Protecting biodiversity by improving connectivity

By Samantha Hobbs, South Cape York Catchments

In fragmented landscapes, wildlife corridors that connect healthy ecosystems are necessary to maintain biodiversity. They allow populations to interbreed which improves long-term genetic viability; they provide access to larger habitats which ensures a wider range of food sources and shelter; and they provide an avenue for animals to move or shelter in times of stress, during wild fires and climate change impacts.

Wildlife corridors must be wide enough to allow easy movement for even the largest animals. For a Cassowary at least 50 metres wide is recommended. However, wildlife corridors also work at smaller scales to provide habitat connectivity for other species, including amphibians, fish, and birds. They are particularly beneficial along riparian corridors, where they provide both aquatic and terrestrial connectivity.

Wildlife corridors are vulnerable, and must be managed with extreme caution. For instance, wildfires encroaching onto a corridor might reduce the size and provide an avenue for weed encroachments, in turn reducing habitat diversity and connection function.

South Cape York Catchments (SCYC) has been working on wildlife corridor rehabilitation for the last three years. The biggest project has been the Annan River National Park to the Wet Tropics World Heritage area Wildlife Corridor.  This site was identified as a critical link for animal movement that could function as an avenue for animals to move north or south when facing threats such as climate change. Upon inspection with Rangers and Traditional owners it was identified that rehabilitation was needed. In some areas the site was burnt right down to the creek and Lantana had formed a thick mono-culture. The width of the wildlife corridor had been reduced due to late season wild fires, lantana encroachment and roaming cattle impacts.

Working with our project partners the team constructed a cattle fence around the riparian zone to exclude cattle from the creek, removed all lantana infestations and revegetated the riparian zone. Early burns to reduce the impact of late season wild fires were also undertaken. Works conducted at the site have protected the area from wild fire impacts allowing the rainforest tree species to re-establish, increasing the canopy cover and preventing lantana from re-establishing.

Recent follow-up riparian condition monitoring has shown the site has gone from a “poor” riparian condition rating to a “good” riparian condition rating.

By working together the team has protected the biodiversity of the area and provided a healthier and more resilient wildlife corridor.

SCYC would like to thank our partners in this project; The Traditional Owners, Bana Yarralji rangers, Queensland Parks and Wildlife Service, Rossville Rural Fire Brigade, local landholders, local schools and community volunteers along with funding provided by Caring For Our Country and Cape York NRM. Together we have worked to build resilience and increase connectivity of the corridor.