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| Adult Balkan green lizard (Lacerta trilineata), subspecies trilineata, Alonissos (C) Stamatis Kalogiannis |
Introduction
The Balkan green lizard (Lacerta trilineata) is a large lizard of the family Lacertidae, and the largest lizard with legs that can be found in Greece. It inhabits most of the Balkan peninsula, including countries such as Albania, Bosnia and Herzegovina, Bulgaria, Croatia, Kosovo, Montenegro, North Macedonia, Romania, Serbia and Greece. It is common and very widespread in Greece, where it occurs throughout the mainland (with the exception of Thrace), the Peloponnese and on several islands in the Aegean and Ionian sea. The “Balkan green lizard (Lacerta trilineata)” is actually a species complex and has recently been split into two additional species that can be distinguished chiefly based on distribution, but they also differ morphologically, often to considerable extents (see Lacerta citrovittata and Lacerta diplochondrodes). The taxonomy of the species complex has likely not been completely resolved yet.
Description
TL: Typically up to 50cm; SVL: up to 18cm. Sexually mature individuals can be as small as 8 cm SVL. Very robust and brightly colored lizard. The legs are large and strong. Dorsal coloration of adults usually green or emerald with tiny black spots, which gives the illusion of a uniform color. Throat and belly bright yellow. Neck area often blue in males. Juveniles brownish, either uniform or with three white or yellow lines on the dorsal area and light spots on the flanks. In some instances, females will retain the white dorsal stripes in adulthood, though on a green background. The head is large with a rather pointed snout. Temporal scales typically small and up to 20 or more, although this may not be the case in most southern populations. Sexually dimorphic – males larger-bodied and with a broader head and larger jowls compared to females. Can be confused with the Eastern green lizard (Lacerta viridis) with which it also coexists in several locations, but the latter is generally smaller, has a relatively blunt snout, typically occurs in more lush habitats and frequently shows bright blue heads in males during the mating season.
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| Adult, subspecies trilineata, head detail; note the rather pointed snout, Achaea (C) Ioannis Gourogiannis |
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| Head detail of a large, old adult male, subspecies trilineata, Attica; note the very narrow snout (C) Plato Stefanopoulos |
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| Adult, subspecies trilineata, Alonissos (C) Stamatis Kalogiannis |
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| Juvenile, subspecies trilineata, Volos (C) Stamatis Kalogiannis |
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| Adult, subspecies trilineata, Euboea (C) Stamatis Kalogiannis |
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| Adult, subspecies trilineata, Attica (C) Plato Stefanopoulos |
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| Juvenile, subspecies trilineata, Attica (C) Plato Stefanopoulos |
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| Juvenile, subspecies trilineata, Attica (C) Ioannis Gourogiannis |
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| Juvenile, uniform morph, subspecies trilineata, Attica (C) Ioannis Gourogiannis |
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| Adult, subspecies trilineata, Achaea (C) Ioannis Gourogiannis |
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| Juvenile, subspecies trilineata, Pieria (C) Charis Kouelis |
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| Adult, subspecies trilineata, Skiathos (C) Stamatis Kalogiannis |
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| Adult male with a particularly vibrant color, subspecies trilineata, Attica (C) Plato Stefanopoulos |
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| Striped hatchling (C) Stamatis Kalogiannis |
Biology
It is a diurnal and mainly terrestrial lizard, though it will very frequently climb various surfaces including stone walls, logs and thick vegetation. It brumates underground where the temperature is more stable in the colder months (usually November to late February), but brumation is often interrupted on warm winter days so that the lizard can bask and potentially look for food. It can often be seen basking in early spring and is very frequently seen crossing roads in late spring and early summer, when activity reaches its peak. It is very shy and skittish, well-adapted to evade threats and it will retreat to a refuge or up a tree with great speed at the slightest disturbance. When cornered, it will assume a defensive position, hiss and gape its mouth as a threat display. It will usually bite down hard if caught, but the bite is completely harmless. Its tail can be dropped and regenerated. Males are territorial and will defend their turf aggressively. Breeding starts in early spring and as in most Lacertids, the male will bite the female before, during or after copulation, which often results in tail loss for the female. By early-mid summer, the female will have laid anywhere from 6 to 30 eggs in exceptional cases. It is not uncommon for a female to lay more than one clutch in a single year. Juveniles emerge in late summer. Sexual maturity has been shown to be more correlated with size rather than age, and it can be achieved at sizes as small as 80mm SVL. Males tend to mature at a slightly larger size than females. Insular populations are often significantly smaller compared to those in the mainland. It feeds on a plethora of invertebrates and especially most kinds of arthropods, showing a preference for Coleoptera, with Orthoptera being second. Its conical teeth are not sharp and are perfect for crushing the hard exoskeletons of insects. Its diet shifts according to food availability. Though chiefly an invertebrate eater, it is opportunistic and it will also take small vertebrates such as reptiles and even mammals, as well as plant matter such as flowers and fruits, especially in insular populations. It does not tolerate extreme heat and it is often found congregated in and around riparian areas in the summer in search of shade and moisture, like most Greek reptiles.
Habitat
It can be found in almost all Mediterranean habitats that are open and have abundant cover such as rocks or stonewalls and thick vegetation, including but not limited to: open forests and forest edges, maquis shrubland, phrygana, the riparian zone of streams, rivers and lakes, sand dunes in coastal areas, olive groves, other agricultural areas, urban parks, backyards and other degraded habitats. Up to 1,800m asl.
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| Riparian vegetation next to the lowland reaches of a perennial, spring-fed stream – habitat of Lacerta trilineata |
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| Rocky, relatively humid hillside with low vegetation near an agricultural area – habitat of Lacerta trilineata |
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| Coastal Tamarix sp. forest with saltwater influence next to a river mouth – habitat of Lacerta trilineata |
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| Severly degraded cultivations near an urban area - habitat of Lacerta trilineata |
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| Open, dry hill with phrygana, maquis and pine forests – habitat of Lacerta trilineata |
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Open grasslands and cultivated areas at the foothills of a mountain – habitat of Lacerta trilineata
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| Maquis shrubland next to a spring-fed stream and cultivations – habitat of Lacerta trilineata |
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| Coastal plain with halophytes bordering phrygana – habitat of Lacerta trilineata |
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| Olive groves bordering hillsides with phrygana – habitat of Lacerta trilineata |
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| Hilly grassland bordering lush forests – habitat of Lacerta trilineata major |
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| Dry hill with phrygana near an urban area – habitat of Lacerta trilineata |
Distribution
Being one of the most widespread lacertids in Greece, the Balkan green lizard occurs in almost all of mainland Greece, the Peloponnese, Euboea, Crete, Kythera, many Aegean islands such as the Sporades (Skiathos, Tsougrias, Skopelos, Alonissos, Skyros), on some of the Cyclades (Milos, Sifnos, Serifos) and the Ionian sea islands (Corfu, Lefkada, Kefallonia, Ithaca, Zakynthos).
The species also shows a number of different subspecies in Greece, namely:
- Lacerta trilineata trilineata: Most of the mainland & several islands
- Lacerta trilineata major: Epirus, Corfu & Lefkada
- Lacerta trilineata hansschweizeri: Milos, Sifnos, Serifos
- Lacerta trilineata polylepidota: Crete & Kythera
Furthermore, a recent study by Kornilios et al. (2019) proposed a split into two more species based on genetic data. The former subspecies diplochondrodes and citrovittata are now treated as full species (see map below for distribution). The contact zone between trilineata and diplochondrodes in NE mainland Greece remains poorly known.  |
Approximate distribution of the Lacerta trilineata complex in Greece
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