For centuries the Tower of London was home to a royal menagerie of exotic animals, from polar bears to elephants. Lions took pride of place at the tower's entrance, as a symbol of the strength and nobility of the throne. Museum research on 2 lion skulls found in the surrounding moat has revealed insights into the animals' life history.
Tower of London. © Peter Pikous, CC BY 2.0
Workmen digging up the old moat around the Tower of London in 1937 were surprised to find 2 extraordinarily well-preserved lion skulls.
By carbon dating the skulls, Museum scientists determined that one of the lions lived between 1420 and 1480. The other lived between 1280 and 1385, making it the oldest lion found in the UK since the extinction of wild cave lions, Panthera spelaea, during the last ice age.
Close-up of the partly in-filled hole at the base of the Barbary lion skull, which suggests the animal had a poor diet.
Studying the younger skull, Museum scientists found clues about the lion's health.
The hole where the spinal cord passes through the base of the skull to the brain is partially obstructed, suggesting problems with the lion's diet. The resulting pressure on the spinal cord may have caused blindness, deafness and difficulty moving.
Lions in captivity are usually only fed parts of other animals. This can mean they don't receive all the nutrients they would get in the wild from eating the whole of their prey.
Such evidence is helping to inform the care of captive meat-eaters. Zoos now keep their lions healthy by feeding them joints of meat including hair, fat and bone, enriched with supplements.
Barbary lions used to roam North Africa from Morocco to Egypt, but they are now extinct in the wild. © M Watson ardea.com
Analysis of DNA obtained from the lion skulls shows that they were pure-breed North African Barbary lions, Panthera leo leo.
This subspecies is now extinct in the wild, but a handful of lions in captivity have been identified as potential descendants. Scientists are comparing their DNA to Barbary lion specimens in museums to discover whether they are indeed Barbary lions and, if so, how similar they are to their pure-breed ancestors. By selectively breeding the purest zoo animals it may one day be possible to reintroduce Barbary lions to the wild.