They respond to danger by diving rather than flying, and are in any case much less wary than ducks. Extant species range in size from the least grebe, at 120 grams (4.3 oz) and 23.5 cm (9.3 inches), to the great grebe, at 1.7 kg (3.8 lbs) and 71 cm (28 inches).hey respond to danger by diving rather than flying, and are in any case much less wary than ducks. Extant species range in size from the least grebe, at 120 grams (4.3 oz) and 23.5 cm (9.3 inches), to the great grebe, at 1.7 kg (3.8 lbs) and 71 cm (28 inches).
Noun. 1. productivity-the quality of being productive or having the power to produce. productiveness. fruitfulness, fecundity-the quality of something that causes or assists healthy growth.
1 Productivity is not the same as production. 2  Productivity growth may occur even when output (production) remains the same. 3  It is also not a measure of competitiveness or profitability. 4  Finally, productivity is not a complete performance management tool.