Cell‐mediated immunity predicts the probability of local recruitment in nestling blue tits

Abstract

We investigated whether the variation in T‐cell‐mediated immune function of blue tit nestlings affected their fledgling success and the probability of local survival. We studied the relationship between immune function and survival under two rearing conditions: control, unmanipulated, and experimentally enlarged broods. Brood enlargement had negative effects on nestling immune response. Immune response was positively related to fledgling success and it predicted the probability of local recruitment. However, the relationship between immune response and the probability of recruitment was significantly positive only among control broods and nonsignificant among enlarged broods. The effect of immune response on the recruitment probability was not affected by variation in body mass. Our study suggests that selection for immune responsiveness seems to be weak or even absent under unfavourable rearing conditions as simulated by brood size enlargement. Therefore, year‐to‐year environmental variation and environmental heterogeneity may constrain evolution towards higher immune responsiveness.

Sex-biased terminal investment in offspring induced by maternal immune challenge in the house wren ( Troglodytes aedon )

“…Bowers 2009-2011, unpublished data). Cutaneous immune response, as assessed by the PHA assay, is also a positive predictor of nestling survival in other species ( [39][40][41], but see Butler et al [42]). Thus, the increased body mass and condition index of sons and increased PHA response of daughters produced by LPSinjected females should afford them a substantial fitness advantage in that they are more likely to survive and reproduce than offspring of control females.…”

Heterozygosity–fitness correlations in blue tit nestlings (Cyanistis caeruleus) under contrasting rearing conditions

“…Such a manipulation appears to be an effective way of increasing within-brood competition, as negative effects of brood size enlargement on various nestling characteristics has been repeatedly reported in many species including blue tit (e.g. Cichoń and Dubiec 2005;Voegeli et al 2012). We expected the HFCs to be particularly expressed among offspring from experimentally enlarged broods.…”

“…Cellmediated immunity appears to provide an adequate framework to study our question because it has frequently been shown to be a heritable and condition-dependent trait (Saino et al 1997;Cichoń et al 2006;Drobniak et al 2010) and to predict survival in nestling blue tits (Cichoń and Dubiec 2005) and longevity in zebra finches (Birkhead et al 1999). In order to test, whether environmental conditions may influence the magnitude and direction of HFCs, we manipulated environmental conditions during nestling growth by altering brood sizes.…”

Relationship between avian growth rate and immune response depends on food availability

“…The ability to mount a strong immune response is a significant determinant of fitness in young altricial birds (Christe et al, 1998;Christe et al, 2001;Merino et al, 2000;Møller and Saino, 2004;Cichon and Dubiec, 2005;Moreno et al, 2005). Since immune function is costly (Lochmiller and Deerenberg, 2000;Norris and Evans, 2000;Klasing, 2004), one can expect it to drain essential resources away from other important traits, in particular growth of nestlings.…”