Nest, but not egg, fidelity in a territorial salamander

Egg recognition and subsequent egg brooding are costly forms of parental in vestment in many species of vertebrates. Life history factors, such as colo niality or risk of brood parasitism, may constrain egg recognition in verte brates. Female red-backed salamanders (Plethodon cinereus) from my study si te are territorial and do not share nest sites with other females. They are terrestrial and neither they nor their eggs are likely to be displaced by environmental factors such as flooding. I experimentally tested, in the lab oratory, the hypothesis that female red-backed salamanders can discriminate between their own eggs and the eggs of unfamiliar females. Each female was allowed to move about a test chamber containing two clutches of eggs, one clutch with which it was found in the forest and one that had been found wi th a distant female. Most females remained with one clutch of eggs, which t hey brooded during the entire observation period. However, they did not sig nificantly prefer to brood their own eggs over the eggs of another female. In a corollary field experiment, I tested whether brooding females that wer e displaced 1 m from their nest sites would return to their territories and commence brooding behaviour within 3 d. All 10 displaced females returned to their own nest within this time period and were found brooding their egg s. Because female red-backed salamanders at my study site do not tend to sh are nest sites with other females and because their eggs remain in stationa ry nests, selection may not have favoured egg recognition. However, the res ults suggest that female salamanders indirectly recognize their own eggs by actively recognizing their territorial nest sites.