Foraging in animals ranges from a sedentary, ambush mode to more active patterns. Among the plethodontid genus Desmognathus, early observations have indicated that small species and small members of large species may forage more actively than large individuals. Therefore, we tested the hypothesis that foraging within and across the genus depends on body size. We chose species ranging from the largest (D. amphileucus) to the small members of the D. ocoee complex (D. ocoee and D. perlapsus). We also included two species intermediate in size, D. monticola and D. folkertsi. We analyzed foraging of 570 individual salamanders, collecting them at night and determining whether they were foraging while partially within a refuge, indicating an ambush posture, or outside of a refuge in a more active mode. Using replicate streams, we determined that, for each species or species complex, refuged animals had significantly larger snout–vent lengths (SVLs) than individuals outside of a refuge. Moreover, the proportion of individuals foraging in an ambush posture in a refuge increased with mean SVL of the population sampled with 76% of the variance in proportion of search modes being predicted by mean SVL. The results of a replicated laboratory-based experiment did not match the patterns observed in the field, indicating that the trend of larger individuals to remain in refugia is not a simple reflexive response to refugia. However, the trend of larger individuals to forage while remaining in a sedentary, ambush posture in a refuge in resident streams helps to explain ecological and evolutionary patterns within the tribe Desmognathini.

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