Feeding schedule and daily food consumption in red-throated loons (Gavia stellata) over the prefledging period

We describe parental feeding activities of Red-throated Loons (Gavia stellata) throughout the prefledging period at two freshwater nesting territories in coastal British Columbia. The nesting lake contained resident fish populations, but adult loons fed marine fish to their young, making an average of 11 flights per day (average duration 60 min per flight) to the ocean and returning each time with a single fish. Small shallow-bodied fish (Ammodytid , Pholid ), which were easily swallowed by chicks, predominated in the diet during the 3 days following hatching. The total weight of fish fed to the chicks per day (8-194 g) increased over the prefledging period: adults returned fewer but larger fish (Embiotocid ) as the chick aged. Of the fish offered, 4% were too large for the chick to swallow.

T. E. Reimchen and Sheila Douglas, The Auk 101: 593-599. July 1984