In Tanzania, we watched on many occasions when small flocks of red-billed birds descended upon the backs of giraffes, cape buffalo, elephants and hippopotamuses, prancing around like they owned them.

CORVALLIS, Ore. – The analysis of a termite entombed for 100 million years in an ancient piece of amber has revealed the oldest example of "mutualism" ever discovered between an animal and ...

We do this every day with domesticated species such as dogs or horses: They help us find something or carry us somewhere, and, in return, we provide them with food and shelter. In biological terms, ...