TY - JOUR
T1 - The effect of depth on the diving behaviour of common eiders
AU - Guillemette, M
AU - Woakes, Anthony
AU - Henaux, V
AU - Grandbois, JM
AU - Butler, Patrick
PY - 2004/1/1
Y1 - 2004/1/1
N2 - Diving in endotherms is largely constrained by the depth of the foraging area, as they withstand long periods without breathing. Foraging theory predicts that all phases of a dive cycle, including travel, bottom, and surface durations, are positively correlated with depth. With continued increase in depth, bottom duration should level off and then decline. We tested these qualitative predictions with common eiders (Somateria mollissima (L., 1758)), a sea duck foraging routinely on the bottom. Using data loggers implanted in the body cavity of four females for I year, we showed that average diving depth over the summer and winter was distinct for each female. When averaged for each female, the data were qualitatively similar to theoretical predictions since travel, bottom, and surface durations all increased with depth. However, within individual females, the data only supported the theory partially because some relationships between depth and phases of a dive cycle were not significant. In particular, bottom duration failed to increase with depth for two individual females during the summer. In addition, significant relationships differed substantially among individual females and even within individual females when summer and winter seasons were compared. We suggest that the large variation observed in the diving behaviour of female ciders reflects individual female diving capability, which is probably related to their physiological states.
AB - Diving in endotherms is largely constrained by the depth of the foraging area, as they withstand long periods without breathing. Foraging theory predicts that all phases of a dive cycle, including travel, bottom, and surface durations, are positively correlated with depth. With continued increase in depth, bottom duration should level off and then decline. We tested these qualitative predictions with common eiders (Somateria mollissima (L., 1758)), a sea duck foraging routinely on the bottom. Using data loggers implanted in the body cavity of four females for I year, we showed that average diving depth over the summer and winter was distinct for each female. When averaged for each female, the data were qualitatively similar to theoretical predictions since travel, bottom, and surface durations all increased with depth. However, within individual females, the data only supported the theory partially because some relationships between depth and phases of a dive cycle were not significant. In particular, bottom duration failed to increase with depth for two individual females during the summer. In addition, significant relationships differed substantially among individual females and even within individual females when summer and winter seasons were compared. We suggest that the large variation observed in the diving behaviour of female ciders reflects individual female diving capability, which is probably related to their physiological states.
UR - http://www.scopus.com/inward/record.url?scp=16844379119&partnerID=8YFLogxK
U2 - 10.1139/z04-180
DO - 10.1139/z04-180
M3 - Article
SN - 0008-4301
VL - 82
SP - 1818
EP - 1826
JO - Canadian Journal of Zoology
JF - Canadian Journal of Zoology
ER -