A slow unpicking of the landscape thread? Changes in tropical savanna birds on a gradient of habitat modification over 12 years of monitoring

In south-eastern Australia, land clearing has been extensive, resulting in an avifauna that has been significantly depleted. In northern Australia, land clearing is less but increasing. In this study, I examined the change in bird composition in a Queensland tropical savanna woodland where some land clearing has commenced. The data were collected from 60 sites sampled seven times between 2004 and 2016. I used a range of multivariate and non-parametric methods to examine the variation in species composition over the three categories of habitat modification, and years of survey. 21 899 bird records, representing 116 species were recorded. The was a significant difference in species composition across years, habitat modification and the interaction though marginal tests for environmental variables (green and non-green fractional cover, preceding 12-month rainfall, and Yellow-throated Miner Manorina flavigula abundance) indicated a low of explanatory power (45%). Forty-eight species were recorded in significantly different abundances across the three habitat modification categories (22 more abundant in intact vegetation, 12 in thinned, and 14 in cleared) and 53 species were recorded in significantly different abundances over the seven years of survey. Species associated with cleared sites were the Zebra Finch Taeniopygia castanotis , Budgerigar Melopsittacus undulatus , Nankeen Kestrel Falco cenchroides , with intact sites, Grey Shrike-thrush Colluricincla harmonica , Crested Bellbird Oreoica gutturalis , Striped Honeyeater Plectorhyncha lanceolata and thinned sites, Jacky Winter Microeca fascinans and Brown Treecreeper Climacteris picumnus . This study indicated that in largely intact tropical savanna landscape, small scale modifications can result in significant changes to the bird community.