First record of Mucuna analuciana (Fabaceae) for the flora of the Southern Cone of South America and of pollination by bats in Northeastern Argentina

Abstract

In tropical and subtropical regions of the world, phytophagous bats are among the most efficient pollinators. In northern Argentina, they marginally inhabit subtropical forests and, according to recent findings they act as pollinators, at least in the western sector, represented by the Yungas. We set out to corroborate whether pollination by bats also takes place in the northeastern subtropical margin of Argentina (NEA), represented by the Alto Paraná Atlantic Forests. To this end, first, we analyzed pollen in feces from a colony located in the Osununú Natural Reserve, Misiones Province, inhabited by two phytophagous bats species (family Phyllostomidae), one nectar-feeding (Glossophaga soricina) and another fruit-feeding (Carollia perspicillata). Second, we analyzed local chiropterophilous plants for claw marks on flowers, which are attributable to bats when taking nectar. Palynological analysis revealed pollen attributable to Mucuna (Fabaceae) specimens collected in NEA. Marks on Mucuna flowers agree with those expected by visiting bats. Of the specimens of Mucuna collected so far in Argentina, only one can be assigned to M. sloanei, the only species known from Argentina, while the remaining specimens can be assigned to Mucuna analuciana. Thus, M. analuciana can be included as a new member of the flora of Argentina and the Southern Cone of South America extending its recorded range 1300 km to the south-west. Pollen found in the feces and marks on the flowers lend strong support to the occurrence of pollination of M. analuciana by bats and represent the first evidence of pollination by bats for this species and for the NEA. M. analuciana and G. soricina coexist in Corrientes, so bat pollination may occur in the NEA farther southwest than recorded here. It is auspicious that interactions between these locally rare species are taking place while the relevance of the Reserve and its recognition as an Area of Importance for the Bat Conservation is highlighted.