Sutherland Shire Council is sticking with its management program for the Grey-headed Flying-Fox camp in the Camellia Gardens, which continues to grow.
A council staff report says numbers during the autumn breeding season have grown in four years from an average of 1000 to 5100.
A year ago, the council said the peak number was "about 4000".
Grey-headed Flying-Foxes are listed as a threatened species and are protected by law.
The council at its last meeting "received and noted" a staff update on the management of the colony within the current funding allocation.
The "bats" took up residence in the Camellia Gardens in July 2016 as a result of efforts to disperse a camp at Kareela.
An increase in Camellia Gardens camp numbers, noise, faecal drop and odour in autumn of 2019, led to a rise in complaints from residents and as well as pressure on the staff who work there.
In 2019, the council adopted "enhanced in-situ management" in preference to other options, which included engaging specialists "to nudge the camp out of unsuitable vegetation" and an attempt to disperse the colony.
A report to the last council meeting said, "For the past four years, the camp's population has experienced significant growth during the autumn breeding season, increasing from an average of 1000 to a peak of 5100".
The report said management measures included:
- An additional staff member to undertake cleaning and maintenance required at the site $30,000 a year.
- Community education and awareness, costing $5000 a year.
- Assistance to directly affected community to aid in Cocos Palm management, $10,000 a year.
- Sprinkler and ultrasonic installation and buffer maintenance (roosting deterrents), $10,000 a year.
The report said the additional staff member, together with other staff working overtime, had resulted in a noticeable improvement to the cleanliness of paths and railings.
"Council received fewer complaints regarding faecal drop and general mess produced by the camp, and the gardens staff reported an improvement in site conditions," the report said.
"The amount of overtime hours spent cleaning decreased in the 2020 / 2021 period due to the effects of COVID-19 (less visitors to the gardens), heavy rain periods."
The report said the council also continued to manage the Kareela camp.
"This camp has benefited from the creation of a habitat free buffer of 50m between the core areas of the camp and adjoining residential and educational premises," the report said.
"This has resulted in significant improvements in amenity in the area, and a dramatic reduction in complaints.
"Ongoing management consists primarily of maintenance of the buffer through weeding and removal of vegetation that has potential to grow into roosting habitat."