Aerial photography of Ross Sea region Adélie colonies
Cape Royds from 2 500' agl. Image - Kerry Barton
The aim is to census Adélie (Pygoscelis adeliae) populations to provide basic data against which future population levels can be compared in order to monitor environmental change of the Antarctic Ocean ecosystem, both natural and man-induced.
Background
The Adélie penguin is one of the dependent species studied by the Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR) members and used as a monitoring tool to detect any anthropogenic effects on the marine ecosystem. One of the key goals of CCAMLR is to ensure that commercial fishing does not irreversibly harm ecosystem relationships. One mechanism to avoid this is to use monitoring of top-trophic predators (Adélie penguins) to gauge ecosystem health.
Aerial reconnaissance and photography are used in the Ross Sea sector of Antarctica to determine the breeding locations of Adélie penguins and to count the numbers of nests occupied during the early incubation period. From 1981 to present, all islands and sea coasts between 158°E and 175°E have been searched, and 11 previously unreported breeding colonies discovered.
Searchable database
Data is available on the number of breeding pairs of Adélie penguins at colonies in the Ross Sea region 1981-2000.
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Technique
Preparing to photograph Adelie colony. Image - Phil Lyver
Adélie colonies are photographed from the air, the images processed and the number of birds nesting at each colony counted from the images. Colonies on Ross Island are photographed from helicopter flying at >2500' agl to prevent disturbing the birds. The colonies along the Victoria Land coastline are photographed through the open paratroop doors of a C-130 Hercules (flying at approximately 2000' agl).
The protocols used for the aerial photography and counting have been adopted by CCAMLR as a standard method (CCAMLR Standard Method A3B).
Due to logistic constraints it is not possible to photograph all colonies in the Ross Sea region each year. Ross Island colonies are photographed each year and indicator colonies along the Victoria Land coast, selected because of their size, topography and locality, are photographed every 2–3 years to maintain a continuous database.
Timing
The aerial census is carried out in late November or early December to coincide with the incubation phase of breeding. At this stage in the cycle, one bird is incubating while its mate is at sea feeding. As there are few non-incubating birds ashore, an accurate count of breeding birds can be obtained.
For more information:
Taylor RH, Wilson PR, Thomas BW 1990. Status and trends of Adelie penguin populations in the Ross Sea region. Polar Record 26(159): 293–304.