Albatross Island

Albatross Island

Shy Albatrosses in Australia: Population & Conservation Assessment. Report for the Wildlife and Marine 2007/08 field Conservation Section season Biodiversity Conservation Branch: DPIW Introduction ....................................................................................................................................... 3 1 Methods ............................................................................................................................................ 4 Albatross Island............................................................................................................................. 4 Fledgling winter trip .................................................................................................................... 4 Breeding effort trip...................................................................................................................... 4 Hatching success trip ................................................................................................................. 5 Chick Banding trip ...................................................................................................................... 5 Aerial flights................................................................................................................................ 6 Pedra Branca ................................................................................................................................ 6 Island Visits ................................................................................................................................ 6 Aerial photographs ..................................................................................................................... 6 Mewstone ...................................................................................................................................... 6 Island Visits ................................................................................................................................ 6 Aerial photographs ..................................................................................................................... 6 Results .............................................................................................................................................. 7 Geologger status ........................................................................................................................... 7 Albatross Island............................................................................................................................. 7 Breeding effort............................................................................................................................ 7 Breeding effort in breeding success plots ..................................................................................... 8 Hatching success ..................................................................................................................... 11 Chick success .......................................................................................................................... 12 Productivity and breeding success........................................................................................... 13 ABBBS Data............................................................................................................................. 14 Albino chicks ............................................................................................................................ 15 Pedra Branca .............................................................................................................................. 17 Mewstone .................................................................................................................................... 18 Discussion....................................................................................................................................... 19 Factors influencing Chick success ........................................................................................... 20 Pedra Branca ........................................................................................................................... 21 Mewstone ................................................................................................................................. 21 Recommendations: .................................................................................................................. 21 References...................................................................................................................................... 23 2 Introduction The Shy Albatross, Thalassarche cauta, breeds exclusively on three small islands offshore Tasmania; Albatross Island in the northwest and Pedra Branca and the Mewstone to the south. The species is classified as Vulnerable under Commonwealth Legislation, with an annual breeding population most recently estimated around 12500 pairs. Interactions with fisheries, particularly long-lines, have been identified as a major threat facing albatross populations worldwide. In the 1980's and 1990's, significant numbers of Shy albatross were killed annually on tuna longlines operating in Tasmanian waters. The amount of longline effort around Tasmania has since been reduced, however this species is still at risk of being killed on longlines operating elsewhere. Juvenile birds are particularly vulnerable during the several years of absence after fledgling from their natal colony, during which time they may forage widely at sea. Band returns and satellite tracking have shown that some individuals traverse the high seas of the Indian Ocean to forage off the coast of South Africa. It is this capacity for flight that means albatross may be killed during interactions with fishing industries operating far from their natal territory. The potential for negative interactions with other fishing activities, particularly trawl fishing, is of growing concern. The Australian trawl fishery operates within the foraging range of breeding shy albatrosses from all three populations, as well as overlapping extensively with the foraging range of non breeding (i.e. post breeding and juvenile) birds. The closely related white capped albatross, T. steadi, is killed in high numbers by trawl fisheries within the New Zealand EEZ. A range of other anthropogenic influences potentially impact albatross populations, including competition for food with fisheries, augmentation of diet by fisheries discards, alteration of oceanic food webs due to human exploitation and global warming (summarised in Issues Paper). Given the ongoing concerns about actual and potential threats, the Biodiversity Conservation Branch maintains a long-term monitoring program of Shy albatrosses on Albatross Island, since the early 1980’s. This program is designed to provide an ongoing review of the population and conservation status through the assessment of key demographic parameters including breeding success, adult survival and juvenile recruitment. The Recovery Plan for Albatrosses and Giant petrel’s (DEH 2001) states that existing long term monitoring programs the measure demographic and breeding parameters of Shy albatrosses on Albatross Island, Pedra Branca and the Mewstone are maintained (Action D. 12.2). This program fulfils that requirement of the recovery plan. 3 Australia is signatory to the international Agreement for the Conservation of Albatrosses and Petrels (ACAP). It is a requirement of the Convention that member states support and facilitate monitoring and research into albatross population status and trends, and the information collected on Shy albatrosses by DPIW fulfils this requirement. Methods Albatross Island Fledgling winter trip 20/7/2007 Rachael Alderman and Drew Lee visited Albatross Island on 20th July 2007 to collect bands from chicks banded in March/April 2007 that had failed to fledge. Breeding effort trip 9/10/2007 – 17/10/2007 Personnel on this trip included Rachael Alderman, Drew Lee and Isabel Beasley from the Wildlife and Marine Conservation Section, assisted by Matt Larcombe from the Threatened Species Section (BCB). This trip was delayed by for two weeks by unfavourable weather. The aims of the September/October trip are to obtain band resights for estimates of survival and to record breeding effort from various subsamples of the population. Figure 1 shows the location of the various colonies and breeding success plots on Albatross Island. One major task of this trip is to locate individual study birds in the south and north colonies (>400 individuals), mark their nest Figure 1: Location of colonies and breeding success plots on location (using a combination of Albatross Island concrete nest markers and aerial maps), record nesting status and partner information. The resight information that is obtained underpins estimation of survival rates. 4 Another major aim of the September trip is to monitor trends in the breeding population (by recording the number of eggs laid). These estimates of breeding effort in turn allow the calculation of breeding parameters, i.e hatching, chick and overall breeding success. As the size of the Albatross Island population has increased over time, ground counts of eggs have been scaled back to reduce disturbance whilst maintaining research effort and accuracy. On ground estimates of breeding effort are typically conducted on population subsamples, including of the study nest

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