Comparative foraging behaviour of sympatric Humboldt and Magellanic Penguins reveals species-specific and sex-specific strategies
Andrea Raya Rey A H , Klemens Pütz B , Alejandro Simeone C , Luciano Hiriart-Bertrand C F , Ronnie Reyes-Arriagada D G , Victoria Riquelme D and Benno Lüthi E
+ Author Affiliations
- Author Affiliations
A Consejo Nacional de Investigaciones Científicas y Técnicas, CADIC, Bernardo Houssay 200, Ushuaia, Tierra del Fuego, Argentina.
B Antarctic Research Trust, Am Oste-Hamme-Kanal 10, D-27432 Bremervörde, Germany.
C Universidad Andrés Bello, Departamento de Ecología y Biodiversidad, Republica 470, Santiago, Chile.
D Instituto de Zoología, Facultad de Ciencias, Universidad Austral de Chile, Casilla 567, Valdivia, Chile.
E Antarctic Research Trust (Switzerland), c/o Zoo Zürich, Zürichbergstr. 221, CH-8044 Zürich, Switzerland.
F Present address: Center for Marine Biodiversity and Conservation, Scripps Institution of Oceanography, University of California San Diego, 9500 Gilman Drive 0202, San Diego, CA 92093-0202, USA.
G Present address: Centro Universitario Puerto Williams y Parque Etnobotánico Omora, Universidad de Magallanes, Teniente Muñoz 396, Puerto Williams, Chile.
H Corresponding author. Email: arayarey@cadic-conicet.gob.ar
Emu 113(2) 145-153 https://doi.org/10.1071/MU12040
Submitted: 15 May 2012 Accepted: 14 February 2013 Published: 27 May 2013
Abstract
How closely related marine organisms mitigate competition for resources while foraging at sea is not well understood, particularly the relative importance of interspecific and intraspecific mitigation strategies. Using location and time–depth data, we investigated species-specific and sex-specific foraging areas and diving behaviour of the closely related Humboldt (Spheniscus humboldti) and Magellanic (S. magellanicus) Penguins breeding in sympatry at Islotes Puñihuil in southern Chile during the chick-rearing period. The average duration of foraging trips was <20 h and did not differ significantly between species or between sexes of each species. Magellanic Penguins made significantly deeper and longer dives than Humboldt Penguins. Males of both species made significantly longer dives than females. Total distance travelled per foraging trip was significantly greater for males than for females, and females made more direct trips (less sinuous) than males. Foraging effort was concentrated in waters up to 15 km to the west and south-west of the colony. The overlap in density contours was lower between species than between sexes within a species. In general, dive characteristics and foraging areas differed more between Magellanic and Humboldt Penguins than between the sexes of each species. In contrast to the findings of studies of flying seabirds, the foraging behaviour of these penguins differs more between species than between sexes.
Additional keywords: Chile, diving, segregation, spatial ecology, Spheniscidae.
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