Show simple item record

dc.creatorApple, Trent Curtisen_US
dc.descriptionDue to the character of the original source materials and the nature of batch digitization, quality control issues may be present in this document. Please report any quality issues you encounter to, referencing the URI of the item.en_US
dc.descriptionIncludes bibliographical references (leaves 107-116).en_US
dc.descriptionIssued also on microfiche from Lange Micrographics.en_US
dc.description.abstractVariation in sperm whale codas, short rhythmic series of clicks, was examined across annual, seasonal, and time-of-day temporal categories. Recordings were made from towed linear arrays during two-week seasonal cruises of the Northern Gulf of Mexico (NGOM) spanning May 1992 - August 1994 and October 1996 - August 1997. Archived sperm whale vocalizations were randomly sampled posthoc and codas were classified by the number and temporal pattern of their clicks: Short ([] 5 clicks) versus Long ([] 6 clicks), as well as Regular (equally-spaced clicks), Variable (unevenly-spaced clicks), and Plus-one (double intervals between the last two clicks). A total of 842 codas were analyzed, comprising 17 different coda types. The high number of Regular codas across all years and the lack of consistently significant temporal variation in codas suggest that a resident population of animals inhabits the NGOM. The high percentage of shared coda types between the Caribbean and NGOM may indicate movement of whales between these two regions. More codas (predominantly Long and Variable) were heard during 1996, compared to a greater diversity of coda types during 1997. In 1996, cows and calves were aggregated near the Mouth of the Mississippi River (MOM) and in 1997, whales were found in loose associations over DeSoto Canyon and in the presence of dolphins. More Plus-one codas were found during Spring than Fall, as were more Regular and Short codas recorded in Summer than Fall. During Spring, groups were concentrated near the MOM, and in Summer whales were sparsely distributed across broad areas. High diversity of coda types as well as the abundance of Long and Variable codas is likely related to crepuscular peaks observed in foraging activity and a three-hour cycle associated with deep diving. The proximate differences observed between temporal scales may be attributed to variation in oceanographic conditions affecting the spatial distribution and abundance of sperm whales as well as to contextual differences in behavior. Further research involving more acoustic data as well as comparisons with photo-identification, genetic, and behavioral information are needed to further corroborate the variation observed.en_US
dc.publisherTexas A&M Universityen_US
dc.rightsThis thesis was part of a retrospective digitization project authorized by the Texas A&M University Libraries in 2008. Copyright remains vested with the author(s). It is the user's responsibility to secure permission from the copyright holder(s) for re-use of the work beyond the provision of Fair Use.en_US
dc.subjectwildlife and fisheries sciences.en_US
dc.subjectMajor wildlife and fisheries sciences.en_US
dc.titleTemporal patterns and types of sperm whale (Physeter macrocephalus) codas in the Northern Gulf of Mexico: a metadata analysisen_US
dc.typeThesisen_US and fisheries sciencesen_US
dc.format.digitalOriginreformatted digitalen_US

Files in this item


This item appears in the following Collection(s)

Show simple item record

This item and its contents are restricted. If this is your thesis or dissertation, you can make it open-access. This will allow all visitors to view the contents of the thesis.

Request Open Access