Publication Date:
2016-02-20
Description:
The immune system is one of the most important adaptations that has evolved to protect animals from a wide range of pathogens they encounter from early life onwards. During the early developmental period this is particularly true for the innate immunity, as other components of the immune system are, as yet, poorly developed. But innate immunity may not only be crucial for early life survival, but may also have long-lasting effects, for example if early life immunity reflects the functioning of the immune system as a whole. For this reason, we investigated the importance of four constitutive innate immune parameters (natural antibodies, complement activity, concentrations of haptoglobin, and concentrations of nitric oxide) for recruitment in free-living great tits. We compared nestling immunity of recruits with nestling immunity of their nonrecruited siblings. We also investigated within individual consistency of these innate immune parameters for those individuals that recruited, which may be taken as a measure of immune capacity. In accordance with previous studies, we found a clear effect of tarsus length and a trend for body mass on the likelihood to recruit. Nevertheless, we found no evidence that higher levels of constitutive innate immunity as a nestling facilitated local recruitment. Furthermore, individual innate immunity was not consistent across life stages, that is to say, nestling immune parameters did not determine, or respectively, reflect adult innate immune parameters. This plasticity in innate immune components may explain why we did not find long-lasting survival benefits. In our field study on free-living great tits ( Parus major ), we investigated the importance of four constitutive innate immune parameters for recruitment and studied within-individual consistency of these innate immune parameters across life stages for those individuals that managed to recruit. Our findings have a broad significance for a wide range of behavioral and evolutionary ecological topics. They contribute valuable information to the relatively unexplored field of innate immunity, while also showing the relevance of investigating different immune traits simultaneously.
Electronic ISSN:
2045-7758
Topics:
Biology
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