We determined the thermoneutral zone of six young northern fur seals by measuring their metabolism in ambient air and controlled water temperatures (0°C–12°C) from ages 8 to 24 mo. We found that the ambient air temperatures within
our study (overall 1.5°C–23.9°C) did not affect resting metabolic rates. Calculated lower critical temperatures in water varied between 3.9°C and 8.0°C, while an upper Selisistat supplier critical temperature in water was only discernible during a single set of trials. These thermal responses provide insight into the possible physiological constraints on foraging ecology in young northern fur seals, as well as the potential energetic consequences of ocean climate change and altered prey distributions. “
“The route taken by northward migrating gray whales during spring between Vancouver Island and southeastern Alaska, a distance of about 575 km, has long been uncertain. It is generally PF-01367338 molecular weight believed that the whales closely follow the western, outer coastline of Haida Gwaii (formerly the Queen Charlotte Islands), an archipelago lying between Vancouver Island and southeastern Alaska, consistent with their pattern of migrating close to shore over the majority of their northward migratory
corridor. By tracking satellite-tagged individuals and surveying whales from shore bases, we provide evidence that this is not the primary migratory corridor, but instead that most whales migrate through Hecate Strait and Dixon Entrance,
broad waterways that lie to the east and north Resminostat of Haida Gwaii. By using this route, northbound gray whales potentially face a wider range of industrial activities and developments than they would by migrating along the outer coast. “
“Previous studies of the odontocete forelimb have not considered flipper anatomy in an evolutionary context. This study of 39 cetacean species (1 extinct archaeocete, 31 extant and 3 extinct odontocetes, and 4 mysticetes), provides a detailed comparative analysis of the major bones and muscles of the odontocete flipper. Differences across families in the anatomy of the deltoid, supraspinatus, coracobrachialis, and subscapularis muscles correspond directly to size and shape of forelimb elements. Specialization of the different shoulder girdle muscles allows for more maneuverability of the flipper by independent control of muscular columns. Maximum likelihood analyses helped determine the correlation of characters studied by ancestral state reconstruction, and revealed independent evolution of osteological and external characters among various lineages. Comparative Analyses by Independent Contrast (CAIC), found several contrasts between flipper area and body length for several extant odontocetes and a linear relationship was inferred.