[Biology of the volcano mouse (N. a. alstone). XVI. Comparison of the reproductive capacity of wild females in the laboratory, following 3 mating systems].

The aim of the present work was the comparison of the reproductive capacity of the wild volcano mouse (Neotomodon alstoni alstoni) in the laboratory, using 3 mating systems: pair, harem and collective. The mice were captured in the Sierra del Volcán Ajusco (Cerro Pelado, Parres, D. F.) The animals were kept in plastic cages with sawdust bedding under room conditions of light, humidity and temperature. They were fed with ALBI-LAB Pellets and tap water, supplemented with carrots and lettuce. All mice were under quarantine for 30 days before the matings begun. These were done in 2 series: pair versus harem (1 male with 4 females), and pair versus collective (2 males with 4 females). Each system had initially 25 females; 4 consecutive pairings were done with each mating system used in both series, with a duration of 12 days each mating. Statistical analysis of the results was done using the square chi test. The data registered in the 4 matings of each pairing system used in the 2 series were: number of mated females, number and percentage of pregnant females, total of offspring born, mean litter number, number and percentage of live offspring at the and of the first week after birth and at weaning, and relation and proportion males-females. The comparative tables of the reproductive records of all the 4 matings of each pairing system used in the 2 series, were analyzed separately and as a whole; the global comparative table (totals of the 2 series) of the reproductive record of neotomodon, according to the 3 systems of mating, i. e., pair (P), harem (H) and collective (C) showed the following results: P = number of mated females, 189; number of pregnant females, 94; percentage of pregnant females, 49.7; total of offspring born, 286; mean litter number, 3.04; number of offsprings alive at the end of the first week after birth, 173; percentage of offsprings alive at the end of the first week after birth, 60.5; number of offsprings alive at weaning, 172; percentage of offsprings alive at weaning, 60.1.(ABSTRACT TRUNCATED AT 400 WORDS)