In a production facility, labor and material costs are usually variable costs that increase as the volume of production increases. It takes more labor and material to produce more output, so the cost of labor and material varies in direct proportion to the volume of output.
The harpy eagle's name comes from. the harpies of Greek mythology which were ferocious winged creatures with sharp claws, a woman's face and a vulture's body. The average weight of a harpy eagle is 18.4 lbs (8.2 kg). Female harpy eagles are larger than the males. A female can weigh from 14 to 18 lbs (7-9 kg), while the males weigh 10 to 16 lbs (5-8 kg). Their body length is between 36 and 40 inches (1 meter). Their feathers are slate-black above and white to light gray underneath.
The harpy eagle was first described by Linnaeus in his Systema Naturae in 1758 as Vultur harpyja, after the mythological beast harpy. The harpy eagle is the national bird of Panama and is depicted on the coat of arms of Panama. 2  The harpy eagle was the inspiration behind the design of Fawkes the Phoenix in the Harry Potter film series.