Coccidiosis in wild rabbits, Oryctolagus cuniculua (L.) at four sites in different climatic regions in eastern Australia II.The relationship of oocyst output to climate and to some aspects of the rabbit's physiology

Abstract

Rabbit populations were sampled regularly during 1962-64 at four sites in different climatic regions (subalpine, mediterranean, subtropical, and semi-arid) in eastern Australia. A total of 2981 rabbits were taken by shooting at night. Oocysts in the faeces were identified as Eimeria stiedae, E. media, E. perforans, E. irresidua, E. magna, E. piriformis, and E. exigua. Infections were highest and most frequent at the subalpine site, less at the sites with mediterranean and subtropical climates, and were not common at the semi-arid site. Regular seasonal fluctuations occurred at the subalpine and mediterranean sites, with troughs occurring in summer. Multiple regression analysis of oocyst count on several anatomical and climatic measurements showed that, except at the semi-arid site, oocyst count was significantly related to measurements highly correlated with host age, and to evaporation (during the preceding 8 weeks); at the semi-arid site rainfall was the only really significant factor. Differences between species of coccidia were small compared with the differences between sites.