Spermophilus

Spermophilus is a genus of ground squirrels in the squirrel family. In the past, this genus included many kinds of squirrels living in Europe, Asia, and North America. But scientists found that some squirrels in this genus were more closely related to prairie dogs, marmots, and antelope squirrels, which are clearly different. Because of this, all the Spermophilus squirrels in North America were moved to other genera. Now, only the European and Asian squirrels are true Spermophilus, except for two types in Asia called Urocitellus.

Some kinds of these squirrels are sometimes called susliks (or sousliks). The word suslik comes from the Russian word суслик. In some languages, similar words are used, like suseł in Polish. The scientific name Spermophilus means "seed-lovers." It comes from the Greek words sperma (seed) and philos (friend or lover).

 Habitat and behavior 
Spermophilus are ground squirrels. They live in open places like grassy fields, meadows, dry plains, and semideserts. They eat low plants and make burrows where they sleep and hide.Kryštufek, B.; B. Vohralík (2012). "Taxonomic revision of the Palaearctic rodents (Rodentia). Part 1 (Eutamias and Spermophilus)". Lynx, N. S. (Praha). 43: 17–111. They are active during the day and mostly live in groups, but some live alone. They can be found in both low and high areas. They sleep through cold months (up to about 8 and a half months in some kinds). In dry places, they may also rest during hot times in summer or fall. Different types usually live apart, often divided by big rivers, but in some places, up to three types can live close together. Rarely, two types may even share burrows, and some types mix to create hybrids where they meet.

 Appearance 
Spermophilus are yellowish, light orange, light brown, or grey. Many have soft spots or marks, but they do not have strong patterns. One kind, S. suslicus, has brown fur with clear white spots. Their size depends on the type. They are about  from head to body. The biggest S. fulvus can weigh up to  before winter, and S. major can weigh nearly . Other types are much smaller, often less than  even when ready for hibernation. Their tails are short, about 10–45% of their head-and-body length.

 Relationship with humans 
Ground squirrels may carry fleas that spread diseases like the Black Death. They also cause damage by digging tunnels under buildings.

 Species 
In 2007, scientists used a method called phylogenetic analysis with a special gene called cytochrome b to study Spermophilus. This led to dividing Spermophilus into eight groups, along with prairie dogs, marmots, and antelope squirrels, which were placed in numbered groups (clades). The exact relations between these groups are not completely clear. Some species found only in Palearctic areas are kept under the strict name Spermophilus sensu stricto.

A 2024 genetic study divided the genus into four main groups that split apart in the Late Miocene.

Spermophilus sensu stricto, Old World ground squirrels

 East Asian group
 Alashan ground squirrel, Spermophilus alashanicus
 Daurian ground squirrel, Spermophilus dauricus
 Asia Minor/European group
 European ground squirrel, Spermophilus citellus
 Podolian souslik, Spermophilus odessanus
 Speckled ground squirrel, Spermophilus suslicus
 Taurus ground squirrel, Spermophilus taurensis
 Asia Minor ground squirrel, Spermophilus xanthoprymnus
 Pygmaeus group
 Caucasian Mountain ground squirrel, Spermophilus musicus
 Little ground squirrel, Spermophilus pygmaeus
 Colobotis group
 Brandt's ground squirrel, Spermophilus brevicauda
 Red-cheeked ground squirrel, Spermophilus erythrogenys
 Yellow ground squirrel, Spermophilus fulvus
 Russet ground squirrel, Spermophilus major
 Pallid ground squirrel, Spermophilus pallidicauda
 Spermophilus ralli
 Relict ground squirrel, Spermophilus relictus
 Spermophilus selevinus
 Spermophilus vorontsovi

 Prehistoric species 
Scientists found a very well-preserved Eurasian ground squirrel fossil that helped them learn more about their skull structure. This led to new ideas about their relations. Three Pleistocene species that were once part of Urocitellus were moved to Spermophilus:

 †Spermophilus nogaici
 †Spermophilus polonicus
 †Spermophilus primigenius

There are also three extinct species from Europe:

 Spermophilus citelloides lived from the Middle Pleistocene to early Holocene in central Europe. It is closely related to S. suslicus.
 Spermophilus severskensis lived in the late Pleistocene in Ukraine and was a specialized grazer, related to S. pygmaeus.
 Spermophilus superciliosus lived from the Middle Pleistocene until possibly the early 1900s across much of Europe. It was similar in size to S. major and likely an ancestor of S. fulvus.

 References 

 Citations 

Category:Mammals of North America
Category:Mammals of Asia
Category:Rodents