Cox's sandpiper

Cox's sandpiper is a hybrid between a male pectoral sandpiper (Calidris melanotos) and a female curlew sandpiper (Calidris ferruginea). First discovered in Australia in the 1950s, it was originally described as a species new to science and named after Australian ornithologist John B. Cox. However, it was later found to be a hybrid. Most if not all birds found to date are males, in accord with Haldane's rule.