266 TELFORD: MULTIMAMMATE RAT POPULATION BIOLOGY IN TANZANIA




TABLE 5. Monthly and annual variation in intrauterine mortality ofPraomys natalensis.


 Litters Embryos


Year No. % w/resorbing % Embryos No. % Resorbing
 Months embryos resorbing


1982
 May-Jun 34 0.0
 Jul 31 0.0 -
 Aug 42 2.4 25.0 445 0.9

1983
 Mar-Apr 3 0.0 -
 May-Jun 17 0.0 -
 Jul 31 3.2 15.4 561 0.4
 Aug 86 26.7 11.9 1020 3.2

1984
 Feb 36 8.3 9.1 388 0.8
 Mar-Apr 33 15.2 10.5 362 1.7
 May-Jun 36 13.9 8.7 470 1.3
 Jul 39 12.8 14.9 499 1.6
 Aug 28 7.1 8.3 316 0.6





TABLE 6. Proportion of gravid females simultaneously lactating.


 % Gravid females lactating

Year # Gravid
Months Females < 25 mm > 25 mm


1982
 May-Jun 31 38.7 3.2
 Jul 31 16.1 6.5
 Aug 42 21.4 4.8

1983
 May-Jun 17 41.2 0.0
 Jul 43 14.0 0.0
 Aug 80 35.0 0.0

1984
 Mar-Apr 33 3.0 0.0
 May-Jun 36 2.8 0.0
 Jul 39 0.0 0.0
 Aug 28 3.6 0.0