Postnatal Development of Speckled Ground Squirrel (Spermo-philus suslicus Guld, 1770) (Sciuridae, Mammalia) in Captivity

The catastrophic decline in the number of the speckled ground squirrel (a previously numerous, now-threatened species) requires the adoption of urgent measurements to protect and restore its local populations. The paper presents the results of our observations of the development of pups in the postnatal period, which is necessary for the development of an integrated approach combining the creation of semi-natural reserve populations of the species in natural mega-enclosures with raising litters in ex situ conditions. Pregnant speckled ground squirrel females (n = 8) mated in nature (in situ) were captured at the Kosyrovsky cemetery (Lipetsk City) in April 2017. The females were observed from their trapping until delivery, pups (n = 32) were observed from their birth to 64–77 days. The survival rate of pups was 59%. The obtained data on the dynamics of body mass and the timing of the appearance of some morphological features allow using the devised scale to estimate the age from birth to one month of age with an accuracy of two–three days. After the age of one month when pups start feeding by their own, their keeping in cages favors fat accumulation, and at the age of 7–8 weeks the weight of the animals from cages and nature becomes similar with the further better advance of the first ones. Further improvements in the methods of keeping pregnant females and their litters ex situ are necessary for more successful growing squirrel pups during the first weeks of their life.