Developmental temperature influences color polymorphism but not hatchling size in a woodland salamander

Maternal Body Size and Condition Predict Measures of Reproductive Success and Future Reproductive Allocation in Territorial Eastern Red-Backed Salamanders

“…We measured clutch sizes as the number of eggs present at the time of collection, which may have underestimated the original clutch sizes. However, this underestimation may be minimal, given that the mean original clutch size was not smaller than the mean number of developing oocytes in females used in this study, and clutch sizes were similar to those found in other studies (e.g., Yurewicz and Wilbur, 2004;Evans et al, 2020). The observed relationship between maternal SVL and clutch size may be due to (1) greater number of eggs produced by larger females (e.g., Nagel, 1977;Lotter, 1978), (2) better protection of eggs (from desiccation, fungal or bacterial infections, and predation) by larger females (Crespi and Lessig, 2004), and/or (3) some other attribute not measured in our study.…”

“…In our study, the number of new oocytes that were visible through the body wall of females after 185 d since hatching of their last clutch was positively related to maternal condition. Evans et al (2020) also found a positive relationship between tail length (their measure of condition) and number of developing oocytes and clutch size. We conducted a post hoc analysis using tail length as a main factor, and found no significant relationship with tail length and either developing oocyte number or clutch size.…”

“…Following hatching, the neonates remain near their mothers for up to three months (Gillette, 2003). This brooding period can be costly because brooding females do not forage for prey and lose a significant amount of mass that results in insufficient reserves to produce a clutch in the next year (Ng and Wilbur, 1995;Yurewicz and Wilbur, 2004), and females in better condition (e.g., more mass for a given body length or having intact tails) also produce more and larger maturing oocytes than females in worse condition (Fraser, 1980;Yurewicz and Wilbur, 2004;Evans et al, 2020). However, brooding provides protection that is beneficial to the eggs including increased survival and larger hatchling size (Heatwole, 1961;Highton and Savage, 1961;Crespi and Lessig, 2004;Tornick, 2010).…”

Eastern red-backed salamanders: A comprehensive review of an undervalued model in evolution, ecology, & behavior

“…Over development, Evans, Urban, & Jockusch (2020) found that temperature may play a role in the expression of the color phenotype. The authors reared eggs at different temperatures, and found a higher proportion of unstriped individuals hatch at higher temperatures.…”

“…The authors reared eggs at different temperatures, and found a higher proportion of unstriped individuals hatch at higher temperatures. The authors note, however, that it is difficult to know if this is true phenotypic plasticity in color phenotypes (i.e., high temperatures induce expression of unstriped morph) or simply differential mortality based on temperature (i.e., eggs containing unstriped individuals are more likely to survive rearing at high temperatures compared to eggs containing striped individuals; Evans et al, 2020). Further work is needed to tease these apart.…”