Levaillant's woodpecker green woodpecker. The call is a loud ringing laugh, "plue, plue, plue", very like the green woodpecker’s yaffle, but perhaps slightly faster. This woodpecker’s insect food is captured by a rapid outward flick of the long tongue, and gummed to its tip by sticky saliva. Though a large and heavy bird it has an easy, bounding flight. The nest is a hole in a tree, and 4-8 glossy white eggs are laid on wood chips. Levaillant's woodpecker The Levaillant’s woodpecker or Levaillant’s green woodpecker ("Picus vaillantii") is a large African member of the woodpecker family Picidae. Levaillant's woodpecker is sometimes
An Essay on the Nature and Significance of Economic Science on economic methodology in generating a range of tightly-argued, radical implications from a simple definition, for example in admitting an "aspect" of behaviour (rather than a list of behaviours) but not limiting the subject-matter of economics, provided that the influence of scarcity impinges on these (pp. 16–17). The broad behavioural definition is credited for its consistency with the expanding boundaries of economics decades later. In this Robbins both narrows the definition of economics, thereby demonstrating the usefulness of deduction, and opens up the subject-matter of economics. Robbins's "Essay" is one of the most-cited works on the methodology and philosophy of