Male spotted bowerbirds propagate fruit for use in their sexual display

Figure 1. Fruits propagated by bowerbirds. (A) Solanum ellipticum plant and fruit. Scale in cm. (B) Established bower surrounded by Solanum plants. (C) Mean (±1 s.e.) numbers of Solanum plants in 2010 at: randomly selected sites within the study area (n = 20); new bower sites that were being used for the first time (n = 11); established bower sites that had been used for more than one year (n = 14). (D) Visual properties of Solanum fruit. The inset shows mean reflectance spectra, and the main panel shows all fruits as points in avian V-type LMSU colour space. Circles and solid line: fruits collected on bowers; solid dots and broken line: fruits collected <10m from bowers; stars and dotted line: fruits collected >300m from bowers. In LMSU colour space what humans call hue is represented by the angle a point drawn to the origin subtends on the axes (up = red, clockwise through green, blue, uv), and what we call ‘chroma’ or ‘purity’ is represented by the distance from the origin. The fruit found on bowers is slightly greener and less chromatic than those found off the bowers, with fruit with higher chroma and relatively more yellow far from the bower. On bower vs. near fruit permutation test effect size = 0.08, p < 0.0001; on bower vs. far fruit effect size = 0.21, p < 0.0001, combined on and near bower fruit vs. far fruit effect size = 0.14, p < 0.0001. Male spotted bowerbirds propagate fruit for use in their sexual display