European green woodpecker It also occurs in western Asia. The European green woodpecker has a large range and an Estimated Global Extent of Occurrence of between 1 million to 10 million square kilometres, and a population in the region of 920,000 to 2.9 million birds. Populations appear to be stable, so the species is considered of Least Concern. The species is highly sedentary and individuals rarely move more than around 500 m between breeding seasons. A combination of old deciduous trees for nesting, and nearby feeding grounds with plenty of ants, is essential. This is usually found in semi-open landscapes with small woodlands,
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