“…Several studies have investigated the causes of within-site amongindividual isotopic variance through exploratory approaches such as correlation analysis and model selection (e.g., Clegg et al, 2003;Meehan et al, 2003;Smith and Dufty, 2005;Langin et al, 2007;Reese et al, 2018; see also Hobson et al, 2012;Nordell et al, 2016). Relationships between feather δ 2 H values and age have been observed for several taxa (e.g., Meehan et al, 2003;Smith and Dufty, 2005;Langin et al, 2007;Haché et al, 2012;Studds et al, 2012;Gomez et al, 2019) and attributed to age-related differences in diet, access to water, metabolism (Meehan et al, 2003;Langin et al, 2007;Storm-Suke et al, 2012), and/or evaporative water loss (Wolf and Martinez del Rio, 2000;Meehan et al, 2003, McKechnie et al, 2004Smith and Dufty, 2005; but see Kirkley and Gessaman, 1990;Marder et al, 2003). Differences in the magnitude and patterns of local among-individual variance observed for shore birds (Wunder et al, 2005;Rocque et al, 2006), raptors (Meehan et al, 2003;Smith and Dufty, 2005), and passerines (Langin et al, 2007) have been attributed to differences in molt phenology and evaporative water loss among these taxa (Smith and Dufty, 2005).…”