The smaller clutch size of tropical as opposed to north temperate birds has intrigued researchers for a long time. An untested hypothesis posits that higher nest predation in the tropics favors smaller nests thereby constraining clutch-size. We tested this hypothesis by conducting an experiment to test whether nest predation increases with nest size in a tropical forest. Furthermore, we studied north temperate and tropical birds to examine if: (1) predation rates increased with nest size, (2) nest sizes were smaller in the tropics, and (3) clutch size was explained by nest size controlled for body size. We used data on predation rates, nest sizes, and clutch sizes for > 2000 north temperate and tropical bird nests of 36 altricial bird species that nest in open cups. Nest predation risk increased with nest size in both the experiment and in the comparison across latitudes, justifying a major premise underlying the nest size hypothesis. However, nest sizes were not smaller in the tropics. As a result, clutch sizes were not related to nest sizes either between latitudes or within sites. Nest sizes were strongly correlated with adult body sizes. Hence, (1) body size might influence reproductive success by affecting nest predation through nest size; and (2) we rejected the hypothesis that nest size explains clutch size in the tropics.
| Identifer | oai:union.ndltd.org:MONTANA/oai:etd.lib.umt.edu:etd-04292009-160802 |
| Date | 12 May 2009 |
| Creators | Biancucci, Atilio Luis |
| Contributors | Thomas E. Martin |
| Publisher | The University of Montana |
| Source Sets | University of Montana Missoula |
| Language | English |
| Detected Language | English |
| Type | text |
| Format | application/pdf, application/msword |
| Source | http://etd.lib.umt.edu/theses/available/etd-04292009-160802/ |
| Rights | restricted, I hereby certify that, if appropriate, I have obtained and attached hereto a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dissertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to University of Montana or its agents the non-exclusive license to archive and make accessible, under the conditions specified below, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report. |
Page generated in 0.0022 seconds