Plant microfossil analysis of coprolites of the critically endangered kakapo (Strigops habroptilus) parrot from New Zealand

Abstract

We present here results of analysis of pollen, spores, starch and other microscopic plant material in 52 coprolites of the critically endangered kakapo (Strigops habroptilus), a New Zealand endemic parrot. The six sampling sites (caves, rock overhangs) are in widely separate geographic regions in the South Island, across an altitudinal range encompassing lowland, montane and near sub-alpine environments. Radiometric testing gives average ages of discrete coprolite groups ranging from modern to 2514 ± 43 14C yr BP.

A wide variety of plant taxa is identified in the coprolites, comprising cones, flowers, leaves and fronds of ~30 podocarps, dicotyledonous trees, shrubs and lianas, grasses, ferns, lycopods, mosses and liverworts. This supports previous observations that kakapo are versatile feeders, using a broad spectrum of foods which may only be available for short periods and intermittent years. Many of the food taxa we identify are consistent with studies of modern kakapo diet. We also identify several new foods, potentially of value in developing food supplements to increase breeding frequency of the current kakapo population. The most commonly identified plant parts in coprolites were fern fronds (monoletes, Hymenophyllum, Cyathea smithii), followed by podocarp cones and leaves. Lack of starch in the coprolites suggests that the lycopod and fern rhizomes reported in modern kakapo diet were not commonly eaten. The data provide initial botanical evidence of diet from coprolites of an extant bird.

Keywords

Coprolites, plant microfossils, palaeodiet, Strigops habroptilus, New Zealand.