Pukeko (Porphyrio porphyrio melanotus) road death at Otukaikino Reserve, Christchurch, New Zealand

Abstract

Pukeko (Porphyrio porphyrio melanotus, Temminck 1820) are vulnerable to road death and spend time in roadside environments. This thesis examined characteristics of pukeko road death, roadside behaviour, and grit and invertebrate collection. The characteristics of road death examined were the spatial and temporal distribution of road deaths, the life stage and sex of road-kills, and vehicle-caused injury of pukeko on the roads surrounding Otukaikino Reserve, Christchurch, New Zealand. The spatial distribution of road-kills was clustered while no seasonal distribution was detected. The difference in life stage of pukeko road-kills was found to be highly significant as no juvenile pukeko were killed. No significant difference was found between the sex of road-kills.

Roadside presence and road-related behaviour of pukeko was investigated from November 1998 to October 1999. Pukeko at the roadside were found to be strongly aggregated in pairs or trios. This behaviour was found to be very characteristic of pukeko, a communal species (Craig 1974). Most of the time spent at the roadside was spent foraging. The time spent at the roadside was often coincided with the presence of rain, recent mowing events and time of day (early morning and early evening).

It was hypothesised that pukeko were spending time at the roadside collecting grit or invertebrates. While evidence did not indicate that pukeko were collecting invertebrates at the roadside, the theory of grit collection looks promising. The evidence to support these theories came from the analysis of gizzard, crop and roadside samples. Many invertebrates are present at the roadside but analysis of five crops of road-killed pukeko showed no evidence of recently eaten invertebrates. In addition, a colour preference trial was used to determine which colour grit pukeko preferred. Red grit was preferred by pukeko at three out of four sites. Red grit may be suitable as a preferential grit supply to keep pukeko away from roadsides.