ADAPTATION AND CONSTRAINT IN THE GROWTH-PATTERN OF LAPWING VANELLUS-VANELLUS CHICKS

The growth and development of lapwing chicks were studied on farmland in Central Scotland [UK]. Selective pressures and constraints imposed by initial priority, limited resources and limitations of the food processing efficiency of the chicks explain the general growth pattern. Those structures with a high early priority, e.g. locomotory and feeding apparatus, were comparatively mature at hatching and developed early. By contrast, wing development was delayed until the chicks had reached a suitable feeding area and were feeding efficiently. Habitat, season and size and weight at hatching were additional intrinsic and environmental factors affecting growth.