Koford 137 Cynomys ludovicianus June 13, 1955 Devil's Tower, Wyoming g yesterday. I saw a few litters of 5, none surely larger, judging by no. budding on mound. About noon on 2A screen plot near road counted 26 grown & 19 juv., C.l. This is high den- sity near road where fed. After we can fed dogs, about 8 grown over within space 5 yds. wide. 11 juvs., more shy than many older dogs. I set live trap next to burrow with juvs., one came out & fed by traps, but an adult C. caught (released). Feeds adult grew, loose, wet, with loose manure smell. 11 Near road some C.l. can be fed from hand. Some are killed on road. One found dead near road, a few seen to wold across paved road. Some burrows at very edge pavement. A few in dirt parking area where cars push soil repeatedly. This substantiates my thesis that food determines presence & absence, & where burrows dug. 11 Several dogs seen to scratch from time to time. Some harvesters put mouse & some other ants on area. They quickly started eating bite of walnut put out for bait. 11 Due & I saw what appeared to be a Citellus 13-linicatus at two burrows, far apart. I heard apparent Spreytys once yesterday. 11 On colony I found no food corn waste digging & found no carnivore scats. Citellus apparently rare this area, Geological Survey men have colt- ed here several summers & have rarely seen one. 11 Several Bria on colony, walking about, apparently feeding (on?). No reaction with C.l. noted. Two adults often seen in same burrow, 11 Sept. McDutye said few rabbits he knew of no Spreytys on colony in past years. Bobcats present but not common, not seen to take C.l. here.