Haemoglobin concentration and body condition of nestling Great Tits Parus major : a comparison of first and second broods in two contrasting seasons |
| |
Authors: | ADAM KALI SKI ,JAROS AW WAWRZYNIAK,MIROS AWA BA BURA,JOANNA SKWARSKA,PIOTR ZIELI SKI,& JERZY BA BURA |
| |
Affiliation: | Department of Experimental Zoology and Evolutionary Biology, University of Łódź, Banacha 12/16, 90-237 Łódź, Poland;Museum of Natural History, University of Łódź, Kilińskiego 101, 90-011 Łódź, Poland;Department of Ecology and Vertebrate Zoology, University of Łódź, Banacha 12/16, 90-237 Łódź, Poland |
| |
Abstract: | The physiological condition of nestling altricial birds depends on the quantity and quality of food delivered to them by parents. One indicator of the condition of Great Tit Parus major nestlings is the haemoglobin concentration in their blood. The present study demonstrates the influence of weather conditions (temperature and rainfall) on nestling haemoglobin concentrations during two consecutive breeding seasons in two different habitat types (parkland vs. woodland) in the city of Łódź in Central Poland. This influence probably results from the effects of weather on the trophic base of the Tits. Dry, hot weather strongly affected bush and herbal foliage later in the breeding season (mid-June to mid-July) in 2006, presumably by interfering with the development of herbivorous arthropod populations. This in turn caused food shortages for second broods of Great Tits, which resulted in nestlings having low haemoglobin levels. In the following year, temperature was on average lower, and rainfall was regular but not very heavy. These conditions enabled the development of arthropod assemblages, and the trophic base for birds was much richer. Haemoglobin concentrations in the blood of nestlings from second broods were significantly higher than those of first broods and, unexpectedly, second-brood nestlings in 2007 were on average in better physiological state than first-brood nestlings in 2006 in both habitats. The relationship between haemoglobin concentration, brood category and year was very similar to that for nestling body mass. However, it was independent of both body mass and brood size. In some years and under certain conditions, second broods can be more successful than first broods. |
| |
Keywords: | haemoglobin Parus major physiological condition second clutches trophic conditions weather |
|
|