There is a world somewhere between reality and fiction. Although ignored by many, it is very real and so are those living in it. This forum is about the natural world. Here, wild animals will be heard and respected. The forum offers a glimpse into an unknown world as well as a room with a view on the present and the future. Anyone able to speak on behalf of those living in the emerald forest and the deep blue sea is invited to join.
Some researchers prefer to use round numbers and round conversions. In that case, the lion could weigh between 495 - 505 lb, but as the scale is moving in some occasions, they just put the number that they think is the correct.
Contrary to this document, modern scales are digitals and show the number of the mass recorded, so they is no need of estimations with the eye. Besides, the weight of the chain and other implements most be subtracted. For example, the famous Amur tiger "Professor" scaled 210 kg in the raw number, but after subtract the implements used they net weight of the animal was of 204 kg.
Plus, conversions are also problematic. Some ones use round numbers (i.e. 570 lb - 260 kg) while others use the most aproximated real value (i.e. 570 lb - 258.5 kg). Modern scales give kilograms, and this is the correct way. Pounds are from the past century.