Reproductive Notes on Peromyscus leucopus and Peromyscus gossypinus in Louisiana

In Louisiana, there is a lack of published reproductive information for the white-footed mouse (Peromyscus leucopus) and cotton mouse (Peromyscus gossypinus). We recorded reproductive data from the voucher tags of preserved P. leucopus (n = 652) and P. gossypinus (n = 1460) specimens captured in Louisiana, summarized monthly variation in reproductive activity, and compared our findings to those in other states throughout each species geographic range. The average number of embryos for females was 3.93 (SD = 0.87) for P. leucopus and 4.42 (SD = 1.30) for P. gossypinus. Average testis length for male P. leucopus was 10.78 mm (SD = 3.22 mm) (scrotal) and 6.63 mm (SD = 3.38 mm) (abdominal), whereas for P. gossypinus, average testis length was 13.50 mm (SD = 5.05 mm) (scrotal) and 11.31 mm (SD = 4.39 mm) (abdominal). Similar to other southern states, both species appear to be year-round breeders with reproductive evidence appearing in every month except August for P. leucopus and July for P. gossypinus.