(This article originally appeared in BirdLife South Africa's IBA NEWSLETTER 3 – WINTER 2013 and it reproduced with the permission of the Editor. Contact Dale Wright at firstname.lastname@example.org if you want to receive the newsletter in future. - Ed.)
The mountain ranges guarding fynbos endemic birds Six bird species are recognised as endemic or globally restricted to the fynbos biome of the Western Cape: the Cape Sugarbird, Orange-breasted Sunbird, Victorin’s Warbler, Cape Siskin, Protea Seedeater and Cape Rockjumper. Currently there is a lack of knowledge regarding these species’ population sizes, their abundance in different areas and their dispersal patterns. However, this knowledge gap is being addressed through the post-doctoral research project of Dr Alan Lee. Dr Lee’s investigation into the abundance of these species is essential for designing the conservation measures required for their persistence.
These endemic fynbos birds are faced with a number of threats, in particular habitat loss as a result of alien plant invasion and increasing fire frequencies. Added to this is the ever-increasing threat of climate change. Climate-change models for the Western Cape predict a hotter and drier future for the area. As the climate changes, vegetation is often the first component to respond and research suggests that vegetation shifts could occur in both altitude and latitude. Vegetation or habitat types will thus shift up slopes to cooler climates or southwards for the same reason. If one considers that these habitat types exist on mountains at the southern tip of a continent, there isn’t really much space to move either up or south!
The principal habitat on which the six fynbos endemic bird species rely exists mostly in the Cape Fold Belt Mountains. In the analysis of IBAs for southern Africa, Barnes (1998) identified all these mountain ranges as IBAs because they hosted these endemics as well as other threatened bird species. In order for a suite of species such as the fynbos endemics to survive in the light of predicted climate change, it is essential that they have a large network of sites they can move between, rather than being isolated at a single site. This is akin to the metaphor of putting all your eggs in one basket. If there is only one mountain range or IBA where these species occur, any drastic changes to this environment could ultimately lead to their extinction. However, through identifying and managing a network of connected sites across the landscape, we’re able to provide the birds with the opportunity to move in response to different factors. Thus, if the environment of one mountain range were to become more arid, the birds could migrate to a nearby range which could still provide their ideal habitat. This ability to adapt to changes in the environment is essential for all species, and has allowed for many species’ long-term persistence on this dynamic planet of ours. This is also the reason conservation biologists seek to conserve networks of sites which allow species to respond in their own ways to changing environments.
The six fynbos endemic bird species occur in all seven of the Cape Fold Mountain IBAs: Anysberg, Kouga-Baviaanskloof, Cedarberg, Eastern False Bay Mountains, Southern Langeberg, Outeniqua and Swartberg. These mountain IBAs therefore form the network that is necessary for the long-term persistence of these birds. Dr Lee’s research will assist in identifying the most important mountain ranges for the fynbos endemics and how best to maintain existing connections between these patches. By protecting these mountain IBAs through reducing the threats to their habitat quality and maintaining a network of connected sites, we’re better able to assist the fynbos endemic species’ adaptation to climate change and give them the best chance at survival.
Regional Conservation Manager: Western Cape,
Important Bird Areas Programme, BirdLife South Africa,