Colorado College Logo


Use AND (in capitals) to search multiple keywords.
Example: harmonica AND cobos

Maximum weight capacity of leaves used by tent-roosting bats : implications for social structure and plant species usage

by Parker-Shames, Phoebe Amelia


Fewer than 2% of bats have the capacity to modify their environment to construct roosts. Tent-roosting bats cut and fold leaves to form roosts called “tents” and often use specific plant species for this purpose. Unlike the caves or hollow trees used by some bats, leaves possess an upper limit on their capacity to support weight. I tested the hypothesis that the maximum weight capacity that leaves can support limits the maximum social group size of bats that roost in them. I tested a secondary hypothesis that the bat Dermanura watsoni would preferentially use the plant species that can support more weight. I conducted research in the Tirimbina Biological Reserve (TBR), Sarapiquí, Costa Rica, between March and April 2012. To test the first hypothesis, I added weight incrementally to new leaves of three plant species until the angle of the leaves fell below that which bats naturally use. Philodendron fragrantissimum and Heliconia imbricata support one-third more weight than Asterogyne martiana. To address the second hypothesis, I determined plant abundance by systematic-random plot sampling along main paths in the reserve and systematically surveyed tents along the same paths. Patterns of leaf use by D. watsoni suggest a preference for A. martiana and complete avoidance of H. imbricata. Dermanura watsoni did not show a preference for plant species that support a greater maximum weight capacity. This study demonstrates that the maximum weight that the leaves can support is similar to the mean social group weight of D. watsoni and Ectophylla alba reported in the literature for these plant species and lower than the maximum reported social group weights. Therefore, it is possible that the maximum weight capacity of the leaves used to construct roosts limits the maximum social group size but may not be an important factor used for plant selection.


Colorado College Honor Code upheld.

Includes bibliographical references.

Confirmed with Biology Department that date on title page should be 21st day of May, 2013.

Administrative Notes

Colorado College Honor Code upheld.

Confirmed with Biology Department that date on title page should be 21st day of May, 2013.

Copyright restrictions apply.
Colorado College
Digital Origin
born digital
32 pages : illustrations (some color), color maps
Senior Thesis -- Colorado College
Thesis Advisor
Snyder, Marc Ebersole, Jim
Degree Name
Degree Type
Bachelor of Arts
Degree Grantor
Colorado College
Date Issued