DOES HUMAN SCENT BIAS SEED REMOVAL STUDIES?

Field estimates of seed removal rates are often determined by monitoring the survival of seeds placed at stations. Such experiments may unintentionally provide seed predators with unnatural olfactory cues. We compared the removal of seeds that had direct contact with human skin (scented) vs. seeds that had no contact with human skin (unscented). At three Florida sites in 1997–1998, four to five species were tested by placing five conspecific seeds at each station; 40–50 stations per species, per treatment, per site were monitored for 30 d. Seed removal was greater for scented than unscented seeds, but most differences were significant only with all species and sites pooled. At two Illinois sites and one Florida site in 1999–2000, one seed of one of two species was placed at each of 400 stations and monitored for 30 d. Scented seeds were removed significantly faster than unscented seeds at Illinois sites (14% scented vs. 5% unscented removed after one day), but not at the Florida site. The effect of scent on removal was pronounced during the first week, then disappeared. Fortunately, these results suggest scent biases are weak and short‐lived, and most studies are unaffected. Studies that may be affected are those of short duration.