ADU travels, expeditions and events

Michelle du Toit & Dumile Tshingana
Marine & Coastal Management, Department of Environmental Affairs & Tourism
Pvt Bag X2, Roggebaai 8012, South Africa

Wandering Albatross caught using a bird-crook

The micro data logger is a miniaturized geolocation and activity-recording device developed for seabird research by the British Antarctic Survey.  The device weighs 13 g and can be re-used for subsequent deployments for the life of the battery (c. 36 months).  Light-intensity measurements allow the calculation of positional data of long-distance movements from day length (latitude) and times of sunrise and sunset (longitude).  The accuracy is affected by cloud cover, shading, proximity to the equinox and the distance covered.  The electrodes can be used as a salt-water detector, enabling the calculation of the percentage of time spent on the sea surface against time flying or time spent ashore (activity data).

Data logger deployment is not very stressfull for the bird or the handlers

These devices were deployed on 20 adult Grey-headed Albatrosses Thalassarche chrysostoma and 30 adult Wandering Albatrosses Diomedea exulans between 10 April and 30 June 2002 on sub-Antarctic Marion Island (46º 54'S, 37º 45'E), Prince Edward Islands, southern Indian Ocean.  The albatrosses fitted with data loggers are from study colonies where long-term research is being conducted.  The age and sex of the majority of the birds are known, as well as long-term data on breeding success (26 years' data in the case of the wandering Albatross); also, these birds are already marked with alpha-numeric plastic colour bands.  The loggers should be easy to recover, as the birds return biennially to breed at these study colonies that are regularly checked.

The logger, attached to a Darvic ring width a cable-tie is easy to apply

Three data loggers were placed for a period of one week, with a clear view to the horizon, close to each of the two albatross colonies, and the GPS co-ordinates recorded.  The data from these loggers were then downloaded before deployment, and will be used to calibrate the loggers' positional data.  The loggers were each attached to a black plastic leg band by means of a UV-resistant cable tie threaded through two pre-drilled holes in the band.  The band, logger and cable tie were glued together for extra hold.  The loggers were then deployed on the bird by simply applying the colour band in the normal way, though care had to be taken that the ring was warm when opened with the pliers, or it would break.

Micro data logger deployed on Wandering Albatross

Grey-headed Albatrosses were caught in the main study colony at Grey-headed Albatross Ridge as they came in to feed their chicks, which were soon to fledge.  On 10 and 21 April, any adult seen landing in the colony was caught using a bird-crook, taken out of the colony to minimize disturbance, and the data logger placed above the bird's metal band  The depth of the bill at the nail was measured to aid in sexing the bird: males have a bill depth of 29 mm or greater, and females 28 mm or less.  Data loggers were fitted onto 10 males, five females and five birds of unknown sex.

The latest in "Albatross accessories. I"

Both adults of thirteen pairs of Wandering Albatrosses, and a further three females and one male were fitted with data loggers - 16 females and 14 males in total.  These were all within the Macaroni Bay study colony, or between there and the Meteorological Station (Base).  The birds were caught with the bird-crook, and the data logger placed above the metal band, as with the Grey-headed Albatrosses.  The sex of the bird was determined using existing data and plumage colouration.

The Grey-headed Albatrosses departed from the colony soon after the loggers were fitted, as their chicks fledged early in May.  The movements of the adults will be tracked for their 'sabbatical year', and possibly compared with movements by the same birds during incubation and chick-rearing when they return for the next breeding season.  The Wandering Albatross chicks will fledge between November and February, so movements of the adults during chick-rearing and the 'sabbatical year' can thereafter be compared.  Movements can also be plotted against known positions of longline fishing vessels and weather systems, and comparisons drawn between males and females.  Activity

The latest in "Albatross accessories. II"

data may be used to calculate time feeding or resting on the sea surface.  One Wandering Albatross chick, of which both adults have been fitted with data loggers, died early in June.  It will be interesting to see whether the adults return to breed next season or take an extended 'sabbatical year', and how this affects their movements.

Albatrosses with data loggers fitted, have been sighted two months after the deployment of the device, and in each case the logger is still firmly attached to the leg-band and the bird seems oblivious to the tiny device.

Acknowledgements

We thank Samantha Petersen and John Cooper for their help in deploying the data loggers and the Australian, New Zealand and United Kingdom Governments for sponsoring two loggers from funds left over from their contributions to the running of the successful second and final negotiation meeting for the Agreement for the Conservation of Albatrosses and Petrels (ACAP) held in Cape Town, South Africa in January-February 2001.