Search results for " Trade-offs"
showing 3 items of 13 documents
The energetic cost of humoral immunity in the Collared Dove, Streptopelia decaocto : is the magnitude sufficient to force energy-based trade-offs?
2005
International audience; 1. Energy saving is often suggested as the basis of a resource trade-off between immunocompetence and other fitness-relevant traits. This suggests that the energetic cost of an immune response is significant and sufficient to force trade-offs. To date, few studies have investigated the energetic cost of the humoral component of the immune system in birds and furthermore, existing results are contradictory. 2. We addressed this question through two experiments. In experiment 1, the basal metabolic rate (BMR) of Collared Doves, Streptopelia decaocto , challenged with sheep red blood cells (SRBC) was compared with the BMR of control birds. The energetic cost of immunity…
Data from: The oxidative cost of reproduction depends on early development oxidative stress and sex in a bird species
2016
In the early 2000’s, a new component of the cost of reproduction was proposed: oxidative stress. Since then the oxidative cost of reproduction hypothesis has, however, received mixed support. Different arguments have been provided to explain this. Among them, the lack of a life history perspective on most experimental tests was suggested. We manipulated the levels of a key intracellular antioxidant (glutathione) in captive zebra finches (Taeniopygia guttata) during a short period of early life and subsequently tested the oxidative cost of reproduction. Birds were allowed to mate freely in an outdoor aviary during several months. We repeatedly enlarged or reduced their broods to increase or …
Diversity in warning coloration: selective paradox or the norm?
2019
Aposematic theory has historically predicted that predators should select for warning signals to converge on a single form, as a result of frequency-dependent learning. However, widespread variation in warning signals is observed across closely related species, populations and, most problematically for evolutionary biologists, among individuals in the same population. Recent research has yielded an increased awareness of this diversity, challenging the paradigm of signal monomorphy in aposematic animals. Here we provide a comprehensive synthesis of these disparate lines of investigation, identifying within them three broad classes of explanation for variation in aposematic warning signals: …