To date, c.18% of Amazonia’s tropical forest has been cleared (INPE 2011) and models have been developed projecting up to 40% forest loss by 2050 (Soares-Filho et al. 2006). A recent study used these published models to project rates of population decline in Amazonian birds (Bird et al. 2011), and apply these to the Red List A4 criterion.
The A4 criterion has thresholds for observed, estimated, inferred, projected or suspected population reduction (up to a maximum of 100 years) where the time period must include both the past and the future, and where the causes of reduction may not have ceased or may not be understood or may not be reversible’ (IUCN 2001). The thresholds for declines over 10 years or three generations (whichever is longer), are: >80% for Critically Endangered, >50% for Endangered and >30% for Vulnerable.
BirdLife International’s distribution maps for all bird species (http://www.birdlife.org/datazone/info/spcdownload3) were used to identify a total of 814 species for which more than 50% of their global range lies within the limits of Amazonia (see Bird et al. 2011 for details) and which are coded as having ‘medium’ or ‘high’ forest dependence in BirdLife’s World Bird Database (see definitions in attached spreadsheet).
Generation lengths from BirdLife’s World Bird Database were used to define three generation trend periods for calculating population trends for applying criterion A4. Percentage population reductions were calculated based upon the proportion of forest projected to be lost within each species’ range over three generations beginning in 2002 and extending into the future, under optimistic and pessimistic deforestation scenarios from Soares-Filho et al. (2006).
The attached excel table presents for 814 species that are largely restricted to the Amazon (ie >50% of range in the Amazon) and which have high or medium forest dependence: generation lengths and the underlying parameters used to calculate them, projected population trends under different scenarios (including adjustment for those species more susceptible to fragmentation, edge-effects and hunting), current and proposed revisions to IUCN Red List categories (see Bird et al. 2011 for further details).
The table is filtered in column V to show the 180 species for which Red List category revisions are proposed.
We would like to seek comments on the following issues for any of these species:
1. Is the classification of forest dependence correct?
2. Is the classification of susceptibility to edge-effects, fragmentation and hunting correct?
3. Does the generation length estimate seem reasonable?
4. Is the deforestation rate in the non-Amazonian part of the species’s range likely to be substantially higher or lower than that projected in the Amazon?
5. Does the overall revised classification seem reasonable?
Bird, J. P., Buchanan, G. M., Lees, A. C., Clay, R. P., Develey. P. F., Yépez, I. and Butchart, S. H. M. (2011) Integrating spatially explicit habitat projections into extinction risk assessments: a reassessment of Amazonian avifauna incorporating projected deforestation. Diversity and Distributions DOI: 10.1111/j.1472 4642.2011.00843.x. http://wileyonlinelibrary.com/journal/ddi.
INPE (2011) Monitoramento da Floresta Amazônica Brasileira por Satélite: Projeto PRODES (in Portuguese). Instituto Nacional de Pesquisas Espaciais, Saõ José dos Campos, Saõ Paulo. Available at: http://www.obt.inpe.br/prodes/index.html (accessed 15 June 2011).
IUCN (2001) IUCN Red List categories and criteria: version 3.1. IUCN Species Survival Commission. International Union for the Conservation of Nature, Gland, Switzerland and Cambridge, UK.
IUCN (2008) Guidelines for using the IUCN Red List categories and criteria. Version 7.0. Available at: http://www.iucnredlist.org/documents/redlist_guidelines_ v1223290226.pdf (accessed 10 November 2010).
Soares-Filho, B.S., Nepstad, D.C., Curran, L.M., Cerqueira, G.C., Garcia, R.A., Ramos, C.A., Voll, E., McDonald, A., Lefebvre, P. & Schlesinger, P. (2006) Modelling conservation in the Amazon basin. Nature, 440, 520–523.
EDIT 5 December: Chris Sharpe and Alex Lees have proposed a number of modifications to these proposals based on revised assessments of degree of forest dependence, tolerance or sensitivity to habitat degradation/fragmentation, distribution extent and likely losses outside Amazonia, in particular drawing on the contributions of experts to the ongoing Brazilian Red Data Book process. The revised spreadsheet below shows an updated set of proposed revisions (with comments and justifications given in the right hand most columns):