Generally, large birds and seabirds live longer than small birds. Albatrosses live so long that it is hard to calculate their survival rates - they can live longer than the metal rings that identify them, and probably longer than most humans.
Food chain. Definition. A feeding hierarchy in which organisms in an ecosystem are grouped into trophic (nutritional) levels and are shown in a succession to represent the flow of food energy and the feeding relationships between them. Supplement.
It is when we have a picture of a food web in front of us that the definition of food chain makes more sense. We can now see that a food web consists of interlocking food chains, and that the only way to untangle the chains is to trace back along a given food chain to its source.