Natalie Forsdick is investigating the hybridisation between kaki and poaka, two New Zealand stilt species.
When kaki numbers have been historically low, interbreeding between the two species has occurred, resulting in fertile hybrids that display a range of plumage nodes (hybrid black stilt colour patterns are described as "nodes", ranging from "A", closest to a pied stilt, to "J", closest to a black stilt) intermediate to those of the pure black kaki and the mixed white and black poaka, first described by R.J.
For Natalie's research project, in collaboration with researchers at the University of Otago, the University of Canterbury, and the Kaki Recovery Team at the Department of Conservation, she is sequencing and assembling the genomes of kaki and poaka to investigate what effect this hybridisation has had on the genome of the threatened kaki population, and whether any genetic information from poaka has been incorporated into the kaki genome.
These brooches represent each of the individuals outlined in the original hybrid description by Pierce: a kaki, a poaka, and seven intermediate hybrid birds.
Each brooch depicts the black-and-white plumage of the birds on the front; the back, which represents the hidden, genetic rofile of each, is made from a different metal alloy, pure silver for the kaki, pure copper for the poaka, and varying proportions of silver/copper alloy for the hybrid birds.
MW2017-01-01 Pure Poaka, brooch, copper, 925 silver, aluminium, heat shrink tube, polymer clay, resin, steel pin, 150 x 50 x 10 mm and MW2017-01-09 Pure Kaki, brooch, fine silver, 925 silver, aluminium, heat shrink tube, polymer clay, resin, steel pin, 150 x 50 x 10 mm.
A vast amount of genetic data has been generated to inform these management decisions, including data assessing the threat of hybridisation with poaka, using the most up-to-date genetic techniques available.
They interbreed with poaka (pied stilts), and it tends to happen when the kaki population is really small in the landscape and are having trouble finding mating pairs.
Michelle Wilkinson, A Conglomeration of Stilts: MW2017-01-01, Pure Poaka (left), MW2017-01-09 Pure Kaki(right), 2017, fine silver, 925 silver, copper, aluminium, heat shrink tube, polymer clay, resin, steel pin.
In this collaboration, Natalie and Michelle investigated hybridisation between an endemic endangered New Zealand bird, the Kaki (Black Stilt) and the self-introduced Poaka (Pied Stilt).