Studying the life history of various organisms is essential for ecological and evolutionary inferences. However, publications regarding models of evolutionary shifts to either r- or K-reproductive strategies are scarce. Here, the combined original and previously published data on reproduction and development of Goodwin’s brush-tailed mouse (Calomyscus elburzensis), golden hamster (Mesocricetus auratus), and house mouse (Mus musculus) were compared. An adult male and female in estrous state (from each species) were coupled with each other for a night and embryos were harvested at embryonic days (E) 10–17 from pregnant females. The mean gestation period in Goodwin’s brush-tailed mouse was 31.5±2.1 days; growth was rapid at the first half of this period and after that it was reduced by half. During the postnatal period, growth was rapid up to weaning, but after day 35, the rate of growth decreased abruptly. Growth rate of head and body length was very rapid prior to weaning (PN35) in comparison with weight but the rates of the two characters were inversed following weaning. Totally, weight gain was more dynamic in rate, as compared with head and body length, up to adultness. For golden hamster and house mouse, gestation period was 15.6±0.8 and 20.8±0.8 days, respectively. Growth was slow during approximately the first half of the gestation period in both species but increased during the second half. During postnatal period in golden hamster, growth rate of head and body length was rapid both before and after weaning as compared with that of weight. However, head and body length showed a stable rate of growth before and after weaning (around PN15), but for body weight, the growth rate was slightly faster after weaning. Similarly, changes in head and body length in house mouse were rapid both before and after weaning (PN16) as compared with that of weight. Since approximately two-fold increases were observed in the growth rates of weight and head and body length in the second stage of postnatal development (PN16-adult) compared with the rates during the first stage (PN0-PN16), both showed dynamic changes during the postnatal development in this species. Typically, rstrategic house mouse appeared to be more similar in early morphological development to comparatively K-strategic Goodwin’s brush-tailed mouse, than to comparativelyr-strategic golden hamster. Nevertheless, growth rate and pattern were different in the three species after birth. Hence, results showed that peculiarities of association between an ontogenetic pattern and a tendency in reproductive strategy can differ in diverse groups of myomorph rodents.

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