Staffan Widstrand / RF- Walrus (Odobenus rosmaris) close up head portrait, Svalbard, Norway. (This image may be licensed either as rights managed or royalty free.)

Edwin Giesbers / RF- Jaguar (Panthera onca) head portrait, captive. (This image may be licensed either as rights managed or royalty free.)

Edwin Giesbers / RF- African Lion (Panthera leo) head portrait of male roaring, captive. (This image may be licensed either as rights managed or royalty free.)

Sergey Gorshkov / RF - Leopard (Panthera pardus) close up, Londolozi Private Game Reserve, Sabi Sands Game Reserve, South Africa. (This image may be licensed either as rights managed or royalty free.)

David Tipling / RF - Head portrait of female Southern elephant seal (Mirounga leonina). St Andrews Bay, South Georgia. January. (This image may be licensed either as rights managed or royalty free.)

David Tipling / RF - Southern elephant seal (Mirounga leonina) head portrait of female. Cave Cove, King Haakon Bay, South Georgia. January. (This image may be licensed either as rights managed or royalty free.)

David Tipling / RF - Head portrait of Brown hare (Lepus europaeus) near Holt, Norfolk, England, UK. March. (This image may be licensed either as rights managed or royalty free.)

David Tipling / RF - Brown hare (Lepus europaeus) portrait near Holt, Norfolk, England, UK. March. (This image may be licensed either as rights managed or royalty free.)

Edwin Giesbers / RF- North American river otter (Lutra canadensis) captive, occurs in North America.

Edwin Giesbers / RF- Sumatran tiger (Panthera tigris sumatrae) captive, occurs in Sumatra, Indonesia. (This image may be licensed either as rights managed or royalty free.)

Edwin Giesbers / RF- Head portrait of a European lynx (Lynx lynx), captive, Norway, February. (This image may be licensed either as rights managed or royalty free.)

Edwin Giesbers / RF- Portrait of a European lynx (Lynx lynx), captive, Norway, February. (This image may be licensed either as rights managed or royalty free.)

Edwin Giesbers / RF- Sumatran tiger (Panthera tigris sumatrae) close-up head portrait, captive. (This image may be licensed either as rights managed or royalty free.)

Edwin Giesbers / RF- Alpine marmot (Marmota marmota) close up Hohe Tauern National Park, Austria. July. (This image may be licensed either as rights managed or royalty free.)

Edwin Giesbers / RF- Red fox (Vulpes vulpes) head portrait, captive. (This image may be licensed either as rights managed or royalty free.)

Doug Perrine / RF- Young Steller's / Steller / Northern Sealions (Eumetopias jubatus) curiously approaching photographer. Glacier Island, Columbia Bay, Alaska, USA. July. (This image may be licensed either as rights...

Edwin Giesbers / RF- European Rabbit (Oryctolagus cuniculus) emerging from burrow in warren. The Netherlands. May. (This image may be licensed either as rights managed or royalty free.)

Edwin Giesbers / RF- Jaguar (Panthera onca) head portrait, captive. (This image may be licensed either as rights managed or royalty free.)

Edwin Giesbers / RF- Head portrait of Sumatran tiger (Panthera tigris sumatrae), captive. (This image may be licensed either as rights managed or royalty free.)

Edwin Giesbers / RF- Siberian tiger (Panthera tigris altaica) close up of face, captive. (This image may be licensed either as rights managed or royalty free.)

Staffan Widstrand / RF- Lynx head portrait (Lynx Lynx) head portrait, captive. Sweden. (This image may be licensed either as rights managed or royalty free.)

Staffan Widstrand / RF- Bengal tiger yawning (Panthera tigris tigris). Bandhavgarh National Park, India. (This image may be licensed either as rights managed or royalty free.)

Staffan Widstrand / RF- Harp seal pup on ice (Phoca groenlandicus). White sea, Russia. (This image may be licensed either as rights managed or royalty free.)