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.
The earliest compasses were made of lodestones. This mineral is made of iron oxide which orients itself to a north and south axis.In 1117 Zhu Yu's book Pingzhou Table Talks came out.It was the first time in the history of the compass that the device was mentioned as a tool for navigation.Later in the 8th Century A.D, magnetic needles replaced the loadstones. From the 8th century to 1050's, compass were actively used in ships. The compass was first invented in the Han dynasty, but further improvements were made in the Song dynasty.