European green woodpecker lower black border to the moustache. Juveniles are spotty and streaked all over; the moustache is dark initially, though juvenile males can show some red feathers by early June or usually by July or August. Moult takes place between June and November with the first flight feathers being lost around the time the young fledge. Juveniles moult quickly after fledging and gain their adult plumage between August and November. Although the European green woodpecker is shy and wary, it is usually its loud calls, known as yaffling, which first draw attention. It 'drums' rarely (a soft, fast roll), but often
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