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Habitat values for birds of revegetation in the NSW Southern Tablelands N. Taws, J. Reid, S. Streatfield A study conducted by Greening Australia ACT & SE NSW Inc. With help from the Canberra Ornithologists Group And CSIRO Sustainable Ecosystems INTRODUCTION Throughout southern Australia our wildlife and ecosystems are in crisis. Wherever most of the original vegetation cover has been removed for cropping, meat and wool production, the telltale effects of erosion, soil, water and land degradation, and loss of biodiversity are evident. Native birds have not been immune to these changes and populations of many species dependent on natural habitats have been devastated. In many ways birds make an obvious and ideal focus for environmental restoration initiatives because, and unlike many other plants and animals, they are: 1. a well-researched group of organisms with a stable taxonomy; 2. often near the top of the food chain and so can both integrate across lower trophic levels and serve as useful indicators for change and ecosystem health; 3. highly visible and popular among the general community due to their colour, songs and active behaviour; and they are 4. easily studied, so scientists, non-scientists and community groups alike can make important contributions to their study. As environmental awareness has grown in recent times and partly in response to the emerging perceptions of land degradation and biodiversity problems, there has been a steady increase in the number of trees and shrubs planted in agricultural production landscapes over the last 15 years. There is now an increasing awareness of the need for revegetation efforts to become more strategic and to be accountable because of the large investment of public funds in restoration activities. The current study follows recent Greening Australia research into the effectiveness of direct seeding projects carried out to date in the NSW Southern Tablelands and adjacent SouthWestern Slopes in the greater Canberra region. By examining the establishment success and growth rates of plants in relation to a number of technological and environmental factors, this plant-oriented research has allowed Greening Australia to improve its direct seeding efforts in a variety of ways. However, we still do not know what fauna is using this newly established habitat and whether it is useful to wildlife, generally or at all. In this study we examined the use that birds make of revegetated areas of land in the northern ACT and adjacent parts of New South Wales, largely in the South-Western Slopes bioregion. Specific aims of this study were to: 1. determine the level of habitat value that revegetation has for native birds in this region; 2. evaluate the effect of size, age, plant species composition, and landscape context of revegetation efforts on their usefulness to birds; 3. draw conclusions about those facets of revegetation efforts that maximise their contribution to providing useful bird habitat; and to 4. disseminate the results of the study to Landcare groups, councils, land managers and other community organisations so as to improve the understanding, design and planning of revegetation projects to benefit birds and, by implication, other local fauna. METHODS Multiple bird surveys, 416 in all, were conducted by members of the Canberra Ornithologists Group at 132 sites, comprising 102 revegetation sites (62 direct seeded, 40 tubestock planted), 20 native vegetation control and 10 paddock control sites. These four categories constitute the main treatment effect in this designed survey. Revegetation sites varied in age from 14 months since establishment to 14 years. The 102 revegetation sites totalled just 268 ha in combined area within a region greater than 10,000 km2 in extent. The actual area of revegetation in the region is much greater than just indicated (albeit still a tiny proportion of the total landscape), but the sites selected for study comprise a larger and wider subset of all revegetation. The bird counts conformed to the methods used for the National Atlas of Australian Birds (Barrett 1998), ie. they were each of 20 minutes duration, and covered a 2-ha area where possible except that in narrow strips of revegetation the area surveyed was necessarily less than this. Only species using the revegetation were recorded. The combined area of revegetated sites systematically surveyed was 117 ha. A minimum set of one autumn-winter (= non-breeding) and one spring-summer (breeding) census was carried out at all sites, in a 16 month period from February 2000 to June 2001. RESULTS A total of 108 different bird species was recorded during the study, with 103 species using revegetated areas. Five species, each recorded only once, were found only at natural or remnant woodland (control) sites. The most common species in revegetation were small insectivorous birds such as the Superb Fairy Wren, Yellow-rumped Thornbill, Brown Thornbill, White-plumed Honeyeater, Grey Fantail and Willy Wagtail. The 20 most commonly recorded species by reporting rate are listed in Table 1. The reporting rate is the percentage of the total number of surveys in which a species was recorded. Table 1The twenty most commonly recorded species in revegetation Bird species 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Superb Fairy-wren Yellow-rumped Thornbill Crimson Rosella Grey Fantail Australian Magpie Brown Thornbill Yellow Thornbill Rufous Whistler Willie Wagtail White-plumed Honeyeater Grey Shrike-thrush Eastern Rosella Striated Pardalote Silvereye White-eared Honeyeater Yellow-faced Honeyeater Striated Thornbill Buff-rumped Thornbill Common Bronzewing White-browed Scrubwren Reporting rate % 74 48 41 39 34 31 27 24 24 22 21 19 17 14 13 13 13 12 11 11 Twenty species were recorded using revegetation for breeding, even though specific searches for evidence of breeding were not made. Particularly exciting was the recording of 15 species of declining woodland birds. These were the Painted Button-quail, Brown Treecreeper, Speckled Warbler, Southern Whiteface, Jacky Winter, Red-capped Robin, Hooded Robin, Eastern Yellow Robin, Varied Sittella, Crested Shrike-tit, Rufous Whistler, Restless Flycatcher, White-browed Babbler, Dusky Woodswallow and Diamond Firetail. Another pleasing result was the scarcity of undesirable birds such as the introduced pests House Sparrow and Common Starling, and native increaser species like the Noisy Miner and Pied Currawong - they were infrequently recorded in revegetation and were rarely abundant. Some of the species only encountered in natural woodland remnants included Spotted Quail-thrush and Little Friarbird. We conclude that a wide range of native bush birds uses revegetation. The most important factors influencing the number of species in any patch of revegetation were: Age of the revegetation Habitat complexity Size of the site Width of the site Season Distance to nearest bush remnant >5ha in size Distance to nearest bush remnant >1000 ha in size DISCUSSION Remnant vegetation forms the critical backbone to any native vegetation strategy in the SE NSW region. However existing remnants are frequently too small, isolated or degraded, and on their own cannot sustain woodland bird populations in agricultural areas. Revegetation using native local tree and shrub species has been shown to provide habitat for a significant proportion of the woodland bird fauna of the region, including some of the “declining” species. A number of bird species preferred or were restricted to remnant vegetation where they may be reliant on resources such as hollows, logs, dead limbs, mature bark, abundant nectar and seeds. However a suite of birds appeared to prefer the revegetation to remnants, possibly because of the greater structural variety provided by shrub species and young trees or because of the greater health and vigour of the young vegetation compared to some of the dieback-stricken remnants. A range of mature, scenescing and regenerating vegetation is needed to provide different resources for birds. Options for improving revegetation efforts to benefit the range of woodland bird species include: fencing off existing remnants, increasing the size of remnants by planting around the outside, enhancing remnant structure by re-establishing understorey, using revegetation to create blocks of new vegetation or wide strips between existing patches. increasing the width of existing windbreaks or treelines, restoring ground structure by leaving branches, logs etc. where they fall, or by re-introducing logs from areas where they may not be wanted. REFERENCES Barrett, G. (1998). Atlas of Australian Birds - notes on methodology for the new bird atlas. Birds Australia, Melbourne.