11 October 2015 Last updated at 11:10 BST
The 89 statues were designed by artists, celebrities, community groups and schools, and were dotted around the city.
Money raised from the sale is due to go to Birmingham Children's Hospital for a new rare diseases unit.
Organisers of the auction said they hope to make at least Â£500,000.
Giant owls making up Birmingham's Big Hoot art trail have been gathered in the same place for the last time before being auctioned.