Fruit Characteristics of Species Dispersed by the Black Lemur (Eulemur macaco) in the Lokobe Forest, Madagascar1

Abstract

I describe the fruit characteristics of species closely associated with black lemur seed dispersal (i.e., species that are often dispersed by the black lemur and only dispersed by the black lemur in the Lokobe Forest). A black lemur group was habituated and observed during the day and night for all months of the year (total 1272 h). When fruits were eaten, the plant species was identified, the maturity of the fruit and treatment of the seeds noted, and the fruit described in terms of ripe fruit color, husk thickness, fruit length, and seed length and width. Black lemur feces were searched for seeds; these were identified and signs of damage noted. Other potential dispersers feeding on the fruits of species eaten by the black lemur were also noted. The black lemurs were seen eating the fruits of 70 species. Of these, 51 species were defined as closely associated with black lemur dispersal and 16 species had seeds that were either often preyed upon or wasted by the black lemur, or were seen being eaten by other potential seed dispersers. Fruits of species in the former group were often dull colored (94% of species); rarely less than 1 cm long (6%); rarely had seeds less than 0.1 cm long or less than 0.1 cm wide (2 and 4%, respectively); never had seeds more than 4 cm long or greater than 2 cm wide; and quite often had either thick husks (49%) or thin husks (51%). In contrast, the fruits of the latter group were often brightly colored (75% of species) and nearly always had a thin husk (94%). Also, this latter group included more small and very large fruits and seeds than the former group. Fruit characteristics significantly associated with the former group were: dull color, thick husk, fruit length greater than 2 cm, seed length 1–4 cm, and seed width 1–2 cm. The extent to which these traits are the result of coevolution between plants and the guild of lemur dispersers that includes the black lemur is not clear, but a coevolved lemur–fruit syndrome remains a possibility.