DOI 10.1007/s00227-006-0593-9RESEARCH ARTICLE Diving behaviour of Little Penguins from four colonies across their whole distribution range: bathymetry aVecting diving eVort

• Main Authors: Xedging Success, André Chiaradia, Yan Ropert-coudert, Akiko Kato, Thomas Mattern, Julija Yorke
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Published: 2007
• Subjects: New Zealand; Penguin Island
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.508.4323; http://docyaounde.free.fr/stock/pdf/andre07marbiol.pdf

several small colonies in New Zealand and Australia. In this study, we compare the birds ’ diving perfor-mances at diVerent sites situated throughout their breeding range. Environmental conditions and breed-ing success vary drastically amongst colonies, but all birds feed on similar types of prey and face similar lim-itations on their foraging range. We examined several diving parameters and calculated the proportion of for-aging zone available during breeding to examine whether oceanographic and geographic factors in the foraging zone can explain variations in diving behav-iour and Xedging success among the diVerent colonies. In colonies with high Xedging success, Penguin Island and Oamaru, penguins made shallow dives <50 m depth and had lower diving eVort. More than 90 % of the foraging zone was in waters <50 m depth in these colonies. Motuara Island also has shallow waters with 95 % <50 m depth, but the Xedging success was low. Phillip Island has only 42 % of waters <50 m and com-paratively low Xedging success. Thus, penguins dived deeper and showed a higher diving eVort in colonies with lower Xedging success (Motuara Island and Phillip Island), indicating that they were disadvantaged com-pared to conspeciWcs from other colonies that dived shallower and with a lesser diving eVort. We concluded that bathymetry is an important factor, but not the only one, which inXuences Xedging success.