gardens

nectar quandary Surviving the suburbs

Text ANINA COETZEE & PHOEBE BARNARD

e all delight in seeing a col- ourful flit into our garden to visit some flowers, especiallyW when one of the shyer spe- cies comes through. Have you thought about why some are common in gardens while others are so rare? And whether they will disappear as urban de- velopment increases? These questions are important to us if we are to enjoy the presence of sunbirds and other nectarivorous in our gardens. But the questions are far more important to plants, because nectar-feeding birds pol- linate specific plants, enabling them to pro- duce 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 of- ten 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 Anja Minnaar natural habitat, both birds and plants will suffer. However, urban areas with gar- opportunistically. A different suite of above A male Southern Double-collared Sun- dens can be made less hostile and some plant species is adapted to pollination by bird attracted to an artificial nectar feeder. brave or adaptable birds will enter and these nectar-opportunists. use these new habitats. We at the FitzPatrick Institute of Afri- opposite A sunbird heads towards a red Urban environments that allow nectar- can Ornithology at UCT, the University hot poker to feed on the copious nectar it feeding birds to move between fragments of Stellenbosch and the South African produces. of natural habitats are especially impor- National Biodiversity Institute gained tant in the Western Cape, for two rea- valuable insights into the relationship We found that nectar-opportunistic sons. Firstly, Cape Town and the greater between garden traits and nectar-feeding birds were more common in gardens. Of Boland suburbs are interwoven with nat- birds from questionnaires distributed at the nectar specialists, Southern Double- ural habitat. Secondly, more than bird clubs in the Cape Town metropoli- collared and Malachite sunbirds were 300 fynbos plant species depend on only tan and Drakenstein municipal areas. We the most abundant. This may be because five specialist nectar-feeding bird polli- specifically asked for information about they can occupy different habitats; they nator species. Thus, nectar-feeding birds nectar-specialist birds, namely Cape Sug- use seven different habitat types, includ- play a uniquely important ecological role arbird and Orange-breasted, Malachite, ing fynbos, grasslands and forests, and in the fynbos biome. Southern Double-collared and Amethyst thus are more likely to venture into a new In addition to nectar specialists, sunbirds, and nectar opportunists such as habitat such as urban gardens. Cape Sug- there are birds such as weavers, star- Cape Weaver, Cape Bulbul, Red-winged arbirds and Orange-breasted Sunbirds, lings and bulbuls that feed on nectar Starling and Cape White-eye. on the other hand, are far more choosy, > anton crone

july/august 2018 nectar-feeding birds 71 Oliver S Plokhooy (2) above left A male Southern Double-collared Sugar-water feeders on their own did away from natural plants, reducing seed Sunbird enjoying nectar from a wild dagga not attract many birds, suggesting that production and lowering survival rates of Leonotis leonurus plant. these feeders cannot replace nectar- bird-pollinated plants. producing plants as a food source. How- To address the health-related con- above right Specialist nectar feeders like the ever, it is not just the presence of bird- cerns, sugar-water feeders should be are attracted to bird baths to pollinated plants that is important, but cleaned daily. Also, remember to only maintain their water and energy balances. also their diversity. The more different use diluted cane sugar (1 part sugar: 4 types of plants you have, the more birds parts water). Xylitol and other artificial using only two or three habitat types and and the more species of birds you can sweeteners can be deadly poisonous to rarely visiting gardens, especially those attract. Some bird species are also a bit nectar-feeding birds. further from fynbos habitats. picky about which plants they prefer; Overall, nectar-feeding fynbos birds Considering how important a bird’s for example, you are more likely to at- seem to be adjusting to our cities and habitat is to it, we can understand why tract Cape Sugarbirds with and towns, but some of their biological traits they don’t like crossing large urban areas. Orange-breasted Sunbirds with ericas. limit this adaptation. The sensitive nectar- The number of nectar-feeding birds The other advantage of having a diver- specialist birds are very important pollina- found in gardens therefore drops off sity of plants is that they produce flowers tors and we need to make extra efforts for dramatically as you move deeper into at different times of the year, so the food them, especially in the areas within three suburbia and away from large, natural supply is not limited to one season. In- kilometres of natural habitats. We can protected areas. Consequently these terestingly, bird baths also attract more each contribute to their survival by hav- birds are more likely to frequent gardens of the nectar specialists, since although ing bird-friendly gardens, especially by that are surrounded mainly by parks, they take in lots of fluid through nectar planting a diversity of locally indigenous greenbelts or small reserves with less- feeding, they also drink water to main- and water-wise, bird-attracting plants that developed areas around them. tain their water and energy balances. provide natural foods.  Although there are intrinsic biological traits that hinder nectar-feeding birds he pros and cons of sugar-water ACKNOWLEDGEMENTS from adjusting to suburbia, we can feeders have not yet been formally Many thanks to everyone who partici- make it easier for them by providing tested. On the one hand, feeders pated in the questionnaire survey and to food resources. Specifically, we found Tprovide food where natural resources have the bird clubs that helped to distribute the more species of nectar-feeding birds been removed, and also ‘stepping stones’ questionnaires. and higher numbers of nectar-specialist to enable birds to cross urban areas, which birds in gardens with both natural and is essential for their adaptation to climate Reference artificial nectar. Artificial nectar is sugar and land-use change. On the other hand, Coetzee A et al. 2018. ‘Urban nectarivorous water provided in feeders, while natural sugar-water feeders may increase the rate bird communities in Cape Town, South Af- nectar is provided by bird-pollinated of disease transmission between birds. rica, are structured by ecological generalisa- plants such as proteas, ericas, strelitzias, And if feeders are more attractive to birds tion and resource distribution.’ Journal of aloes, wild dagga and Cape honeysuckle. than flower nectar, they could lure them Avian Biology. DOI: 10.1111/jav.01526

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