Cuckoos and quality control. Cuckoos lay their eggs in the nests of other (host) birds. The eggs are then adopted and hatched by the host birds. But the potential host birds lay eggs of different sizes. Does the cuckoo change the size of her eggs for different foster species? The numbers in the table are lengths (in mm) of cuckoo eggs found in nests of three different species of other birds. The data are drawn from the work of O. M. Latter in 1902 and were used in a fundamental textbook on statistical quality control by L. H. C. Tippett (1902–1985), one of the pioneers in that field.

Cuckoo Egg Length (MM)
Foster Parent Species Sparrow Robin Wagtail 20.85 21.05 21.05 21.65 21.85 21.85 22.05 22.05 21.85 22.85 22.05 21.85 23.05 22.05 22.05 23.05 22.25 22.45 23.05 22.45 22.65 23.05 22.45 23.05 23.45 22.65 23.05 23.85 23.05 23.25 23.85 23.05 23.45 23.85 23.05 24.05 24.05 23.05 24.05 25.05 23.05 24.05 23.25 24.85 23.85 Use a Kruskal-Wallis test to decide whether cuckoos really do adjust the size of their eggs.