Presentation on theme: "July 20121 A report on the comparative study of migratory shorebirds in North West Australia from January 2006 to May 2012 Images: Adrian Boyle, Ian Southey."— Presentation transcript:
July A report on the comparative study of migratory shorebirds in North West Australia from January 2006 to May 2012 Images: Adrian Boyle, Ian Southey
July The journey so far… In 2006, Global Flyway Network (GFN) commenced the comparative study of Bar-tailed Godwit, Great and Red Knot at Roebuck Bay in North West Australia (NWA) In 2010 Black-tailed Godwit were added to the study species for comparisons with European populations In 2011 Red Knots were also marked on 80 Mile Beach which is 165km south west of Roebuck Bay The NWA project is part of a comparative global study to asses annual survival, demography and ecology of a range of migratory shorebird species 2,636 individual birds have been colour marked to date in NWA Since January 2006 there have been 29,592 re-sightings in Roebuck Bay, 80 Mile Beach and throughout the East Asian-Australasian Flyway (EAAF) Each year between April and early June a small team from GFN-Australia has been based in north west (NW) Bohai Bay, China to undertake re-sightings of Red Knots from NWA and New Zealand GFN has collaborated on 3 satellite tracking projects in NWA in conjunction with the United States Geological Survey (USGS) and Massey University, New Zealand In 2008, 15 Bar-tailed Godwits were fitted with satellite transmitters for comparative studies with Bar-tailed Godwits from New Zealand In 2010 and 2011, 30 and 15 Red Knot were fitted with satellite transmitters to attempt to study the migration routes and strategy of a species facing a rapidly changing environment at staging sites in China In 2012, in a joint study with the Australasian Wader Studies Group (AWSG), 49 Geolocators (small light-sensing devices to record birds anywhere on the globe) were attached to 42 Red Knot and 7 Great Knot to attempt to ascertain their migration strategies. However, different from satellite tracking, these birds will need to be re-captured to download the information from the geolocators Over the last 6 years, hundreds of volunteers from the around the world have had the opportunity to be involved with this project and participate in very modern ornithological research
July This project is coordinated by Chris Hassell who is based in Roebuck Bay, Broome, North West Australia. Chris spends his time catching and individually colour marking the study species, conducting regular re-sightings in Roebuck Bay, 80 Mile Beach and Bohai Bay, China, coordinating volunteers and trying to avoid data input and s (unsuccessfully!) Key sponsors, participants and collaborators – this project is making great progress with the support and collaboration of many! Scientific Leader Theunis Piersma Main sponsor: Vogelbescherming-Netherlands Collaborators: Australasian Wader Studies Group (AWSG) Beijing Normal University, China Massey University, New Zealand United States Geological Survey (USGS), Alaska, USA WWF-China WWF-Netherlands Volunteers: Broome Bird Observatory Broome Community
July Study location in North West Australia - all study species are individually colour marked in Roebuck Bay while Red Knots are marked at both Roebuck Bay and 80 Mile Beach Roebuck Bay is adjacent to the township of Broome. The main catching sites are 4 to 13km east of Broome 80 Mile Beach main catching sites at are 165 to 185km south west of Broome Roebuck Bay 80 Mile Beach
July Capture and individual colour marking so far… Commentary… The capture, individual colour marking and resighting of the study species is a major component of the GFN field work A total of 80 successful catches have been made resulting in 2,636 individually marked birds of the four study species. This is an average of 488 birds individually colour marked per year
July Individually colour marked birds by species so far… Commentary… Great Knot are the most numerous species in Roebuck Bay, consequently we have been very successful catching this species over the study period with 938 individually colour marked birds Since 2010, a greater focus has been placed on individually colour marking Red Knot due to counts conducted by Beijing Normal University and GFN showing that up to 80% of the Red Knots from Australia pass through NW Bohai Bay during April and May each year. This has heightened the high conservation concern around the loss of habitat in NW Bohai Bay, China. The focus on Red Knot is proving to be very positive with remarkable success in re-sightings at NW Bohai Bay Whilst there are high numbers of Bar-tailed Godwit in Roebuck Bay, the lower number of individually colour marked birds of this species reflects the difficulty of catching them, as they generally remain on the seaward side of roosting flocks. In 2010, Black-tailed Godwit was added to the study species. Please note that numbers can fluctuate in Roebuck Bay due to seasonal rainfall, but a very positive start has been made with the numbers so far individually colour marked.
July Re-sightings of individually colour marked birds… Commentary… 2,668 re-sighting sessions has produced 25,952 data points for future detailed analysis This graph illustrates the percentage split of the individually colour marked birds that have been seen or unseen. Interestingly, the number of unseen birds is on average around 10% across all the study species Currently, 13% of the individually colour marked Black-tailed Godwit have not been seen, but since they have only been marked since 2010 we expect the percentage for this species to come down The percentage of seen birds reflects sightings from throughout the EAAF. The breakdown is illustrated in the next slide
July Re-sightings of individually colour marked birds (contd)… Commentary… Re-sightings of Red Knot illustrate they are the most mobile of the study species. The high percentage of overseas sightings (38%) is mainly from NW Bohai Bay where GFN conduct annual northward migration studies. This high percentage also includes records of immature birds individually colour marked in NWA during the first year of their life. They subsequently move to New Zealand and make it ‘home’ as adult birds. Bar and Black-tailed Godwit resightings are high in Roebuck Bay, illustrating they are the most ‘site-faithful’ of the four study species. Overseas sightings of Bar-tailed Godwits are low due to their migration strategy does not concentrate them at the well-watched sites in the Yellow Sea. They are particularly scarce at the Bohai Bay study site. There are no overseas resighting records to date of Black-tailed Godwits. As a result of individual colour banding, we have identified that Great Knot are more mobile in NWA than we realised and move south to 80 Mile Beach (and in some cases back again) as much as Red Knot. It is often the immature birds of all study species that move away from the site at which they were individually colour marked.
July The conservation challenge at Bohai Bay, China Commentary… Remarkable numbers of Red Knot still use the rapidly diminishing inter-tidal mudflats of NW Bohai Bay on northward migration, 66,500 on 13 May 2011 The rapid pace of industrialisation and consequent habitat loss is alarming. Between 1994 and 2009, approximately 453 km 2 of sea area, including 156 km 2 of intertidal mudflats have been destroyed, a 36% loss of the total area of 428 km 2 of mudflats This habitat loss shows no sign of abating and a ‘tipping point’ for the Red Knot that use the area and therefore the viable populations of the two subspecies (piersmai and rogersi) in the EAAF are at stake Currently our data of the Red Knot abdominal profiles (a visual score of fat stores for migration - see graph) show that the Red Knot are still able to put on enough fat stores in the required time to propel them on their flights to their northern Siberian breeding grounds. However, without some formal protection (e.g. nature reserve status) for some portion of the intertidal mudflats of the NW of Bohai Bay this will cease to be the case in the next few years Images: Adrian Boyle and Matt Slaymaker
July Satellite tracking Bar-tailed Godwit – in 2008 GFN conducted a successful project in collaboration with the United States Geological Survey (USGS) and Massey University, New Zealand Commentary… Cutting edge technology used to track migration of Bar-tailed Godwits from Roebuck Bay to Yakuita, Siberia and back Unexpected results for the southward migration strategy of the menzbeiri subspecies Accurate assessment of flight speeds over long migrations Subspecies baueri shown to make the longest single flight ever recorded in the avian world International renowned scientists working alongside volunteers from the Broome community Undertaking surgery to be fitted with satellite tracker and alpha numeric flag A9’s migration route A9 sighting in Roebuck Bay 2 days after satellite tracker fitted Graphics: Lee Tibbitts, USGS Images: Jan van de Kam
July Satellite Tracking Publications – “Contrasting extreme long-distance migration patterns in Bar-tailed godwits” was recently published in the Journal of Avian Biology 43: , 2012 on Limosa lapponica by Battley et al Commentary… A paper in a high-end journal from the satellite tracking studies in both New Zealand and North West Australia was recently published illustrating migration routes, migration distances, breeding locations, response on the breeding grounds to extreme weather etc Key findings on the average southward migration baueri 11,690 km direct (n=1) 8.1 days 11,820 ± 450 km estimated (max 9.4 days flying!) menzbeiri (Roebuck Bay birds) 4,070 ± 220 km to Asia (range 3,580-4,280, n=8) 3.0 ± 0.6 days 6,100 ± 380 km to NWA (range 5,700-6,660, n=4) 4.6 ± 0.7 days Graphics: Lee Tibbitts, USGS
July Satellite tracking Red Knot – in 2010 and 2011 in collaboration with the United States Geological Survey (USGS) Commentary… Red Knots were fitted with solar powered satellite trackers with moderate success Technology is still under development to be more effective on smaller species like the Red Knot Limited but valuable data collected, as we were able to successfully track birds into Asia and up to Bohai Bay, China in the northern Yellow Sea Potential discovery of sites in south east Asia previously unknown where birds may stop during ‘emergencies’ extreme weather or poor health Good data generated on how Red Knot utilise Roebuck Bay for foraging and roosting during preparing for migration Solar powered satellite tracker attached to Red Knot Migration route into the Yellow Sea Graphics: Lee Tibbitts, USGS Image: Adrian Boyle
July Special individual re-sightings without expensive technology! – whilst satellite tracking has been able to demonstrate that birds travel at considerable speeds for days at a time on their migratory flights, sometimes our ‘humble’ colour bands can produce valuable information The story… An individually marked Great Knot was seen at a roost in Roebuck Bay one evening in March 2012 and then spotted by Jimmy Choi at Yalu Jiang in northern China 6400km away 137 hours later. It is fair to speculate that the bird migrated within a few hours of its Roebuck Bay sighting, probably flew at approximately 55km/hr for 116 of those hours. That would leave only 21 hours unaccounted for. Image: Provided by international observer
July Education and volunteers - essential for the success of our research! Commentary… GFN in NWA introduces hundreds of people to ornithological research. Everyone who visits the Broome Bird Observatory on the shores of the world- famous Roebuck Bay has the opportunity to join Chris and the GFN team in ‘hands on’ research. Training is given in handling birds. Many visitors to the region describe it as the ‘ the best thing we have done on our trip!’ The age range is from 4 to 84, the GFN- Australia team excel in volunteer participation and education. Images: Chris Hassell and Kandy Curran
July The near-future… Commentary… GFN will continue to mark the 4 study species in Roebuck Bay and Red Knots at 80 Mile Beach. GFN will continue to resight the 4 study species at Roebuck Bay, 80 Mile Beach and Bohai Bay, China. GFN will continue conservation efforts at Bohai Bay in conjunction with NGO’s. Chris Hassell will continue to collate all sightings from other parts of Australia, New Zealand and Asia and communicate that information to observers and all necessary parties. In early 2013, a postdoctoral researcher will commence an analysis of the GFN data, focusing on annual survival as input into the urgent conservation process in the Yellow Sea. A Masters student is currently analysing the GFN data looking at the local movement of Red Knots at wintering and stopover sites in the East Asian-Australasian Flyway. Both projects are under the direct supervision of Theunis Piersma Images: Adrian Boyle, Jan Van de Kam Chung Yu Chiang and Don Hadden