Mistletoe specialist frugivores: latterday "Johnny Appleseeds" or self‑serving market gardeners?

Many plants use birds to disperse their propagules, but mistletoes are especially reliant on their services. As aerial parasites, mistletoe seeds need to be deposited upon branches of suitable hosts, and mistletoe specialist frugivores (from eight different avian families) have long been regarded as their coevolved dispersers. Like the pioneer Johnny 'Appleseed' Chapman who established nurseries that helped open up land for settlement, these birds are considered benevolent dispersers of this keystone resource and often invoked as illustrative examples of mutualistic interactions.

A simple parametric method for reducing sample sizes in gut passage time trials.

Seed dispersal is now regularly analyzed using spatially explicit models, relying in part on frugivore gut passage times to produce model outputs. In determining species-specific gut passage times, there is a trade-off in sample size between minimizing collection effort and maintaining statistical reliability. Here we demonstrate that a two-parameter lognormal parametric distribution reliably fits empirical gut passage time distributions and is easily parameterized using relatively small data sets of approximately 30 defecations.