Costs of reproduction and terminal investment by females in a semelparous marsupial

Fisher, Diana O. and Blomberg, Simon P. (2011) Costs of reproduction and terminal investment by females in a semelparous marsupial. PLoS One, 6 1 Article # e15226: . doi:10.1371/journal.pone.0015226


Author Fisher, Diana O.
Blomberg, Simon P.
Title Costs of reproduction and terminal investment by females in a semelparous marsupial
Journal name PLoS One   Check publisher's open access policy
ISSN 1932-6203
Publication date 2011-01-01
Year available 2011
Sub-type Article (original research)
DOI 10.1371/journal.pone.0015226
Open Access Status DOI
Volume 6
Issue 1 Article # e15226
Total pages 9
Place of publication United States
Publisher Public Library of Science
Language eng
Subject 2700 Medicine
1300 Biochemistry, Genetics and Molecular Biology
1100 Agricultural and Biological Sciences
Abstract Evolutionary explanations for life history diversity are based on the idea of costs of reproduction, particularly on the concept of a trade-off between age-specific reproduction and parental survival, and between expenditure on current and future offspring. Such trade-offs are often difficult to detect in population studies of wild mammals. Terminal investment theory predicts that reproductive effort by older parents should increase, because individual offspring become more valuable to parents as the conflict between current versus potential future offspring declines with age. In order to demonstrate this phenomenon in females, there must be an increase in maternal expenditure on offspring with age, imposing a fitness cost on the mother. Clear evidence of both the expenditure and fitness cost components has rarely been found. In this study, we quantify costs of reproduction throughout the lifespan of female antechinuses. Antechinuses are nocturnal, insectivorous, forest-dwelling small (20-40 g) marsupials, which nest in tree hollows. They have a single synchronized mating season of around three weeks, which occurs on predictable dates each year in a population. Females produce only one litter per year. Unlike almost all other mammals, all males, and in the smaller species, most females are semelparous. We show that increased allocation to current reproduction reduces maternal survival, and that offspring growth and survival in the first breeding season is traded-off with performance of the second litter in iteroparous females. In iteroparous females, increased allocation to second litters is associated with severe weight loss in late lactation and post-lactation death of mothers, but increased offspring growth in late lactation and survival to weaning. These findings are consistent with terminal investment. Iteroparity did not increase lifetime reproductive success, indicating that terminal investment in the first breeding season at the expense of maternal survival (i.e. semelparity) is likely to be advantageous for females.
Keyword Antechinus-stuartii Marsupialia
Natural-selection
Senescence
Populations
Allocation
Success
Fitness
Squirrels
Survival
Mammals
Q-Index Code C1
Q-Index Status Confirmed Code
Institutional Status UQ

Document type: Journal Article
Sub-type: Article (original research)
Collections: Official 2012 Collection
School of Biological Sciences Publications
 
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Created: Sun, 27 Feb 2011, 10:02:48 EST