Author: F. GALIMBERTIPublisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
Demography and breeding biology of a small, localized population of southern elephant seals (Mirounga leonina)
Author: F. GALIMBERTIElephant Seals
Author: Burney J. Le BeoufPublisher: Univ of California Press
ISBN: 0520368177
Category : Nature
Languages : en
Pages : 434
Book Description
The largest of all seals, elephant seals rank among the most impressive of marine mammals. They are renowned for their spectacular recovery from near-extinction at the end of the nineteenth century when seal hunters nearly eliminated the entire northern species. No other vertebrate has come so close to extinction and made such a complete recovery. The physiological extremes that elephant seals can tolerate are also remarkable: females fast for a month while lactating, and the largest breeding males fast for over one hundred days during the breeding seasons, at which times both sexes lose forty percent of their body weight. Elephant seals dive constantly during their long foraging migrations, spending more time under water than most whales and diving deeper and longer than any other marine mammal. This first book-length discussion of elephant seals brings together worldwide expertise from scientists who describe and debate recent research, including the history and status of various populations, their life-history tactics, and other findings obtained with the help of modern microcomputer diving instruments attached to free-ranging seals. Essential for all marine mammalogists for its information and its methodological innovations, Elephant Seals will also illuminate current debates about species extinctions and possible means of preventing them. This title is part of UC Press's Voices Revived program, which commemorates University of California Press’s mission to seek out and cultivate the brightest minds and give them voice, reach, and impact. Drawing on a backlist dating to 1893, Voices Revived makes high-quality, peer-reviewed scholarship accessible once again using print-on-demand technology. This title was originally published in 1994.
An analysis of the southern elephant seal Mirounga leonina breeding population at Kerguelen
Author: M.N. BESTERObservations on the Trend of the Breeding Population of Southern Elephant Seals, Mirounga Leonina, at Marion Island
Author: J. D. SkinnerPublisher:
ISBN:
Category :
Languages : en
Pages : 6
Book Description
Describes the annual haulout pattern of adult southern elephant seal cows. Analyses data collected during nine breeding seasons from 1973 to 1982.
Ethology and Behavioral Ecology of Phocids
Author: Daniel P. CostaPublisher: Springer Nature
ISBN: 3030889238
Category : Science
Languages : en
Pages : 651
Book Description
Phocid (or earless or true) seals are ecologically diverse, occupying habitats from the tropics to the poles in marine and freshwater and feeding on anything from tiny zooplankton to other marine mammals. There are 18 species of phocid seals, the smallest species (ringed seal) is more than 20 times smaller than the largest (southern elephant seal), with marked sexual dimorphism present in some species. This book examines the behavior, ecology, and physiology that allow phocid seals to inhabit such a wide range of habitats. The book is composed of 16 chapters written by 37 authors from 8 countries. The book first describes the general patterns of phocid behavior, followed by descriptions of what is known about well-studied species. We have taken a holistic approach, focusing not only on the behaviors themselves but also on the factors that constrain the expression of behavior and the proximate mechanisms driving behavior. In many cases, the chapters represent collaborations between well-established researchers and early-mid career individuals who bring new perspectives to help carry the field of phocid behavioral ecology well into the future.
Life History Studies of the Southern Elephant Seal Population at Marion Island
Author: P. J. Nico De BruynPublisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
Holistic studies of mammalian life history factors and their consequences on population demography require an intensive, multifaceted field methodology and effort over long temporal scales. A 25-year longitudinal mark-recapture experiment on southern elephant seals, Mirounga leonina, at Subantarctic Marion Island provide such a foundation for demographic analyses and relevant methodology advancement. Two gaps in the methodology related to life history and population demographic research are, the absence of large samples of known mass individuals, and an inability to identify mother-pup relatedness. A novel three-dimensional photogrammetric technique is designed here that allows for mass estimation of large samples of southern elephant seals in the field. An effective temporary marking technique for unweaned pups is implemented that allows for identification of large samples of pups with known mothers prior to the maternal bond being severed at weaning. These known pups can then be marked with more robust tags and relatedness information is preserved long-term. Thus, mass estimates can now be applied as covariates in modelling analyses to address questions of, for example, maternal investment, kinship associated behaviour, and the consequences thereof on survival and reproductive parameters. The state change in the Marion Island southern elephant seal population from decrease to stabilisation/increase is shown to have resulted from improved survivorship in both juvenile and adult female age classes. Male seals of all ages did not indicate improved survivorship following the period of decline. The inflexion in survivorship is identified as 1994, whence improved survivorship of juvenile seals preceded that of young adult females. This inflexion in survivorship is postulated to have resulted in a population trend inflexion around 1998. Female southern elephant seals do not show evidence of actuarial senescence, but reproductive senescence is apparent after 12 years of age. A longterm reproductive cost (reduced breeding effort) is associated with early primiparity (age three) as compared with later primiparity (4- 5- or 6-year-old). The mean proportion of 3-year-old breeders has not increased after 1994 as has been hypothesized in previous studies. Contrary to previous assumptions, females do not as a rule breed every year. Annually interrupted breeding efforts are more common than consecutive breeding efforts. No difference in the proportions of interrupted versus uninterrupted breeding efforts was identified between periods of population decline and stabilisation/increase. Longevity as predicted by survival estimates exceeds the observed frequencies. This study provides unique longevity and fertility schedules for the species. The improved survivorship, reproductive senescence and breeding schedules of female southern elephant seals in this population provide groundwork for reevaluation of previous studies and their conclusions. The addition of relatedness and body condition information will allow for sophisticated multistate modelling of population demography in future studies. However, analytical procedures and techniques employed need to be meticulously designed and thoroughly thought through to avoid mis-interpretation of biological data. In addition to a multistate single species analytical approach, the importance of an ecosystem approach to species population demographic studies is highlighted through the augmenting of data on relevant potential drivers of population change, such as killer whales, Orcinus orca.
Southern Ocean Sentinels
Author: Marine DesprezPublisher:
ISBN:
Category : Seal populations
Languages : en
Pages : 145
Book Description
Some of the clearest expressions of climate change have been found in the Southern Ocean, one of the biggest marine ecosystems and a major component of the Earth's climate system. Top predators living in this ecosystem are considered to be one of the best indicators of these global changes as their population fluctuations reliably integrate and reflect prevailing environmental conditions. Southern elephant seals (Mirounga leonina) are pole-ward predators that feed throughout the Southern Ocean. In the past decades, their worldwide populations have been stable or increasing with the single exception of the Macquarie Island population that has been declining for unknown reasons over the past 50 years. This study, based on an 18-year capture-recapture dataset involving more than 6,000 individually marked females, aims to explore and understand the demographic mechanisms driving this decline and the potential impact of a changing environment on a key predator.
Notes On The Sea Elephant, Mirounga Leonina (linné)
Author: Robert Cushman MurphyPublisher: Legare Street Press
ISBN: 9781022638853
Category :
Languages : en
Pages : 0
Book Description
A fascinating and detailed study of the behavior and ecology of the southern elephant seal. Murphy combines firsthand observations with scientific data to paint a vivid picture of this incredible species and the unique challenges it faces in its environment. Notes on the Sea Elephant is a must-read for anyone interested in marine biology or wildlife conservation. This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work is in the "public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.
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