These are real "silver fox" skulls! Silver foxes are a melanistic version of the red fox, which have a bluish-grey coat. These are captive-bred specimens and are available worldwide!
Thanks to its uncanny ability to adapt to new surroundings, the red fox (Vulpes vulpes) is one of the most widespread carnivores in the northern hemisphere, ranging from as far north as the Arctic circle to as far south as North Africa, Central America and Asia. It has also been introduced to Australia, where it had a negative effect on the local fauna. It is the largest species of fox, with their average weight being 2.2 to 14 kg (4.9 to 31 lb).
Their natural diet is omnivorous, mostly consisting of small rodents, birds and sometimes even smaller ungulates. They will also eat berries and are able to sustain themselves exclusively on fruit during the fall months.