Carrion-Tacuri et al • PREDATION OF LANTANA CAMARA SEEDS 
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HO. I. Activity of Ceospiza fortis <92% of records) and G. tmgnirostris (8% of records) when feeding on Lantcma 
tamara fruits during the 2009 cool-dry season in the Dry Zone of Santa Cruz. Galapagos Islands. 
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i i Flyaway 
i 1 Nearby tree 
i 1 Nearby L. camara 
r / a Ground 
G. fortis G. magnirostris 
(92%) (8%) 
ate more fruits per infructescence. G. fortis thus 
moved less on each I.. canurni shrub and would 
probably stimulate less fruit fall. Thus, G. fortis 
may be a more effective seed predator and 
perhaps a less effective short-distance disperser 
of L. camara, as it ate a larger proportion and 
dislodged a smaller proportion of the fruit than 
were removed from the bush by its activity at each 
visit. 
Both species of finches also foraged on the 
ground, which reduces their role as short distance 
dispersers. Fifteen percent of the fallen fruits 
appeared to have been removed by the two finch 
species from the ground during just 1 month. 
A great number of fruits on the ground were 
removed, many of them probably by introduced 
rodents. This may be effectively equivalent to 
predation since rodents either eat seeds or store 
them in deep larder hoards from which successful 
seedling establishment is unlikely (Montgomery 
and Gurnell 1985. Hulme 1998). Reducing 
dispersal distances acts to concentrate seeds 
FIG. 2. Fate of fruit on shrubs due to foraging activity by ground finches (A), and fate of fallen fruits during 1 month 
(B) of the cool-dry season in the Dry Zone of Santa Cruz Island (Galapagos). Percentage for each fruit class is in 
parentheses (n = 10 shrubs). 
