S. Arizaga et al., Pollination ecology of Agave macroacantha (Agavaceae) in a Mexican tropical desert. II. The role of pollinators, AM J BOTANY, 87(7), 2000, pp. 1011-1017
We did a series of observational studies and manipulative experiments on th
e guild of nocturnal visitors of Agave macroacantha, including (1) a descri
ption of the hourly patterns of visits by moths and bats, (2) an evaluation
of the relative contribution of bats and moths to flowering success, and (
3) an evaluation of the pollination efficiency of the different bar species
. Scapes exposed to moths but excluded to bats yielded similar to 50% fewer
fruits than those exposed to both pollinator groups. Flowers exposed to th
e bat species Leptonycteris curasoae showed similar fruiting success to tho
se exposed to Choeronycteris mexicana and to those exposed to the whole noc
turnal visitor guild. However, the fruits originated from flowers pollinate
d by Lepronycteris curasoae yielded significantly more seed than those expo
sed to Choeronycteris mexicana or to the whole pollinator guild. It is conc
luded that Agave macroocantha is extremely dependent on nocturnal pollinato
rs for its reproductive success and that bats are especially important for
successful pollination. Some of these pollinators are migratory and have be
en reported to be steadily declining. A continuing decline in the populatio
ns of pollinators may impede the successful sexual reproduction of the plan
t host and may put the long-term survival of this agave species under risk.