Sunbird Restoration Project
What will the world be like without birds? We know that birds pollinate many plant species, they disperse the seeds of an even greater number; in addition they are predators that prey on innumerable insects every day. Nevertheless, the world without birds is difficult to imagine because so many factors interact in complex ways to shape the natural world around us.
In the Cape region of South Africa, the long-tailed Cape Sugarbird (Promerops cafer) and the iridescent Sunbirds (Nectarinidae), pollinate approximately 400 plant species, including the dominant Protea shrubs, which are a favorite source of nectar. The birds are threatened by habitat fragmentation, urbanization, disease, alien plant invasion and honeybee farming [2-4] . In addition, they are likely to be sensitive to climate change because their abundance is strongly influenced by fires .
All over the world birds and other pollinators are declining in number[6, 7] . One possible outcome is that the human-caused loss of these mutualists will trigger a cascade of linked extinctions [6, 8-13] . On the other hand, pollination is often considered to be of little ecological importance because, in the absence of their primary pollinator, many plants can make seed by self-pollinating or switching to other pollinators [14-16] . Even if seed production fails, little may change, because many plants can reproduce by vegetative propagation, or are simply very long-lived[12, 14] .
To answer the question of the ecological significance birds as pollinators we are conducting a bird exclusion experiment on an unprecedented scale. We are simulating the “World without Birds” in five walk-in cages, each of which excludes birds from a 20 X 20 m area of natural Fynbos vegetation in the Cape Mountains. To assess the effect of losing birds we are comparing areas inside the exclosures with adjacent areas outside. We are particularly interested in the effect of bird exclusion on the architecture of plant-pollinator networks and seed production, but because birds also play other roles we are additionally monitoring seed dispersal, insect community composition and leaf damage inside and outside the cages. Additionally the exclosures offer the opportunity to assess the role of birds as vectors of Protea mites, which are themselves important in the transmission of fungal spores and possibly pollen .
After three years of bird exclosure the vegetation in the study area will be burned as part of the normal fire management routine. Fire triggers the regeneration of Fynbos vegetation, but its ability to recover from fire might be compromised by the loss of birds. If the lack of pollination services provided by birds meaningfully reduces seed production, we predict that important plant species will be lost and that the composition of the recovering vegetation will shift from one dominated by bird-pollinated plants to one dominated by insect- and wind-pollinated plants including alien species.
The research component of the project dovetails with a community-based, science outreach project in disadvantaged areas of the Cape Town. We aim to identify young people with a talent for working with biodiversity and guide them to become environmental leaders. We hope to do this by engaging strategically located high schools in a pollinator restoration project with the Sunbirds and Sugarbirds as the focus. The project will guide learners to establish gardens of bird-pollinated plants on school grounds. These gardens will relink broken migration routes for birds by acting as stepping-stones across urban areas. The learners will monitor the progress of restoration by observing flower-visiting birds and reporting the data to the Animal Demography Unit via a cellphone application and website (http://mybirdpatch.adu.org.za). The data will be mapped on Google Earth to monitor the progress of restoration. Interested and talented students can easily be identified because the electronic data capture system will not only collect data on birds but will simultaneously track the progress of the learners as they submit the data. The subset of keen students identified in this way will be invited to participate as field assistants in the bird exclosure study.
The researchers involved in this project are: Prof. Anton Pauw (Stellenbosch University), Dr Phoebe Barnard (South African National Biodiversity Institute), Dr Sjirk Geerts (Cape Peninsula University of Technology), Bongani Mnisi (M.Sc. student and Biodiveristy Manager City of Cape Town), Anina Heystek (Ph.D. student), Pieter Botha (M.Sc. student) and Adam Van Nieuwenhuizen (Landscape Architect).
News / Links / Resources
The Iingcungcu Project on facebook
Bird exclusion project
School garden project: Make way for the Birds
As die laaste suikerbekkies verdwyn
Birds in gardens questionnaire
Stepping Stones through fragmented environments: A film about the Iingcungcu Project produced by www.caretakers.co.za
The Iingcungcu Project - Signage for school grounds
Bird-pollinated plants suitable for planting in sandy soil around Cape Town
Bird-pollinated plants suitable for planting in loam or clay soils around Cape Town
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- Geerts, S. and Pauw, A. (2011) Easy technique for assessing pollination rates in the genus Erica reveals road impact on bird pollination in the Cape fynbos, South Africa. Austral Ecol. 36, 656-662
- Geerts, S. and Pauw, A. (2012) The cost of being specialized: Pollinator limitation in the endangered geophyte Brunsvigia litoralis (Amaryllidaceae) in the Cape Floristic Region of South Africa. S. Afr. J. Bot. 78, 159-164
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