No. 113: Sep-Oct 1997
When farmers and ranchers wish to keep livestock from exiting a fenced pasture via an entrance road, they can either install an inconvenient gate or a "cattle guard." The latter is a grid of metal bars bridging a shallow pit. Cattle cannot cross because their feet would slip between the bars. Neat idea! But some sheep, normally considered rather dull animals with miniscule initiative, have invented a scheme to thwart cattle guards. When they see greener pastures, in particular succulent gardens on the nether side of a cattle guard, one sheep volunteers (?) or is picked (we don't know which). It altruistically flings itself across the grid and stoically endures while the rest of the flock trots across its body. The selfless sheep is usually marooned on the wrong side of the grid, but at least it has the pasture all to itself.
(Anonymous; "Selfless Sacrifice Puts Sheep in Clover," London Times, March 20, 1997. Cr. A.C.A. Silk.)
Comment. Yes, contrary to some animal behaviorists, animals can be altruistic. Furthermore, sheep can size up a problem, conceive a solution, and act collectively.
Reference. The question of altruism in mammals is discussed in Section BMB4 in our Catalog Mammals I. To order, visit here.