Nectar Quandary

Surviving the suburbs

- Anina Coetzee & Phoebe Barnard

We all delight in seeing a col-ourful sunbird flit into our garden to visit some flowers, especially when one of the shyer species comes through. Have you thought about why some sunbirds are common in gardens while others are so rare? And whether they will disappear as urban development increases?

These questions are important to us if we are to enjoy the presence of sunbirds and other nectarivorous birds in our gardens. But the questions are far more important to plants, because nectar-feeding birds pollinate specific plants, enabling them to produce seeds. This mutual relationship fosters plants dependent on the birds, while the birds in turn rely on the plants for food.

As cities grow, they tend to crowd out natural areas, and residential areas are often avoided by birds. If the development of towns and cities means that nectar bearing plants and nectar-feeding birds become isolated in small fragments of natural habitat, both birds and plants will suffer. However, urban areas with gardens can be made less hostile and some brave or adaptable birds will enter and use these new habitats.

Urban environments that allow nectar feeding birds to move between fragments of natural habitats are especially important in the Western Cape, for two reasons. Firstly, Cape Town and the greater Boland suburbs are interwoven with natural fynbos habitat. Secondly, more than 300 fynbos plant species depend on only five specialist nectar-feeding bird pollinator species. Thus, nectar-feeding birds play a uniquely important ecological role in the fynbos biome.

In addition to nectar specialists, there are birds such as weavers, starlings and bulbuls that feed on nectar opportunistically. A different suite of plant species is adapted to pollination by these nectar-opportunists.