Optimal Life Histories, Optimal Notation, and the Value of Reproductive Value

1982 ◽  
Vol 119 (6) ◽  
pp. 803-823 ◽  
Author(s):  
Daniel Goodman
Keyword(s):  
Life Histories ◽  
Reproductive Value ◽  
Optimal Life Histories

Life histories of North American game birds: a reanalysis

1988 ◽  
Vol 66 (8) ◽  
pp. 1906-1912 ◽  
Author(s):  
Todd W. Arnold
Keyword(s):  
Life History ◽  
North American ◽  
Life Histories ◽  
Life History Traits ◽  
Reproductive Effort ◽  
Cost Of Reproduction ◽  
Reproductive Value ◽  
Trade Offs ◽  
Game Birds ◽  
The Cost

Recently, Zammuto (R. M. Zammuto. 1986. Can. J. Zool. 64: 2739–2749) suggested that North American game birds exhibited survival–fecundity trade-offs consistent with the "cost of reproduction" hypothesis. However, there were four serious problems with the data and the analyses that Zammuto used: (i) the species chosen for analysis ("game birds") showed little taxonomic or ecological uniformity, (ii) the measures of future reproductive value (maximum longevity) were severely biased by unequal sample sizes of band recoveries, (iii) the measures of current reproductive effort (clutch sizes) were inappropriate given that most of the birds analyzed produce self-feeding precocial offspring, and (iv) the statistical units used in the majority of analyses (species) were not statistically independent with respect to higher level taxonomy. After correcting these problems, I found little evidence of survival–fecundity trade-offs among precocial game birds, and I attribute most of the explainable variation in life-history traits of these birds to allometry, phylogeny, and geography.

Reproductive strategies in Akodon azarae (Rodentia, Muridae)

2004 ◽  
Vol 82 (10) ◽  
pp. 1572-1577 ◽  
Author(s):  
Olga V Suárez ◽  
María Busch ◽  
Fernando O Kravetz
Keyword(s):  
Litter Size ◽  
Reproductive Strategies ◽  
Life Histories ◽  
Reproductive Period ◽  
Early Summer ◽  
Reproductive Value ◽  
Central Feature ◽  
Birth Season ◽  
Akodon Azarae

The balance between litter size and the quality of offspring is a central feature to many optimal litter-size theories. We analyzed the reproductive strategies of Akodon azarae (Fischer, 1829) females, according to maternal life histories and the time of birth. Litter size decreased significantly from spring to autumn. A significant birth–season effect on mass at birth was observed. A compensatory effect of growth rate was evident during lactation. During spring and early summer, over-wintered females produced an average of 5 young, with maximum survival at weaning (100%). Females born during the current reproductive season showed a smaller litter size, probably because they favor residual reproductive value with respect to current reproduction since they have a higher life expectancy and future chances of mating than over-wintered females. Mortality reached 50% at weaning for summer litters from young mothers, whereas it declined to 22.2% in autumn. Differences in both parental investment and offspring survival suggest that litter size in A. azarae varies along the reproductive period and is dependent both on females' life history and on environmental conditions.

Evolutionary perturbations of optimal life histories

1995 ◽  
Vol 9 (5) ◽  
pp. 478-494 ◽  
Author(s):  
Maria-Josefina Hernandez ◽  
Jesus Alberto Le�n
Keyword(s):  
Life Histories ◽  
Optimal Life Histories
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