Forehead patch size in 30 male Collared Flycatachers measured in two
consecutive years.
A data frame with 30 observations on the following 2 variables.
- patch98
a numeric vector
- patch99
a
numeric vector
Source
Griffith, S.C. and B.C. Sheldon. 2001. Phenotypic plasticity in the
expression of a sexually selected trait: neglected components of variation.
Animal Behaviour 61: 987-993.