Tropical Fruit-Eating Birds and Their Food Plants: A Survey of a Costa Rican Lower Montane Forest

Abstract

In the lower montane forests of Monteverde, Costa Rica, at least 70 bird species rely on fruits to different degrees. We present over 700 records of birds feeding on the fruits of 171 plant species in a survey of a single site intended to complement Snow's (1981) world survey of fruit-eating by birds. The frequency with which birds visited plants and the characteristics of the fruits (dimensions, color patterns, nutritional traits) are also described. The number of bird species recorded feeding on the fruits of a particular plant species was positively correlated with the size of the plant and with its commonness. Because biases may also be introduced by observing plant species for different amounts of time, we distinguish those plant species that were thoroughly studied from others studied only casually. Plants in five genera (Acnistus, Citharexylum, Ficus, Hampea, and Sapium) attract more than 20 bird species; at about half of all plant species, we observed fewer than three bird species. These results should lead to a better understanding of the characteristics of neotropical fruits and the diets of fruit-eating birds.