268 |Habitat assessment
Weins, J.A. (1973). Pattern and process in grassland bird communities. Ecol. Monogr., 43,
237–270.
Wiersma, P. and Piersma, T. (1994). Effects of microhabitat, flocking, climate and migra-
tory goal on energy expenditure in the annual cycle of red knots. Condor, 96, 257–279.
Woiwod, I.P. and Harrington, R. (1994). Flying in the Face of Change: The Rothamsted Insect
Survey. In Long term Experiments in Agriculture and Ecological Sciences, eds. R.A. Leigh and
A.E. Johnston, pp. 321–342. CAB International.