TREE SWALLOWS TRADE OFF IMMUNE FUNCTION AND REPRODUCTIVE EFFORT DIFFERENTLY ACROSS THEIR RANGE

Ecology ◽  
2005 ◽  
Vol 86 (8) ◽  
pp. 2040-2046 ◽  
Author(s):  
Daniel R. Ardia
The Condor ◽  
2007 ◽  
Vol 109 (3) ◽  
pp. 585-594 ◽  
Author(s):  
Linda A. Whittingham ◽  
Peter O. Dunn ◽  
Jan T. Lifjeld

Abstract Abstract. Maternal allocation of resources to eggs and nestlings can potentially have a profound influence on offspring phenotype and fitness. However, it is often unclear how much of the variation in offspring quality is due to maternal or environmental effects. We examined the influence of maternal and environmental effects on egg mass and nestling quality (growth and immune function) in Tree Swallows (Tachycineta bicolor). There was no evidence that the allocation of maternal resources to eggs varied with laying order or offspring sex. Thus, there was no evidence of adaptive maternal allocation to eggs in terms of mass. Instead, egg mass in Tree Swallows appeared to be influenced primarily by ambient temperature during egg formation and differences among females. Nonetheless, female Tree Swallows were likely to realize substantial benefits from producing larger eggs because those young were larger at hatching and grew faster. Furthermore, nestlings that grew faster had a stronger immune function at 11 days of age. Our results suggest that the positive relationship between nestling growth and survival may be due, in part, to the effects of an enhanced immune response.


1991 ◽  
Vol 69 (9) ◽  
pp. 1977-1983 ◽  
Author(s):  
Jeanne C. Chambers

The relationships of clone area and neighborhood to ramet size, reproductive effort, and spatial distribution within Geum rossii clones were studied in an alpine ecosystem on the Beartooth Plateau, Montana. Clones growing on an early seral site in relative isolation were compared to clones on a late seral site within dense, heterogeneous neighborhoods. Individual clones of G. rossii required a minimum clone area of about 200 cm2 before maximum ramet size and reproductive effort were achieved. Mean ramet size and reproductive effort were fairly constant among clones larger than 200 cm2 on both the early and later seral sites. Within clones the size and reproductive effort of ramets were positively related. Pattern analysis revealed that ramets became more widely and irregularly spaced as clone area increased on the early seral site. This may have been a geometric function of an increase in the space required as clones aged and became larger. On the late seral site, clones were characterized by ramets that were widely and erratically spaced, that had low leaf numbers and mass, and that had low reproductive effort. For clones of comparable area on the early seral site, ramets were more closely and uniformly spaced, and leaf number, mass, and reproduction per ramet were higher. Conservative patterns of growth and reproduction make G. rossii well suited to dominate in dense, heterogeneous neighborhoods of late seral sites and to colonize mineral soils of early seral sites. Similar to other clonal species, site characteristics and the type of neighborhood determine the trade-off between the physical occupation of space and the allocation to ramet growth and reproduction in G. rossii. Key words: Geum rossii, alpine, reproductive effort, growth, clone area, pattern analysis, succession, neighborhood.


Oecologia ◽  
2005 ◽  
Vol 145 (4) ◽  
pp. 564-574 ◽  
Author(s):  
Philippe Rivalan ◽  
Anne-Caroline Prévot-Julliard ◽  
Remi Choquet ◽  
Roger Pradel ◽  
Bertrand Jacquemin ◽  
...  

2013 ◽  
Vol 181 (6) ◽  
pp. 761-774 ◽  
Author(s):  
Michael W. Butler ◽  
Zachary R. Stahlschmidt ◽  
Daniel R. Ardia ◽  
Scott Davies ◽  
Jon Davis ◽  
...  

2007 ◽  
Vol 169 (1) ◽  
pp. S137
Author(s):  
Fitze ◽  
Tschirren ◽  
Gasparini ◽  
Richner
Keyword(s):  

2019 ◽  
Author(s):  
Charly Jehan ◽  
Manon Chogne ◽  
Thierry Rigaud ◽  
Yannick Moret

Abstract Background The disposable soma theory of ageing assumes that organisms optimally trade-off limited resources between reproduction and longevity to maximize fitness. Early reproduction should especially trade-off against late reproduction and longevity because of reduced investment into somatic protection, including immunity. Moreover, as optimal reproductive strategies of males and females differ, sexually dimorphic patterns of senescence may evolve. In particular, as males gain fitness through mating success, sexual competition should be a major factor accelerating male senescence. In a single experiment, we examined these possibilities by establishing artificial populations of the mealworm beetle, Tenebrio molitor , in which we manipulated the sex-ratio to generate variable levels of investment into reproductive effort and sexual competition in males and females.Results As predicted, variation in sex-ratio affected male and female reproductive efforts, with contrasted sex-specific trade-offs between lifetime reproduction, survival and immunity. High effort of reproduction accelerated mortality in females, without affecting immunity, but high early reproductive success was observed only in balanced sex-ratio condition. Male reproduction was costly on longevity and immunity, mainly because of their investment into copulations rather than in sexual competition.Conclusions Our results suggest that T. molitor males, like females, maximize fitness through enhanced longevity, partly explaining their comparable longevity.


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