We examined pollen receipt by robbed and unrobbed flowers using a mixed-model repeated-measures ANOVA with robbing treatment (robbed and unrobbed flowers) as a fixed effect, plant nested within floral treatment as a random effect, and date as the repeated measure.
For both the low and high robbing treatments, these estimates of female fitness decreased as the season progressed.
In 1995, the average percentage of natural nectar robbing per plant in plants in the natural robbing treatment ranged from 0% to 97.
For sites in which we measured dye donation and pollen receipt in 1995, two of the three sites contained plants with high levels of natural robbing ([greater than]75% of available flowers robbed; N = 3 plants), and two of the three sites contained plants with low levels of natural robbing ([less than]15% of available flowers robbed; N = three plants).
Plants in the high robbing treatment donated significantly fewer dye particles than plants in the low robbing treatment ([F.
Plants in the high robbing treatment received significantly fewer pollen grains than plants in the low robbing treatment in 1996 but not in 1995 (Table 2; [ILLUSTRATION FOR FIGURE 2 OMITTED]).
high artificial robbing treatments (mean [+ or -] 1 SE, low robbing = 54.
Seed set per fruit was significantly lower in plants that received the high robbing treatment ([F.