title: Hematological parameters in brood-rearing great tits in relation to habitat, multiple breeding and sex.
abstract: Very little is known about the causes and correlates for variation of individual condition in the wild. However, such knowledge is essential for understanding the mechanisms that mediate environmental effects to populations. We studied the variation of several hematological condition indices (hematocrit, albumin, globulin and triglyceride concentrations, albumin/globulin ratio, lymphocyte and heterophile concentrations and heterophile/lymphocyte ratio) and body mass in brood-rearing great tits (Parus major) in relation to habitat, multiple breeding and gender. Although great tits prefer deciduous forest to coniferous forests, individuals breeding in coniferous forests tended to be in a superior health state than those breeding in deciduous habitat. We suggest that this difference in adult condition can be caused by differences in breeding densities between habitats. Although there was some variation in condition indices between breeding attempts, none of these parameters measured at the end of the first breeding attempt predicted the probability of double breeding. We also found that females were in poorer condition and probably more stressed than males, both during the first and the second breeding attempt. These findings demonstrate that hematological parameters can be used to assess spatial and temporal variation of individual condition in the wild.
authors.affiliation: Institute of Zoology and Hydrobiology, Centre of Basic and Applied Ecology, University of Tartu, Vanemuise 46, Tartu 51014, Estonia. prkil@ut.ee
authors.forename: Priit
authors.initials: P
authors.lastname: Kilgas
authors.forename: Raivo
authors.initials: R
authors.lastname: Mänd
authors.forename: Marko
authors.initials: M
authors.lastname: Mägi
authors.forename: Vallo
authors.initials: V
authors.lastname: Tilgar
mesh_terms: D000818:Animals; D000835:Animals, Wild / Q000097:blood; D001798:Blood Proteins / Q000032:analysis; D001835:Body Weight; D001947:Breeding; D004777:Environment; D005260:Female; D006400:Hematocrit; D007962:Leukocytes; D008297:Male; D009425:Nesting Behavior; D046109:Passeriformes / Q000097:blood*; D011336:Probability; D012098:Reproduction; D012621:Seasons; D012727:Sex Characteristics; D012737:Sex Factors; D012726:Sexual Behavior, Animal / Q000502:physiology; D014280:Triglycerides / Q000097:blood
chemical_list: D001798:Blood Proteins; D014280:Triglycerides