Fire regime effects on annual grass seeds as food for threatened grass-finch

Date: 01, May, 2019
Author(s):   Anna Weier, Ian J. Radford, Leigh-Ann Woolley, Michael J. Lawes
Publisher: Fire Ecology

The Gouldian finch (Erythrura gouldiae, Gould 1844) is a threatened grass finch (Estrildidae) endemic to the tropical savannas of northern Australia. Current fire regimes, consisting of frequent and extensive fire across these savanna grasslands, affect the type and availability of grass seed for granivores. Gouldian finches are particularly affected as they feed exclusively on grass seed and, unlike other finches, do not supplement their own or their hatchlings’ diet with other protein sources. Annual Sorghum spp. provides the main source of seed to Gouldian finches throughout the monsoonal dry season and concurrent breeding season, making it a critical resource throughout breeding habitat. This study examined the effects of fire regimes, including fire frequency, time since the last fire, seasonality of fire on plant density, seed production, and overall seed abundance of the annual grass Sorghum stipoideum (Ewart & White) C.A. Gardn. & C.E. Hubb. Monitoring of S. stipoideum took place across Gouldian finch breeding habitat over three consecutive years and these measures were used in conjunction with local fire history at these sites to test for effects of fire attributes on Sorghum spp. seed ecology.