Selfies of Imperial cormorants (Phalacrocorax atriceps): What is happening underwater?

GÓMEZ-LAICH, A.; YODA, K.; ZAVALAGA, C.; QUINTANA, F.

Ciudad del Cabo

Conferencia; 2nd World Seabird Conference; 2015

During the last few years, the development of animal-borne still cameras and video recorders has enabled researchers to observe what a wild animal sees in the field. In the present study, we deployed miniaturized video recorders to investigate the underwater foraging behavior of Imperial cormorants (Phalacrocorax atriceps). Video footage was obtained from 16 animals and 56 dives comprising a total of 10.8 h of foraging data. Video information revealed that Imperial cormorants are almost exclusively benthic feeders. While foraging along the seafloor, animals did not necessarily keep their body horizontal but inclined it downward. The head of the instrumented animal was always visible in the videos and in the majority of the dives and it was moved constantly forward and backward by extending and contracting the neck while travelling on the seafloor. Animals detected prey at very short distances, performed quick capture attempts and spent the majority of their time on the seafloor searching for prey. Cormorants foraged at three different sea bottom habitats and the way in which they searched for food differed between habitats. Dives were frequently performed under low light conditions suggesting that cormorants would locate prey with other sensory systems in addition to sight. Our video data support the idea that Imperial cormorants? efficient hunting involves the use of specialized foraging techniques to compensate for their poor underwater vision.