Physiological tools can be used to identify the
sources and consequences of stressors on animals. Understanding
the influences of variation in habitat quality and anthropogenic
disturbance on organism condition and health may
improve future management and conservation. We present
results concerning variation in haemoglobin and glucose
concentrations in the blood of about 14-day-old nestling Pied
FlycatchersFicedula hypoleuca in central Poland over a 4-year
period, 2011–2014, in a deciduous forest. The most important
findings of the study are: (1) the concentration of haemoglobin
and glucose of the nestlings from the same brood tended to be
consistently similar, with much variation occurring among
broods; (2) repeatability of haemoglobin concentration was
higher than repeatability of glucose concentration; (3) mean
levels of haemoglobin and glucose varied among years; (4)
haemoglobin and glucose concentrations were negatively
correlated; and (5) there was a positive relationship between
haemoglobin levels and breeding success.All procedures were approved by the Local
Ethical Committee and the State Office for Environment Protection.
We thank A. Jaksa, D. Man´kowska, M. Janiszewska and J. Białek for
their help and consent in conducting research in the areas under their
administration. The study was founded by a grant from the Polish
Ministry of Science and Higher Education No. N N304 045136 and
University of Ło´dz´ (No. 506/829). We are obliged to P. Procter for
linguistic consultation. We thank both reviewers for their valuable
and constructive comments
