Consequences of trace metal cocktail exposure in zebra finch (Taeniopygia guttata) and effect of calcium supplementation

Abstract

Trace metal elements are significant stressors in urban areas. Their harmful effects on physiological parameters are demonstrated, but current laboratory studies are not representative of wild chronic exposure to a trace metal cocktail. Calcium can reduce the accumulation and toxicity of several metals, but soil acidification in cities leads to a decrease in bioavailability of this mineral. The objective of this study was to investigate the accumulation and toxicity of a trace metal cocktail representative of urban exposure on passerine birds, and test the importance of calcium availability on these toxic effects. We exposed zebra finches (Taeniopygia guttata) to a cocktail of seven metals and one metalloid in drinking water, with or without calcium supplementation. We monitored the concentration of metals in the blood and feathers, and their effects on oxidative status and telomere length. The metal cocktail led to higher concentration of all elements in the feathers, and of arsenic and lead in the blood. Birds with a higher concentration of cadmium, arsenic and lead in the feathers had shorter telomeres, but no impact of the cocktail was detected on oxidative status. Birds of the 'calcium' group and the 'calcium and metal' group accumulated higher concentrations of zinc, chromium and nickel in feathers. The 'calcium and metal' group also accumulated lower concentrations of arsenic and lead in feathers compared to the 'metal' group. Our results suggest that chronic exposure to a cocktail of metals at low concentrations has deleterious effects on birds, which can be limited through calcium intake.

The Power of Stress: The Telo-Hormesis Hypothesis

“…In humans, the shortening effect of ethanol appears to be mediated by oxidative stress ( Figure 2 ), mainly induced by alcohol dehydrogenase [ 69 , 71 ]. Nevertheless, zebra finches exposed to trace metal elements exhibit decreased TL with no change in oxidative stress [ 72 ]. Overall, the effect of chemical stress on TL varies depending upon the nature of the chemical, the mode and duration of exposure and the organism exposed.…”

Foster rather than biological parental telomere length predicts offspring survival and telomere length in king penguins

“…Telomeres are repeated DNA sequences at the end of chromosomes that play a key role in maintaining genome integrity (Gomes, Shay, & Wright, 2010). Telomere length can shorten over time in response to both cell division and stressors (including environmental stressors, psychosocial stressors or poor early life conditions) (Boonekamp, Mulder, Salomons, Dijkstra, & Verhulst, 2014; Chatelin, Drobniak, & Szulkin, 2019; Hanssen, Schutte, Malouff, & Epel, 2017; Levy, Allsopp, Futcher, Greider, & Harley, 1992; Noguera & Velando, 2019; Tomiyama et al., 2012; Saulnier et al., 2020; but see Cerchiara et al., 2017). As a consequence, telomere lengths and their dynamics have been related to individual health and stress at a proximate level (Verhulst et al., 2016) and to fitness outcomes at various life history stages (Bauch, Becker, & Verhulst, 2013; Bize, Criscuolo, Metcalfe, Nasir, & Monaghan, 2009; Heidinger et al., 2012; Salomons et al., 2009).…”

Bird Feces as Indicators of Metal Pollution: Pitfalls and Solutions

“…Selection of toxic elements was based on earlier information on the emission profile of the smelter [35,37]. Calcium was included because it interacts with toxic metals, and therefore it is often measured together with the other metals [46,47]. These concentrations were first log 10 transformed to make them better conform to normal distribution, which was confirmed by visual inspection of histograms.…”