Birds, people and papyrus swamps: balancing livelihoods and biodiversity conservation
Ilya Maclean [email protected]
Environment and Sustainability Institute, University of Exeter
Background
Birds good indicators of ecosystem health:
• occur in wide variety of habitats
• sensitive to environmental change
• Well known and easy to monitor
Much conservation policy is based on birds
• EU Birds Directive
• Ramsar Convention
• BirdLife International IBA programme Background
Wide variety of birds associated with papyrus swamps
Most not solely reliant on papyrus
Five species considered endemic / near-endemic
Maclean et al. (2003) Bird Conservation International, 13: 283-97 Background
Papyrus Yellow Warbler Papyrus Gonolek Chloropeta gracilirostris (VU) Laniarius mufumbiri (NT)
White-winged Swamp Warbler Carruthers’s Cisticola Cisticola carruthersi Papyrus Canary Serinus koliensis Bradypterus carpalis Maclean et al. (2003) Bird Conservation International, 13: 283-97 Background
Wide variety of birds associated with papyrus swamps
Most not solely reliant on papyrus
Five species considered endemic / near-endemic
Regionally, among most- threatened and least adequately protected
Maclean et al. (2003) Bird Conservation International, 13: 283-97 Key questions
• How threatened papyrus birds (and why)?
• Can conservation resources be targeted?
• Are bird-based policies compatible with people?
Methods
• Biodiversity surveys across Lake Victoria basin
• Analysis of satellite imagery
• Socio-economic modelling
Results: taxonomy
Albertine Rift • Papyrus Yellow Warbler probably three species:
• Three highly disjunct populations Western Kenya
• Plumage, biometrics, size, bare parts & vocals all differ
• Species / population in Kenya Critically Endangered Lake Mweru
• Confined to very small number of sites
• All sites highly threatened
Maclean et al. (2003) Bulletin of the African Bird Club, 10: 94-100
Results: habitat loss
Rice schemes Dredging & Brick-making
Extensive cultivation & dairy farming
Mean percentage annual rates of wetland loss (1984-2000)
Maclean et al. (2011) Diversity & Distributions, 17: 480-90. Results: bird loss
Annual rates of wetland loss Rarity weighted bird density index Bird densities higher in areas of high drainage
Bird declines >> wetland loss Red = high Blue = low
60
2000) 40 -
20 Mean wetland loss 0 1985-2000 White- Papyrus Carruthers's Papyrus Papyrus winged Yellow Cisticola Gonolek Canary
Percentage Percentage loss (1985 Warbler Warbler
Maclean et al. (2011) Diversity & Distributions, 17: 480-90. Results: avian responses to disturbance
A small proportion of wetlands host a high proportion of the birds:
c. 75% of birds hosted by c. 5% of wetlands
Maclean et al. (2011) Diversity & Distributions, 17: 480-90. Results: avian responses to disturbance
10 Papyrus Yellow Warbler Bird densities 8 Papyrus Canary highest in swamps 6 Carruthers's Cisticola with low-intensity White-winged Warbler 4 disturbance Density Papyrus Gonolek 2 0 High 0 0.2 0.4 0.6 0.8 1 disturbance PrincipalProportion component of swamp of disturbed vegetation structure indicative of disturbance
Maclean et al. (2006) Biological Conservation, 131: 349-58. Conclusions: birds
Birds adversely affecting by habitat loss
Birds not adversely affected by low-intensity disturbance
• Long history of disturbance + extinction filter?
• Mimics of disturbance of evolutionary time scales – e.g. large herbivores?
Possible to target conservation resources efficiently Results: value to people
• Drainage lowers value
• Value maximised with low-intensity use
• If people are poorer, optimum value changes
Maclean et al. (2003) CSERGE ECM 03-10 Results: value to people
Poorest people use wetlands the most
Everyone has One person has equal income all income
Maclean et al. (2003) CSERGE ECM 03-09 Conclusions: people
Papyrus used unsustainably Poverty & income inequity increase Two equilibria:
(1) Sustainable resource use, moderate poverty & income inequity
(2) Unsustainable resource use, high poverty & income inequity
As human population increases, switch from state (1) to (2) increasingly likely
Maclean et al. (2011) Environmental Management, 47: 218-29. Conclusions: general
Win-win for birds and people depends on poverty reduction The way forward
1. Recognise that low-intensity resource use is compatible with conservation
2. Poverty-reduction should be pivotal to conservation policy
3. Seek to diversify income sources as this will break circle of poverty Acknowledgements
Fieldwork assistance: Jez Bird, Mark Hassall, Steven Katungi, Simon Mahood, Rob Martin, Rowan Martin, Richard Moores, Nicodemus Nalianya, Oliver Nasirwa, Johnson Ruhakana, Johnson Tumahairwe
Logistic support / advice: Leon Bennun, Achillis Byaruhanga, Nigel Collar, Lincoln Fishpool, Janet Havers, Alfred Owino, Derek Pomeroy, Charlie Williams
Academic Collaboration: Ros Boar, Mark Hassall, Iain Lake, Charles Lugo, Nicodemus Nalianya, Oliver Nasirwa, Rob Tinch, Rob Wilson
Funders: University of East Anglia, British Ecological Society, Royal Geographic Society, African Bird Club, British Airways