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Summary.

  • 1
     The Tatera brantsi material consisted of 360 females collected between January and December 1946 from the Reef area around Johannesburg. Transvaal, and also of seventeen females which were kept in captivity for eleven months.

The oestrus cycle of the laboratory females was studied by means of daily vaginal smears. The cycle lasted from four to six days from one pro-oestrus to the next. The average length of gestation was twenty-two and a half days and of lactation twenty-two to twenty-four days. It was apparent that in captivity the gerbils tended to go into anoestrus and only aporadic pregnancies occurred.

The clean body-weight of females from the field ranged from 12 to 106 gm. with a mean of 60.05. The estimated weight at birth was 5.5 grams the lightest adult female weighed 37 gm. and the lightest pregnant female 52 gm.

Breeding occurred all the year round but was reduced to a minimum in October, November and December. The age at puberty is discussed. It is estimated that a single female produces five to six litters in one year. The mean number of corpora lutea was 2.94 and of embryos 2.64. The different stages of the reproductive cycle are described.

  • 2
     The T. afra material consisted of 422 females obtained between January and December 1946, in the region of the South-west Cape. The females ranged from 15 to 90 gm in weight with a mean of 52.2 gm. The estimated weight at birth was 4.5 gm., the lightest adult female weighed 36 gm. and the lightest pregnant female 43 gm.

The breeding season lasted eight months from the beginning of August until the end of March. The age at puberty is discussed. It was estimated that one female could produce six to seven litters in one season. The mean number of corpora lutea was 4.06 and of embryos 3.98. The relationship of the number of ova ovulated to the season, the body-weight and to intra-uterine mortality is discussed.

  • 3
     The main features of reproduction and breeding in T. afra and T. brantsi are compared and contrasted with those of some other small African mammals and British rodents.