LAUSR

all ages compared to 4–6 month old females (p < 0.0001). The proportion of females who exhibit regular cycling are maintained at 75% for up to 12 months of age, declining to 57% at 24 months and 63% at 36 months. We found no differences in the cycle length, cycle stages or correlations with weight and cycle length between these ages. Morphological data on reproductive tissues and ovarian follicular quantification are ongoing. Conclusions: Our preliminary results suggest the average age of reproductive decline in spiny mice is over 3 years. We will correlate ovarian reserve with age to determine whether the spiny mouse could serve as a pre-clinical model for menopause and to closely examine effects of age on fertility.