Resumo

GRASES, C  e  RAMIREZ, N. Biología reproductiva de cinco especies ornitófilas en un fragmento de bosque caducifolio secundario en Venezuela. Rev. biol. trop [online]. 1998, vol.46, n.4, pp.1095-1108. ISSN 0034-7744.

The floral biology, the pollination biology and the mating system were studied in two native and three introduced species of an arboretum in Venezuela. All the species presented thin, long, tubular corollas; predominantly red. The antheses were diurnal (between 04:00 and 11:00 hr). Nectar production was high, except for Salvia coccinea (Lamiaceae) (native). Nicotiana glauca (Solanaceae) (native) and Erythrina mitis (Fabaceae) (introduced) shared their hummingbird pollinators, Chlorostilbon mellisugus and Amazilia tobaci (Apodiformes, Throchilidae). S. coccinea was pollinated by Heliconius erato (Lepidoptera). Kalanchöe pinnata and K. daigremontiana (Crassulaceae) (exotic) did not receive any visits. All the species were hermaphrodite. K. daigremontiana and K. pinnata were obligate outcrossers, and S. coccinea N. glauca and E. mitis were partialy outcrossers and non-autogamus. The species presented high total biomass allocation, compared to other polination systems. The reproductive biomass allocation were allways smaller than the attraction and vegetative biomass allocation. The male biomass allocation were greater than the female biomass allocation in N. glauca, S. coccinea and E. mitis; and smaller in K. daigremontiana and K. pinnata. The introduced species did not seem to affect the reproductive efficiencies of the native species during our observation period. The lowest reproductive efficiencies in introduced species resulted as a consequence of the absence of their natural pollinators.

Palavras-chave : Hummingbirds; hummingbird pollination; deciduous forest; biomass allocation; reproductive system; reproductive eficiency; introduced species.