1. Mistletoe infection prevalence typically differs between host tree species. Differences in infection prevalence between hosts are probably the product of mistletoe-host compatibility and frequency of seed deposition on that host by dispersers. 2. We recorded patterns of infection prevalence of two mistletoes, Phragmanthera dschallensis Engl. and Plicosepalus kalachariensis Schinz (Loranthaceae), on different host species. We then tested the importance of mistletoe-host compatibility mechanisms and disperser preferences in determining infection prevalence patterns among different host species. 3. Mistletoe-host compatibility was tested by planting mistletoe seeds on different hosts and recording germination and establishment up to 1 year after planting. There were no significant differences in seed germination, but seedling survival was significantly different among hosts. However, seedling survival was not correlated with infection prevalence among hosts. 4. Disperser preferences were calculated from observations of birds that disperse mistletoe fruits. Both the duration and frequency of disperser visits to trees were greater among parasitized trees. Dispersers did not visit unparasitized trees in proportion to their abundance, but showed preferences for certain tree species. Disperser preferences for trees were correlated with infection prevalence. 5. Mistletoe-host compatibility mechanisms could not explain patterns of prevalence among hosts in this study. In contrast, disperser preferences were related to prevalence of mistletoe infections among different host tree species.
- Host specificity
ASJC Scopus subject areas
- Ecology, Evolution, Behavior and Systematics