Lake Pikrolimni (

Greek Greek may refer to: Greece Anything of, from, or related to Greece, a country in Southern Europe: *Greeks, an ethnic group. *Greek language, a branch of the Indo-European language family. **Proto-Greek language, the assumed last common ancestor ...

: Πικρολίμνη 'bitter lake') is an

endorheic An endorheic basin (; also spelled endoreic basin or endorreic basin) is a drainage basin that normally retains water and allows no outflow to other external bodies of water, such as rivers or oceans, but drainage converges instead into lakes ...

, alkaline

salt lake A salt lake or saline lake is a landlocked body of water that has a concentration of salts (typically sodium chloride) and other dissolved minerals significantly higher than most lakes (often defined as at least three grams of salt per litre). ...

Kilkis prefecture Kilkis ( el, Περιφερειακή ενότητα Κιλκίς) is one of the regional units of Greece, in the Geographic regions of Greece, geographic region of Macedonia (Greece), Macedonia. It is part of the Modern regions of Greece, region o ...

Greece Greece,, or , romanized: ', officially the Hellenic Republic, is a country in Southeast Europe. It is situated on the southern tip of the Balkans, and is located at the crossroads of Europe, Asia, and Africa. Greece shares land borders with ...

. It is located on the border of the Kilkis and Thessaloniki regional units, about 40 km northwest of

Thessaloniki Thessaloniki (; el, Θεσσαλονίκη, , also known as Thessalonica (), Saloniki, or Salonica (), is the second-largest city in Greece, with over one million inhabitants in its Thessaloniki metropolitan area, metropolitan area, and the capi ...

. The lake is

hypersaline A hypersaline lake is a landlocked body of water that contains significant concentrations of sodium chloride, brines, and other salts, with saline levels surpassing that of ocean water (3.5%, i.e. ). Specific microbial species can thrive in h ...

, has rather shallow waters (0.5–0.7 m) and a shoreline of about 8.5 km. The water surface area shows significant seasonal variation (3.2–4.5 km²) due to evaporation in the summer months, with an average value of 3.7 km². Pikrolimni is the only salt lake in Greece and constitutes a

biotope A biotope is an area of uniform environmental conditions providing a living place for a specific assemblage of plants and animals. ''Biotope'' is almost synonymous with the term "habitat", which is more commonly used in English-speaking countrie ...

with rare

halophytic A halophyte is a salt-tolerant plant that grows in soil or waters of high salinity, coming into contact with saline water through its roots or by salt spray, such as in saline semi-deserts, mangrove swamps, marshes and sloughs and seashores. T ...

vegetation surrounded by common reeds, which is home to various common and endangered bird species. The habitat has been listed since 1996 as a

Natura 2000 Natura 2000 is a network of nature protection areas in the territory of the European Union. It is made up of Special Areas of Conservation and Special Protection Areas designated under the Habitats Directive and the Birds Directive, respectively ...

site of community interest and special protection area, while also protected by the

Ramsar convention The Ramsar Convention on Wetlands of International Importance Especially as Waterfowl Habitat is an international treaty for the conservation and sustainable use of Ramsar sites (wetlands). It is also known as the Convention on Wetlands. It i ...

. The lake was known in ancient times as Chalastra (

Ancient Greek Ancient Greek includes the forms of the Greek language used in ancient Greece and the ancient world from around 1500 BC to 300 BC. It is often roughly divided into the following periods: Mycenaean Greek (), Dark Ages (), the Archaic peri ...

: Χαλάστρα), a famous source of

natron Natron is a naturally occurring mixture of sodium carbonate decahydrate ( Na2CO3·10H2O, a kind of soda ash) and around 17% sodium bicarbonate (also called baking soda, NaHCO3) along with small quantities of sodium chloride and sodium sulfate. N ...

and

trona Trona (trisodium hydrogendicarbonate dihydrate, also sodium sesquicarbonate dihydrate, Na2CO3•2NaHCO3•3H2O) is a non- marine evaporite mineral. It is mined as the primary source of sodium carbonate in the United States, where it has replace ...

for Graeco-Roman

glassmaking Glass production involves two main methods – the float glass process that produces sheet glass, and glassblowing that produces bottles and other containers. It has been done in a variety of ways during the history of glass. Glass container ...

. In modern times it has been a site of

pelo Pelo is a surname. Notable people with the surname include: *Brad Pelo Brad Pelo (born February 6, 1963) is an American businessman, entrepreneur, and co-founder and chief executive officer of i.TV, the company behind tvtag, a second screen app ...

- and

balneotherapy Balneotherapy ( la, balneum "bath") is a method of treating diseases by bathing, a traditional medicine technique usually practiced at spas. Since ancient times, humans have used hot springs, public baths and thermal medicine for therapeutic eff ...

, with a

spa A spa is a location where mineral-rich spring water (and sometimes seawater) is used to give medicinal baths. Spa towns or spa resorts (including hot springs resorts) typically offer various health treatments, which are also known as balneoth ...

specialising in such treatments using the lake's briny water and characteristic black mud.

Location and origin

The lake is located about 40 km northwest of Thessaloniki and 25 km south of Kilkis, at the border between the former municipalities of Pikrolimni and

Kallithea Kallithea (Greek: Καλλιθέα, meaning "beautiful view") is a district of Athens and a municipality in south Athens regional unit. It is the eighth largest municipality in Greece (96,118 inhabitants, 2021 census) and the fourth biggest i ...

(now merged into

Kilkis Kilkis ( el, Κιλκίς) is a city in Central Macedonia, Greece. As of 2011 there were 22,914 people living in the city proper, 28,745 people living in the municipal unit, and 51,926 in the municipality of Kilkis. It is also the capital city o ...

and

Oraiokastro Oraiokastro ( el, Ωραιόκαστρο) is a municipality in the Thessaloniki regional unit, Greece and a suburb of Thessaloniki. Municipality The municipality Oraiokastro was formed at the 2011 local government reform by the merger of the foll ...

municipalities, respectively). The lake is surrounded by villages

Nea Filadelfeia Nea Filadelfeia ( el, Νέα Φιλαδέλφεια, meaning ''New Philadelphia'') is a suburb of Athens, Greece. Since the 2011 local government reform it is part of the municipality Filadelfeia-Chalkidona, of which it is the seat and a municip ...

, Mikrokampos, the homonymous Pikrolimni, Xylokeratia and Mpakeika. Multiple studies using hydrologic isotope analysis prove that the origin of the water in the lake is almost exclusively meteoric. This makes the lake truly endorheic and not cryptorheic, with the dominant process of water exchange being evaporation during the summer months followed by flooding from precipitation in the winter. The cause of the famously high salinity of the lake is from the

percolation Percolation (from Latin ''percolare'', "to filter" or "trickle through"), in physics, chemistry and materials science, refers to the movement and filtering of fluids through porous materials. It is described by Darcy's law. Broader applicatio ...

and deep circulation of the shallow lake water in volcano-sedimentary rocks found in the region's underground, with mineral dissolution helped by the local hydrothermal gradient.

History

Pikrolimni has been identified as the location of the ancient lake Chalastra based on archaeological finds in the vicinity and geochemical-hydrological evidence matching exactly with descriptions of the Macedonian lake by ancient authors such as

Pliny the Elder Gaius Plinius Secundus (AD 23/2479), called Pliny the Elder (), was a Roman author, naturalist and natural philosopher, and naval and army commander of the early Roman Empire, and a friend of the emperor Vespasian. He wrote the encyclopedic '' ...

. From Chalastra the ancient Greeks extracted a type of

specifically called ''chalestraion'' 'nitron''(Ancient Greek: χαλεστραῖον �ίτρον Latin: ''nitrum chalestricum'') which was used extensively in Hellenistic and Roman times as a source of

soda Soda or SODA may refer to: Chemistry * Some chemical compounds containing sodium ** Sodium carbonate, washing soda or soda ash ** Sodium bicarbonate, baking soda ** Sodium hydroxide, caustic soda ** Sodium oxide, an alkali metal oxide * Sod ...

and flux in

. The processing of the lake's

evaporites An evaporite () is a water-soluble sedimentary mineral deposit that results from concentration and crystallization by evaporation from an aqueous solution. There are two types of evaporite deposits: marine, which can also be described as ocean ...

to yield the natron and

mixture was done by the residents of the nearby ancient city of Clitae (Ancient Greek: Κλῖται), the ruins of which have been found in a small distance from Pikrolimni, near the modern village of Xylokeratia. ''Chalestraion'' natron is first mentioned by

Plato Plato ( ; grc-gre, Πλάτων ; 428/427 or 424/423 – 348/347 BC) was a Greek philosopher born in Athens during the Classical period in Ancient Greece. He founded the Platonist school of thought and the Academy, the first institution ...

in the

Republic A republic () is a "state in which power rests with the people or their representatives; specifically a state without a monarchy" and also a "government, or system of government, of such a state." Previously, especially in the 17th and 18th c ...

(book 4, section 430a). Although the main source of natron in antiquity was Egypt's "valley of natron" (

Wadi El Natrun Wadi El Natrun (Arabic: "Valley of Natron"; Coptic: , "measure of the hearts") is a depression in northern Egypt that is located below sea level and below the Nile River level. The valley contains several alkaline lakes, natron-rich salt dep ...

), the rarer ''chalestraion nitron'' was praised, particularly by Pliny, as being of much higher quality and optical clarity. Although it is hard to prove when natron extraction from Pikrolimni stopped, this can be assumed to be near the

9th century The 9th century was a period from 801 ( DCCCI) through 900 ( CM) in accordance with the Julian calendar. The Carolingian Renaissance and the Viking raids occurred within this period. In the Middle East, the House of Wisdom was founded in Abbasid ...

AD when plant ash replaced natron as the basic material for glassmaking in Europe and the Near East. In recent years, as a result of a series of earthquakes in the 1960s and 1970s the lake shrunk by 150–200 m in length and width, but has been steadily growing towards its former size with each passing yearly evaporation-precipitation cycle. The most notable modern development around Pikrolimni is the creation of a

hotel specialising in

mud bath A mud bath is a bath of mud, commonly found in areas where hot spring water can combine with volcanic ash. Mud baths have a long history that dates back thousands of years. Mud baths are conceived as public bathing spaces created in open areas ...

treatments (pelotherapy) on the southeast shore of the lake.

Chemistry

The water of the lake is characterised as

brine Brine is a high-concentration solution of salt (NaCl) in water (H2O). In diverse contexts, ''brine'' may refer to the salt solutions ranging from about 3.5% (a typical concentration of seawater, on the lower end of that of solutions used for br ...

, with a very high average

salinity Salinity () is the saltiness or amount of salt dissolved in a body of water, called saline water (see also soil salinity). It is usually measured in g/L or g/kg (grams of salt per liter/kilogram of water; the latter is dimensionless and equal ...

of 153‰ (''i.e.'' there are 153 g of salt per kg of lake water). In comparison, this is about five times the salinity of the

Mediterranean Sea The Mediterranean Sea is a sea connected to the Atlantic Ocean, surrounded by the Mediterranean Basin and almost completely enclosed by land: on the north by Western and Southern Europe and Anatolia, on the south by North Africa, and on the ea ...

and half that of the

Dead Sea The Dead Sea ( he, יַם הַמֶּלַח, ''Yam hamMelaḥ''; ar, اَلْبَحْرُ الْمَيْتُ, ''Āl-Baḥrū l-Maytū''), also known by other names, is a salt lake bordered by Jordan to the east and Israel and the West Bank ...

. Of course, evaporation in the summer and flooding in the winter create significant variation of water volume (and hence salt concentration) throughout the year, with 153 g·kg⁻¹ being only the average value. The brine consists of a high proportion of

sodium chloride Sodium chloride , commonly known as salt (although sea salt also contains other chemical salts), is an ionic compound with the chemical formula NaCl, representing a 1:1 ratio of sodium and chloride ions. With molar masses of 22.99 and 35.45 g ...

and

sulfate The sulfate or sulphate ion is a polyatomic anion with the empirical formula . Salts, acid derivatives, and peroxides of sulfate are widely used in industry. Sulfates occur widely in everyday life. Sulfates are salts of sulfuric acid and many ar ...

, as well as appreciable amounts of

carbonates A carbonate is a salt of carbonic acid (H2CO3), characterized by the presence of the carbonate ion, a polyatomic ion with the formula . The word ''carbonate'' may also refer to a carbonate ester, an organic compound containing the carbonate g ...

and

bicarbonates In inorganic chemistry, bicarbonate (IUPAC-recommended nomenclature: hydrogencarbonate) is an intermediate form in the deprotonation of carbonic acid. It is a polyatomic anion with the chemical formula . Bicarbonate serves a crucial biochemica ...

which in addition to hypersaline, make the lake

alkaline In chemistry, an alkali (; from ar, القلوي, al-qaly, lit=ashes of the saltwort) is a base (chemistry), basic, ionic compound, ionic salt (chemistry), salt of an alkali metal or an alkaline earth metal. An alkali can also be defined as ...

. The pH of the waters has a value around 9.3 (slightly higher than neutral pH 7 or seawater mean pH 8). The pH, presence of species such as and along with the high chloride:bromide ratio make Pikrolimni's water consistency considerably different from marine water, reflecting its non-marine origin from meteoric waters with dissolved volcanic sediments. The physical and chemical properties of the black

mud A MUD (; originally multi-user dungeon, with later variants multi-user dimension and multi-user domain) is a Multiplayer video game, multiplayer Time-keeping systems in games#Real-time, real-time virtual world, usually Text-based game, text-bas ...

at the bottom of the lake have been also studied due to its application as a peloid. The solid (dry) component is classified as

sandy loam Loam (in geology and soil science) is soil composed mostly of sand (particle size > ), silt (particle size > ), and a smaller amount of clay (particle size < ). By weight, its mineral composition is about 40–40–20% concentration of sand–sil ...

, containing on average 71%

sand Sand is a granular material composed of finely divided mineral particles. Sand has various compositions but is defined by its grain size. Sand grains are smaller than gravel and coarser than silt. Sand can also refer to a textural class of s ...

, 24%

silt Silt is granular material of a size between sand and clay and composed mostly of broken grains of quartz. Silt may occur as a soil (often mixed with sand or clay) or as sediment mixed in suspension with water. Silt usually has a floury feel when ...

and 5%

clay Clay is a type of fine-grained natural soil material containing clay minerals (hydrous aluminium phyllosilicates, e.g. kaolin, Al2 Si2 O5( OH)4). Clays develop plasticity when wet, due to a molecular film of water surrounding the clay par ...

. Chemically, the main component is

silica Silicon dioxide, also known as silica, is an oxide of silicon with the chemical formula , most commonly found in nature as quartz and in various living organisms. In many parts of the world, silica is the major constituent of sand. Silica is one ...

, with additional major contributions from alumina,

iron(III) oxide Iron(III) oxide or ferric oxide is the inorganic compound with the formula Fe2O3. It is one of the three main oxides of iron, the other two being iron(II) oxide (FeO), which is rare; and iron(II,III) oxide (Fe3O4), which also occurs naturally ...

, sulfate and carbonate salts. These are found as minerals like

quartz Quartz is a hard, crystalline mineral composed of silica (silicon dioxide). The atoms are linked in a continuous framework of SiO4 silicon-oxygen tetrahedra, with each oxygen being shared between two tetrahedra, giving an overall chemical form ...

clay minerals Clay minerals are hydrous aluminium phyllosilicates (e.g. kaolin, Al2 Si2 O5( OH)4), sometimes with variable amounts of iron, magnesium, alkali metals, alkaline earths, and other cations found on or near some planetary surfaces. Clay mineral ...

(mainly kaolinite with some montmorillonite and illite),

halite Halite (), commonly known as rock salt, is a type of salt, the mineral (natural) form of sodium chloride ( Na Cl). Halite forms isometric crystals. The mineral is typically colorless or white, but may also be light blue, dark blue, purple, p ...

, thenardite, burkeite,

calcite Calcite is a Carbonate minerals, carbonate mineral and the most stable Polymorphism (materials science), polymorph of calcium carbonate (CaCO3). It is a very common mineral, particularly as a component of limestone. Calcite defines hardness 3 on ...

muscovite Muscovite (also known as common mica, isinglass, or potash mica) is a hydrated phyllosilicate mineral of aluminium and potassium with formula K Al2(Al Si3 O10)( F,O H)2, or ( KF)2( Al2O3)3( SiO2)6( H2O). It has a highly perfect basal cleavage ...

and

albite Albite is a plagioclase feldspar mineral. It is the sodium endmember of the plagioclase solid solution series. It represents a plagioclase with less than 10% anorthite content. The pure albite endmember has the formula . It is a tectosilicate. I ...

Pelotherapy

In addition to the lake's saline water being used in

, the black mud found on the lake's north shore has been promoted as a

peloid Peloid is mud, or clay used therapeutically, as part of balneotherapy, or therapeutic bathing. Peloids consist of humus and minerals formed over many years by geological and biological, chemical and physical processes. Numerous peloids are avai ...

(therapeutic mud) for use in pelotherapy (mud therapy). Pelotherapy can have medical or cosmetic purposes; a mixture of the peloid with lake brine is claimed to possess a beneficial effect on certain pathologies, skin appearance and to a lesser extent overall health when applied in a

bath Bath may refer to: * Bathing, immersion in a fluid ** Bathtub, a large open container for water, in which a person may wash their body ** Public bathing, a public place where people bathe * Thermae, ancient Roman public bathing facilities Plac ...

or as a cataplasm. Specifically for peloids derived from Pikrolimni, their grain coarseness requires a

sieving A sieve, fine mesh strainer, or sift, is a device for separation process, separating wanted elements from unwanted material or for controlling the particle size distribution of a sample, using a screen such as a warp and weft, woven mesh or n ...

process before application, and their dark colour originates from the surface interaction of amorphous clay minerals with

organic matter Organic matter, organic material, or natural organic matter refers to the large source of carbon-based compounds found within natural and engineered, terrestrial, and aquatic environments. It is matter composed of organic compounds that have c ...

. Additionally, the concentration of potentially toxic through skin absorption elements Cr, Ni, Cu, Zn, Cd, As and Pb has been examined to determine the suitability of the lake's muds as safe peloid treatments; they all lie within normal ranges except for As and Pb, which are found slightly enriched but comparable to other therapeutic muds and judged to be of "no significant concern".

Ecological habitat

The hypersaline lake itself, its muddy shore and the surrounding vibrantly vegetated

endorrheic basin An endorheic basin (; also spelled endoreic basin or endorreic basin) is a drainage basin that normally retains water and allows no outflow to other external bodies of water, such as rivers or oceans, but drainage converges instead into lakes ...

comprise an important

habitat In ecology, the term habitat summarises the array of resources, physical and biotic factors that are present in an area, such as to support the survival and reproduction of a particular species. A species habitat can be seen as the physical ...

for the local flora and fauna of Pikrolimni, a protected

Ramsar Ramsar may refer to: * Places so named: ** Ramsar, Mazandaran, city in Iran ** Ramsar, Rajasthan, village in India * Eponyms of the Iranian city: ** Ramsar Convention concerning wetlands, signed in Ramsar, Iran ** Ramsar site, wetland listed in a ...

wetland A wetland is a distinct ecosystem that is flooded or saturated by water, either permanently (for years or decades) or seasonally (for weeks or months). Flooding results in oxygen-free (anoxic) processes prevailing, especially in the soils. The ...

which is also a designated Corine biotope and since 1996

site of community interest (for

flora Flora is all the plant life present in a particular region or time, generally the naturally occurring (indigenous) native plants. Sometimes bacteria and fungi are also referred to as flora, as in the terms '' gut flora'' or '' skin flora''. E ...

) and special protection area (for

avians Birds are a group of warm-blooded vertebrates constituting the class Aves (), characterised by feathers, toothless beaked jaws, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a strong yet lightweig ...

). With respect to vegetation, the

halophytes A halophyte is a salt-tolerant plant that grows in soil or waters of high salinity, coming into contact with saline water through its roots or by salt spray, such as in saline semi-deserts, mangrove swamps, marshes and sloughs and seashores. Th ...

of the lake are both unusual and characteristic as the very different chemical composition of the water necessitates the differentiation from coastal halophytic growth. The most notable halophytes of Pikrolimni are the

alkali grass ''Puccinellia'' is a genus of plants in the Poaceae, grass family, known as alkali grass or salt grass. These grasses grow in wet environments, often in Saline water, saline or alkaline conditions. They are native to temperate to Arctic regions ...

(''

Puccinellia convoluta ''Puccinellia'' is a genus of plants in the grass family, known as alkali grass or salt grass. These grasses grow in wet environments, often in saline or alkaline conditions. They are native to temperate to Arctic regions of the Northern and S ...

''), pricklegrass ('' Crypsis aculeata''), herbaceous seablite (''Suaeda maritima''), ('' Camphorosma annua''), buck's-horn plantain (''Plantago coronopus''), Siberian

statice ''Limonium'' is a genus of 120 flowering plant species. Members are also known as sea-lavender, statice, caspia or marsh-rosemary. Despite their common names, species are not related to the lavenders or to rosemary. They are instead in Plumbag ...

(''

Limonium gmelinii ''Limonium gmelini'', the Siberian statice, is a species of flowering plant in the family Plumbaginaceae, native to east-central and southeastern Europe, Russia, the north Caucasus, Turkey, Iran, Kazakhstan, Kyrgyzstan, parts of Siberia, Xinjiang ...

''), sandspurry (''

Spergularia nicaeensis Spergularia is a genus in the family Caryophyllaceae, containing salt-tolerant plants known as sandspurrys and sea-spurreys. There are about 60 species. Selected species * ''Spergularia azorica'' – endemic to the archipelago of the AzoresSecre ...

'') and tall wheatgrass ('' Elymus elongatus''). These are accompanied by scattered

reed bed A reedbed or reed bed is a natural habitat found in floodplains, waterlogged depressions and estuaries. Reedbeds are part of a succession from young reeds colonising open water or wet ground through a gradation of increasingly dry ground. As ...

formations of the

common reed ''Phragmites australis'', known as the common reed, is a species of plant. It is a broadly distributed wetland grass that can grow up to tall. Description ''Phragmites australis'' commonly forms extensive stands (known as reed beds), which may ...

(''Phragmites australis''). Regarding fauna, Pikrolimni is an important site for the breeding, passage and wintering of

waterbirds A water bird, alternatively waterbird or aquatic bird, is a bird that lives on or around water. In some definitions, the term ''water bird'' is especially applied to birds in freshwater ecosystems, although others make no distinction from seabi ...

as well as raptors, with more than 47 bird species listed in the Natura 2000 special protection area's data form. Some representative avians that can be found in the lake biotope include the

greater flamingo The greater flamingo (''Phoenicopterus roseus'') is the most widespread and largest species of the flamingo family. It is found in Africa, the Indian subcontinent, the Middle East, and in southern Europe. Taxonomy The greater flamingo was desc ...

(''Phoenicopterus roseus'') in large flocks,

Dalmatian pelican The Dalmatian pelican (''Pelecanus crispus'') is the largest member of the pelican family, and perhaps the world's largest freshwater bird, although rivaled in weight and length by the largest swans. They are elegant soaring birds, with wingspan ...

(''Pelecanus crispus''),

great crested grebe The great crested grebe (''Podiceps cristatus'') is a member of the grebe family of water birds noted for its elaborate mating display. Taxonomy The great crested grebe was formally described by the Swedish naturalist Carl Linnaeus in 1758 in t ...

(''Podiceps cristatus''),

Eurasian curlew The Eurasian curlew or common curlew (''Numenius arquata'') is a very large wader in the family Scolopacidae. It is one of the most widespread of the curlews, breeding across temperate Europe and Asia. In Europe, this species is often referred t ...

(''Numenius arquata''),

little grebe The little grebe (''Tachybaptus ruficollis''), also known as dabchick, is a member of the grebe family of water birds. The genus name is from Ancient Greek ''takhus'' "fast" and ''bapto'' "to sink under". The specific ''ruficollis'' is from Latin ...

(''Tachybaptus ruficollis''),

merlin Merlin ( cy, Myrddin, kw, Marzhin, br, Merzhin) is a mythical figure prominently featured in the legend of King Arthur and best known as a mage, with several other main roles. His usual depiction, based on an amalgamation of historic and le ...

(''Falco columbarius'') and

short-toed snake eagle The short-toed snake eagle (''Circaetus gallicus''), also known as the short-toed eagle, is a medium-sized bird of prey in the family Accipitridae, which also includes many other diurnal raptors such as kites, buzzards and harriers. The genus na ...

(''Circaetus gallicus''). Animals other than birds which can be found around the lake include reptiles, ''i.e.'' multiple species of

toads Toad is a common name for certain frogs, especially of the family Bufonidae, that are characterized by dry, leathery skin, short legs, and large bumps covering the parotoid glands. A distinction between frogs and toads is not made in scientif ...

, treefrogs and water snakes, or mammals such as the

red fox The red fox (''Vulpes vulpes'') is the largest of the true foxes and one of the most widely distributed members of the Order (biology), order Carnivora, being present across the entire Northern Hemisphere including most of North America, Europe ...

(''Vulpes vulpes''), common weasel (''Mustela nivalis'') and even the endangered

European ground squirrel The European ground squirrel (''Spermophilus citellus''), also known as the European souslik, is a species from the squirrel family, Sciuridae. It is among the few European species in the genus ''Spermophilus''. Like all squirrels, it is a member ...

(''Spermophilus citellus'').

References