Birds and marine mammals as sentinels of global change
Program 109 : ORNITHOECO
French Polar Institute Paul Emile Victor
Programme 109: ORNITHOECO French Polar Institute Paul Emile Victor
Birds and Marine Mammals Sentinels of Global Change in the Southern Ocean
The program uses marine birds and mammals as indicators of global changes affecting the Southern Ocean ecosystems. Through a network of 4 observatories from Antarctica to the subtropics, populations of 25 species of top predators have been monitored for 50 years. Long-term individual information, combined with annual studies, particularly on the feeding ecology of the species, is used to understand the processes by which climate affects marine ecosystems and to make predictions on the future effects of climate change. The programme also integrates the impact of fisheries in order to propose conservation measures.
Data for the conservation and protection of seabirds in the Southern Ocean
Example A
Variations in the population size of 7 species of marine predators in the Southern Ocean. Data from the observatory show contrasting trends over the whole period, with populations declining (4 species including the yellow-billed albatross in red) while one is stable (the black-browed albatross in goose pook-green) and 2 are increasing (like the Amsterdam albatross in dark green).
Nest Counting and Data Analysis
To count the nests of nesting birds, scientists take aerial images using a kite. On this picture it is a colony of gorfous macaroni in Kerguelen. By enlarging the picture it is possible to count the number of pairs of birds and to compare the breeding success of this species from one year to another.
Life story of a snow petrel
Example B
Banding makes it possible to follow the fate of individuals throughout their lives because seabirds are very loyal to their colony and nest. The example below shows the life history of a snow petrel in Terre Adélie wearing ring n°FL11617 between 1982 and 2013. The life histories of all banded individuals are coded as 0 (not seen that year) and 1 (seen that year), making it possible to calculate the proportion of individuals that survive from one year to the next in the population. For snow petrels, the annual survival rate varies around 95%, which corresponds to an average life expectancy of about 30 years. Tracking banded individuals also makes it possible to calculate the number of juveniles reared over the course of a lifetime. For example, individual FL11617 reared 17 chicks between 1982 and 2012.
Life Story Board
Table of a petrel’s life history detailing by breeding season whether the bird has bred (or not), with which partner, and whether it has raised a chick.
Encoding
Life history coding for demographic analyses in order to estimate certain parameters such as the survival rate
Results
This graph shows that the annual survival rate of adult snow petrels varies around 95%.
Impact of fisheries on mortality of large albatrosses
Example C
Long-term monitoring of large Crozet albatrosses using Argos beacons and miniaturized GPS allows to know their distribution at sea and the time spent by sectors (colored grids on the map below). Here the albatrosses spend more time in the meshes where the colour is dark. For this species and for many other seabirds, interactions with industrial fisheries are a source of accidental mortality and a threat. By crossing the distribution area of large Crozet’s albatrosses with that of industrial longline fisheries (area in red), we can estimate the impact of incidental mortality of albatrosses in this fishery on population dynamics.
