Table 1.

The hatching success of Sterna hirundo eggs in nests which hosted foster eggs during 2017. Eggs were fostered into nests when only 1–2 eggs were present, and the number of eggs reported includes the foster egg. Eggs were considered likely to have hatched if the egg was no longer present within the nest 19–31 days after clutch initiation, and were considered confirmed hatched if a chick was either captured or observed at the nest. Eggs were considered not to have hatched if the egg was no longer observed in the nest < 19 days or > 31 days after clutch initiation, or if observation indicated the egg was no longer viable (i.e., holes in the egg or obvious lack of parental care).