1. 1.

   A biplot is a tool to visualise the results of multivariate techniques such as principal component analysis, correspondence analysis, redundancy analysis, or canonical correspondence analysis. Using specific rules in the PCA biplot, correlations (or covariances) among the original variables, relationships among observations, and relationships between observations and variables can be inferred. There are various ways to scale the biplot, and the interpretation of the biplot depends on this scaling.

2. 2.

   In Chapter 2 we provided an explanation forWingcrd,Tarsus,Head, andWt.Culmen measures the length of the top of the bill from the tip to where feathering starts, andNalospi the distance from the bill top to the nostril.

Authors and Affiliations

1. Highland Statistics Ltd., 6 Laverock Road, Newburgh, UK, AB41 6FN

   Alain F. Zuur & Elena N. Ieno

2. IMARES, Institute for Marine Resources & Ecosystem Studies, 1797 SH ’t Horntje, The Netherlands

   Erik H. W. G. Meesters

Corresponding author

Correspondence toAlain F. Zuur.

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