Mating Behaviors Exhibited by a Captive Male Pacific Walrus (Odobenus Rosmarus Divergens) PDF Download
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Author: Jessica Marie McCord Publisher: ISBN: Category : Animal psychology Languages : en Pages : 40
Book Description
Understanding mating behaviors of a species can be utilized to help protect the species. Results of population surveys have shown the walrus population to be on the decline, and over the history of walruses being held in captivity, few pups have been born or survived. Not much is known about Pacific walruses (Odobenus rosmarus divergens) due to the isolated Arctic habitats in which walruses live making wild population studies difficult. Few studies have examined wild observations of walrus mating behaviors and virtually none for captivity. The purpose of this study was to observe a captive male Pacific walrus for mating behaviors, examine frequency of behaviors, and describe observations. The subjects, one male and two females, were video recorded in the pool area of the walrus exhibit at Six Flags Discovery Kingdom from November 2013 through January 2014. Only behaviors exhibited directly by the male were noted. Behaviors directly associated with mating were considered grabs, rolls, and holds, which could also be coupled with tusk strikes or nuzzles. Grabs were the most frequently observed behavior, and holds were not significantly observed which could elude to an issue with successful walrus mating in captivity. The male walrus used other sexual outlets such as self-gratification and toy use; however, these behaviors were not as significant as sexual encounters with females. There appeared to be mate preference for the female with tusk as interactions with this female occurred significantly more. Pharyngeal sac inflation (PSI) was described as a vocal and visual behavior that has frequently been noted in previous research. PSI and other mating behaviors are likely learned from other males, which could explain possible behavioral differences exhibited by the male of this study. --Page iv.
Author: Jessica Marie McCord Publisher: ISBN: Category : Animal psychology Languages : en Pages : 40
Book Description
Understanding mating behaviors of a species can be utilized to help protect the species. Results of population surveys have shown the walrus population to be on the decline, and over the history of walruses being held in captivity, few pups have been born or survived. Not much is known about Pacific walruses (Odobenus rosmarus divergens) due to the isolated Arctic habitats in which walruses live making wild population studies difficult. Few studies have examined wild observations of walrus mating behaviors and virtually none for captivity. The purpose of this study was to observe a captive male Pacific walrus for mating behaviors, examine frequency of behaviors, and describe observations. The subjects, one male and two females, were video recorded in the pool area of the walrus exhibit at Six Flags Discovery Kingdom from November 2013 through January 2014. Only behaviors exhibited directly by the male were noted. Behaviors directly associated with mating were considered grabs, rolls, and holds, which could also be coupled with tusk strikes or nuzzles. Grabs were the most frequently observed behavior, and holds were not significantly observed which could elude to an issue with successful walrus mating in captivity. The male walrus used other sexual outlets such as self-gratification and toy use; however, these behaviors were not as significant as sexual encounters with females. There appeared to be mate preference for the female with tusk as interactions with this female occurred significantly more. Pharyngeal sac inflation (PSI) was described as a vocal and visual behavior that has frequently been noted in previous research. PSI and other mating behaviors are likely learned from other males, which could explain possible behavioral differences exhibited by the male of this study. --Page iv.
Author: Lisa Triggs Publisher: ISBN: Category : Walrus Languages : en Pages : 218
Book Description
Reproduction of walrus (Odobenus rosmarus) in zoos and aquaria has met with limited success. While basic information on reproductive characteristics is available, there is limited knowledge of reproductive physiology and endocrinology for walrus. The overall goal of the research was to monitor reproductive events and seasonal changes that occur in ex situ walrus of North America by utilizing a variety of methods. To track changes in males, longitudinal hormonal analysis of saliva samples, changes in testicular size, presence or absence of spermatozoa and seasonal fluctuations in behavior were examined. Saliva samples were collected from six male walrus for periods of 12 to 36 months. Measurements of testicular length and width were collected on a weekly basis. Baseline testosterone values for each animal were established using an iterative process that eliminated elevated values. Elevations were defined as values ≥ 2 times the individual's baseline (range 0.838-4.228 ng/ml). The mean combined baseline testicular measurement for individuals (R linear length + R linear width + L linear length + L linear width) was 54.81±2.13 cm while the mean combined increased testicular measurement (an increase of 15% or more over minimum values) was 65.38±1.71. Three of six animals displayed the typical rise and fall of testosterone concentrations observed in seasonal breeders in the wild and elevations were coincident with reproductive behaviors. Behaviors included visual and vocal courtship displays, pursuit of females, clasping and penetration. Sperm presence in a single walrus during two years coincided with increased testicular measurements and mean duration of spermatozoal presence was 131±3 days. Endocrine profiles varied extensively among animals, demonstrating within-animal decline in testosterone levels over time, a lack of testosterone elevations coincident with the wild walrus breeding season and a blind male with a unique derivation in his endocrine profile, hormone elevations directly opposite the wild walrus breeding season. To track female reproductive cycles, longitudinal hormonal analysis of saliva samples and seasonal fluctuations in behavior were examined. Saliva samples were collected from six female walrus at least three times a week for periods of 12 to 55 months. Salivary estradiol-17[beta] was deemed an unreliable indicator of the follicular phase because hormone concentrations did not display a rise in estrogen concentrations prior to a rise in progesterone concentrations nor increased estrogen concentrations coincident with estrus behaviors. The most commonly reported signs of behavioral estrus were soliciting male attention, clasping and penetration. In general, behavioral observation also was not a consistently reliable method for detecting impending estrus. Salivary progesterone was found to be unsuitable for monitoring the functional capacity of the corpus luteum because profiles were difficult to interpret biologically or physiologically. Progesterone profiles did not appear to coincide with behavioral or seasonal changes. However, periods of elevated progesterone concentrations were demonstrated in two of six females and were most likely representative of consecutive pseudopregnancies (mean 204.27 days). An inconsistency elucidated in this study involved a blind female with a unique derivation in her endocrine profile, inconsistent with the wild walrus breeding season and varying in time frame each year. Issues with walrus reproduction elucidated by this study included: within-animal decline in testosterone levels over time, unsynchronized cycles between animals residing together and the inconsistent timing of reproductive events in blind animals. To increase breeding success of the ex situ walrus population the following changes are proposed: a) increase the number of walrus in the population or consolidate existing walrus into larger social groups; and b) separate the genders during the non-breeding season or move animals to different facilities. Facility collaboration and continued monitoring of reproductive functioning via endocrine, anatomical and behavioral parameters would allow evaluation of the efficacy of the proposed changes.
Author: Claudio Campagna Publisher: Springer Nature ISBN: 3030591840 Category : Nature Languages : en Pages : 667
Book Description
This book is focused on the marine mammalian groups the Otariidae and the Odobenidae, otherwise known as fur seals, sea lions and the walrus. In 30 chapters, more than 60 authors from 30 institutions and 13 nationalities, discuss a broad suite of topics from maternal care and mating behavior, through play, cognition and personality, to adaptation to life in the Anthropocene. The authors explore the behaviors that have allowed these semi-aquatic mammals to thrive in the marine realm. Many populations have recovered following historical decimation, with interesting evolutionary consequences which are explored. Detailed, selected, individual species descriptions are also provided, showcasing the behavioral diversity of this engaging, adaptive and highly successful group of marine mammals.
Author: Frances M.D. Gulland Publisher: CRC Press ISBN: 1351384163 Category : Medical Languages : en Pages : 2340
Book Description
AAP Prose Award Finalist 2018/19 For three decades, this book has been acknowledged as the most respected scientific reference specifically devoted to marine mammal medicine and health. Written by approximately 100 contributors who are recognized globally as leaders in their respective fields, the CRC Handbook of Marine Mammal Medicine, Third Edition continues to serve as the essential guide for all practitioners involved with marine mammals including veterinarians, technicians, biological researchers, students, managers, keepers, curators, and trainers. The 45 chapters provide essential information for the practitioner on pathology, infectious diseases, medical treatment, anesthesia, surgery, husbandry, health assessment, species-specific medicine, medically pertinent anatomy and physiology, and global health concerns such as strandings, oil spills, and entanglements of marine mammals. Covers all aspects of marine mammal veterinary practice Written by internationally acknowledged experts Adds new chapters on Ophthalmology, Dentistry, Ethics, Oil Spill Response, Health Assessments, Whale Entanglement Response, Dive Response, and Biotoxins Richly illustrated in color throughout the new edition including updated anatomical drawings and extensive photographs of ocular lesions Provides guidance to websites that regularly present updated information and images pertinent to current marine mammal medicine such as imaging and stranding network contacts Discusses ethics and animal welfare. The book guides the reader through the veterinary care of cetaceans, pinnipeds, manatees, sea otters, and polar bears. In addition to summaries of current knowledge, chapters provide information on those digital resources and websites which present the latest information as it emerges in the field. The CRC Handbook of Marine Mammal Medicine, Third Edition gives a call to action for scientists to experiment with new endeavors to engage and inspire current and future generations to care for marine mammals and the marine environment, and work together to find solutions. As the most trusted reference for marine mammal conservation medicine and for marine mammal medical facilities around the world, this book needs to be in your library.
Author: Jenell T. Larsen Tempel Publisher: ISBN: Category : Subsistence hunting Languages : en Pages : 260
Book Description
An interdisciplinary approach is used in understanding change and resiliency in St. Lawrence Island (SLI) resources and resource users throughout this dissertation. Historically SLI inhabitants have relied on the Pacific walrus (Odobenus rosmarus divergens) for their survival and this resource is still highly valued for cultural and dietary purposes. The responses of Pacific walruses and SLI subsistence users to environmental change was analyzed. In walruses, reproductive capacity was analyzed using an anatomical approach as well as reproductive plasticity which was determined using a physiological approach to characterize their estrus cycle. A suite of anatomical measurements were developed to characterize reproductive capacity of walruses by analyzing ovaries from three distinct time frames during a 35-year period. Reproductive capacity was reduced during time frames when carrying capacity (K) was reached and when large environmental changes occurred in the Bering Sea, including years of very low sea ice extent. Reproductive capacity was high in times when K was lower and harvest levels were greater. Our results explained how perturbations in K and environmental changes may have influenced reproductive capacity of the population in the past. Endocrine techniques were used in ovarian tissues to determine if progesterone and total estrogens are useful indicators of female reproductive status in walruses harvested during the spring hunt. Progesterone and total estrogen concentrations were greater in the reproductive tissues of unbred and pregnant females than postpartum females, however neither hormone could distinguish between pregnant and unbred animals. These results provide the first physiological evidence for pseudopregnancy in this species, rather than a postpartum estrus. Lastly, discussions were held with SLI community members to determine changes in key subsistence resources and community resiliency with regard to food security. Walruses ranked highest among key resources. Stakeholders reported limited access and increased effort to hunt walruses, changes in crab abundance, and increases in commercially exploitable fish stocks. Changes were attributed to loss of sea ice, “bad” weather, and climate change. In order for SLI communities to continue their subsistence-based way of life, inhabitants may need to expand their diet to include less-preferred food items in place of harvested ice-associated species. In conclusion, loss of sea ice and rapid environmental changes in the Bering Sea have the potential to greatly impact walrus reproduction and the marine subsistence way of life that is practiced by SLI stakeholders.
Author: Samuel Denes Publisher: ISBN: Category : Languages : en Pages :
Book Description
This work aimed to develop source characteristics and transmission effects for the acoustic breeding displays of male Pacific walrus (Odobenus rosmarus divergens). Pacific walrus breeding activities occur in late winter in the Bering Sea, an area renowned for extreme weather conditions and high biological productivity. During the breeding season, males perform acoustic displays while swimming in the vicinity of females hauled out on ice. Underwater vocalizations heard by individuals hauled out on ice may be important in the mate selection process. The extreme environment in which walrus breeding activities occur precludes direct observation of these animals during this important period and has resulted in a lack of data. A combination of remote-sensing data, captive animal research, controlled environment experiment, and computational modeling was used to increase our understanding of the acoustic displays of Pacific walrus.Analysis of recordings of captive and wild male Pacific walrus vocalizations during breeding season provided quantification of source characteristics. Working with a captive animal provided the ability to make direct observations of a male producing breeding vocalizations and the direct calculation of source level. The mean peak to peak source level of the impulsive knocks produced by the captive male was 183 dB (re: 1 [mu]Pa) with the middle 95% of the knocks between 168 dB and 195 dB. The broadband knock signals contained significant acoustic energy up to 13 kHz. To estimate source level from wild vocalizations, the location of the source walrus first needed to be determined. Using a method of relative multipath arrival time, more than 37,000 knocks were localized from six years of data from autonomous recorders deployed in the Bering Sea. The mean peak-peak source level from the wild recordings was 177 dB (re: 1 [mu]Pa) with 95% of the knocks between 163 dB and 189 dB. For both wild and captive vocalizations, a significant relationship between ambient noise level and source level was identified. The Lombard effect, the increase in source level in response to an increase in noise level has not previously been identified in any pinniped species. In both datasets, an increase of approximately 5 dB in source level was found for an increase in 10 dB of noise level. A propagation experiment was conducted to measure the transmission of an impulsive acoustic signal, similar to a walrus knock, from an underwater source through ice and into air. Peak to peak pressure measured in air was approximately 2,500 times lower than pressure measured in water separated by two meters of shorefast ice. The results from this experiment were used to verify the adequacy of a wavenumber integration acoustic propagation model for determining transmission loss in this multi-media environment. Propagation model environments were generated from historical ice thickness and oceanographic data. Modeled received signals were compared with walrus audiometric data to determine what factors impact signal detectability with source level, ice thickness, and range having the greatest impact. The findings of this work suggest that the underwater vocalizations of males making breeding vocalizations are received by females hauled out on ice at audible levels when the females are within a few hundred meters of the males. As the signals exceed the levels estimated to be perceived, these signals may play a role in mate selection by the females. If climate change affects the ice conditions, water depth, and bathymetry where walrus congregate for breeding, mate selection and therefore offspring fitness may be impacted.
Author: Douglas Wartzok Publisher: ISBN: Category : Remote sensing in marine biology Languages : en Pages : 57
Book Description
Important questions on the natural history of marine mammals need to be answered before management can be placed on a more certain basis. We investigated one aspect of the natural history of Pacific walruses, Odobenus rosmarus divergens. We concentrated on walrus hauling-out behavior and the associated environmental factors which influence this behavior. We employed primarily visual photography and infrared imaging in order to gain new insights into the relationship between behavior and the environment. High-resolution color film proved to be the best remote sensing technique for distinguishing walruses from their haulout areas and for counting the animals. Infrared imaging was much better for detecting small groups of animals, particularly when the ice was broken up into many small floes. Most remote sensing flights were conducted at an altitude of 300 to 400 m since this altitude gave the best resolution for counting animals on the photographs.
Author: Jessica Marie McCord
Author: Jessica Marie McCord
Author: 
Author: James Spencer Taggart
Author: Lisa Triggs
Author: Claudio Campagna
Author: Jennifer Siembieda
Author: Frances M.D. Gulland
Author: Jenell T. Larsen Tempel
Author: Samuel Denes
Author: Douglas Wartzok