Over winter, the council issued guidelines for building owners on "evicting" the birds from their premises.
This followed the example of measures taken by Countdown, which had up to 900 gulls nesting on its roof last year.
Council heritage, environment and regulatory group manager Lichelle Guyan said yesterday while there were still red-billed gulls in Oamaru's business area, the numbers were "greatly reduced".
"The last drone operation which covered those buildings where seagulls were [previously] congregating provided no evidence that the gulls were nesting on building roofs," she wrote in an emailed response to Otago Daily Times questions.
"It appears the various mechanisms being used by building owners has made a difference.
"It is not known where the gulls have gone to nest."
She said the council continued to liaise with building owners who had questions.
At the end of winter, the council cleared boxthorn from a roughly 100sqm area in a remote corner of Cape Wanbrow, some distance from its well-used walking tracks, in an attempt to provide a more natural habitat for the birds before the breeding season began.
Once nests were formed, they could not be removed, as red-billed gulls were protected under the Wildlife Act.
Mrs Guyan did not answer whether the council had had any success in attracting the birds to Cape Wanbrow, but said the council had decoys ready to be deployed.
The council also had "trap stations ready to go" to start predator control.
