Beeping horns, banging fences and cracking stock whips keep thousands of flying foxes moving in Katherine

Updated 28 Apr 2016 Editor's note: The word "invade" has been removed from the title of this article with respect to the fact these native animals are passing through or visiting the region.

Thousands of flying foxes have settled in the Northern Territory town of Katherine and are proving a challenge for Parks and Wildlife rangers to remove.

A colony of around 2,000 red flying foxes moved into trees in and around Prior Park two weeks ago.

Parks and Wildlife rangers, with the help of local residents, have been making loud noises early in the morning in an attempt to scare the animals away.

"We use metallic banging noises, banging bin lids, the odd crack of the stock whip or beeping of car horns," Parks and Wildlife ranger John Burke told ABC Rural as the sky filled with circling flying foxes.

"If it annoys us then it annoys the flying foxes.

"It does not take a lot [of noise] to get them to lift off, it is just trying maintain a consistency so they think 'this is not a good place to roost, let's go somewhere else'.

"We will do a patrol around the surrounding area to check they are not starting to roost in other parts of the residential area, otherwise we will try to get them to move on from there."

Rangers have been trying to get the colony to move out of the town, to settle in trees along the Katherine River.

"There is plenty of room there for them to roost [along the river] and they don't have the same impact on the people around town," Mr Burke said.

"I don't know how successful we will be in the next few days.

"Last week we managed to get about 1,000 of them to go down into the river corridor; unfortunately some of those have come back, but even if we halve the colony it is better than none at all."

Mr Burke said the flying foxes were a public safety hazard, with the weight of the massed animals causing large branches to fall from trees.

"For the residents surrounding the area the noise of the flying foxes wakes people up as they come back to roost," he said.

"A sustained period of that, people start getting cranky with the flying foxes and want them moved.

"If the colony has been here quite a while it will start to smell a bit and a lot of people don't like the smell."

The flying foxes had settled in the town because of the large number of native and exotic tree species, Mr Burke said.

"They have a lot of shady roosting trees as well as a lot of exotic plants that are flowering and fruiting, so they have a food source very close," he said.

As for how long the colony would roost in the park, Mr Burke was unsure.

"That is a hard one, you don't really know unless you're one of the [flying foxes] hanging in the tree," he said.

"Some days they will move overnight, other times we won't have any success at all or we may reduce the colony size but end up with a smaller permanent size until they choose to leave.

"They potentially could be here for three or four months."