PERSONAL DE APOYO
SAENZ SAMANIEGO Ricardo Andres
artículos
Título:
Species-specific population trends detected for penguins, gulls and cormorants over 20 years in sub-Antarctic Fuegian Archipelago
Autor/es:
ANDREA RAYA REY; NATALIA ROSCIANO; MARCELA LILJESTHRÖM; RICARDO SÁENZ SAMANIEGO; ADRIAN SCHIAVINI
Revista:
POLAR BIOLOGY
Editorial:
SPRINGER
Referencias:
Lugar: Berlin; Año: 2014 p. 1343 - 1360
ISSN:
0722-4060
Resumen:
Understanding the dynamics and causes of
population trends are essential for seabird conservation.
Long-term studies of seabirds at high-latitude (Antarctic,
sub-Antarctic and Arctic) regions have shown contrasting
species-specific trends in population size in response to
climate change and anthropogenic pressures. We have
studied for the last 20 years (1992?2012) the population
trends of seven seabird species that breed in the Beagle
Channel, south-eastern Tierra del Fuego and at Staten
Island, a sub-Antarctic region in southern Argentina. The
numbers of Magellanic and Gentoo Penguins increased
significantly since 1992 (by[15 % year-1). In comparison,
the populations of Imperial Cormorants, Dolphin Gulls and
Kelp Gulls increased at slower rates (\5 % year-1), while
the Rock Cormorant population even decreased by 1.3 %
year-1. At Staten Island, the numbers of Rockhopper
Penguins decreased by 24 % between the censuses of 1998
and 2010, whereas the population of Magellanic Penguins
increased by 227 % during the same period. Over the study
period, air and sea-surface temperatures remained stable in
our study area, suggesting that the detected population
changes are not driven by the climate. This finding contrasts
with the detected links between increasing temperature
trends and seabird population changes reported from
Antarctic and Arctic regions. The level of tourism and size
of the permanent human population has increased in the
Beagle Channel area during the last 20 years and could be
responsible for the increase of gull populations. The seabird
species that received the highest number of visitors
(Imperial Cormorants and penguin species) seem to be
adapted or at least indifferent to pressures exerted by
tourism, as their populations increased during the study
period. In addition, increasing numbers of seabirds in the
area may generally be leading to higher abundances of
scavenging species (e.g. gulls).