A huge herd of swans has descended on Cambridge, with ten times the usual number of birds residing on the city’s river bank.

More than 100 swans have now made a home along a picturesque stretch of the River Cam.

Conservationists are asking people not to feed the swans as the River Cam is unable to cope with the influx of the birds.

The increase has been attributed to a large influx of tourists and visitors who typically feed the swans bread.

A diet based on white bread represents a stark contrast from their normal diet for swans, who typically forage on underwater vegetation or grass. Leftover bread can cause a whole host of problems for resident swans on the river, the lack of nutrients in bread potentially harming the birds by causing long-lasting effects, such as vitamin deficiency and weak limbs.

It may seem helpful to feed a growing population of swans, but the river is currently struggling to accommodate the vast number of swans descending on the river.

Conservationists have also warned that the population spike is also posing problems for other birds who currently nest along the river Cam.

Speaking to Cambridge News, Jed Ramsey, river manager for the Cam Conservators, said: “My staff have noticed that this year there is larger than usual number of swans on the Cam, particularly in the city centre.”

Feeding the swans is not recommended, as it will aggravate bird numbers along the river Cam, leading to unsustainable population levels.

Swans are currently a legally protected species, so there is little that can be done apart from encouraging the public to refrain from feeding them.

The increase in swan numbers can pose problems for people rowing or punting along the river Cam. Swans often swim down the river in large flocks and are typically territorial.

With the sharp increase in numbers of swans, conservationists are warning that it is important to be mindful of the fact that they can become quite aggressive, especially when minding their young.

Feeding swans bread can also pose significant health problems for people who row or punt down the river Cam. Bread attracts rats, which can promote the transmission of the deadly Weil's disease, a bacterial infection spread by rats that causes mild 'flu-like symptoms.

It can occasionally cause life-threatening symptoms including organ failure and internal bleeding. Weil's disease is of particular concern for those with compromised immune systems.