Bird communities and effects of management in Heathy Woodlands in the Grampians/Gariwerd National Park

Abstract

ABSTRACT Measuring biodiversity across time and space is fundamental in assessing effects of ecological management actions. Monitoring bird species richness and abundance within the Victorian Grampians/Gariwerd National Park (GGNP) Heathy Woodland Ecological Vegetation Class (EVC) is used to assess seasonal changes in bird community and foraging guild composition. Two 2-ha/20-min bird surveys were undertaken at 36 sites in each of six seasonal surveillance periods over 2 years (total 432 surveys), detecting 90 species. Mean site diversity was 8.40 species (se = 1.91, n = 36 sites) and mean abundance was 19.52 birds (se = 6.91, n = 36 sites). Spatial and temporal shifts in abundance and species richness are compared with data collected using the same method by Possingham et al. in SA’s Mt Lofty Ranges (MLR) stringybark habitat and with data from the same GGNP sites in 2008 after widescale 2006 wildfires. Neither mean diversity nor abundance at each site changed significantly in the same season between years, but mean diversity in spring was higher than in both autumn and winter. Within Heathy Woodland habitat, the foliage searcher guild was the most diverse and abundant foraging guild across sites. With potential for ecosystem collapse in the MLR stringybark community and threats to the GGNP community, ongoing study of avian communities has potential to guide effective management both in the MLR and the GGNP. We assessed outcomes of GGNP fire history on avian diversity and abundance. A more diverse bird community may result where a mosaic burn of stringybark woodlands is achieved and in longer unburnt sites.