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

Abstract

Because telomere length and dynamics relate to individual growth, reproductive investment and survival, telomeres have emerged as possible markers of individual quality. Here, we tested the hypothesis that, in species with parental care, parental telomere length can be a marker of parental quality that predicts offspring phenotype and survival. In king penguins (Aptenodytes patagonicus), we experimentally swapped the single egg of 66 breeding pairs just after egg laying to disentangle the contribution of prelaying parental quality (e.g., genetics, investment in the egg) and/or postlaying parental quality (e.g., incubation, postnatal feeding rate) on offspring growth, telomere length and survival. Parental quality was estimated through the joint effects of biological and foster parent telomere length on offspring traits, both soon after hatching (day 10) and at the end of the prewinter growth period (day 105). We expected that offspring traits would be mostly related to the telomere lengths (i.e., quality) of biological parents at day 10 and to the telomere lengths of foster parents at day 105. Results show that chick survival up to 10 days was negatively related to biological fathers’ telomere length, whereas survival up to 105 days was positively related to foster fathers’ telomere lengths. Chick growth was not related to either biological or foster parents’ telomere length. Chick telomere length was positively related to foster mothers’ telomere length at both 10 and 105 days. Overall, our study shows that, in a species with biparental care, parents’ telomere length is foremost a proxy of postlaying parental care quality, supporting the “telomere – parental quality hypothesis.”

Population differences in the length and early-life dynamics of telomeres among European pied flycatchers

“…Interestingly, stronger associations between offspring telomere length and foster, but not biological mother telomere length were found for the king penguin (Viblanc et al, 2020), suggesting the importance of parental care for offspring early-life telomere length. Accordingly, a study cross-fostering chicks of the collared flycatcher (Ficedula albicollis), a close relative of the pied flycatcher, shows the heritability of telomere length to be much lower (h 2 = 0.09) than in this study (Voillemot et al, 2012).…”

The influence of phylogeny and life history on telomere lengths and telomere rate of change among bird species: A meta‐analysis

“…In addition, experimental evidence is lacking for a causal link between telomere length or TROC and life span (Simons, 2015 ; Young, 2018 ; but see Varela et al., 2016 ). Telomere length and TROC need not be highly correlated (Tricola et al., 2018 ), since the telomere length an individual starts with in life with may have a strong heritable basis (Vedder et al., 2021 ; but see Becker et al., 2015 ; Viblanc et al., 2020 ), and both variables may be differently regulated by up‐stream cell mechanisms (i.e., oxidative stress or telomerase activity; Grasman et al., 2011 ). As a consequence, they may not display similar associations with life span when comparing species.…”

How does early‐life adversity shape telomere dynamics during adulthood? Problems and paradigms

“…[ 22,29–32 ] Importantly, such effects often correlate with survival or recruitment probability over the juvenile life stages. [ 29,33,34 ] We also have good evidence indicating that adult telomere dynamics may be an even better marker of adult performance than absolute telomere length. In adults, there is often a large inter‐individual variability in telomere dynamics and this variability has been linked with the occurrences of environmental challenges (reviewed in [ 35,36 ] ) or physiological stress exposure (reviewed in, [ 23 ] including infection, [ 37 ] low‐quality habitat, [ 38 ] harsh weather, [ 39 ] or pollution [ 40 ] ).…”