the proposal for monitoring methods of two species from Anguidae family occurring in Poland such as slow-worm A. fragilis and Eastern slow-worm A. c. incerta. Until recently, both species were considered to be the same taxon. Thanks to genetic research the Eastern slow-worm was isolated from the species A. fragilis. In recent years, phenotypic differences between A. fragilis and A. c. incerta have been described, but it has not been noticed whether there are any behavioral or habitat preference differences. Only the approximate boundary of the occurrence of both species in Poland is known. It may be important to distinguish common areas, as there are known cases of hybridization of A. c. incerta with A. fragilis in the Czech Republic and Hungary. Due to the recent isolation of the Eastern slow-worm, it is still not legally protected in Poland, unlike the partially protected slow-worm.

Greven Harmut, Heiligtag Sabine and Stevens Michael // Zeitschrift für Feldherpetologie 13: 1–14 Oktober 2006

In 2002 we studied a population of the slow worm Anguis fragilis in the SAC «Knechtstedener Wald» (Lower Rhine Embayment) using two types of artificial refuges. From April to the end of September we saw 158 slow worms; 156 of them under the shelters (99 % of all observations). From these, two individuals were recaptured repeatedly. Biometric data were taken from 119 specimens including the recaptures. Sex was determined in 91 individuals mainly by means of their colouration. Length of the pileus proved as sufficient for sex determination by some authors did not differ between males and females. Sex ratio was 2:1 (59 females, 32 males). 67 specimens were classified as adults, 52 as semiadults. Approximately 50 % of the animals showed tail regenerates; nine individuals lost parts of the tail during capture.

Молчан В. О., Куликова Е. А., Хейдорова Е. Э., Демянчик В. В., Корзун Е. В., Никифоров М. Е. // Вес. Нац. aкад. навук Беларусі. Сер. біял. навук. – 2024. – Т. 69, № 4. – С. 271–279.

В работе представлены обзор данных о распространении веретеницы на территории Беларуси и результаты молекулярно-генетической видовой идентификации по данным региона COI мтДНК 19 представителей  рода Anguis, собранных в 13 административных районах 5 областей Беларуси (кроме Могилевской области) в период  c 2018 по 2023 г. Установлено, что на территории Беларуси обитает только один вид безногих ящериц – колхидская  веретеница (Anguis colchica Nordmann, 1840). Показано, что белорусская популяция вида характеризуется низкими значениями нуклеотидного (π = 0,00090) и гаплотипического (Hd ± SD = 0,351 ± 0,111) разнообразия и представлена двумя ранее не известными гаплотипами, отстоящими от гаплотипов других видов на генетическую дистанцию от 0,05740‒0,05995 (A. graeca) до 0,09439‒0,09694 (другие виды рода Anguis). 

Grzegorz Skórzewski, Bartosz Borczyk, Stanislaw Bury, Daniel Kulik and Jan Kotusz // PeerJ. 2025 Jan 6;13:e18563

Background. Legless lizards, the slow worms of the genus Anguis, are forming secondary contact zones within their Europe-wide distribution.
Methods. We examined 35 populations of A. fragilis and A. colchica to identify the level of morphological and genetic divergence in Poland. We applied a conventional study approach using metric, meristic, and categorial (coloration) features for a phenotype analysis, and two standard molecular markers, a mitochondrial (NADH-ubiquinone oxidoreductase chain 2; ND2) and a nuclear (V(D)J recombination-activating protein 1; RAG1) one.
Results. We found clear differences between A. fragilis and A. colchica in molecular markers and phenotype in meristic features, e.g., ear opening, number of scales rows around the body, and higher than so far known diversity in ND2 and RAG1 haplotypes. The presence of five hybrids was detected in three populations in the Polish part of the European contact zone. In all hybrids, homozygous alleles of RAG1 were detected, which suggests a back-crossing within the genus.
Conclusions. The ability to produce fertile offspring by A. fragilis x A. colchica hybrids shows inefficient mechanisms of reproductive isolation of the two legless lizards. The hybrids were indistinguishable from parental species in head proportions (principal components and discriminant analyses) but more resembling A. colchica in meristic traits.

Кидов А. А., Иванов А. А., Иволга Р. А., Кондратова Т. Э., Ерашкин В. О., Туниев Б. С. // Nature Conservation Research. Заповедная наука 2025. 10(2): 20–30

В границах ареала на Кавказе Anguis colchica распространена от низменностей до субальпийского пояса. В Сочинском национальном парке (Россия) вид является одним из наиболее многочисленных среди рептилий. У животных, собранных в апреле и июле 2019 г., измеряли длину тела и купировали кончик хвоста.  Взрослых самок содержали в лаборатории до рождения потомства. Трех новорожденных особей продолжали содержать в искусственных условиях в течение двух лет, дважды устраивая им зимовку при температуре 6–11°C в течение 90 суток. Определение возраста осуществляли стандартным методом скелетохронологии. В качестве регистрирующих структур использовали хвостовые позвонки, а у погибших на дороге особей также зубные кости нижней челюсти и ребра. Отловленных животных и их потомство возвращали в природу. У изученных погибших особей установлено тождественное число линий склеивания на срезах хвостовых позвонков, ребер и зубной кости нижней челюсти. Лабораторные эксперименты показали соответствие этих линий количеству пережитых зимовок. Особи в изученной предгорной популяции Anguis colchica доживают до 9 (самки) – 11 (самцы) лет. Интенсивный рост продолжается до возраста 2–3 лет, а в последующем почти останавливается. Самки приносят потомство с трехлетнего возраста и сохраняют способность к размножению до конца своей жизни. Большинство взрослых самок (77.3% от всех особей возрастом три года и старше) ежегодно принимают участие в размножении. Для Anguis colchica в предгорном поясе Сочинского национального парка свойственна относительно невысокая плодовитость (до 13, в среднем шесть молодых), но крупные размеры новорожденных (длина тела до 59.8 мм). При этом число молодых особей в потомстве увеличивается с возрастом самки, а масса молодых особей возрастает с увеличением плодовитости самки. Авторы заключают, что особенности репродуктивной биологии, наряду с большой продолжительностью жизни, способствуют высокой численности вида в Западном Закавказье.

Patterson J.W. // Amphibia-Reptilia Volume 11: Issue 3 (1990): 295–306

Cooper J. S. // J. Zool., Lond. (1966) 150, 235-248

The dentition of the Slow worm (Anguis fragilis) has been carefully observed in a range of individuals from birth to advanced age. Although a considerable volume of carefully prepared dead material has been used, emphasis in the investigation is placed upon three living specimens kept in near-natural conditions and examined by taking impressions of the teeth every week throughout a whole season. A general description of the gross anatomy of the dentition is given, and the changes that occur with increasing age. The tooth attachment and the process of replacement in the individual tooth is considered and found to conform to the Anguinomorphan type of replacement described by McDowell & Bogert (1954). The evidence obtained from both dead arid living material as to the pattern and order of tooth replacement is presented and found to be in agreement with the theoryof Edmund(1960). Further details of the replacement pattern, discernible only in the records from the living specimens, and the effects of season and age upon tooth replacement are described. Anguis is found to provide an excellenl illustration of the fundamentalprinciples in reptilian tooth replacement, being relatively uncomplicated in the featuresof its replacement pattern. The species also appears to be a promising subject for the further investigation1 oftooth replacement phenomena.

Ricardo Ferreiro, Pedro Galan // Animal Biology, Vol. 54, (2004), No. 4, pp. 353-371

The reproductive characteristics of the slow worm (Anguis fragilis) were studied in A Coruña (Galicia, NW Spain) in 1999, 2000, 2001 and 2002. Data were mainly obtained through pregnant females captured in natural populations which subsequently gave birth under controlled conditions in the laboratory and the resulting neonates were examined. Marked individuals in a field population were also monitored. This field study allowed us to gain knowledge of the activity and reproductive cycle of the monitored population. A total of 68 births and 468 neonates were obtained, allowing us to determine the basic reproductive characteristics of the populations studied such as the litter size, offspring weight, offspring size and minimum maturity size for females: 135-150 mm snout vent length (SVL). The relationship between several variables related to offspring and their mothers showed a positive relation between size and mass of the litter and offspring with maternal size. A relationship between maternal tail length and litter mass was not observed. Unlike other studied populations of this species, most of the females of the A Coruña population (88.8%) reproduce annually. We found a probable relationship between female annual reproductive output and latitude, likely related to differences in environmental temperature. The activity cycle for the monitored population (from February to mid-December) is the longest known for the species. 

Четанов Н.А., Белоусова Н.А., Галиулин Д.М. // Вестник Пермского государственного гуманитарно-педагогического университета. Серия 2 «Физико-математические и естественные науки». - 2022. - № 1. - С. 62-66.

В работе подробно описана первая за 25 лет достоверная находка колхидской веретеницы на территории г. Перми. Указывается точное место обнаружения, характеризуются условия обитания, приводятся некоторые термобиологические характеристики и морфологические данные.

Vaclav Gvozdik, Tadeas Necas, Daniel Jablonski, Emily Moriarty Lemmon, Alan R. Lemmon, David Jandzik, Jiri Moravec // Molecular Phylogenetics and Evolution 180 (2023) 107674

A dated phylogenetic hypothesis on the evolutionary history of the extant taxa of the Western Palearctic lizards Anguis and Pseudopus is revised using genome-wide nuclear DNA and mitogenomes. We found overall concordance between nuclear and mitochondrial DNA phylogenies, with one significant exception – the Apennine A. veronensis. In mitochondrial DNA, this species forms a common clade with the earliest diverging lineage, the southern Balkan endemic A. cephallonica, while it clusters together with A. fragilis in nuclear DNA. The nuclear phylogeny conforms to the morphology, which is relatively similar between A. veronensis and A. fragilis. The most plausible explanation for the mitonuclear discordance is ancient mitochondrial capture from the Balkan ancestor of A. cephallonica to the Apennine population of the A. fragilis-veronensis ancestor. We hypothesize that this capture occurred only in a geographically restricted population. The dating of this presumed mitochondrial introgression and capture coincides with the Messinian event, when the Balkan and Apennine Peninsulas were presumably largely connected. The dated nuclear phylogenomic reconstruction estimated the divergence of A. cephallonica around 12 Mya, while the sister clade representing the A. fragilis species complex consisting of the sister species A. fragilis–A. veronensis and A. colchica–A. graeca further diversified around 7 Mya. The depth of nuclear divergence among the evolutionary lineages of Pseudopus (0.5–1.2 Mya) supports their subspecies status.

Желанкин Р.В., Скотникова И.Г. // Эволюционная и сравнительная психология в России: Современные исследования. – 2021. – С. 92-97

Работа является частью цикла исследований характеристик принятия решения рептилиями в зрительных задачах выбора из альтернатив.

Желанкин Р. В. // Известия Иркутского государственного университета. Серия Психология. 2021. Т. 36. С. 16–37.

Изучались экологически значимые для рептилий способности к зрительному различению пространственных и цветовых стимулов, а именно: поведение безногих ящериц веретениц ломких в Т-образном лабиринте при зрительном различении красного и зеленого цветовых тонов и размеров геометрических фигур круглой формы. Анализировались основные поведенческие характеристики принятия решения при выборе из возможных вариантов: процент ошибочных выборов, время выбора и число поворотов ящериц в стороны альтернативных путей в лабиринте к сравниваемым стимулам до выбора одного из них. При цветоразличении все эти три поведенческие характеристики были минимальными, а при различении размеров геометрических фигур более высокими. Делается вывод, что различение красного и зеленого цветовых тонов у веретениц было более успешным и менее трудным, чем различение размеров геометрических фигур круглой формы.