Eremopezus more than a large emu—and more than 10 kg—slightly more than the largest living storks (which reach over 150 cm in height) and the shoebill. The general limit for weight in flying birds is at about 25 kg, the exceptional "Argentavis magnificens" with its size and weight of a good-sized adult human notwithstanding as it evolved under unusual ecological conditions. Large males of the kori bustard ("Ardeotis kori") and great bustard ("Otis tarda") are perfectly capable of flight, while weighing in excess of 20 kg. A wing loading of c. 25 kg/m is the known limit for bird flight under
Xylota tarda Xylota tarda Xylota tarda is a Palearctic species of hoverfly. External images For terms see Morphology of Diptera<br> Wing length 5·5-8·5 mm. Large red areas on black abdomen. Wing membrane not infuscated. Dorso-apical white bristle on metatarsus 1. Antero-dorsal pale hairs on the basal half of femur 3 uniform not longer than 1/4 the depth of femur. The male genitalia are figured by Hippa (1968). The larva is illustrated in colour by Rotheray (1994) ). See references for determination (but see Speight for contradiction) Palearctic Fennoscandia South to Spain. Northern Italy (Apennines) Slovenia. Ireland East through Central Europe into European