Nutritional Value of the Aril of Trichilia cuneata, a Bird-Dispersed Fruit

Fruits of Trichilia cuneata (Meliaceae), a common tree in dtiet fotests of Central America, are eaten by a numbet of birds. The fruits are 10 to 12 mm in diameter, covered by a yellowish-brown, capsular exocarp, and contain three to six seeds distributed among three locules. Each seed is covered by an orangish-red aril that averages 59.7 percent lipid and 15.1 petcent protein, which makes this species one of the most nuttitious known. The fleshy tissue of only 15 of 59 other species for which we found data contained at least 10 petcent ptotein (dry wt.). Only nine species of 57 had fleshy tissue containing more than 40 percent lipid (dry wt.). Between 1971 and 1972, weights of whole ftuits decreased by 36 percent, perhaps in response to a severe drought in the area. The decrease was not equally distributed among component tissues of the ftuit. Exocarp decreased by 36 percent, aril by 4 percent, and seeds by 62 petcent, Howevet, the teduction in weight per seed was not so dramatic, fot two teasons. First, the numbet of seeds pet ftuit decreased by 26 percent. Secondly, many seeds did not develop. Thus, the decrease in weight per normally developed seed was only 18 percent. The fruit of Trichilia cuneata was atttactive to both specialized (4 species) and opportunistic (11 species) ftugivorous bitds and is intermediate ("a generalist") in several dispersal-related characteristics.