Defenders of Richmond Park’s annual deer cull have said critics should consider the fact many deer die from human contact instead of focusing on the yearly cull.

Community group Friends of Richmond Park (Forp) said investigations into the unexpected death of deer in the royal park have revealed rope, dog excrement bags and discarded bits of plastic are also responsible for the deaths of many deer every year.

John Karter, a Forp spokesman, said the impact of human activity on the health of deer was greater than many people thought.

He said: “There is a lot of emphasis on the culling as cruel but there’s a reason for it – of course not everyone likes it.

“The other side of the picture is actually humans cause a lot of damage.”

A statement issued by the group added: “Deer, much like goats, will eat anything, which helps them survive in the wild, but this can be disastrous when humans are around.

“Litter kills about five deer a year. Rope and string, black dog waste bags, other plastics, and parts of clothing [are] all material that deer cannot digest [and] the deer die slow, agonising deaths from starvation.”

But Kate Fowler, anti-cull campaigner at animal right’s group Animal Aid, said while people did need to be more aware of the human impact on wildlife they should also continue to oppose the culling.

She said: “We recognise land is at a premium, but I don’t think enough work has gone into finding humane alternatives to deer culling – other measures can be looked at.

“We should not just rush to cull them.”

Previous statements issued by Richmond Park manager Simon Richard said the yearly cull was necessary to maintain numbers at a specific level to avoid problems of disease and damage to the natural environment.

He said: “The British Deer Society and the Deer Initiative of England and Wales recognise parkland deer numbers must be managed and that removal of some of the deer is necessary each year to keep populations at acceptable levels.... [and] fully endorse the humane shooting of deer as the optimum method of deer control in the royal parks.”