The pygmy sperm whale (Kogia breviceps) is currently the second-most commonly stranded cetacean in the Southeastern United States (SEUS), but information concerning their population structure is severely limited. This study utilized stable isotope analysis to investigate the possible migratory patterns and population structure of K. breviceps among six different regions in the SEUS. Combined growth layers from different regions of the teeth were subsampled via dental drill and analyzed representing four different age classes: calf, juvenile, sub-adult, and adult, as well as four yearlings that had stranded with their mothers. Stable isotope ratios of carbon and nitrogen were measured in the organic component of 46 teeth, and oxygen isotope ratios were measured in the inorganic (hydroxyapatite) component of 21 teeth obtained from stranded individuals. There was a high degree of individual variability in δ13C, δ 15N, and δ18O resulting in no significant differences between the six different regions: South Carolina, Georgia, Northern, Central, and Southern Florida, and the Gulf of Mexico. Differences between the age classes were significant for δ13C and δ 15N. Adults exhibited significantly more negative δ13 C than subadults. These results support a previously hypothesized inshore-offshore migration for Kogia breviceps. Yearlings displayed significantly higher δ15N values than all other age classes due to nursing. A slight increase in δ15N from juvenile to adult supports a possible ontogenetic shift in the trophic level of prey. Results from this study provide the first carbon and nitrogen isotope values from different age classes of pygmy sperm whales as well as the first reported oxygen isotopes values for this species.
|Commitee:||Day, Russell, Nowlin, Matt, Ziegler, Michelle|
|School:||College of Charleston|
|School Location:||United States -- South Carolina|
|Source:||MAI 54/04M(E), Masters Abstracts International|
|Keywords:||Pygmy sperm whale, Stable isotopes|
Copyright in each Dissertation and Thesis is retained by the author. All Rights Reserved
The supplemental file or files you are about to download were provided to ProQuest by the author as part of a
dissertation or thesis. The supplemental files are provided "AS IS" without warranty. ProQuest is not responsible for the
content, format or impact on the supplemental file(s) on our system. in some cases, the file type may be unknown or
may be a .exe file. We recommend caution as you open such files.
Copyright of the original materials contained in the supplemental file is retained by the author and your access to the
supplemental files is subject to the ProQuest Terms and Conditions of use.
Depending on the size of the file(s) you are downloading, the system may take some time to download them. Please be