Poster presentation 12th International Mammalogical Congress

Who contributed to the evolution of multiple fruits in Asian dogwoods (Cornus)? (#675)

Akito Toge 1
  1. Primate Research Institute, Kyoto University, Inuyama, Aichi, Japan

Cornus is a genus of woody plants, commonly known as dogwoods. Various species of dogwoods are native throughout much of temperate and boreal Eurasia and North America. Though most Cornus species produce simple fruits, which is the ancestral character, some Asian dogwoods including C. kousa make red multiple fruits. Flowers are separated in these species, but the separability is lost as flowers change to fruits. Eyde (1986) insists that multiple fruits have evolved via seed dispersal by Asian monkeys, who can discriminate red from green, and American dogwoods fruits remain simple because the New World monkeys, blind to red and living in warmer region, never took up foraging on them. This traditional view, however, seems to be incorrect. I monitored the number of C. kousa fruits on the ground and on the tree for two weeks, and found that the proportion of ripe fruits on the ground was constantly high. This shows that the fruits tended to fall off trees soon after they get ripe. On the other hand, I stayed nearby C. kousa trees, observed animals visiting there, and found that, though wild Japanese monkey (Macaca fuscata) ate many unripe fruits on the tree, they consumed few fruits on the ground even though many ripe ones still existed. When monkeys ate unripe fruits, I heard them chewing and fracturing seeds. These results suggest that terrestrial mammals other than monkeys could be the better seed dispersers of C. kousa, and have contributed to the evolution of multiple fruits in dogwoods.