The same economies of increased dimension can be seen in transport (e.g. the advantage
of large oil tankers, juggernaut lorries, etc). It also helps to explain how heat loss is
less per unit of capacity in larger buildings, as such a loss takes place through the outside
walls. By the same principle, in a harsh winter small birds are more likely to die than
larger birds as their heat loss per unit of body volume is greater. The principle of
economies via increased dimension can be a significant source of scale economy.