Habitat Management Principle 2: Well connected habitat patches assist bird movement and ensure long term survival.
Many of the smaller bush birds are unable or unwilling to cross large open spaces in search of new or additional habitat to support their population. To do so may exhaust their energy supplies and expose them to high risk of predation (e.g. by feral cats or birds of prey). This reduces the survival rate of individuals, lessens the chance of interbreeding, and hinders dispersal of young birds from their home territory in search of food and shelter.
Consequently, native vegetation patches that are isolated from other native vegetation will generally contain fewer species and smaller populations of birds. Scientific evidence shows that some birds are absent from otherwise suitable habitat patches that are more than 500 metres from surrounding habitat areas. What’s more, patches that are isolated by more than one kilometre have significantly fewer species than less isolated and large intact patches.
Connectivity, the degree to which native vegetation is linked across the landscape, is usually spoken of in terms of corridors. These are continuous and more-or-less linear strips of vegetation, most commonly seen along watercourses, fence-lines and roads. They may be natural areas of remnant or regrowth vegetation, or strips that are revegetated using native plants from the local area.
Connectivity is also provided by stepping stones - small patches of remnant, regrowth or re-planted vegetation, strategically placed between larger remnants. These patches reduce the amount of open-space that small birds have to fly across between areas of shelter, as they move between large patches.
Significant connectivity is also provided for some birds by scattered paddock trees and shrubs. Corridors and stepping stone patches also provide productivity benefits to the farm in the form of shade and shelter for livestock and crops. They also harbour significant populations of beneficial insects, birds and bats that help to reduce pest populations in crops and pastures. Riparian corridors along watercourses help improve water quality by reducing erosion and minimising the entry of sediment and nutrients into the stream.