male of the stag beetle, lucanus cervus, sitting on oak tree. a rare and endangered beetle

invertebrate arthropod dragonfly wildlife honeybee animal insect nature flower beetle green pest leaf fly bee animal antler background beetle beetles big bug cervus close closeup czech czechia detail endangered entomology environment europe european fauna giant green horned horns insect insecta invertebrate large lucanus macro male mandibles natural nature oak protected rare republic stag stag stag-beetle summer tree wild wildlife wood