Wildlife photography on northern Tàan, sea lion (Prince of Wales Island). I was hosted by Don and Andrea Hernandez at …2017 | Richard Carstensen | 2 minutes
Who eats who?
Southeast food pyramids
When you catch a fish, do you open its stomach to learn about its last few meals? If you hunt grouse or mallards, do you examine crops? Before enjoying the first tenderloin from guwakaan, the peace keeper (Sitka black-tailed deer), do you search for plant fragments on the back of its tongue, or open the rumen—that magic sack that converts the mostly-humanly-inedible flora of our bioregion into the tastiest meat on the planet?
One of the oldest books in my natural history library is American wildlife & plants: A guide to wildlife food habits. Martin, Zim & Nelson, 1951. The reason it remains relevant 65 years later, while other ecological works of the period have been supplanted, is that nowadays people look askance at shooting a couple hundred herons just to see what’s in their stomachs: 43% non-game fish, 25% “useful species,” 8% each of insects & crayfish, 5% mice & shrews, 4% herps. (Another thing ecologists rarely do anymore—applied entomologists perhaps excepted—is classify species as “useful,” which would sort of beg the question as to who is non-useful.)
This trophic diagram shows why salt marshes—constituting less than 1% of our land mass—are so essential to resident and migratory species from land and sea. Dashed arrow lines lead from eaten to eater. For more background on salt marsh trophics, see pages 80 to 85 in the 3rd edition of Nature of Southeast Alaska.