The number of parental visits to the nest per hour during incubation for bellbirds on Aorangi Island, where exotic predators were never introduced, for bellbirds in Waiman Bush, where exotic predators were removed, for bellbirds in Kowhai Bush, where all exotic predators are present, and for honeyeaters in Tasmania, which evolved with a range of native mammalian predators.

<p>Shared letters within bars denote non-significant (i.e., <i>p</i>>0.05) statistical differences based on LSD tests. Figures above bars are the number of nests filmed in each study site.