Mortalities of hihi/stitchbird nestlings at Zealandia (Karori sanctuary)

Twenty-five dead hihi/stitchbird (Notiomystis cincta) chicks were recovered from nests at Zealandia (Karori sanctuary) during the breeding season (late 2008 to early 2009), and examined at necropsy, and histopathologically. Starvation was diagnosed as the primary cause of death in four, and respiratory failure, characterised by collapsed airways and accumulation of proteinaceous fluid, was found in a further six chicks all in younger age groups. Mortality of chicks in both these groups was associated with unseasonably low minimum daily temperatures of <11°C. Eight of 25 (32%) chicks in older age groups were found to have ventriculitis, in which fungi and bacteria were present, and these were often associated with the penetration of insect stings (presumably from honey bees) into the wall and serosa of the gizzard. A small number of chicks also died from trauma, aspergillosis, a congenital anomaly, or an unidentified haemoparasite.