Title Fruiting and flushing phenology in Asian tropical and temperate forests: implications for primate ecology

19 In order to understand the ecological adaptations of primates to survive in 20 temperate forests, we need to know the general patterns of plant phenology in 21 temperate and tropical forests. Comparative analyses have been employed to 22 investigate general trends in the seasonality and abundance of fruit and young 23 leaves in tropical and temperate forests. Previous studies have shown that 1) 24 fruit fall biomass in temperate forest is lower than in tropical forest, 2) non-fleshy 25 species, in particular acorns, comprise the majority of the fruit biomass in 26 temperate forest, 3) the duration of fruiting season is shorter in temperate forest, 27 and 4) in most temperate forests the fruiting peak occurs in autumn. Through 28 our comparative analyses on the fruiting and flushing phenology between Asian 29 temperate and tropical forests, we revealed that 1) fruiting is more annually 30 periodic (the pattern in one year is similar to the one in the next year) in 31 temperate forest in terms of the number of fruiting species or trees, 2) there is no 32 consistent difference in inter-annual variations in fruiting between temperate and 33 tropical forests, although some oak-dominated temperate forests exhibited 34 extremely large inter-annual variations in fruiting, 3) the timing of the flushing 35 peak is predictable (in spring and early summer) and 4) the duration of the 36 flushing season is shorter. The flushing season in temperate forests (17-28% 37 of that in tropical forests) was quite limited, even compared to the fruiting season 38 (68%). These results imply that temperate primates need to survive a long 39 period of scarcity of the young leaves and fruits, but the timing is predictable. 40 Therefore, dependence on low-quality foods would be indispensable for 41 temperate primates, such as mature leaves, buds, bark and lichens. Due to the 42 high predictability of the timing of fruiting and flushing in temperate forests, fat 43 accumulation during the fruit-abundant period and fat metabolization during the 44 subsequent fruit-scarce period can be an effective strategy to survive the lean 45 period (winter). 46