title: Differential passage time of mistletoe fruits through the gut of honeyeaters and flowerpeckers: effects on seedling establishment.
abstract: McKey's (1975) hypothesis that avian dispersers with a specialized gut provide higher quality seed dispersal than unspecialized frugivores was tested using grey mistletoe (Amyema quandang) fruits, and captive mistletoebirds (Dicaeum hirundinaceum) and spinycheeked honeyeaters (Acanthagenys refogularis) in arid South Australia. Mistletoebirds have a specialized gut, unlike spiny-cheeked honeyeaters. The gut passage time of A. quandang fruits through mistletoebirds was 820±29 s (mean±SE, n=188), compared to 2434±36 s (n=436) for honeyeaters. The seeds defecated by both bird species were deployed on twigs of host trees. Despite the longer retention time of fruit in the gut of honeyeaters, the germination percentage of seeds defecated by mistletoebirds (85% of 485 seeds) and honeyeaters (81% of 485 seeds) did not differ significantly 1 week after deployment. However, after 5 months, a significantly greater proportion of seedlings had established from seeds passed by mistletoebirds (42.7%) than from seeds defecated by honeyeaters (31.1%). The data support the notion that the more gentle treatment of seeds in the gut of specialized dispersers translates into higher seedling establishment.
authors.affiliation: Department of Ecosystem Management, University of New England, 2351, Armidale, NSW, Australia.
authors.forename: S R
authors.initials: SR
authors.lastname: Murphy
authors.affiliation: Department of Ecosystem Management, University of New England, 2351, Armidale, NSW, Australia.
authors.forename: Nick
authors.initials: N
authors.lastname: Reid
authors.affiliation: Department of Ecosystem Management, University of New England, 2351, Armidale, NSW, Australia.
authors.forename: Zhaogui
authors.initials: Z
authors.lastname: Yan
authors.affiliation: Department of Statistics, University of Adelaide, PO Box 498, 5001, Adelaide, SA, Australia.
authors.forename: W N
authors.initials: WN
authors.lastname: Venables
keywords: Bird dispersal; Coevolution; Gut passage time; Mistlctoe; Seedling establishment