Progesterone concentrations of non-reproductive females were always much lower than those of reproductive females (Table 1). Nipple index was lower than that of reproductive females and remained low throughout the reproductive period.
Progesterone concentrations (ng/ml) for M. flaviventris.
Values are mean SE (N) N = number of females.
|Reproductive||2.40±0.26 (40)||2.57±0.50 (31)||0.84±0.24 (14)
|Non-reproductive||0.51±0.13 (35)||0.47±0.08 (30)||0.14±0.04 (13)
|Failed reproduction||1.64±0.23 (9)||0.51±0.15 (4)||0.48±0.11 (4)
|Yearling||0.92±0.37 (6)||4.13±1.78 (8)||0.29±0.19 (4)
|Adult||0.12±0.05 (31)||0.17±0.05 (24)||0.11±0.05 (13)
|Yearling||0.18±0.18 (4)||0 (3)||0.12±0.12 (3)
|Yearling||0.18 ±0.08 (5)|
Progesterone concentrations of failed-reproduction females were higher than those of non-reproductive females and lower than those of reproductive females (Table 1). The peak value occurred in late gestation and a second peak occurred in late lactation. Nipple index was higher than that of non-reproductive females and lower than that of reproductive females except during gestation.
Progesterone concentrations of males and juveniles were always low and those of non-reproductive yearling females were higher than those of non-reproductive females and were unusually high during lactation (Table 1).
The pattern of progesterone concentrations differs from that of most small mammals,but is similar to that of M. monax and Spermophilus beecheyi.
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