Origin-related, environmental, sex, and age determinants of immunocompetence, susceptibility to ectoparasites, and disease symptoms in the barn owl

摘要: Knowledge of the role origin-related, environmental, sex, and age factors on host defence mechanisms is important to understand variation in parasite intensity. Because alternative components may be differently sensitive various factors, they not necessarily covary. Many should therefore considered tackle evolution host-parasite interactions. In a population barn owls (Tyto alba), we investigated environmental (i.e. year, season, nest rearing, body condition), 12 traits linked immune responses [humoral towards sheep red blood cells (SRBC), human serum albumin (HSA) toxoid toxin TT, T-cell mediated response mitogen phytohemagglutinin (PHA)], susceptibility ectoparasites (number fecundity Carnus haemapterus, number Ixodes ricinus), disease symptoms (size bursa Fabricius spleen, proportion proteins that are immunoglobulins, haematocrit concentration leucocytes). Cross-fostering experiments allowed us detect heritable component only four out nine parasitic parameters SRBC- HSA-responses, haematocrit, C. haemapterus). However, because nestlings were always cross-fostered just after hatching, finding 44% probably an overestimation. These also showed five these environment PHA-responses, Female more infested by blood-sucking fly haemapterus than their male nestmates, was less concentrated leucocytes. The effect reflecting degree maturation system), brood size, position within-brood hierarchy, mass strongly differed between parameters. Different equally potentially explaining why most did (c) 2007 Linnean Society London.