title: Differential foraging preferences on seed size by rodents result in higher dispersal success of medium-sized seeds.
abstract: Rodent preference for scatter-hoarding large seeds has been widely considered to favor the evolution of large seeds. Previous studies supporting this conclusion were primarily based on observations at earlier stages of seed dispersal, or on a limited sample of successfully established seedlings. Because seed dispersal comprises multiple dispersal stages, we hypothesized that differential foraging preference on seed size by animal dispersers at different dispersal stages would ultimately result in medium-sized seeds having the highest dispersal success rates. In this study, by tracking a large number of seeds for 5 yr, we investigated the effects of seed size on seed fates from seed removal to seedling establishment of a dominant plant Pittosporopsis kerrii (Icacinaceae) dispersed by scatter-hoarding rodents in tropical forest in southwest China. We found that small seeds had a lower survival rate at the early dispersal stage where more small seeds were predated at seed stations and after removal; large seeds had a lower survival rate at the late dispersal stage, more large seeds were recovered, predated after being cached, or larder-hoarded. Medium-sized seeds experienced the highest dispersal success. Our study suggests that differential foraging preferences by scatter-hoarding rodents at different stages of seed dispersal could result in conflicting selective pressures on seed size and higher dispersal success of medium-sized seeds.
authors.affiliation: Center for Integrative Conservation, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla 666303, China.|State Key Laboratory of Integrated Management of Pest Insects and Rodents in Agriculture, Institute of Zoology, Chinese Academy of Sciences (CAS), Beijing 100101, China.|Key Laboratory of Bio-Resources and Eco-Environment, Ministry of Education, College of Life Science, Sichuan University, Chengdu 610064, China.
authors.forename: Lin
authors.initials: L
authors.lastname: Cao
authors.affiliation: College of Life Sciences, Jiangxi Normal University, Nanchang 330022, China.
authors.forename: Zhenyu
authors.initials: Z
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Integrated Management of Pest Insects and Rodents in Agriculture, Institute of Zoology, Chinese Academy of Sciences (CAS), Beijing 100101, China.
authors.forename: Chuan
authors.initials: C
authors.lastname: Yan
authors.affiliation: Center for Integrative Conservation, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla 666303, China.
authors.forename: Jin
authors.initials: J
authors.lastname: Chen
authors.affiliation: Key Laboratory of Bio-Resources and Eco-Environment, Ministry of Education, College of Life Science, Sichuan University, Chengdu 610064, China.
authors.forename: Cong
authors.initials: C
authors.lastname: Guo
authors.affiliation: State Key Laboratory of Integrated Management of Pest Insects and Rodents in Agriculture, Institute of Zoology, Chinese Academy of Sciences (CAS), Beijing 100101, China.
authors.forename: Zhibin
authors.initials: Z
authors.lastname: Zhang
mesh_terms: D000818:Animals; D003710:Demography; D005247:Feeding Behavior / Q000502:physiology*; D012377:Rodentia / Q000502:physiology*; D058614:Seed Dispersal; D012639:Seeds / Q000033:anatomy & histology*
keywords: larder-hoarding; scatter-hoarding; seed dispersal; seed dispersal success; seed size selection; seedling establishment; small rodents