A feather-precipitation hydrogen isoscape model for New Zealand: Implications for eco-forensics

Abstract

Feathers were sampled from extant museum archived birds of known origin to determine feather hydrogen isotopes (δ2Hf) in order to assign their origin and location over time by a comparison with a recently constructed model precipitation (δ2Hp) isoscape. We used feathers from two non-migratory bird species that are widely distributed around New Zealand, Tui (Prosthemadera novaeseelandiae) and California Quail (Callipepla californica). Feathers were sampled from archived birds that were collected between 1880 and 2006 obtained from three New Zealand museum collections located at Auckland, Wellington and Christchurch. Forensic isotopic assays of feather from known locations were compared with the precipitation isoscape model with the aim of establishing a relationship which could be applied to link feathers from unprovenanced historical Māori cloaks held in museums to their region of manufacture (and potentially an associated tribe or iwi) in New Zealand. In order to test this approach, we assessed the modelled δ2Hp values within the distribution area of each tribe. Distribution areas of tribes were isotopically different and in the future, this tool will help to link to feathers from historical artefacts, reconnecting them to their tribal origin.