Secondary removal of seeds dispersed by chimpanzees in a Nigerian montane forest Paul E. Dutton 1 *, Hazel M. Chapman 1 and Elena Moltchanova 2 1 School of Biological Sciences, University of Canterbury, Private Bag 4800, Christchurch 8140, New Zealand and 2 Department of Mathematics and Statistics, University of Canterbury, Private Bag 4800, Christchurch 8140, New Zealand Abstract The effectiveness of chimpanzees as seed dispersers may be influenced by the secondary removal and/or dispersal of seeds by other taxa. This study documents species involvement and their influences on seed treatments (fresh seed, dry seed and seeds rubbed in fresh chimpanzee faeces). Field experiments conducted on ten large-seed species consumed by chimpanzees in a Nigerian montane forest showed that secondary seed removal after 24 h varied between species. After 96-h, seed removal still varied between species, but no previous significant differ- ences were observed among treatments, which suggested treatment becomes insignificant with time. Dispersal by chimpanzees may be more important for some large-seeded species than others. The taxa removing seeds varied across seed species but were mainly restricted to rodents. Key words: Africa, chimpanzee, faeces, rodents, secondary dispersal, seed removal R esum e L’efficacit e des chimpanz es en tant que disperseurs de semences pourrait ^ etre influenc ee par les pr el evements et/ou les dispersions par d’autres taxons. Cette  etude documente l’implication de l’esp ece et son influence sur les traitements des semences (semences fra ^ ıches, s eches ou modifi ees par leur passage par les excr ements de chim- panz es). Des exp eriences de terrain men ees sur dix grandes esp eces de semences consomm ees par les chimpanz es dans une for^ et de montagne nig eriane ont montr e que l’ elimin- ation secondaire des semences apr es 24 heures variait selon les esp eces. Apr es 96 heures, l’enl evement des semences variait encore selon les esp eces, mais aucune des diff erences significatives ant erieures n’ etait observ ee selon les traitements, ce qui laisse penser que le traitement devient insignifiant avec le temps. La dispersion par les chimpanz es pourrait ^ etre plus importante pour certaines esp eces  a grosses semences que pour d’autres. Les taxons qui enl event des semences diff erent selon l’esp ece de semence mais ce sont principalement des rongeurs. Introduction Chimpanzees (Pan troglodytes) consume large fruit meals from many tree species, have large home ranges and use a variety of habitats so that they play an important role in dissemination of seeds in many African forests (Wrangham, Chapman & Chapman, 1994). They are one of the largest African primate species (Mack, 1993), and because in frugivores, there is a positive correlation between body size and gape width, they are especially important for the dispersal of large-seeded species (Moermond & Denslow, 1985; Wrangham, Chap- man & Chapman, 1994; Lambert, 1999). However, in African forests and elsewhere in the tropics, hunting and forest fragmentation are leading to defaunation and associated loss of primate-mediated seed dispersal (McCon- key et al., 2011; Effiom et al., 2013; Harrison et al., 2013). In Nigerian montane forests, the marked decrease in the abundance of the Nigerian–Cameroon chimpanzee, Pan troglodytes ellioti, over the past 30 years (Chapman, Olsen & Trumm, 2004; Morgan et al., 2011), has inevitably influenced dispersal of large-seeded species. While other dispersers of large seed include the putty-nosed monkey (Cercopithecus nictitans), the tantalus monkey (Chlorocebus tantalus), the olive baboon (Papio anubis), and large birds such as the grey hornbill (Tockus nasutus) none of these fulfil the role of chimpanzees. Cercopithecus nictitans disperse seeds in relatively low abundances and small *Correspondence: E-mail: duttonpe@hotmail.com 438 © 2014 John Wiley & Sons Ltd, Afr. J. Ecol., 52, 438–447