Average price (in US dollars) of Mexican parrots in Mexico and the USA in relation to their attractiveness.

<p>Attractiveness scores are those shown in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0107546#pone-0107546-g002" target="_blank">Figure 2</a>. Prices were recorded in 1999–2006. Black dots represent <i>Ara</i> and <i>Amazona</i> species, while empty dots represent other parrot species.</p>