In the early 1980s the Warty comb jelly or Sea walnut was introduced (probably from the ballast water of ships from North America) to the Black Sea, a habitat in which it had no natural predators. By the summer of 1989 it was proliferating in such numbers and consuming so much plankton in the Black Sea that the fisheries dependent on the plankton crashed.

The bird Ibis falcinellus is parasitized by at least seven species of mallophagous insects, each of which is specialized on a single feather type.

Since either haystack is better than starvation, and since neither haystack is known to be worse than the other, Buridan's ass has a good reason to choose either. Suppose it chooses haystack A, rejecting haystack B as well as starvation.

The Latin tong, euen whan it was, as the Grecians say, in ακμη, that is, at the hiest pitch of all perfitenesse.