Landscape patterns of variation in blood glucose concentration of nestling blue tits (Cyanistes caeruleus)

Abstract

Integration of landscape ecology and conservation physiology has been recommended as a potentially useful way to investigate consequences of human-induced changes in habitats for animal populations. A central goal of this paper was to examine if a simple physiological parameter displays any consistent patterns of spatio-temporal variation. Blood glucose concentration in birds reflects their high metabolic demands and may be influenced by a number of environmental factors. Therefore we present results concerning variation in glucose concentration in the blood of c. 14-day-old nestling blue tits (Cyanistes caeruleus) in central Poland in an 8-year period, 2005-2012, in two landscapes: an urban parkland and a deciduous forest. The most important findings of the study were: (1) mean levels of blood glucose varied markedly among years, most probably due to variable weather conditions, (2) glucose concentrations were significantly higher in the parkland study site than in the forest site, (3) heavier nestlings had lower glucose levels, and (4) high glucose levels were negatively correlated with fledging and breeding success. Thus we have confirmed that a consistent spatio-temporal pattern really exists.

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

“…The weather seems to fit as such a factor. Effects of temperatures per se, as described by Kaliński et al (2014), in some cases could be too complex to interpret and can influence many processes also in an indirect way. It was shown for nestling Pied Flycatchers that year-to-year variation in the level of haemoglobin correlated with daily minimum temperature (Glądalski et al 2015a).…”

“…It was shown for nestling Pied Flycatchers that year-to-year variation in the level of haemoglobin correlated with daily minimum temperature (Glądalski et al 2015a). Low temperatures could reduce female capacity for warming chicks efficiently and a combination of mild temperatures and regular, but not heavy rainfall provides good conditions which enable the development of rich arthropod communities (Kaliński et al 2009;Kaliński et al 2014).…”

“…Variation in nestling body performance could be expected to have consequences for breeding success (Nadolski et al 2006;Kaliński et al 2014). Body condition of nestlings is usually connected to the chance of survival to the fledging stage and, later, for ultimate individual success in recruitment to the breeding population (Brown 1996).…”

“…Because the measuring of habitat quality in a direct way is often not feasible, the evaluation of individual condition offers an alternative method to assess habitat quality (Homyack 2010;Ellis et al 2012). Body condition indices have been used to evaluate impacts of stressors and disturbances, assessing habitat fragmentation or to provide insights into the nutritional status of animals in different habitat types Bańbura et al 2013;Milenkaya et al 2013;Kaliński et al 2014;Minias 2015). Currently, relatively few landscape ecologists employ physiological approaches to evaluate habitat quality.…”

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

“…Glucose is also considered to be an indicator of the nutritional condition of birds (Fairbrother et al 1990;Remage-Healey and Romero 2001;Casado et al 2002;Dunbar et al 2005;Kaliński et al 2014). The level of this monosaccharide in passerine birds usually ranges from 200 to 500 mg/dL (Lewandowski et al 1986;Harris 1991), and is more than 800 mg/dL in hummingbirds (Diamond et al 1986).…”