Kowhai Bush

Recruitment, survival and breeding success in a declining rifleman population

We used detailed life-history data collected over a six-year period from a colour-banded population of riflemen (Acanthisitta chloris) at Kowhai Bush, Kaikōura, to estimate population vital rates and assess their likely contribution to a concurrent population decline. Both mean juvenile survival (18%) and mean adult survival (49%) were low in comparison with reports from other populations. In contrast, breeding success was high, with pairs producing c. 3 fledglings per season on average. High breeding success was likely associated with nestbox use.

Introduced blackbirds and song thrushes: useful substitutes for lost mid-sized native frugivores, or weed vectors?

The New Zealand avifauna has declined from human impacts, which might leave some larger-seeded native plants vulnerable to dispersal failure. We studied fruit dispersal in a lowland secondary forest near Kaikoura, where the only remaining native frugivores are relatively small (silvereye Zosterops lateralis, and bellbird Anthornis melanura). We tested whether two larger exotic frugivores (blackbird Turdus merula and song thrush T. philomelos) dispersed native plants with seeds too large for the two smaller native frugivores.