M.S. Foster
L. Marquez-Valdelamar
R. Greenberg
1995
<p>White-eyed vireos (<span class="italic">Vireo griseus</span>) winter in the forests and secondary growth of the Yucatan Peninsula where<span> </span><span class="italic">Bursera simaruba</span><span> </span>(Burseraceae) is an abundant tree. Twenty-five per cent of all white-eyed vireos observed foraging visited<span> </span><span class="italic">Bursera</span><span> </span>trees. In addition, presence and abundance of territorial white-eyed vireos in small forest patches were correlated with the size of the<span> </span><span class="italic">Bursera</span><span> </span>crop. Vireos were the most reliable dispersers of<span> </span><span class="italic">Bursera</span><span> </span>seeds. These birds visited 32 of 35 trees observed for at least three hours. They accounted for approximately half of all bird visits, and two-thirds of the seeds dispersed. Most of the other species rarely visited (<5% of visits) or failed to remove seeds from the tree.</p><p>Peculiarities of phenology and fruit structure may contribute to the tendency of<span> </span><span class="italic">Bursera</span><span> </span>to be dispersed by relatively few species. The capsules of<span> </span><span class="italic">Bursera</span><span> </span>fruits do not open when the fruit ripens; birds apparently locate ripe fruit using visual cues, although these are few. In addition, only a small portion of the crop ripens daily over a 7- or 8-month period. The vireo-<span class="italic">Bursera simaruba</span><span> </span>relationship, found regionally on the Yucatan Peninsula, may result from the prolonged fruit ripening period (October-March), the relatively depauperate frugivore community and the relatively high density of small<span> </span><span class="italic">Bursera</span><span> </span>trees in the hurricane-disturbed dry forests.</p><p>Small trees at all times, and all trees from October to February, depend upon territorial vireos for continuous, highly efficient local dispersal of a small number of fruits. In March and April residual fruits ripen rapidly and synchronously, attracting a greater variety of visitors for broad spectrum dispersal during a period of food scarcity. Thus,<span> </span><span class="italic">Bursera</span><span> </span>has an unusual two-phase phenological pattern, perhaps alternately to take advantage of both specialized and opportunistic dispersers.</p>
application/pdf
10.1017/S0266467400009184
en
Cambridge University Press
The role of the white-eyed vireo in the dispersal of Bursera fruit on the Yucatan Peninsula
article