This year a colony has been established in Ploughmans Lane since January. Cook Park has been occupied since the beginning of March.

Prior to 2010, regular occurrences of large numbers of flying foxes were rare. Since then, we have had almost yearly invasions.

The grey-headed flying fox is naturally distributed along Australia's Eastern seaboard. It's preferred habitat is gullies and rainforest, where it feeds on eucalypt blossoms and rainforest fruits.

It is an important pollinator and distributor of seeds, and as such is necessary for the maintenance of ecosystems in which it is native.

The species was listed as vulnerable in 2001. The reason for this listing was due to a significant decline in numbers because of habitat loss through land clearing for coastal development, and other issues associated with the interaction between populations of flying foxes and human activity.

VIDEO: Flying foxes in full voice in Orange ...

It is thought that initially, large numbers of flying foxes relocated inland because adverse weather conditions on the coast affected food sources. Once arrived, they realised that easy access to food through the local orchards, access to water, cooler summer temperatures and great roosting sites made Orange a very attractive flying fox destination for the summer and autumn months.

Cook Park during summer and autumn provides everything a flying fox requires. This includes tall trees for roosting, access to water and a food supply which is within 20 kilometres of home.

Fortunately flying foxes are not fond of cold weather, so they are unlikely to take up permanent residence. They have well-developed spatial memories to assist them in utilising their complex habitats, enabling individuals to remember the locations of camps and associated feeding sites.

They are also unlikely to remain once the fruit is finished.

At this point in time because of the favourable conditions it is highly likely that we will be visited by large numbers of grey-headed flying foxes on an annual basis for several months from summer to late autumn.

If we accept this will be the case, we can adopt strategies to manage their presence for this period during the year.

Management plans need to include compensation to orchardists for loss of income caused by flying foxes, as orchardists (albeit reluctantly) are contributing to the survival of the species.