ENVIRONMENTAL FACTOR INVESTIGATION OF EXUDATIVE CLOACITIS IN KAKAPO (STRIGOPS HABROPTILUS) ON WHENUA HOU (CODFISH ISLAND), NEW ZEALAND

Kakapo (Strigops habroptilus) are critically endangered nocturnal parrots endemic to New Zealand. Exudative cloacitis is a disease only affecting the breeding population of Kakapo on Whenua Hou (Codfish Island), for which a consistent primary pathogenic organism involved has not been identified. This epidemiological study was conducted to identify the environmental factors contributing to the initiation of this disease in Kakapo by 1) producing and describing a case series; 2) mapping the geographic distribution of exudative cloacitis cases; 3) investigating the chemical characteristics of Kakapo roosting sites; and 4) assessing the effects of climatic factors on the incidence of exudative cloacitis each year. Soil samples from the Kakapo roost sites and other areas of the Whenua Hou were examined for pH, ammonium, and moisture contents. From 2002 to 2017, 22 sporadic cases of exudative cloacitis have been diagnosed and the disease distribution on Whenua Hou overlaps the Kakapo distribution. A mixed group of adults and juveniles was affected and there was no evidence of spatial or temporal clustering of the disease. Current findings on the chemical characteristics of Kakapo roosting sites do not show any evidence that these factors are involved in the initiation of the exudative cloacitis. Nevertheless, the results suggest that the ammonium and moisture levels of the roosts are worthy of more detailed study in future cases. We were not able to demonstrate any significant influence of broad measures of climate on the incidence of exudative cloacitis on Whenua Hou. Prospective data collection would help for a complete epidemiological investigation of this disease in future cases.

Automated summary

This epidemiological study aimed to identify the environmental factors contributing to the initiation of exudative cloacitis in critically endangered Kakapo. The study found no direct relationship between the chemical characteristics of Kakapo roosting sites and the disease, but suggested further investigation of ammonium and moisture levels. Climate factors did not show significant influence on the incidence of the disease. Prospective data collection would aid in a more comprehensive epidemiological investigation of this disease.