Yellow ground squirrels ( (Tsytsulina, et al., 2008)) can be found as far north as Russia and Kazakhstan, ranging as far west as the Caspian Sea and the Volga River and as far east as Lake Balkash. The contiguous southern range spreads down through Uzbekistan, western Tajikistan and Turkmenistan. There are additional disjunct populations of yellow ground squirrels that are found in northeastern Iran, Afghanistan, and Kashi, China.
Yellow ground squirrels live in a terrestrial biome. The habitat of yellow ground squirrels consists of sand, clay, and loess deserts and semi-deserts. The ground squirrels also live in forest zones with alkali and saltwort alkali soils. The maximum elevation of the habitat of these squirrels is 1000 meters. Yellow ground squirrels use natural and artificial elevated areas to construct their burrows. Titov et al., (2012) found that man-made disturbed steppe and semi-dessert areas, such as dumping sites and non-structured cattle pastures in settlements, are where many burrows of yellow ground squirrels are found. Other sources suggest that the squirrels do not come into contact with humans or agricultural areas often. (Titov, et al., 2012; Tsytsulina, et al., 2008; Vasilieva and Tchabovsky, 2014)
As their name suggests, yellow ground squirrels have a yellowish upper body with black tipped hairs that create a finely speckled look. With an adult body mass ranging from 307 to 1428 grams and a body length (not including the tail) ranging from 230 to 370 millimeters, the yellow ground squirrel is the largest-sized genus Spermophilus ground squirrel. The juvenile body mass of the yellow ground squirrel ranges from 173 to 555 grams. Volodina et al., 2010 reports that the overall average body mass of juvenile yellow ground squirrels to be 283 grams and the overall average body mass of adults to be 819 grams. Matrosova et al., 2011 found that the male juvenile average body mass is 309 grams, the male adult average body mass is 1343 grams, the female juvenile average body mass is 275 grams, and the female adult average body mass is 856 grams. The average body mass for male yellow ground squirrels is larger than the average body mass for female yellow ground squirrels. (Matrosova, et al., 2010; Matrosova, et al., 2011; Volodina, et al., 2010)
Yellow ground squirrels are seasonal breeders, usually breeding during March and April. The male yellow ground squirrels emerge from hibernation 1-2 weeks before the females. Beyond this, nothing else is known about the mating habits of this species. (Vasilieva and Tchabovsky, 2014)
Yellow ground squirrels are iteroparous and reproduce sexually. Female yellow ground squirrels can produce one litter per year and have an average of 5 pups per breeding season but can range from 1 pup to 10 pups. The average gestation period is 30 days. The breeding season usually starts in March and early April, right after they emerge from hibernation in mid-February. Male yellow ground squirrels emerge from hibernation first, and about 1-2 weeks later the females will emerge. Female ground squirrels have about 3 months to mate and gain body weight before entering hibernation in late June. Juvenile ground squirrels emerge usually in April-May, giving them about 2 months to gain weight before their first hibernation. The average offspring mass at birth is 191 grams with a range of 104 to 290 grams. The squirrels will reach their adult size by the summer after their first hibernation. The female yellow ground squirrels are capable of reproducing after their first hibernation while the males are not able to reproduce until after their second hibernation. The average age at reproductive maturity for the females is one year old and the average age at reproductive maturity for the males is two years old. (Hayssen, 2008; Kashkarov and Lein, 1927; Matrosova, et al., 2007; Matrosova, et al., 2008; Vasilieva and Tchabovsky, 2014)
Yellow ground squirrel pups are born in burrows which allows for protection from predators. The ground squirrel pups are born undeveloped and require care and feeding from their mothers. The female squirrels protect and care for the young, having extended social contact with their young up until their first hibernation. The mothers teach the pups how to make alarm calls. It is not apparent that the males are involved except during the mating process. (Hayssen, 2008; Matrosova, et al., 2008; )
Yellow ground squirrels live between five to six years in the wild. Once the female ground squirrels reach sexual maturity, around one year of age, the mortality rate increases. Seventy percent of female ground squirrels die before their third hibernation and eighty-seven percent die before their fourth hibernation. The longest captive lifespan for members of the genus Spermophilus is 11 years. (Carey and Judge, 2000; Vasilieva and Tchabovsky, 2014)
Yellow ground squirrels live in burrows underground and are active during the day. The squirrels typically have low population densities of about 3 to 10 individuals per hectare. The female ground squirrels tend to stay close to their natal burrows whereas the males move farther away.
Yellow ground squirrels usually emerge from hibernation in mid-February when the vegetation starts to green up. In the middle of March the ground squirrels begin mating and during this time, they do not eat very much. After mating, the squirrels will spend all day eating and they gain weight quickly. When the sun rises, the ground squirrels exit their burrows and begin to eat the vegetation nearby. Around the middle of the day, as it warms, the squirrels will return to their burrows. Later in the afternoon, the ground squirrels will come back out of the burrow for a short period. In 24 hours, the ground squirrels will have consumed, on average, 275 grams of vegetation. The squirrels continue to eat until the availability of suitable forage declines, usually early June, and then they enter hibernation. (Kashkarov and Lein, 1927)
The home range of yellow ground squirrels is unknown. (Kashkarov and Lein, 1927)
Yellow ground squirrels have an advanced sociality compared to the smaller species in the genus Spermophilus. They have burrows in close proximity to each other which allows them to hear the alarm calls of neighbors and respond to them. The alarm call is the most common and the loudest call used by yellow ground squirrels. The structure of the alarm calls of the ground squirrels is the same in all predatory situations, such as humans, some harmless animals, terrestrial predators, and raptors. Juvenile ground squirrels have an alarm call that is very close to the alarm call of the adult squirrels. The pitch of the alarm call is lower in the juveniles than in the adults, which is not common among mammals. (Matrosova, et al., 2010)
Yellow ground squirrels are herbivores. The ground squirrels that inhabit the desert and semi-desert areas feed on desert vegetation which is their only source of metabolic water. The main sources of vegetation that yellow ground squirrels consume is bulbous bluegrass (Poa bulbosa), Carex grasses (Carex hostii), and a flowering plant (Malcolmia turkestanica). Yellow ground squirrels are active as long as the period of vegetation lasts. During the mating season the ground squirrels don't spend much time eating. After the mating season the squirrels spend most of the day eating to gain weight before hibernation. (Kashkarov and Lein, 1927)
Yellow ground squirrels are one of the main prey of eastern golden eagles (Aquila chrysaetos), imperial eagles (Aquila heliaca), and steppe eagles (Aquila nipalensis). These squirrels warn others of predators through an alarm call. Steppe polecats (Mustela eversmanii) and marbled polecats (Vormela peregusna) hunt in burrows and prey upon young ground squirrels. These polecats do not eat adults. Matrosova et al. (2007) state that there are cases of infanticide where neighbors, both male and female ground squirrels, will kill the young. They further suggest that because some predators that only attack juvenile squirrels, the young may mimic the adults alarm calls as a way to discourage such juvenile-specific predators. (Karyakin, et al., 2011; Matrosova, et al., 2007; Matrosova, et al., 2008)
Yellow ground squirrels eat desert grasses. The squirrels provide a food source for the predators that hunt them, such as eagles and polecats. Common parasites of yellow ground squirrels are northern rat fleas (Nosopsyllus fasciatus), sucking lice (Enderleinellus propinquus and Linognathoides laeviusculus), ticks (Hyalomma asiaticum), and protists (Eimeria airculensis, Eimeria berkinbaevi, Eimeria deserticola, and Eimeria susliki). (Apanaskevich and Horak, 2010; Durden and Musser, 1994; Hamidi, et al., 2016; Karyakin, et al., 2011; Kashkarov and Lein, 1927; Wilber, et al., 1998)
Yellow ground squirrels are hunted by humans. The squirrels are often hunted commercially and sold for profit. There was not much information found on the price, uses, or locations of the hunting. (Tsytsulina, et al., 2008)
There are no adverse economic effects of yellow ground squirrels on humans. (Kashkarov and Lein, 1927)
There is no special status listed for yellow ground squirrels for the CITES appendices or the United States Endangered Species Act list, but it is listed as "Least Concern" on the IUCN Red List. Commercial hunting is a potential threat and has affected some populations in areas of Russia and Kazakhstan but has not caused a substantial decline in the population. There are no conservation acts to protect the yellow ground squirrels. (Tsytsulina, et al., 2008)
Rebekah Shorter (author), Radford University, Cari Mcgregor (editor), Radford University, Zeb Pike (editor), Radford University, Karen Powers (editor), Radford University, April Tingle (editor), Radford University, Jacob Vaught (editor), Radford University, Tanya Dewey (editor), University of Michigan-Ann Arbor.
living in the northern part of the Old World. In otherwords, Europe and Asia and northern Africa.
living in landscapes dominated by human agriculture.
young are born in a relatively underdeveloped state; they are unable to feed or care for themselves or locomote independently for a period of time after birth/hatching. In birds, naked and helpless after hatching.
having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.
uses smells or other chemicals to communicate
in deserts low (less than 30 cm per year) and unpredictable rainfall results in landscapes dominated by plants and animals adapted to aridity. Vegetation is typically sparse, though spectacular blooms may occur following rain. Deserts can be cold or warm and daily temperates typically fluctuate. In dune areas vegetation is also sparse and conditions are dry. This is because sand does not hold water well so little is available to plants. In dunes near seas and oceans this is compounded by the influence of salt in the air and soil. Salt limits the ability of plants to take up water through their roots.
animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.
parental care is carried out by females
an animal that mainly eats leaves.
A substance that provides both nutrients and energy to a living thing.
forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.
Referring to a burrowing life-style or behavior, specialized for digging or burrowing.
An animal that eats mainly plants or parts of plants.
the state that some animals enter during winter in which normal physiological processes are significantly reduced, thus lowering the animal's energy requirements. The act or condition of passing winter in a torpid or resting state, typically involving the abandonment of homoiothermy in mammals.
offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).
having the capacity to move from one place to another.
the area in which the animal is naturally found, the region in which it is endemic.
breeding is confined to a particular season
reproduction that includes combining the genetic contribution of two individuals, a male and a female
uses touch to communicate
Living on the ground.
reproduction in which fertilization and development take place within the female body and the developing embryo derives nourishment from the female.
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