Australian National Directory of Important Migratory Shorebird Habitat Discussion Primary authors: Dan R. Weller, Lindall R. Kidd, Connie V. Lee, Steve Klose, Roger Jaensch and Joris Driessen Contributing authors: Paul G. Handreck, Kerryn Herman and Chris Purnell BirdLife Australia, Suite 2-05, 60 Leicester Street, Carlton, Vic. 3053, Australia. Citation This publication should be cited as follows: Weller, D., Kidd, L., Lee, C., Klose, S., Jaensch, R. and Driessen, J. 2020. Directory of Important Habitat for Migratory Shorebirds in Australia. Unpublished report prepared for Australian Government Department of Agriculture, Water and the Environment by BirdLife Australia, Melbourne. Copyright © BirdLife Australia This document is subject to copyright and may only be used for the purposes for which it was commissioned. Copying this document in whole or part without the permission of BirdLife Australia is an infringement of copyright. Disclaimer Although BirdLife Australia has taken all the necessary steps to ensure that an accurate document has been prepared, the organisation accepts no liability for any damages or loss incurred as a result of reliance placed upon the report and its content. 1 Discussion & Conclusions For this Directory, recent survey data collected on migratory shorebirds from around Australia and available through databases held by BirdLife Australia were analysed to identify important shorebird habitat. A range of sites of national and/or international importance for migratory shorebirds that regularly visit Australia was identified. Accounts of the sites found to be significant, as well as species accounts, are presented. Number and distribution of sites of international importance A total of 97 sites in Australia were identified as being internationally important for migratory shorebirds (Table 1). Table 1. Number of internationally important sites for migratory shorebirds in Australia, showing differences between the previous Directory (Bamford et al. 2008) and the present Directory. Jurisdiction Number Number of Sites not Sites added in Total sites in of sites sites in 2020 included in 2020 2020 either year* in 2008 EXT 1 1 0 0 1 NT 20 6 14 2 20 QLD 14 $ 23 6 13 29 NSW 14 7 10 4 17 ACT 0 0 0 0 0 VIC 16 19 3 5 21 TAS 7 4 4 2 9 SA 17 19 6 13 25 WA 25 $ 18 11 7 29 Totals 114 97 54 46 151** $ Does not include two sites that were listed in 2008 only for Australian Pratincole. * Number of sites in 2020 added to the number of sites (from 2008) no longer included in 2020. This method attempts to account for situations where lists have been affected by changes to site boundaries, e.g. boundary expanded to include a previously separate site (e.g. Gulf St Vincent now incorporating three previous sites, two of which were separate saltfields), or the site was split into components (e.g. former Western Port Phillip Bay now listed as two sites). ** Some minor changes to analyses in this chapter may have occurred since the text was prepared due to late inclusion of some shorebird count data. Queensland and Western Australia were among the jurisdictions with the highest number of such sites, which is unsurprising in view of their large areas of shorebird habitat. South Australia and Victoria also had high totals despite smaller areas of habitat. This may partly reflect high levels of survey effort. Directory of Important Habitat for Migratory Shorebirds in Australia 2 Tasmania had almost as many important sites as some much larger jurisdictions. The way in which shorebird areas have been defined for survey purposes may also impact these results (see details in methods section). Another contributing factor is the geographic variation in where shorebird species tend to congregate during their non-breeding season (see below for further discussion). The previous assessment of internationally important sites (Bamford et al. 2008) employed, in part, different methods, including a longer period for source data. Nevertheless, these previous assessments allow for some useful comparisons with results from the present Directory (Table 1). The fact that the national total was somewhat higher in 2008 may be partly explained by differences in the data period. Sites in remote coastal or inland regions that are difficult to access are typically seldom visited; hence, the longer data period for the 2008 compilation allowed greater prospect for visitations, favouring inclusion of more sites. The higher total in 2008 also relates to coverage of inland and northern regions: considerable exploration of remote shorebird habitat occurred in the last three decades of the 20th century, including surveys commissioned for the first edition of the Directory of Important Wetlands in Australia (ANCA 1993). In summary, data accessed for the present Directory have been drawn primarily from a monitoring program, rather than from a monitoring program supplemented by an inventory program, resulting in many changes to the list of internationally important sites. A large number of sites (47% of the 2008 total) did not meet significance criteria in the present Directory, whereas many internationally important sites (47% of the 2020 total) were identified as such for the first time. Possible explanations for these changes include counts of one or more species being markedly lower (or higher), change in the 1% threshold (updated from Bamford et al. 2008 by Hansen et al. 2016), data deficiency or improved coverage in the source data period, and changes to site boundary for surveys. The population size of many Flyway species has also continuously declined, resulting in seven being listed as Threatened under the EPBC Act 1999; in most cases there has been a consequent and proportionate lowering of the 1% threshold, so the influence of threshold declines on site totals is not always clear 1. Raised thresholds are most likely to cause formerly important sites to not be listed in this Directory. Whereas reduced survey coverage of many inland and remote shorebird areas in recent years will have caused some sites to not be listed, expanded coverage of coastline in southern and eastern Australia (e.g. Queensland) has introduced new sites. Consolidation or splitting of a relatively small number of shorebird survey areas was a lesser influence on the changes. In terms of jurisdictions, the number of internationally important sites decreased markedly from 2008 to 2020 in the Northern Territory (70% decline), New South Wales (50%) and Western Australia (28%). In the Northern Territory, the 2008 assessment was able to draw on results from a program of surveys along the whole coastline by government wildlife officers (Chatto 2003) but this logistically challenging, high-cost coverage has not been replicated subsequently. Expanded survey effort, spearheaded by the Queensland Wader Study Group and including some work by Indigenous Rangers (e.g. Jackson et al. 2016) and around industrial development sites (Choi et al. 2016) contributed to a 64% increase in number of sites in Queensland. Importance of Australia for migratory shorebird conservation Taking into account some recent consolidations and splits of previous shorebird areas, and ignoring past and present circumstances at each site, the total number of internationally important sites for migratory shorebirds identified in either 2008 or the present assessment is about 150 (Table 1). There has been no Flyway-wide update of internationally important sites, but only two other countries — 1 The 1% threshold increased by more than 500 individuals for five species and decreased by 500 for four species. Species for which change was most marked included Greater Sand Plover (1% threshold 1100 in 2008, but increased to 2000 in 2020); and Sharp-tailed Sandpiper (1% threshold 1600 in 2008, but lowered to 850 in 2020). Directory of Important Habitat for Migratory Shorebirds in Australia 3 Japan and China — are known to have more than 50 such sites (Table 3.3 in Bamford et al. 2008). The scope of survey effort and knowledge of shorebirds, and the size of territory, vary enormously between the Flyway countries and size of sites as delineated by shorebird counters is highly variable. Nevertheless, the fact remains that — as measured by numbers of internationally important sites — Australia is extremely important for migratory shorebirds, to which its location and availability of suitable habitat contribute. Australia is especially important for 11 species of migratory shorebird for which at least 67% of the population in the Flyway is present during the non-breeding season (Bamford et al. 2008): Latham’s Snipe; Little Curlew; Eastern Curlew; Grey-tailed Tattler; Great Knot; Red-necked Stint; Sharp-tailed Sandpiper; Curlew Sandpiper; Greater Sand Plover; Oriental Plover; and Oriental Pratincole. Without comparable updates from all other countries along the Flyway, presently it is not possible to determine if this remains true. It is reasonable, however, to assume that the importance of Australia has not changed because the species accounts in this Directory show that large numbers of these species still occur here. That internationally important sites are fewer for Little Curlew, Oriental Plover and Oriental Pratincole in the present Directory compared to 2008 is due partly to reduced coverage of prime habitats of these grassland-inhabiting species and probably also to non-recurrence of the special environmental conditions (Sitters et al. 2004) that seem to have triggered some of their past, occasionally huge, congregations. Another measure of the global significance of Australia for migratory shorebirds is the number of species for which the country has internationally important sites. The previous assessment (Bamford et al. 2008) cites 27 such species, behind China (46 species) and Russia (41), whereas data in the present Directory indicate 24 species for Australia. The small change may be explained by lack of internationally important sites for one species, Oriental Pratincole, and the omission of Australian Pratincole from the present Directory. Therefore, this gauge of Australia’s global significance still holds true.