A large baleen whale, adult right whales can reach up to 60 feet in length and weigh up to 100 tons. Even calves weigh a ton, and right whales are thought to live for 70 years or more.
Hunting of right whales peaked in New Zealand and Australia in the 1830s and 1840s, the researchers noted in their report, and small remaining populations were further depleted by illegal harvest by the Soviet Union in the early 1960s. None were seen around mainland New Zealand for decades of the 20th century.
A small population of this species survived, however, near the Auckland and Campbell Islands south of New Zealand in sub-Antarctic waters. But right whales have a strong "maternal fidelity" in which migration and calving grounds are passed along from mother to calf. Mainland New Zealand had once been a favored breeding ground, but once the last individuals there were killed, they didn't come back.
"This maternal fidelity contributed to the vulnerability of these local populations, which were quickly hunted to extinction using only open boats and hand-held harpoons," said Emma Carroll, lead author on the study and a doctoral student working with Baker, who has an adjunct appointment at the University of Auckland.
The researchers wrote in their report that "fidelity to calving grounds can be viewed as a type of cultural memory, and it seems the memory of the suitable calving ground can be lost along with the whales that formerly inhabited such areas."
Just lately, however, a few right whales started finding their way back home. By 2005, there were estimates of fewer than a dozen reproductive females sited near the mainland, and there are still only a few dozen. But the new study showed that some of them definitely ar
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Oregon State University