Recent decline in suitable environmental conditions for A frican great apes

• Published in: Diversity & distributions Vol. 18; no. 11; pp. 1077 - 1091
• Main Authors: Junker, Jessica, Blake, Stephen, Boesch, Christophe, Campbell, Geneviève, Toit, Louwrens du, Duvall, Chris, Ekobo, Atanga, Etoga, Gilles, Galat‐Luong, Anh, Gamys, Joel, Ganas‐Swaray, Jessica, Gatti, Sylvain, Ghiurghi, Andrea, Granier, Nicolas, Hart, John, Head, Josephine, Herbinger, Ilka, Hicks, Thurston Cleveland, Huijbregts, Bas, Imong, Inaoyom S., Kuempel, Noëlle, Lahm, Sally, Lindsell, Jeremy, Maisels, Fiona, McLennan, Matthew, Martinez, Laura, Morgan, Bethan, Morgan, David, Mulindahabi, Felix, Mundry, Roger, N'Goran, Kouamé Paul, Normand, Emmanuelle, Ntongho, Anne, Okon, David Tiku, Petre, Charles‐Albert, Plumptre, Andrew, Rainey, Hugo, Regnaut, Sébastien, Sanz, Crickette, Stokes, Emma, Tondossama, Adama, Tranquilli, Sandra, Sunderland‐Groves, Jacqueline, Walsh, Peter, Warren, Ymke, Williamson, Elizabeth A., Kuehl, Hjalmar S.
• Format: Journal Article
• Language: English
• Published: 01-11-2012
• ISSN: 1366-9516; 1472-4642
• DOI: 10.1111/ddi.12005

Abstract
Aim
To predict the distribution of suitable environmental conditions (
SEC
) for eight
A
frican great ape taxa for a first time period, the 1990s and then project it to a second time period, the 2000s; to assess the relative importance of factors influencing
SEC
distribution and to estimate rates of
SEC
loss, isolation and fragmentation over the last two decades.
Location
Twenty‐two
A
frican great ape range countries.
Methods
We extracted 15,051 presence localities collected between 1995 and 2010 from 68 different areas surveyed across the
A
frican ape range. We combined a maximum entropy algorithm and logistic regression to relate ape presence information to environmental and human impact variables from the 1990s with a resolution of 5 × 5 km across the entire ape range. We then made
SEC
projections for the 2000s using updated human impact variables.
Results
Total
SEC
area was approximately 2,015,480 and 1,807,653 km
2
in the 1990s and 2000s, respectively. Loss of predicted
SEC
appeared highest for Cross River gorillas (−59%), followed by eastern gorillas (−52%), western gorillas (−32%), bonobos (−29%), central chimpanzees (−17%) and western chimpanzees (−11%).
SEC
for
N
igeria‐
C
ameroon chimpanzees and eastern chimpanzees was not greatly reduced. Except for
C
ross
R
iver and eastern gorillas, the number of
SEC
patches did not change significantly, suggesting that
SEC
loss was caused mainly by patch size reduction.
Main conclusions
The first continent‐wide perspective of
A
frican ape
SEC
distribution shows dramatic declines in recent years. The model has clear limitations for use at small geographic scales, given the quality of available data and the coarse resolution of predictions. However, at the large scale it has potential for informing international policymaking, mitigation of resource extraction and infrastructure development, as well as for spatial prioritization of conservation effort and evaluating conservation effectiveness.