Spotting and photographing the Steller’s Sea Eagle (Haliaeetus pelagicus) is always one of the highlights of my annual Hokkaido Nature Birding Photo workshop. The Steller’s Sea Eagle is one of the most magnificent and fierce diurnal birds on Earth, which is why they are such formidable hunters, tracking prey since the age of the dinosaurs. Their plumage is blackish brown-black all over except on the shoulders, rump, tail, thighs, and forehead, which are white. Their HUGE, wickedly hooked bill is a vibrant yellowish-orange and razor sharp. This bill and their natural raw power are some of the main reasons that the Steller’s Sea Eagle has never needed to evolve through three ice ages. These eagles in mass, are the biggest eagle on our planet, weighing up to and over 10 kg (22 pounds). They are also tall, measuring up to 94 cm (3 ft), sometimes even taller, with a huge wingspan of up to 250 cm (8 - 9 ft). While photographing them from the deck of a boat, they usually circle above Hokkaido’s pack ice at heights of 6 - 15 m (20 - 50 ft) above the water, but they only circle until they spot prey, or a hand out from fishermen, then they dive bomb and snatch it from the icy waters.
While leading my annual Hokkaido nature birding workshops participants and I always spot and photograph mobs of Steller’s Sea Eagles and White-tailed on the pack ice, either feeding, relaxing and sometimes participants and I see them simply pluck fish from the water with their razor sharp talons. With these two species of raptors close cousins, there is always a thin truth between the local wildlife, the White-tailed Eagle (Haliaeetus albicilla), and the seasonal migrating Steller's Sea Eagle! But as soon as a raptor has caught a fish the truths is off, and conflicts often turn vicious especially when fresh fish is the topic. But the white-tailed eagle the fourth largest raptor on our planet is known to hold their own agains the Steller’s sea eagle. Haliaeetus albicilla eagles measure from 65-95cm in length with a wingspan of 170cm to 260cm or about 5ft 5 to 8ft 5 inches. It is said this raptor has the largest wingspan of any living eagle. The male and female are similar in coloring and appearance, the accurate way to tell them apart is by tarsus width and depth and bill depth, but this is next to impossible unless they are captive or captured then released with tracking devices on their legs. I usually tell them apart by their size in which females are generally about 30% heavier and about 15% greater in linear dimensions.
The migrating Steller's Sea Eagle is acclimated to sub-arctic temperatures in winter, and climate change will eventually have an impact on their access to rich fishing grounds. Melting ice and warmer waters mean a change in eating habits, and habitat. In the next 50 to 100 years, the Steller’s Sea Eagle may not migrate to Japan due to warming temperatures with little, or no pack-ice around Hokkaido?