There are three major families of shorebirds: 1  Waders, about 220 species, include sandpipers, lapwings, snipes, plovers, stilts and various other species. These birds inhabit coasts and shorelines, as well as other open habitats. 2  Gulls, terns, skuas, jaegers and skimmers form a group of a little over 100 species.
The compass was probably invented in the Qin Dynasty (221-206BC) by Chinese fortune-tellers who used the lodestones to construct their fortune telling boards.
Numerous developments were made during this period in culture and mathematics, examples include an important literary achievement, the Zuo Commentary on the Spring and Autumn Annals, which summarizes the preceding Spring and Autumn period and the bundle of 21 bamboo slips from the Tsinghua collection, which was invented during this period dated to 305 BC, are the worlds' earliest example of a two digit decimal multiplication table, indicating that sophisticated commercial arithmetic was ...