The functional ecology of bat pollination in the African sausage tree Kigelia africana (Bignoniaceae)

Plants often interact with a wide range of animal floral visitors that can
vary in their pollination effectiveness. Flowers of the African sausage
tree Kigelia africana are be visited by bats and bush babies during the
night and by birds during the day. We studied floral traits (phenophases,
scent, colour and nectar chemistry) and the visitation frequency and
pollination effectiveness of different flower visitors to determine if K.
africana is functionally specialized for bat-pollination. We found that
flower opening corresponds with bat activity, flowers emit scent dominated
by aliphatic esters and alcohols, and that nectar is produced in copious
amounts accessible to bats. Pollen deposition on stigmas was twenty-fold
greater per-visit by bats than it was per-visit by birds, likely a result
of the close morphological fit between snouts of bats and the flowers.
However, bat visits appear to be rare at some sites and the delayed
senescence of flowers that are open throughout the morning provides an
opportunity for additional pollination by birds. We conclude that K.
africana is primarily adapted for bat pollination, but is also able