Caucasian Brown Frog
Rana macrocnemis
A brown frog with a horizontal pupil. Widespread in Georgia; harmless to people.
At a glance
Key facts in one look
Size
ca. 4–8 cm
Habitat
forest, stream, mountain pond
Activity
Spring–summer breeding
Status in Georgia
Confirmed
Human risk
Family
Ranidae
Conservation
LC
Human interaction: Not venomous and not a medical threat to people. Do not handle it; the skin produces mucus, as in other amphibians.
Overview
What is Caucasian Brown Frog
The Caucasian brown frog (Rana macrocnemis) is a brown frog of the family Ranidae, biologically confirmed in Georgia and harmless to people. It is a largely terrestrial Rana, not the marsh frog (Pelophylax ridibundus), which stays at open water. Boulenger described it in 1885; the type locality is Bursa, Türkiye. Georgian also uses კავკასიური მურა ბაყაყი; English names include Caucasian brown frog and long-legged wood frog. Tarkhnishvili et al. 2026 confirm the species and name two neighbouring forms in Georgia — R. m. macrocnemis and R. m. camerani; the formal rank of camerani still needs genomic work and is not treated as a separate species here. COI barcodes are from Tabatskuri (camerani) and Bjolieti, Guria (macrocnemis); the checklist figure is Guria, Bjolieti. IUCN Least Concern.
Last updated
Gallery
Caucasian Brown Frog in photos
Photo: Zauri Khachidze
Borjomi-Kharagauli National Park ·
Photo: Zauri Khachidze
Borjomi-Kharagauli National Park ·
Photo: Zauri Khachidze
Borjomi-Kharagauli National Park ·
Photo: evgeniy_57 · iNaturalist
Photo: Sandro Khakhva
Photo: Sandro Khakhva
Photo: Tereza Bohatá · iNaturalist
Photo: Jan Ebr & Ivana Ebrová · iNaturalist
Identification
How to identify Caucasian Brown Frog
A medium brown frog with a horizontal pupil, dorsolateral folds and a dark mask behind the eye. It is the only Rana in Georgia. The usual confusion is the marsh frog.
The pupil is horizontal. A large dark temporal patch sits behind the eye — the usual mark of brown frogs. The back is olive, grey, brown, reddish or dark violet; the number of dark spots varies. A pale mid-dorsal stripe may be present or absent. The belly is usually unmarked, pinkish, orange-red or whitish. The hind legs are long (macrocnemis means a long shank); the heels overlap when the shins are set at right angles to the body. The inner metatarsal tubercle is oval and relatively small. AmphibiaWeb: males have internal vocal sacs and nuptial pads on the first finger. Adult length at species level is often about 4–8 cm: 40–79 mm in a Turkish series; breeding frogs in the Nedzura canyon exceed 50 mm before the second hibernation. This page has no separate Georgian size series.
Two neighbouring forms are described in Georgia. Forest macrocnemis is smoother-skinned, with a pale spot pattern, often no mid-dorsal stripe, and a small metatarsal tubercle. Plateau camerani is more rugose, with a stronger dorsal spot pattern and a contrasting mid-dorsal stripe. Where the forms meet, for example on the northern Trialeti slopes, intermediate animals occur. That is a field difference, not evidence for two species in this atlas.
The marsh frog (Pelophylax ridibundus) stays at water, is often green or olive and calls loudly; the brown frog is in forest or meadow away from the breeding season. The Caucasian parsley frog (Pelodytes caucasicus) is smaller, with a vertical pupil and an oblique cross on the back. The eastern spadefoot (Pelobates syriacus) is stocky, with a large digging spade, in the dry east. Toads are warty, with large glands behind the eyes. Tree frogs have toe pads and climb. The agile frog (Rana dalmatina) does not occur in Georgia — old records are treated as confusion with this species.
It is not venomous. A brown frog with a horizontal pupil and a mask behind the eye at a forest-road puddle or a mountain pond matches this species more than a marsh frog. Do not handle it.
Tarkhnishvili et al. 2026 confirm the species and name two neighbouring forms in Georgia — R. m. macrocnemis and R. m. camerani; the formal rank of camerani still needs genomic work and is not treated as a separate species here. It is Georgia’s only Rana. COI barcodes are from Tabatskuri (camerani) and Bjolieti, Guria (macrocnemis). The agile frog (Rana dalmatina) does not occur in Georgia.
Biology
Habitat, diet, behavior, and conservation
Habitat and range
It is widespread in Georgia and is not tied to a single region. Tarkhnishvili (1996) lists 42 Georgian localities of typical macrocnemis — including Sokhumi, Gagra, Batumi, Kobuleti, Lomis Mt. in the Borjomi district, Kazbegi, Lagodekhi, Svaneti, Turtle Lake near Tbilisi, the Nedzura valley, Omalo and the Telavi area — and 11 of typical camerani, mainly on the Javakheti plateau: Tabatskuri, Akhalkalaki, Paravani, Khanchali, Tsalka, Tskhratskaro. This atlas map marks every administrative region from that literature set; the 2026 checklist rates distribution confidence as medium. Type localities of camerani are in Georgia: Lake Tabatskuri at about 2,500 m and Akhalkalaki. In the Nedzura canyon (Borjomi district) breeding sites sit at about 900–1,200 m. AmphibiaWeb places the species in forest, subalpine and alpine belts; in dry country it stays near permanent water, and adults usually remain within a few hundred metres of it. Photos on this page were taken on 1 June 2015 in Borjomi-Kharagauli National Park. CBG also lists cave records — a trogloxene, not a cave resident. Do not assume it on dry eastern plains away from water.
Diet
This page has no Georgian stomach-content study. At species level adults are predators and take whatever invertebrates are available. In a Turkish series (Çiçek 2011, Uludağ) about 96% of prey items were insects, mainly beetles, flies and hymenopterans; that is a Turkish sample, not a Georgian diet. Tadpoles feed in water. Do not treat it as garden pest control.
Behavior
It is more terrestrial than the marsh frog, but it returns to puddles, ponds or stream pools to breed. AmphibiaWeb records hibernation on land or in water, from about September–November to February–May depending on altitude — a species-level window, not a calendar for every Georgian site. Breeding in that source runs from February to late August, usually April–May; it is later at high elevation. Pairing is axillary amplexus (the male clasps behind the female’s forelimbs). Each female lays one clutch per season; AmphibiaWeb gives about 580–3,500 eggs in a single mucous clump. In the Borjomi Canyon the brown-frog guild, including this species, spawns once a year (Tarkhnishvili 1993). In the Nedzura canyon eggs are laid in many temporary pools along the river; most froglets come from a few source sites, and some pools dry out (Tarkhnishvili and Gokhelashvili 1999). Metamorphosis is usually in June–July; tadpoles may overwinter in cold highland ponds. Sexual maturity is usually at 2–3 years.
Conservation
IUCN Red List Least Concern (IUCN SSC Amphibian Specialist Group 2023). CBG also lists LC on the Georgian Red List. Not on CITES. AmphibiaWeb treats it as one of the most common amphibians in the Caucasus; that does not mean every local population is secure. Tarkhnishvili et al. 2026 accept it as biologically confirmed; camerani is not a separate species here — formal rank still needs genomic work. Nikolskii’s Rana dalmatina / R. agilis records in Georgia are treated as confusion with this species and have not been confirmed later in the Caucasus. Do not collect wild amphibians.
Questions
Frequently asked questions
Short answers to the most important questions about Caucasian Brown Frog.
Yes. Tarkhnishvili et al. 2026 list it as biologically confirmed. Barcodes are from Tabatskuri and Bjolieti (Guria).
In forest, subalpine meadow or beside mountain ponds, close to water. Named localities include the Colchis coast and western forests, Borjomi-Kharagauli and the Nedzura canyon, the southern Greater Caucasus (Kazbegi, Svaneti, Lagodekhi, Omalo) and the Javakheti plateau (Tabatskuri, Paravani, Akhalkalaki). Do not assume it on dry plains away from water.
A brown or olive frog with a horizontal pupil, a dark mask behind the eye, dorsolateral folds and relatively long hind legs. It is not tied to open water like a marsh frog and does not have the parsley frog’s vertical pupil.
Adults are often about 4–8 cm at species level. Breeding animals in the Nedzura canyon exceed 50 mm. This page has no separate Georgian size series.
Not in this atlas. The checklist names two neighbouring subspecies; camerani rank may be revised, but the listed species remains R. macrocnemis.
This is Rana — a browner, more terrestrial frog with a mask behind the eye. The marsh frog (Pelophylax) stays at water and is often green.
It is not venomous. Do not handle it.
Globally Least Concern (2023). CBG also lists LC on the Georgian Red List. Do not collect wild amphibians.
References
Sources
References
Sources
- Tarkhnishvili et al. 2026 — Annotated checklist of Georgia's amphibians and reptiles
- Tarkhnishvili 1996 — Distribution and ecology of amphibians of Georgia and the Caucasus
- Tarkhnishvili, Arntzen & Thorpe 1999 — Morphological variation in Caucasian brown frogs
- Tarkhnishvili, Hille & Böhme 2001 — Differentiation in Rana macrocnemis
- Tarkhnishvili & Gokhelashvili 1999 — Population structure of R. macrocnemis in the Nedzura canyon
- Tarkhnishvili 1993 — Anurans of Borjomi Canyon, clutch parameters
- Tarkhnishvili & Gokhelashvili 1999 — The amphibians of the Caucasus
- AmphibiaWeb — Rana macrocnemis
- Amphibian Species of the World — Rana macrocnemis
- IUCN SSC Amphibian Specialist Group 2023 — Rana macrocnemis
- CBG Iliauni — Rana macrocnemis
- Çiçek 2011 — Food composition of R. macrocnemis at Uludağ, Türkiye
Species profiles are compiled from peer-reviewed literature and established biodiversity databases, and are reviewed as new taxonomic and conservation data become available.
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