Adaptive Features of Mammalian Reproduction

Millar, John S.

doi:10.1111/j.1558-5646.1977.tb01019.x

Cited by 299 publications

(169 citation statements)

References 97 publications

(35 reference statements)

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“…Resting metabolism (Kleiber, 1961), existence metabolism (Kendeigh, 1969), birth and weaning masses (Millar, 1977), birth weight (Leitch et ai, 1959), and gestation length (Kihlström, 1972;Eisenberg, 1981), among others, demonstrate an exponential relationship to body size where the exponent of these relationships is < 1.0. In contrast, functions describing capacity terms, for example digestive capacity (Kleiber, 1961) and storage capacity (Calder, 1984), bear a nearly linear relationship to body mass.…”

Section: Problems and Perspectives In The Costs Of Mammalian Reproducmentioning

confidence: 99%

“…On behavioral (Eisenberg, 1981), hormonal (Rosenblatt and Siegel, 1983) and physiological (Millar, 1977) grounds, mammalian reproduction can be compartmentalized into the following continuous sequence of reproductive events: mating (courtship, estrous period), gestation, parturition, lactation (suckling period), post-lactational parental care, and post-lactational/post-parental care maternal recovery. Most energetic studies have focused on either caloric consumption or maternal metabolic rate, in conjunction with changes in maternal (during gestation) and offspring mass, during only one reproductive event (usually gestation or lactation).…”

Section: Problems and Perspectives In The Costs Of Mammalian Reproducmentioning

confidence: 99%

“…Gra- ham, 1964;Myrcha et al, 1969;Studier et al, 1973;Havera, 1979;Oftedal, 1985). Neonatal mass (birth weight) is often employed as an indirect measure of uterine and placental tissue masses and consequently may estimate the energetic cost of pregnancy (Millar, 1977(Millar, , 1981Oftedal, 1985;Kunz, 1987;Kurta and Kunz, 1987). Caloric consumption studies reveal considerable variation in net production of fetal and placental tissues.…”

Section: Gestationmentioning

confidence: 99%

“…Although the causal mechanisms of these results are not known, it appears from more extensive data on other species that smaller mammals may be more "hard-wired" to gestation length itself rather than storage. After controlling for body size, birth weight, litter size, and body temperature (Racey, 1981), increases in ingestion rates correlate most closely with gestation length {e.g., Millar, 1977Millar, , 1978McClure, 1987).…”

mentioning

confidence: 99%

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Energy Allocation in Mammalian Reproduction

Gittleman

Thompson

1988

Am Zool

732

523

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SYNOPSIS. On behavioral, hormonal, and physiological grounds, mammalian reproduction can be compartmentalized into the following continuous sequence of events: mating (courtship, estrous), gestation, parturition, lactation, post-lactational parental care, and maternal recovery. We point out that comparing the relative allocation of energy for these events across mammals is difficult because of life history variability (e.g., litter size, birth weight), allometry, phylogeny, and individual variation. We review the empirical and theoretical literature on each of these events with respect to: different methodologies in measuring energy use; broad patterns of energy consumption across diverse mammalian taxa; and, identification of particular reproductive characteristics {e.g., birthing, parental care) which may be costly but have yet to receive energetic measurements. Although most studies have considered gestation and lactation the critical reproductive events for energy expenditure, variation in these events is substantial and almost certainly is a function of relative allocation of time to gestation vs. lactation as well as the presumed energetic costs of mating, birthing and parental care. In addition, repeated observations show that behavioral compensation is an extremely important strategy for minimizing energy requirements during reproduction. From this review, we argue that more complete analyses will come from (1) incorporating energetic measurements in studies of mammalian behavior and (2) including mechanisms of behavioral compensation into physiological studies.

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Section: Problems and Perspectives In The Costs Of Mammalian Reproducmentioning

confidence: 99%

Section: Problems and Perspectives In The Costs Of Mammalian Reproducmentioning

confidence: 99%

Section: Gestationmentioning

confidence: 99%

mentioning

confidence: 99%

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Energy Allocation in Mammalian Reproduction

Gittleman

Thompson

1988

Am Zool

732

523

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“…These physiological alterations are required for successful pregnancy and lactation and result from resetting of maternal homeostatic mechanisms to deliver essential nutrients to the fetus and remove heat, carbon dioxide, and waste products from the fetus. The strategies selected by a given species for adaptation to pregnancy (Table 2) appear to depend upon the energy costs of pregnancy (Millar, 1976(Millar, , 1980Metcalf et al, 1988). The energy costs of the physiological adaptations of pregnancy are not surprising given that the time from conception to weaning typically represents 3% of the total life span of an animal and during that time approximately 20% of the adult weight is developed (Peters, 1983).…”

mentioning

confidence: 99%