The last two of our ten most commonly seen and heard forest birds are the rifleman and the wood pigeon (http://www.doc.govt.nz/global/training-courses/bird-id/birds.swf).
The rifleman is our smallest bird. The Maōri name has both the noise of its call, 'Tītiti', and the colour green of its feathers, 'pounamu' (from 'In the Bush', N. Barraud and G. Candler, 2015).
Their big mouth mean wood pigeons can swallow large seeds such as miro. After eating the fruit they poo out the seed. This helps new trees grow in different places in the forest (from 'In the Bush', N. Barraud and G. Candler, 2015).
More on rifleman: http://www.teara.govt.nz/en/small-forest-birds/page-2
Birds role in the ecosystems: http://sciencelearn.org.nz/Science-Stories/Conserving-Native-Birds/Birds-role-in-ecosystems