Overcoming restoration barriers in a degraded coastal environment

Abstract

Restoration techniques that naturally accelerate regeneration by removing ecological barriers, such as limited seed dispersal, could reduce the need for expensive and labour-intensive methods. One potential method to overcome this barrier is the strategic placement of artificial perches in degraded areas. These perches encourage frugivorous birds to fly out from remnant areas to rest and defaecate seed in degraded areas, thereby increasing seed dispersal. This technique has been extensively tested in tropical systems but is yet to be explored in coastal systems. We aimed to determine the success of artificial perches in a degraded coastal environment by investigating: (1) their ability to attract fruit-consuming birds from nearby remnant vegetation; (2) their potential to increase seed rain in comparison to the open landscape, and (3) the seasons in which they are most effective. In this study, nine bird species that consume fruit as part of their diet visited the perches. The most frequent of these visitors were Gymnorhina tibicen (Australian magpie), Acanthagenys rufogularis (spiny-cheeked honeyeater), Sturnus vulgaris (common starling) and Corvus coronoides (Australian raven), which are all greater than 20 cm in size. Smaller fruitconsumers may be less inclined to rest in open areas and risk predation. Artificial perches effectively increased the seed rain of several native fleshy-fruited species in degraded paddocks and were most effective in summer–autumn, when the majority of native species were fruiting. The restoration ability of perches was reduced in some months owing to the abundant defaecation of invasive species. Potential modifications to the restoration technique may overcome this limitation.