IT'S not just chocolate bunnies that are under threat this Easter. State and urban authorities are stepping up efforts to reduce Sydney's burgeoning rabbit population.

The drought-breaking rains over summer and autumn have given a boost to the city's feral rabbits, whose numbers have boomed along with the supply of vegetation in northern suburbs such as Ku-ring-gai, Pittwater, Warringah and Ryde.

Watership Down under the bridge … there are plans to remove the colony of rabbits living under the southern pylon. Credit:Nick Moir

The conditions have also helped propagate a colony of bunnies in Dawes Point Park, a grassy knoll under the Harbour Bridge that has become the city's own Watership Down.

Steve Parker, a ranger with the Cumberland Livestock Health and Pest Authority, said that unlike in rural areas, where breeding tends to be restricted to spring, the wet Sydney basin lets rabbits breed all year round.