We conducted behavioral trials to determine if egg preference by female northern dusky salamanders (Desmognathus fuscus) is influenced by the developmental age of their eggs. Within 72 h of oviposition, we divided 41 clutches in half and monitored the time the female spent with each of the genetically similar half-clutches. We then reared the eggs for 21 days in darkness under two temperature regimes (13 and 23 C) to produce a developmentally advanced and delayed half-clutch for each female. Initially, females divided their time almost equally between half-clutches. After thermal manipulation of embryo development, females spent the majority of their time with the developmentally advanced half-clutch. Of the 25 respondents included in the second trial, 21 spent >60%, and 15 spent more than 80% of their time in the presence of developed eggs. We hypothesize that females assess the developmental status of their eggs in order to optimize the tradeoff between the costs and benefits of parental care.