Caring for the young is a global phenomenon, as is survival of the fittest. Social animals care for their young, usually within a family (or social) unit. What would stand out of the ordinary is when a family unit of one species cares for the young of other species. Mixed-species units are often observed during feeding migrations, notably of species that go after the same type of prey. But mixed-species family units are rarer.
|Photograph by Alexander Wilson and Aquatic Mammals|
Recently, researchers in the
Best, P.B., Canham, P.A.S., and MacLeod, N. (1984). Patterns of reproduction in sperm whales, Physeter macrocephalus. Rep. Int. Whaling Comm. 6(Special Issue), 51-79.
Whitehead, H. (2003). "Sperm whales: social evolution in the ocean." University of Chicago Press, Chicago.
Whitehead, H. (2009). Sperm whale, Physeter macrocephalus. In Perrin, W.F.; Wursig, B.; Thewissen, J.G.M. 2009. Encyclopedia of Marine Mammals, Second Edition. Academic Press: London. 1316pp.