Exceptional visitor levels throughout September, October, November and December were helped by the broadcast of a BBC TV series that explored the story behind the zoo's creation.

According to its annual report, the North of England Zoological Society's total incoming resources increased by 6 per cent to £29.8m in the 2014 calendar year. Income from charitable activities including visitor admissions and memberships increased to £18.7m from £17.5m, voluntary income including donations, adoptions and grants dipped to £2.8m from £2.9m, and turnover from the Chester Zoo Enterprises catering and retail subsidiary rose to £8.2m from £7.7m.

James Christon, managing director of Chester Zoo, said: "2014 was my first full year and was jam-packed with memorable events.

"Many of these were achievements that had been reached in previous years but were then superseded by record-breaking results and outstanding levels of work and commitment in 2014. Examples include record-breaking months of September, October, November and December, which led to the year of 2014 achieving the highest number of visitors ever.

"Our busiest day ever on record in August was soon followed by being voted by our visitors as the number one zoo in the UK by TripAdvisor and sixth in the world."

Professor Peter Wheeler, chairman of the trustees of the North of England Zoological Society, said: "2014 was the busiest ever for the zoo with total visitors numbering 1,432,867. The record-breaking numbers in September, October, November and December were helped not only by the fine autumn weather and successful events such as Lantern Magic, but also the publicity arising from the popular BBC television series Our Zoo, a dramatized version of the founding of Chester Zoo."

Throughout September and October 2014, BBC One broadcast the six-part drama series Our Zoo. The programme told the story of Chester Zoo founder George Mottershead's efforts to create a unique visitor attraction on the outskirts of Chester.

After the period covered by this report, Chester Zoo opened the first phase of its £40m Islands expansion scheme (pictured).

Islands features five different habitats linked by a series of bridges and a 'Lazy River' boat trip for visitors to explore. It hosts habitats and animals from Panay, Papua, Bali, Sumatra, Sumba and Sulawesi.

Phase one of Islands, which is expected to welcome 150,000 visitors in its first year, launched on 13 July 2015.

Phase two of Islands will house Monsoon Forest, the largest indoor zoo exhibit in the UK, which will be home to Sumatran orangutans, Sulawesi macaques and Sunda Gharial, a type of crocodile.