Physical condition and ectoparasite infestation of feral pigs in New Zealand

Abstract

1990. Physical condition and ectoparasite infestation of feral pigs in New Zealand. Acta ther. 35: 299-309. Physical condition and ectoparasite infestation was determined for 2,674 feral pigs harvested by hunters in the northern half of the South Island, New Zealand, during 1986 and 1987. Condition was appraised from sub-dermal and visceral fat deposits. The occurrence of lice and ticks was assessed from a macroscopic examination of the carcass exterior. Feral pids in New Zealand appear in good condition, males more so than females. Such condition varied with age with 71 % of those aged 3 months to 4-5 years in good condition and pigs in older age groups less so. Patterns varied seasonally. Females showed good condition during winter and poor condition during summer, while males showed the opposite pattern. Ectoparasite infestations were mostly low. Females were less infested than males but had consistent infestations, irrespective of age. Male ectoparasite infestations increased with age. Seasonal differences in infestation rates were not evident for females, but were heaviest during winter and spring for males. Regional variations in both parameters were recorded for both sexes. Physical condition was negatively correlated with ectoparasitic infestation in males and in females.