We tested the assumptions of the Mayfield method (Mayfield 1975) using 416 Wood Thrush (Hylocichla mustelina) nests monitored from 1993–1997 in the Great Smoky Mountains National Park. We tested for differences in nest survival throughout the breeding season and throughout the nesting cycle. We compared the Mayfield cumulative survival curve with a modified version of the Kaplan-Meier with staggered entry. In addition, we compared the group of nests found during nest initiation with those found later in the nesting cycle. There was no evidence nest survival varied through the breeding season or with different stages of the nesting cycle. Furthermore, the Kaplan-Meier survival curve agreed with the Mayfield calculation. We found no evidence of heterogeneity. Validation of Mayfield assumptions is important because the method is widely used, allows for statistical comparisons, and is critical for estimating seasonal fecundity in bird populations.