We present the first observations of misdirected parental care by Savannah Sparrows (Passerculus sandwichensis) including a rare occurrence of simultaneous incubation. Two females simultaneously incubated eggs, brooded, and fed nestlings, and two males fed nestlings in one nest. These behaviors may have been prompted by strong parental instincts in combination with a stressful breeding environment mediated by hayfield management, as any genetic benefits were unlikely.
Zalik, Nathan J. and Perlut, Noah G., "Simultaneous Incubation By Two Females And Nestling Provisioning By Four Adults At A Savannah Sparrow Nest" (2008). Environmental Studies Faculty Publications. 19.