Koford 1955 Cynomys ludovicianus February 28, 1955 Nr. Ft. Collins, Colo. Overcast morning, clearing evening moon. Barometer 50°F. in p.m. +4 mod. Breeze. I was at Spring Canyon Dam colony 2-3:30. Took 4 C.l. in steel traps so follows: ♂14 in T6, ♀15 in T4, ♀16 in T1, ♀17 in T15. The ♂ in T4 had broken trap wire + was in hole at T6. I heard its bird-like chirping from burrow + so got it out. In trap, they protrude the 3 oval glands about 3mm. Both ♂14 & ♀15 do this but strong musky smell only from ♂14. Before going to traps I saw 9 out at once. Snow now on 5% of ground + standing water from melting snow in spots. No apparent activity at other trapped bur- rows except T10. For sample, nos. 7, 8, 11, 12, 13. Took one trap #14 rent 10 yrs. 5. fences on E. side colony. (=T16). Set one additional (#17), 2016 out, not over 1/ burrow. ♀16 taken in T1 had little in cecum (cecum + contents weighed 8gms). Fairly sure activity that burrow (Filtr. 17 (tops spring) = 22 (tracks)). Today first females taken this colony, a 3 - suggests seldom out early. One taken T4 that had taken 2 males. March 1, 1955 Larimer Co., Colo. Visited colony on 80 acre preserve near Wellington. Saw at least 6 out. Photographed tunnel one, "Charlie." Staked about 12 bur- rows at N. end colony where there may be no further expansion be- cause of thick growth Kochia about 1 ft. high. This thistle has rabbit trails making openings throughout it. Thistle stood some years a few apparent old burrows (how long vacant?). Temp. +9°C. at 10:30 a.m. Sky 2/10 overcast + 2.5 m.p.h. wind from W. Another green stricita that grows thickly here the only 4-6" tall is Distichlis, prob- ably not invaded by C.l., but perhaps indicates wet site.