Environmental and genetic variation in the haematocrit of fledgling pied flycatchers Ficedula hypoleuca

Abstract

We report a field study of the haematocrit of pied flycatcher (Ficedula hypoleuca) nestlings when close to fledging. First a descriptive study was conducted of both fledgling and adult haematocrit over 2 years to analyse correlates of variation in this trait. Then a swapping experiment was performed to see whether variation among fledglings had a measurable genetic component. Average fledgling haematocrits were lower than those of their male and female parents. Intraclass correlations among sibships in fledgling haematocrit were high in both years, indicating that the estimates of resemblance were inflated, probably by common environmental effects. Fledgling haematocrits were unrelated to date and number of young in the nest. Fledglings with a high haematocrit were heavy and had thick breast muscles. There were no significant relationships between the average fledgling haematocrit and those of the adults caring for them. Nest mite ectoparasites negatively affected fledgling haematocrit. The haematocrits of adults did not differ between sexes or years and in both sexes were unrelated to breeding date, body mass, age, clutch size or number of young reared. Females, but not males, caring for fledglings in nests infested by mites had a lower haematocrit than those rearing young in mite-free nests. The cross-fostering experiment indicated that almost all measured variation in haematocrit was explained by the nest where the bird was reared (67.2% of the explained variance), not by their nest of origin (7.8%), meaning that there was a very small, non-significant resemblance in the haematocrit of genetically related sibs when reared in different environments while unrelated nestlings reared in the same nestbox had similar haematocrits. The low proportion of variance explained by the familial component may be due to the high connection of haematocrit to fitness.

Patterns of year-to-year variation in haemoglobin and glucose concentrations in the blood of nestling Pied Flycatchers Ficedula hypoleuca

“…It could also be that haemoglobin concentration responds more to the factors acting on entire broods during the whole nestling stage, such as general trophic conditions and parasitic pressure in the nest, which would further explain higher intrabrood repeatability of this measure. Potti et al (1999) assessed within-brood repeatability of haematocrit in Pied Flycatcher nestlings and found it to be 0.7, which is similar to our result for haemoglobin.…”

Spatial variation in haemoglobin concentration of nestling Blue Tits (Cyanistes caeruleus): a long-term perspective

“…In nestling Pied Flycatchers (Ficedula hypoleuca) studied in our forest study site the repeatability of haemoglobin was assessed at 0.63 (Glądalski et al 2015a). Potti et al (1999) found that within-brood repeatability of haematocrit in Pied Flycatcher nestlings in Spain was 0.7. Our present long-term result for Blue Tits is high (0.68), which is consistent with previous findings.…”

Genetics, local environment and health as factors influencing plasma carotenoids in wild American kestrels (Falco sparverius)

“…The remaining nestlings were removed and transported in the same manner, and for the same length of time, as the translocated young, and then put back in their original nest to control for potential handling stress. All nests remained with the original number of young hatched, so that breeding chronology, breeding e¡ort of adults and intranest competition of nestlings were held constant (Potti et al 1999). Although we created broods where the same numbers of nestlings from two di¡erent families were raised together in the same nest, mortality resulted in unbalanced sample sizes.…”

“…Genetic and environmental e¡ects on the concentrations of plasma carotenoids of o¡spring were estimated following a widely used approach (MerilÌ 1996;Potti et al 1999). This consists of a two-factor nested ANOVA where the main e¡ects were duplicate (a pair of nests matched by clutch size and hatching date) and nest of origin (nested within duplicates).…”