El Indiferente - Villa de La Orotava

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Los peLícanos
bLancos
como depredadores aviares
MARTA de PONTE MAChAdO
Great White Pelicans as avian predators: population increase and implications
for seabird conservation. The exponential growth of the Western Cape Great
White Pelican Pelecanus onocrotalus population during the 20th century was
fueled by the availability of agricultural offal. This superabundance of food and
increased population instigated changes in the behaviour of the pelicans on the
islands off the coast of the Western Cape. Pelicans adapted cooperative hunting
techniques used to capture aquatic prey to the land, shifting from a mostly
piscivorous diet to become voracious predators of seabird chicks. The spread
of these novel foraging techniques in the Western Cape suggested cultural
transmission of behaviour and caused serious concern for the conservation
of declining populations of local breeding seabirds. The Western Cape pelican
El Indiferente | 21 MARZO 2011 MARZO 2011 21 | El Indiferente
population was found to be genetically less variable than other southern African
breeding colonies. However, pelicans from the Western Cape dispersed and
some individuals entered into contact with pelicans further north, indicating that
cooperative seabird-eating behaviour could be exported to other populations.
With the aim of curbing the impact of pelican predation on seabird populations,
a management intervention, consisting on chasing pelicans from selected seabird
colonies, was implemented on two islands of the West Coast National Park and
proved successful to reduce predation and to protect vulnerable colonies of
seabirds.
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