Potential seed dispersal mechanism of Kigelia africana (Lam.) Benth. in an urban habitat

Abstract

ABSTRACT Kigelia africana is known to exhibit megafaunal syndrome. Many mega faunal taxa having become extinct with time, the species seems to have adapted to its changing environment by ensuring the dispersal of its seeds by alternative dispersers. The present investigation reports the mechanism of seed dispersal adopted by individuals of K. africana grown in India, outside the species natural environment. The massive – ~2.0 kg – indehiscent and unattractive fruits retain the wingless seeds. Of more than 300 seeds present in a fruit in average, approximately 92% remained viable at maturity, and the viability decreased over time after 1 year. We observed that numerous termites (Coptotermes formosanus) initiated the disintegration of the fallen fruits particularly during monsoon. Three-striped squirrels (Funambulus palmarum), classified as scatter hoarding rodents, then accessed these fruits and their seeds, and actively carried about 48% seeds with broken coats to a distance of 40 m away from the mother trees. The coordinated activity of these two dynamic vectors ensured successful seed dispersal in K. africana at the study site, suggesting that the species may have developed a way to adapt to its new environment.