There are calls to save up to 1,000 kangaroos living in a suburban nature reserve in Perth's south from a cull, after a report found the population was damaging the vegetation and had reached "unsustainable" levels.

The Department of Biodiversity, Conservation and Attractions (DBCA) is considering a cull at Thomsons Lake Reserve but some residents want the kangaroos preserved, while the local council has flagged concerns a cull could cause an outbreak of Ross River virus in the area.

The reserve, less than a 30-minute drive from Perth's city centre, is home to an abundance of birdlife and small marsupials — including the western grey kangaroos and their joeys — and is a popular recreation spot for bushwalkers, joggers and local families.

The largely wetland area is also an important breeding ground for a threatened bird species, the Australasian bittern, and the only place in Perth the swamp harrier still breeds.

After the reserve was fenced to keep out vermin in 1993, kangaroo numbers boomed from around 30 to an estimated 1,000.

A cull took place in 2006, but the latest report from the Conservation and Parks Commission says population levels have returned to pre-cull numbers.

The report said the population now needed to be reduced due to its impact on native vegetation.

Options include a cull or the "removal of the entire kangaroo population and replacement with alternative macropod species of higher conservation significance that once inhabited the area".

The previous cull involved shooting the kangaroos living in the reserve, which is bordered by houses.

ABC News: Hugh Sando

Rare chance to see kangaroos in 'suburbia'

Resident Lynsey Duff said she ran with a local group in the reserve at least once a week, and she also took walks in the area with her children, who loved seeing the animals.

"We love running in here with the kangaroos," Ms Duff said.

"It's just a piece of bushland that's on our doorstep, you're in suburbia and it's very unlikely that you'd go to one of the reserves in the Beeliar regional park area and see kangaroos right … up close.

"This area is just so pristine and an amazing place to be in and the kangaroos are part of it."

Lynsey Duff regularly jogs around Thomson's Lake, and takes her children there for walks. ( ABC News: Hugh Sando )

She questioned whether the population had indeed returned to 2006 levels.

"It would be good to look at the actual numbers, because we run through here so often and we don't see … up to 1,000, I reckon there's probably less than that," Ms Duff said.

She said she would prefer to see the animals relocated if numbers had to be reduced.

But local George Abbott, who lives about 500 metres up the road from the reserve, was in favour of a cull.

"It is an enclosed environment so culls are required to stop overpopulation," Mr Abbott said.

"As long as it's done humanely, and ideally the meat is used."

Fears of rise in Ross River virus

The City of Cockburn said it was aware of the need to reduce the population of kangaroos because of a threat to the nature vegetation in the reserve.

But it said the last cull coincided with a rise in the number of Ross River virus (RRV) cases in the surrounding community.

This was linked to subsequent breeding resulting in large numbers of young non-immune kangaroos born, who were carriers for the infection.

"There is strong circumstantial evidence for a link between a large-scale cull of the kangaroo population in 2006, which resulted in increased breeding of the kangaroos and increased numbers of young adults over the (approximately) five years following the cull," the statement said.

"When environmental conditions are supportive, this then results in the scenario of 2011-12 when the Thomsons Lake area became one of Perth's hot spots for RRV, with about 110 cases."

The DBCA, which would be responsible for carrying out the cull, declined to be interviewed by the ABC.

In the report it said it was aware of the importance of limiting the kangaroo population and the need for a control plan to be developed.

"Planning is currently being undertaken to reduce the kangaroo population in the reserve and DBCA intends to progress any required works at the earliest opportunity," it said.

But in a statement, a spokeswoman said no decision around the future management of kangaroo populations had been made.

Thomson's Lake in southern Perth in a popular spot for bushwalkers, joggers and bird enthusiasts. ( ABC News: Hugh Sando )

"The department is undertaking a survey of the kangaroo population within the reserve to better understand numbers and the impact the kangaroos are having on the vegetation and conservation values," the spokeswoman said.

"No decision on management actions will be made until the survey is completed and the information is evaluated."

The spokeswoman said relocation of large numbers of kangaroos was not a practical or preferred management option, and it was often not in their best interests in regards to animal welfare.

It is understood kangaroos can experience capture myopathy, where resulting stress from capture and restraint can cause illness and even death, making it difficult to relocate an animal.

The report also noted the lake has also experienced a drying trend since 2009, putting it at risk of drawdown. A water supplementation program has run since 2004.