Some of the assets of the private estate of Queen Elizabeth II are a bit surprising.

Much of the Queen's expansive jewel collection and the $750 million Duchy of Lancaster estate are included in his inheritance.

According to El Pas, the species became symbolic property of the Crown in order to protect them from traffickers. The monarch is in charge of the annual "Swan Upping" event which is a census of the swan population.

The Queen's Swan Marker has conducted the process of weighing, measuring, and assessing the health of the birds in the past. Metro UK said that the last Swan Upping the Queen was in 2009.

Queen Elizabeth II attends Swan Upping
Queen Elizabeth II (front left) accompanied by Swan Marker David Barber (front right) on the steam launch Alaska, as she watches a swan upper place a swan back into the River Thames near Windsor.
Sang Tan/PA Images via Getty Images

According to Metro UK, the event became an educational opportunity for school children to learn more about the biology of swans.

The Crown took over the ownership of whales and dolphins in 1324. Under the law, the monarch can claim any that are captured or washed up on the shores of the UK.

The animals are part of the crown, which is a collection of assets that are not owned by the reigning monarch. The Queen's total fortune is estimated by El Pas to be 16.2 billion.

During her seven decades on the throne, the Queen's private net worth has grown to $429 million.