Characteristics of vertebrate-dispersed fruits in Hong Kong

Abstract

Hong Kong has a native angiosperm flora of approximately 1800 species, of which 27% (482 spp) bear fleshy, presumably vertebrate-dispersed fruits, including 76% of the 337 tree and shrub species and 70% of the 103 climber species. Morphological characteristics were determined for 255 species and nutritional characteristics of the fruit pulp for 153 species. Most fruit species were black (45 1%) or red (24.3%) and 85.9% had a mean diameter <13 mm Nutritional characteristics varied widely between species with ranges and median values as follows: pulp percentage (range 10.0-99 2%, median 69 2%), water content of pulp (11 1-94 0%, 78%), lipid (0-84 0%, 2 0%), soluble carbohydrate (4-88%, 53%), nitrogen (0.2-3.4%, 0.86%), neutral detergent fibre (1-44%, 14.3%) Fruit development time (50-360 d, 156 d) showed a negative correlation with lipid content, but no significant correlation with fruit or seed size. Principal components analysis of fruit characteristics was dominated by a trend from single-seeded fruits with a thin, lipid-rich pulp layer to multiple-seeded fruits with much, watery, carbohydrate-rich pulp. Bird-dispersed species cover the full range of fruit characteristics except those too large to swallow and too hard to peck bits from. Mammals (bats, civets and/or macaques) are known or suspected to consume most of the fruits too large for birds as well as many bird fruits but none with high-lipid content Summer fruits (May-September) were significantly larger and had significantly higher seed size and carbohydrate content than winter fruits (November-March) Winter fruits took more than twice as long to develop as summer fruits.