The grey speckled hen was taken from the garden of a property on River View Road at around 5.30pm on Monday 9 May 2011.
The owner of the chicken, who lets his birds roam free outside his house, saw two men passing his property along a public footpath. The men appeared to be empty-handed until the owner heard a squawk and saw the suspects walking away, with one of the men carrying something in his arms.
The suspects, who were both wearing jeans, are described as white and aged in their late teens. One of the men was wearing a blue top and the other man was wearing a grey hoody.
Officers are appealing for anyone who was in the area at the time of the theft to come forward with information.
PC Claire Brown, of Ripon Safer Neighbourhood Team, said: “It is believed that other people may have been walking along the same public footpath at the time of the incident.
“I am appealing for anyone who witnessed the theft or saw any suspicious activity in the River View Road area at the time, to contact the police or Crimestoppers.”
Anyone who can help the police with their enquiries is urged to contact PC Claire Brown, of Ripon Safer Neighbourhood Team, on 0845 60 60 24 7, quoting reference number, 12110076357.
Alternatively, Crimestoppers can be contacted anonymously on 0800 555 111.