Male and female Antarctic fur seal (Arctocephalus gazella), showing extreme sexual dimorphism, King Edward Point, South Georgia, Polar Regions

A pair of Mandarin ducks at Martin Mere bird reserve near Ormskirk, Lancashire, England, United Kingdom, Europe

Siskins (Carduelis spinus) feeding on a garden feeder in Ambleside, Cumbria, England, United Kingdom, Europe

A male Mandarin ducks at Martin Mere bird reserve near Ormskirk, Lancashire, England, United Kingdom, Europe

Fallow deers, Dama dama, Germany, Bavaria

European rhinoceros beetle male rhinoceros beetle on bark Animals Nature