Key Biodiversity Areas
Eight areas in Australia have been declared Key Biodiversity Areas (KBAs) based on their significance for Brolgas or Sarus Cranes. In Ozcranes KBAs Part 1 we cover two areas in Queensland, Atherton Tablelands and Gulf Plains, which are both significant for Sarus Cranes. Summaries for six more KBAs important for Brolgas, in Western Australia and the Northern Territory, are in KBAs Part 2».
Key Biodiversity Areas (previously Important Bird Areas) are a global conservation program implemented in Australia by BirdLife Australia. Sites are chosen based on one or more ‘trigger’ species, using criteria on population size and conservation threats. They are non-governmental and impose no restrictions on landowners, but many include private land so working with landowners is an important ongoing part of bird conservation. Golo Maurer, manager for the KBA program in Australia, regularly updates the AU KBA Facebook page.
KBA Guardians: Every year the Guardian for each KBA conducts an Easter Health Check to assess habitat and other factors affecting the trigger species. The Guardian for the Atherton Tablelands KBA is Tim Nevard, who is undertaking a PhD study with Charles Darwin University on interactions between Brolgas and Sarus Cranes.
Australian KBAs and cranes
Eight KBAs in Australia have been chosen based on their critical habitat for Brolgas and Sarus Cranes, as well as significant populations of other waterbirds or range-restricted species.
Australian KBAs critical for Brolgas and Sarus Cranes
|KBA||Location||Significance for Cranes|
|Atherton Tablelands||Qld||>1% global pop. vulnerable Sarus Crane|
|Gulf Plains||Qld||Sarus Crane breeding/>1% global pop. Brolga|
|Lake Gregory/Paraku||WA||>1% global pop. Brolga|
|Mandora Marsh/Anna Plains||WA||>1% global pop. Brolga|
|Cadell/Blyth Floodplains||NT||>1% global pop. Brolga|
|Blue Mud Bay||NT||>1% global pop. Brolga|
|Arafura Swamp||NT||>1% global pop. Brolga|
|Alligator Rivers Floodplains||NT||>1% global pop. Brolga|
For full information on any KBA visit BirdLife Datazone. In the Simple Search form, enter the name of the IBA (as per the above Table), this gives a brief note on the formal criteria. Click on the NAME of the IBA (it is a link, though it looks like text) – to see Tabs with detailed information and maps. The original establishment report for KBAs in Australia can be downloaded here, scroll down to ‘Australia's Important Bird Areas: Key sites for bird conservation’, December 2009, by G Dutson, S Garnett and C Gole.
Atherton Tablelands: a very unusual KBA
This is a highly unusual KBA, one of only two in Australia where much-altered agricultural land – not native vegetation or wetlands – make the area significant habitat for the trigger species (Dutson et al. 2009). Although Least Concern here, the Sarus Crane is globally Vulnerable due to declines and threats in Asia. This KBA has the only known significant congregation of non-breeding Sarus in Australia, with sites regularly containing > 1% of the global population. Feeding substrate studies (JDA Grant unpublished) show cranes favour maize, other grain and peanut stubbles over pasture; and pasture over post-harvest sugar cane fields. Expansion of grain cropping and water impoundments providing roost sites are presumed to have contributed to rapid adoption of the Atherton Tablelands by wintering Sarus from the first sightings in 1967, however there is no evidence of an increase in population (E. Scambler in prep).
The KBA covers all the main Atherton Tablelands feeding and roost sites. A map can be downloaded here (jpg 752KB), with towns marked by initials (Atherton, Kairi, Malanda, Yungaburra). The boundary and baseline population series were derived from the North Queensland Crane Counts 1997-2008» including the highest estimated number of Sarus ever recorded at one time in Australia, over 3,000. BirdLife Northern Queensland continues to monitor this IBA with annual crane counts.
1 Threats and Actions – formal listing
The IBA nomination submission prepared by Graham Harrington and Elinor Scambler (2008) lists Potential Threats...
- Sarus Cranes depend upon the cultivation of maize and peanuts, and grazing. Other crops are of much less value
- Tree planting (revegetation or forestry) excludes cranes from roost or feeding sites
- Deepening of farm dams for fish stocking excludes cranes from roost sites
...and Management Considerations –
- Liaise with agricultural landholders to encourage management regimes that maintain habitat for Sarus Crane
- Investigate the effect of human disturbance on Sarus Crane
- Maintain the current low dam level [refers to proposed raising of the dam wall: Ed] and cattle grazing which maintains short vegetation along the shore of Lake Tinaroo
2 Mortality and injury
Persecution occurs elsewhere but is rare inside the IBA because Sarus Cranes are present post-harvest, and vulnerable crops are planted after they leave for the breeding grounds. Powerline strike is the main known cause of mortality, with some deaths and injury from barb wire fences. (For more, see Ozcranes Conservation Crane Hazards 2»). These threats are not listed in the IBA nomination or monitoring plans, but given the significant knowledge gaps in breeding and population ecology for Australian Sarus Cranes every avoidable mortality should be addressed. BirdLife Australia and other concerned organisations can definitely partner to mitigate this known threat with conservation actions.
3 Land use changes, Atherton Tablelands 1997-2017
This Table shows land use and management changes on feeding sites and roosts from 1997, which could impact numbers of cranes using the KBA during winter. But can these changes be subjected to conservation actions?
|Feeding||Expansion of sugar cane in lieu of other field crops|
|Feeding||Decline in maize and sorghum due to market downturns in purchaser industries (dairy and beef cattle)|
|Feeding||Improved machinery reducing harvest spillage and thus resources for cranes, even if acreage remains constant|
|Feeding||Conversion of field cropping land to horticulture1|
|Feeding||Conversion of field cropping land to tree crops, especially avocados2|
|Roost||Grazing removed from government lands on Lake Tinaroo shore. Overgrown roosts only occupied when falling water levels expose bare shoreline|
|Roost||Environmental tree planting excludes cranes from roosts|
|Roost||Dams fenced off to improve water quality (with remote water points for cattle) exclude cranes|
|Roost||Roosts deserted when shallow dams had water levels raised for fish farming|
1. A 42ha property previously rotated through peanuts, maize, potatoes and legumes, with frequent records of feeding Sarus on stubble or fallow, has been converted to substrate/ tunnel blueberry production by Australia's largest horticultural company Costa Group. Horticultural expansion is expected to continue on similar sites leased to 2025 and beyond
2. High quality avocados bear towards the end of Year 2 so give a fast yield from new plantings. Avocados are are expanding in the KBA with accelerating demand, and plantations have boundary windbreaks, excluding cranes even from field edges
4 Threats and actions – commentary
Threats and Actions for this KBA could be seen as somewhat conflicted, due to the benefits a particular agricultural regime seems to have created for Sarus. However (1) there is no evidence this resulted in a population increase, as compared with a range expansion; and (2) when conservation values are created by particular agricultural activities, it may not be possible or reasonable to expect farmers to collaborate to ‘balance their economic wellbeing with that of the birds in the IBA’ as suggested by Dutson et al. Further, and counterintuitively, conservation actions (e.g. tree-planting) aimed at other goals may impact Sarus Cranes in the KBA if they reduce the value (to cranes) of agricultural lands.
For feeding sites, farmers vary crops and acreages planted in response to market, technical and regulatory opportunities and constraints, and crane habitat on their lands is an accidental by-product of some farmer choices. Most of the KBA is situated on deep, well-drained basalt soils of high agricultural value. This value is recognised and protected in State, regional and local planning schemes (see references) and is crucial for the local economy and employment. Conservation concern has been expressed about expansion of sugarcane but given the even higher impact of tree crops or covered horticulture on available feeding sites, this seems a subjective reaction to sugar as a crop per se, rather than a response to impacts on cranes. Occasionally suggestions are made that if the maize industry declines, dispersal of wintering cranes away from the KBA could be averted by artificial feeding stations, as for Red-crowned Cranes in Japan. The focus of these proposals is tourism, rather than a real risk of population decline.
For roosts, one issue – lakeside suburb expansion – is now limited by restrictions in the new local Planning Scheme (Tablelands Regional Council 2015). Recreational use of Lake Tinaroo is subject to a Management Plan with speed zonings, approved after extended community consultation including disturbance issues to people and wildlife. Other changes are due to competing conservation actions or normal farming practice. Also, though cranes may be displaced temporarily or permanently from a particular roost, Lake Tinaroo has an extensive shoreline with other potential sites and cranes are quick to adopt new suitable habitat created by changes to farm storages.
References: (1) D. Malcolm, B. Nagel, I. Sinclair and I. Heiner (1999). Soils and agricultural land suitability of the Atherton Tablelands, North Queensland. Dept. of Natural Resources, Brisbane. (2) Tablelands Regional Council (2015). One Planning Scheme for the Tablelands. Accessed 1 October 2015.
5 Implications for monitoring
If normal agricultural change is the major factor potentially moving Sarus Cranes away, this implies the KBA is not monitored for its conservation values or potential actions, but as an approximate surrogate for the whole Australian Sarus Crane population. Distribution changes across the region over time can be detected by atlassing, together with surveys targetting the unknown (but presumed significant) Sarus population that winters closer to the breeding areas.
Gulf Plains KBA
Gulf Plains KBA, north-west Queensland (Birdata) →
This KBA contains the only known significant breeding area for Australian Sarus Cranes and supports over 1% of the global population of Brolgas and many species of migratory waders. Over 20 bird species in this area have populations that meet the various criteria to designate a KBA.
Much of the land is held under grazing leases from the Queensland government. Management considerations from the nomination submission prepared by Ian Fox:
Manage invasion of invasive alien weeds including Cryptostegia grandiflora (Rubber Vine) and Parkinsonia aculeata on floodplains and riparian areas, and Cenchrus ciliaris (Buffel Grass) and Ziziphus mauritianus (Chinee Apple) on dunes and abandoned levees. Monitor grazing of wetlands by cattle, feral horses and feral pigs.
IRRIGATION SCHEMES: Large scale impoundments for crop irrigation could reduce flow to Sarus breeding floodplains. The $2 billion IFED scheme has stalled but the Etheridge Shire is proposing further initiatives with potentially, funding from the National Water Infrastructure Fund.
Next: KBAs 2», six KBAs in Western Australia and Northern Territory important for Brolgas