SUPPORTING INFORMATION
Geographical variability in propagule pressure and climatic suitability explain the
European distribution of two highly invasive crayfish
César Capinha, Lluís Brotons and Pedro Anastácio
JOURNAL OF BIOGEOGRAPHY
Appendix S1 List of crayfish species which have co-occurring European populations with
the red swamp crayfish or the signal crayfish and are known competitors for resources or
space. Listed references represent only a subset of studies referring to these biotic
interactions.
Red swamp crayfish
Signal crayfish
Red swamp crayfish
Alonso & Martínez (2006)
(Procambarus clarkii Girard)
Spiny cheek crayfish
(Orconectes limosus
Rafinesque)
-
Hudina et al. (2011)
-
Bäck (1995)
Gherardi & Cioni (2004)
Dunn et al. (2009)
-
Vorburger & Ribi (1999)
-
Holdich et al. (1995)
Noble crayfish
(Astacus astacus Linnaeus)
White-clawed crayfish
(Austropotamobius pallipes
Lereboullet)
Stone crayfish
(Austropotamobius
torrentium Shrank)
Narrow-clawed crayfish
(Astacus leptodactylus
Eschscholtz)
References
Alonso, F. & Martínez, R. (2006) Shelter competition between two invasive crayfish species:
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Bäck, B.S. (1995) Replacement of the native crayfish Astacus astacus by the introduced
species Pacifastacus leniusculus in a Swedish lake: possible causes and mechanisms.
Freshwater Biology, 33, 291-304.
Dunn, J., McClymont, H., Christmas, M. & Dunn, A. (2009) Competition and parasitism in
the native White Clawed Crayfish Austropotamobius pallipes and the invasive Signal
Crayfish Pacifastacus leniusculus in the UK. Biological Invasions, 11, 315-324.
Gherardi, F. & Cioni, A. (2004) Agonism and interference competition in freshwater
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Holdich, D.M., Reader, J.P., Rogers, W.D. & Harlioglu, M. (1995) Interactions between three
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Vorburger, C. & Ribi, G. (1999) Aggression and competition for shelter between a native and
an introduced crayfish in Europe. Freshwater Biology, 42, 111-119.
Appendix S2 Invader’s distribution data and candidate explanatory variables used for
predicting the current European distribution of the signal and the red swamp crayfish. Data
sources are found in the main manuscript and in Text S1 (below).
Figure S1 World-wide occurrences for the signal crayfish.
Figure S2 Candidate explanatory variables used for predicting the current European
distribution of the signal crayfish: (a) country-level introduction effort; (b) mean human
footprint; (c) richness of competing crayfish species; (d) climatic suitability based on the
climatic conditions occupied in the native range; (e) climatic suitability based on the climatic
conditions occupied in invaded areas outside Europe; and (f) climatic suitability based on the
climatic conditions occupied in the native range and in invaded areas outside Europe.
Figure S3 World-wide occurrences for the red swamp crayfish.
Figure S4 Candidate explanatory variables used for predicting the current European
distribution of the red swamp crayfish: (a) country-level introduction effort; (b) mean human
footprint; (c) richness of competing crayfish species; (d) climatic suitability based on the
climatic conditions occupied in the native range; (e) climatic suitability based on the climatic
conditions occupied in invaded areas outside Europe; and (f) climatic suitability based on the
climatic conditions occupied in the native range and in invaded areas outside Europe.
Text S1 Key references used to assess country-level introduction effort.
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(2006) The crayfish plague in the Czech Republic - review of recent suspect cases and
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Pöckl, M. (1999) The distribution of native and introduced species of crayfish in Austria.
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Appendix S3 Additional partial dependence plots.
Figure S5 Smoothed partial dependence plots of one representative boosted regression trees
model for the signal crayfish using a climatic suitability model based on the species native
range. The relative contribution of each predictor in this specific model is show in
parentheses.
Figure S6 Smoothed partial dependence plots of one representative boosted regression trees
model for the signal crayfish using climatic suitability based on the species invasive range
outside the study area. The relative contribution of each predictor in this specific model is
show in parentheses.
Figure S7 Smoothed partial dependence plots of one representative boosted regression trees
model for the red swamp crayfish using a climatic suitability model based on the species
native range. The relative contribution of each predictor in this specific model is show in
parentheses.
Figure S8 Smoothed partial dependence plots of one representative boosted regression trees
model for the red swamp crayfish using climatic suitability based on the species invasive
range outside the study area. The relative contribution of each predictor in this specific model
is show in parentheses.