Ukraine Part 3: Rodents underfoot

 

Signs of the Sandy Mole Rat

In the dry habitat of steppe the main sources of plant food are the leaves, flowers and seeds of the steppe vegetation and their underground storage organs in the form of roots and rhizomes. The ground is usually very hard however, which makes the kind of tunnelling moles are famous for difficult. Rodents on the other hand come equipped with perfect tools for not so much tunnelling as gnawing through the ground, and several groups of rodents have adapted to the lifestyle. In Europe and Asia these are the blind mole rats in the family Spalacidae.

These weird rodents get their name from the complete absence of eyes, which are covered by skin. Ukraine is home to five species. They have a similar lifestyle, digging extensive burrow systems containing nesting chambers, latrines and storage chambers, often many tens of metres across and many metres deep, which is where they survive the cold winters deep underground and protected from frost. Fairly large for rodents, they are mostly around the size of a brown rat or larger. They tend to be solitary animals, only meeting for the breeding season, and as they spend almost their entire lives underground their main natural enemies are snakes and animals such as foxes or other animals that can dig. Not quite as long lived as the famous (and unrelated) Naked mole rat of Africa, some individuals are still on record as reaching 15 years in captivity.

Sandy Mole Rat Spalax arenarius

One of the rarest of Ukraine’s mole rats, and endemic to the country, the Sandy Mole Rat Spalax arenarius is found east of Odessa around the lower Dnepr in sandy soils, mostly within the Black Sea Biosphere Reserve. Outside the 55km2 of total area where it can be found the few remaining populations are highly fragmented and threatened by conversion of habitat to forestry. A solitary species, as far as is known, it breeds only once each year. Currently classed as Endangered by the IUCN, the assessment is 14 years old and needs updating.

S.arenarius range

Balkan Mole Rat Spalax gracus

Not quite as threatened, but still classed as Vulnerable, the Balkan Blind Mole Rat Spalax graecus is slightly misnamed, as it does not come from Greece but rather has a range just east of the Carpathian mountains overlapping Ukraine, Romania and Moldova. Not quite as specialised as S.arenarius, it inhabits steppes, pastures and orchards, often with northern exposures. It occurs at low densities of usually only a few individuals per hectare.

S.graecus range

Podolsk Mole Rat Spalax zemni

S.zemni mounds in habitat

One of the more widespread of Ukraine’s mole rats, the Podolsk mole rat S.zemni has a range that extends over much of central and northwest Ukraine. It is mainly found on virgin steppes, but does not mind some woodland and indeed feeds on the roots of tree seedlings, although it also feeds on roots of many other plants including agricultural crops. Very little is known of its behaviour, as with other mole rats, and although it has a large range it is classed as Vulnerable and is probably declining as a result of agricultural intensification.

Podolsk Mole Rat range

Greater Mole Rat Spalax micropthalmus

One of the largest of all mole rats, the Greater Mole Rat S.micropthalmus can reach 30cm long and 570g in weight. It favours softer soils with black earth, avoiding sandy or loamy soils, and can be a pest. As a single individual can cache 15kg of food in its store chambers the impact of a large population can be large. Its main range is in the east of Ukraine extending into Russia.

Greater Mole Rat range

Lesser Mole Rat Nannospalax leucodon

Classed in a separate genus, the Lesser Mole Rat Nannospalax leucodon may actually be a complex of cryptic species. It has a large range mostly to the south of Ukraine through Greece and the Balkans, where it prefers loose soils to dig extensive burrows. As with the other species ploughing is destructive to its burrows, but it can use orchards and pastureland as well as steppe grassland. Given its range it is probably not a threatened species as a whole, but as with its relatives is probably at least locally threatened by conversion of habitat for agriculture and construction.

Lesser Mole Rat range

Northern Mole Vole Ellobius talpinus. Note the beady eyes

Not at all closely related to the blind mole rats, but with a similar lifestyle, the Northern Mole Vole Ellobius talpinus is much smaller, around 13cm long and a weight of 70g. Unlike the blind mole rats it has well developed eyes. It is also more sociable, with colonies usually consisting of a queen, several males plus one or two litters of young, with a maximum group size of up to 20 individuals, though half that is more usual. Within Ukraine it is found in the southeast of the country.

Northern Mole Vole range

So much for subterranean rodents. Among the grasses above ground there is also a large variety of rodents of various sizes, and those are what I will cover next.

Ukrain Part 2: Squirrels of the grasslands

Although from the perspective of a resident in Britain or most of western Europe the word “squirrel” immediately conjures up a picture of an animal in a tree, terrestrial and usually burrowing squirrels are widespread across the world in semi-deserts and grasslands . Most of these belong to the tribe Marmotini, which includes the highly colonial prairie dogs of North America and the less sociable, but larger, marmots. Ukrains with its extensive grasslands is home to four species, the large Bobak Marmot Marmota bobak and no less than three species of smaller ground squirrels or sousliks in the genus Spermophilus. 

Bobak (Steppe) Marmot

Bobak Marmots are very large for a squirrel – reaching over 7kg and a body length approaching 60cm, and like their relatives are keen burrowers. Their burrows can reach 3m deep and over 20m long, and constitute important refuges for other steppe animals, as well as affecting hydrology of the steppe. They are vegetarian, feeding on grasses, seeds, and various herbs, and are active by day. 

They are sociable creatures, with a typical family group consisting of an adult male, a few females, plus offspring of various ages. Young disperse to start families of their own at around 3 years old. Within a given area the families will usually be within visual or auditory contact, as they need to keep a sharp lookout for predators. These might include wolves, foxes, and various birds of prey such as Eastern Imperial Eagle, and in the east of their range even Snow Leopards. 

M.bobak range

The range extends from Ukraine in the west, where ploughing up of grasslands has severely impacted the range, into central Asia, with most of the modern population being found in Kazakhstan. In history they are most important as, along with related species, being a natural reservoir for bubonic plague. 

Much smaller than marmots are the various species of susliks. These small ground squirrels are mostly around 25cm long or less. Like the marmot they hibernate for long periods – often more than half the year – which is how they avoid the long cold winters. Given its location Ukraine is home to no less than three species, although they are adapted to slightly different habitats and climates and consequently mostly do not compete directly.

European Souslik

Currently classed as Endangered, The European Souslik S.citellus has the most westerly range, extending as far west as Austria and north into Poland. 

European Souslik range

Like their larger relatives the marmots they feed on grasses, seeds and flowers, but also feed on various invertebrates. They are dependent on short vegetation which enables them to keep watch for predators such as raptors, foxes, or weasels and agricultural intensification has seriously impacted their range. They can spend 6 months of the year in hibernation in their burrows. These are not as deep as those of the marmots but can still extend for many metres underground. 

Spotted Souslik

Preferring taller and coarser grassland than the European Souslik, Spotted Sousliks otherwise have a similar lifestyle. Their range extends more to the north and east into European Russia and Poland where grassland can be found. It faces the same sort of problems as its relative, and is currently classed as Near Threatened. 

Spooted Souslik range

Little Souslik

Not actually much smaller than its relatives, the Little Souslik is the most arid-adapted of the three species, and is found in dry grassland and semi-desert into central Asia. Given the extremes of climate it has to deal with it not only hibernates but also aestivates in the summer, with the result it may only be active above ground only a few months out of each year. The years of excavation of their burrows results in characteristic mounds used by generations of animals, and these can be many metres in diameter. From these low mounds the souslik keeps watch over the surroundings, ready to give a warning whistle when danger is seen. 

Little Souslik range

Ploughing up of the steppe and changes in farming practises, especially grazing and livestock numbers, is the main threat to all these grassland rodents. At least they are diurnal and consequently known to local people. Below ground, another set of rodents is far less obvious, and it is to these I will turn next time.

Wildlife of Ukraine Part 1 - ecology and background

 

In view of the terrible situation in Ukraine at the moment I decided that my next series of posts will be dedicated to the wildlife, both obvious and not-so-obvious, to be found in that country. I hope my readers appreciate this and will be inspired to aid as they can the people and nature of this often misunderstood country.

To start with the general layout of habitats, in terms of its ecosystems Ukraine can be divided into three bands of habitats running southwest to northeast. In the south, including the Black Sea coast, dry steppe grassland covers about a third of the country, and extends eastward into central Asia. North of that is a forest steppe zone, with rather more rainfall and at least some tree cover in places. Finally, the north and west of the country is (at least before deforestation from agriculture)   comprises mixed deciduous and coniferous forest, with extensive bogs and wetlands in the north on the border with Belorus and Poland. Most of the country is more or less flat, but in the west the Carpathian mountains are steeper and densely forested, and extend from Ukraine through Poland into Slovakia and south into Romania.

Demoiselle Crane

Ukraine is a land of rivers – over 23,000 in fact. Most of course are fairly small, but they include a short section of the Danube and the second greatest (by volume) river in Europe, the Dnieper. These both eventually form major river deltas on the Black Sea which are important wildlife areas. These large rivers are the natural habitat for some of the worlds most famous (and largest) freshwater fish, the multiple species of sturgeon that produce caviar.

Beluga Sturgeon

In the past the steppe grassland in the south was wide open to repeated waves of invaders from the east, most famously Genghis Khan and his successors, and before that in the last days of the Roman Empire the peoples that became known to history as the Huns. Being too dry for most forms of arable farming without irrigation, the grasslands were natural horse and livestock country. In more recent times arable farming has covered most of the country, resulting in extensive conversion of steppe and grassland for growing wheat and sunflowers for oil among other crops. Much of the wetland has been drained as well for farming and this has inevitable impacted the native wildlife. In addition to this building of hydroelectric dams has impacted fish migrations. and most famously of all the Chernobyl Power station, which was built on the banks of the Pripyat, a river which also flows through Belarus before joining the Dnieper,  has serious implications for radioactive pollution of the rivers and eventually the Black Sea itself.

This agricultural expansion, along with hunting and other forms of persecution, has resulted in localised extinction within Ukraine of several large mammals in particular. Eurasian Wild Ass, Wild Horse, Saiga Antelope, European Bison have all become extinct, although reintroduction projects are now in place for some of them. In the prehistoric period lions also lived at least in the south, preying on the then-abundant wildlife.

Saiga Antelope

In this series of posts I cannot cover every species found in Ukraine, but I aim to cover as wide a variety of mammals, birds, reptiles and insects as I can. I hope my readers appreciate this primer.

Next time I will start with the multitude of rodents, some specialised or unfamiliar, that call Ukraine home.