Sperm whales adopt dolphin with deformed spine

http://animaltracks.today.com/_news/2013/01/23/16649491-wild-sperm-whales-adopt-dolphin-with-deformed-spine?lite

Jan. 23, 2013
By Laura T. Coffey, TODAY

If the ocean were a cocktail party, your average bottlenose dolphin would be hamming it up near the bar, fetching drinks for other marine mammals and regaling them with funny stories. Your average sperm whale would hover quietly near the pretzel bowl, keeping a low profile and avoiding eye contact with that obnoxious dolphin.

The usual aloofness between the two animals explains why researchers were astonished to stumble upon a most unusual sighting near the Azores in the North Atlantic Ocean: a pod of sperm whales that appeared to have accepted a lone bottlenose dolphin calf into their group.

Over a period of eight days in 2011, researchers saw the dolphin and the sperm whales traveling together, nuzzling and generally having a grand time. The dolphin calf had a rare spinal curvature — a deformity that may have made the animal unable to keep up with its own kind, ScienceNOW reported.

-----

Even if the teaming up was only temporary, it still would be unusual given the relationship that typically exists between sperm whales and bottlenose dolphins. Ecologist Mónica Almeida e Silva told ScienceNOW that the dolphins often chase and harass sperm whales and their calves.

"Why would sperm whales accept this animal in their group?" she said. "It's really puzzling to me."

-----