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

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

Avian Feathers as Bioindicators of the Exposure to Heavy Metal Contamination of Food

The aim of this study was to determine the possibility of using feathers of blue tit nestlings to assess the level of endogenous accumulation of lead. For this purpose we conducted an experiment with lead application to randomly chosen nestlings from eight randomly drawn broods. Five days after the exposure, feathers of lead-treated nestlings had significantly higher lead concentrations than control nestlings. This result suggests that feathers can be used as reliable non-destructive bioindicators to assess the level of heavy metals originating from contaminated food, which is of great significance for comparative studies on ecological consequences of pollution

Bacteria_nestboxes_great_tit

Nest boxes bacterial loads.</p

Microsatellite Instability Assay as a Potential Approach to Evaluate Genotoxicity: Lead Exposure in a Nestling Passerine Bird at the Stage of Intensive Erythropoiesis

Although many avian studies have investigated the toxic effects of lead on important biochemical and physiological processes, organ and system function, and behavior, studies evaluating the specific genotoxic effects of exposure to lead are scarce. Nowadays, rapid technological advances can provide new molecular techniques in this regard. In this study, as a novel approach in bird studies, we used a panel of ten microsatellite loci to investigate the microsatellite instability (MSI) in response to experimental lead intoxication in a common hole-nesting species, the great tit Parus major. For this purpose, an experiment based on an intentional single supplementation of a lead (II) acetate trihydrate compound was conducted, with the use of two different doses, applied to randomly chosen great tit nestlings from randomly selected broods, being at the stage of intensive erythropoiesis. Although this preliminary study did not find any MSI in the seven microsatellite markers retained for the final comparison, it contributes to the examination of this molecular technique in field conditions as being potentially applicable in ecotoxicological bird studies. We believe that certain issues should be considered in finding an explanation for our result. First, the single doses of lead used in this study may have been too weak to induce genetic instability. Second, the panel of microsatellite markers studied may have been unsusceptible to lead genotoxicity in general. Third, the relatively short time interval (5 days) between the experimental procedure (lead exposure) and the sampling of post-exposure material (blood) for genetic analyses could have limited the effect of lead genotoxicity. Further analyzes are needed to verify these findings and to evaluate the scope of application of the MSI analysis in wild bird population studies

Nest Box Bacterial Loads Are Affected by Cavity Use by Secondary Hole Nesters

Among the environmental factors that affect bird nesting in nest boxes, the influence of microbial communities is relatively poorly understood. In this study, nest boxes used for breeding by secondary cavity nesters were sampled before the start of the breeding season to assess the bacterial loads of the nest box in relation to their previous year status. Different parts of the wooden nest box offer variable conditions for the development of bacteria. During the breeding season, the nest box entrance hole is wiped out by birds, delivering bacteria to their bodies, but during winter, it is exposed to unfavourable external conditions. The interior of the nest box, in turn, is also wiped by birds, but the conditions during winter are more stable there. Therefore, samples from the entrance hole and the interior of the nest box were taken at two different study sites: an urban parkland and a natural forest. We predicted that both the occupancy of the nest boxes during the previous breeding season by birds and the nesting sites would influence the bacterial load of the nest box. To verify this prediction, two categories of nest boxes were sampled at both study sites: nest boxes occupied by any of the two tit species (Great Tit or Blue Tit) in the previous season for breeding and nest boxes that had remained empty that year. The interior bacterial load of the nest box was higher in the nest boxes occupied in the previous breeding season, but only in the forest area. Furthermore, the bacterial load of both the entrance hole of the nest box and the interior was significantly higher in the forest study area in both occupied and unoccupied nest boxes. Our results show that the bacterial load of the nest box is positively related to the presence of nests in the previous breeding season and can vary between different sites