Fig. 5
From: Demographic outcomes of diverse migration strategies assessed in a metapopulation of tundra swans
Productivity of tundra swans from 4 breeding area in Alaska, as represented by percentage of immature (hatch year) birds observed in winter flocks. Data for the Lower Alaska Peninsula are from 1978 to 2006, non-inclusive, whereas estimates from the other sites are for 1980–2000 (see Methods). Eastern population swans are represented by Colville River Delta swans. Values in parentheses are the number of years with productivity estimates