TIIIO STUII'Kl) (illOlIiNI) S<Ji;iKKELS OF COLORADO 



trai)piiij»' brought an abundant harvest. I found it occupying 

 ])astures of native grass, as well as cultivated fields. 



The soil was sandy, and all parts of llie i-aiidi wei-c full of 

 burrows. 



I also found the little spotted ground scpiirrcH { Citellu-s obso- 

 Icttis) living in the same vicinity. Traps set only w few feet a])art 

 would yield both s])t cies. 



Breeding. — According to Warren (''Mammals of Colorado"), 

 "the young are born in May or June and are from five to eleven 

 in number.'' We have very few data at this office on the breeding 

 habits of the striped ground squirrel. In the breeding season the 

 females are difficult to secure for examination. Of fifty specimens 

 of this squirrel tra]ij;ed in the months of May and July, only 

 nine were females. 



From what information we have, the period of g-estation is 

 about thirty days, and the young are born about the first week in 

 June, and number from nine to eleven. 



The young are born in the underground burrow s. There has 

 been, to our knowledge, only one exception to this rule recorded — 

 that by Mr. K. B. Rockwell, of Denver. He writes as follows in 

 Journal of Annual Behavior , May and June, 1912: 



Some fifteen miles northwest of Denver is a small lake leased by a 

 number of Denver men for duck shooting. The so-called club-house is a 

 frame structure of one room, which serves the manifold purpose of kitchen, 

 sleeping-room, storeroom, etc. It is occupied but one night during the 

 week for only a few weeks in the spring and fall, and is overrun with 

 house mice. The shooting season closed April 15, and the house was not 

 again occupied until the night of June 3. On this evening the writer, 

 with a companion, reached the cabin some time after dark, and prepara- 

 tions were made to retire. In the corner of the cabin was a pile of three 

 folding spring cots, and on top of these was a camp mattress. 



The cots and mattress were taken out of doors and set up (for we 

 were outdoor sleepers), and the writer promptly turned in. I had no 

 sooner become quiet than I heard a chorus of tiny squeaks coming from 

 inside the mattress, and an examination revealed a warm nest in the 

 padding, containing eight tiny, naked, blind creatures whose eyes were 

 not yet opened. Supposing them to be young mice, they were ruthlessly 

 disposed of, as mice usually are, and I prepared to resume my slumbers. 



I was aroused a few minutes later by my friend (who had not yet 

 retired) calling me softly to hurry into the cabin; and, once there, a sight 

 met my eyes that I will long remember. 



Under where the cots had been piled was a knothole in the floor. 

 This, however, was not directly under the portion of the nest, which was 

 rather toward one side of the mattress, but more to the other side of the 

 space which had been covered by the cots, and both were well toward one 

 end of the latter. Emerging from this hole was the mother of the little 

 ones we had just assassinated, but, instead of a mouse, it proved to be a 

 large, handsome pale-striped ground squirrel (Citellus tridecemlineatus 

 pallidus). As this species is, to the best of my knowledge, strictly diurnal, 

 and the time was between 10 and 11 p. m., it seems probable that the 

 animal had been frightened from the nest by our entrance and was now 

 returning. 



