Download or read book Migrating Eastern North Pacific Gray Whale Behavior Compared Over Multiple Timescales written by Regina Anne Guazzo and published by . This book was released on 2018 with total page 165 pages. Available in PDF, EPUB and Kindle. Book excerpt: Mysticetes (baleen whales) often make long, annual migrations from high latitude summer feeding areas to low latitude wintering areas. Eastern North Pacific gray whales (Eschrichtius robustus) migrate within a few kilometers from shore for most of their route from summer feeding areas in the Bering, Chukchi, and Beaufort Seas to wintering areas in the lagoons along the south-western coast of the Baja California Peninsula in Mexico. This dissertation combines passive acoustic recordings, infrared camera video, and visual sightings to investigate gray whale behavior and how it changes across different timescales. I use a four-element hydrophone array in central California to present the first published full-season acoustic monitoring and tracking of migrating gray whales. I describe the characteristics of calls produced by migrating gray whales and analyze how these characteristics change due to propagation. I show that gray whale behavior changes on diel and seasonal timescales. Notably, gray whales increase their vocalizations at night but their mean swimming behavior does not change, contrary to previous assumptions used in population size estimates. Over seasonal timescales, vocalizing gray whale swimming behavior aligns with previous observations. I explore how passive acoustic and infrared camera monitoring can help quantify whales by calculating cue rates or call and blow rates for migrating gray whales. Acoustic calling rates indicate that the gray whale population size is greater than estimated using visual sightings alone and that calling rate increases over the southbound migration. Infrared camera blow rates are less affected by whale behavior and are useful for daytime and nighttime monitoring, but are limited by visibility and distance. To understand gray whale behavior over seven migration seasons, I use visual daily counts at two sites and single-hydrophone call detections which indicate that migratory behavior seems to be driven more by intrinsic than the tested environmental factors. I find that the proportion of the population using a coastal route through the Southern California Bight, especially past Los Angeles, increased over these years. Understanding the behavior of migrating gray whales will help improve abundance estimates and determine how these whales may be impacted by nearshore anthropogenic activities and climate change.
Download or read book The Impact of Anthropogentic Activities on the Behavior of Migrating Eastern North Pacific Gray Whales Eschrichtius Robustus written by Lisa K. Schwarz and published by . This book was released on 2002 with total page 202 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Gray Whale Monitoring Study written by and published by . This book was released on 1989 with total page 208 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Re analysis of Gray Whale Southbound Migration Surveys 1967 2006 written by Jeffrey Lee Laake and published by . This book was released on 2009 with total page 55 pages. Available in PDF, EPUB and Kindle. Book excerpt: Between 1967 and 2007, 23 seasons of shore-based counts of the Eastern North Pacific (ENP) stock of gray whales (Eschrichtius robustus) were conducted throughout all or most of the southbound migration near Carmel, California. Population estimates have been derived from these surveys using a variety of techniques that were adapted as the data collection protocol evolved. The subsequent time series of estimates was used to evaluate trend and population status, resulting in the conclusion that the population was no longer endangered and had achieved its optimum sustainable population (OSP) level. We re-evaluated the data from all of the surveys using a common estimation procedure and an improved method for treatment of error in pod size and detection probability estimation. The newly derived abundance estimates between 1967 and 1987 were generally larger (-2.5% to 21%) than previous abundance estimates. However, the opposite was the case for survey years 1992 to 2006, with estimates declining from -4.9% to -29%. This pattern is largely explained by the differences in the correction for pod size bias which occurred because the pod sizes in the calibration data overrepresented pods of two or more whales and underrepresented single whales relative to the estimated true pod size distribution.
Download or read book The Gray Whale Eschrichtius Robustus written by Mary Lou Jones and published by Academic Press. This book was released on 2012-12-02 with total page 625 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Gray Whale: Eschrichtius robustus provides an introduction to the understanding of Eschrichtius robustus or the gray whale. This book explores the life processes, reproduction, and growth of large cetacean populations. Organized into four parts encompassing 25 chapters, this book begins with an overview of the gray whale evolution, fossils, and subfossil remains, range, and systematics in historical times. This text then presents the historical of gray whale exploitation and the economic importance of these whales to humans. Other chapters consider the gray whale migration, abundance, and seasonal distribution in the wake of the California population's recovery from depletion. This book discusses as well the methods used in shore-based censuses during migration and in aerial surveys of gray whales taken on their winter grounds. The final chapter deals with some innovative approaches to the study of free-ranging cetaceans. This book is a valuable resource for anthropologists, paleontologists, biologists, and naturalists.
Download or read book Status Review of the Eastern North Pacific Stock of Gray Whales written by and published by . This book was released on 1999 with total page 116 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Distribution Numbers and Behavior of Gray Whales in the Channel Islands National Marine Sanctuary During the Southward Migration January 1987 written by Mary Lou Jones and published by . This book was released on 1988 with total page 84 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Gray Whales written by Robert Busch and published by Heritage House Publishing Co. This book was released on 1998 with total page 148 pages. Available in PDF, EPUB and Kindle. Book excerpt: Tells the complete natural history of the gray whale that is illustrated with over 80 colour photographs, including a number of underwater shots. Along with the details of the life history of the whale, this book covers man's exploitations of the whale, its comeback from the brink of extinction, and its current and future management issues.
Download or read book Gray Whale written by Dawn N. Ericson and published by . This book was released on 2017-08 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Despite a nearly disastrous period of interactions with humans that resulted in the near extinction of Gray Whales, protection measures have allowed this species to once again flourish in the Pacific and make theirway into the human consciousness as respected and cherished icons of the sea. This NATURE UNFOLDING © Science Guide coalesce science, literature and vivid imagery to inspire a deeper connection with nature. A compilation of natural history illustrations, poster, photos, and diagrams provide current and reliable research and information. Condensed text written by David W. Weller, Ph.D., Marine Mammal & Turtle Division,Southwest Fisheries Science Center, NOAA - National Marine Fisheries Service. Designed and illustrated by Dawn Navarro Ericson. Editing by Dominique Navarro
Download or read book The Oceanic Society Field Guide to the Gray Whale written by Ben Bennett and published by . This book was released on 1983 with total page 56 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Characterizing Site Fidelity and Habitat Use of the Eastern North Pacific Gray Whale Eschrichtius Robustus in Clayoquot Sound British Columbia written by Jacqueline Ann Clare and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A small number of eastern north Pacific gray whales (Eschrichtius robustus), known as the Pacific Coastal Feeding Group (PCFG) forage during the summer months in the coastal waters between California and Alaska. Although several studies have analyzed the population structure of the PCFG, maternal learning and predator/prey dynamics have not been studied in detail. In this study I characterize fine scale habitat use and site fidelity of eastern north Pacific gray whales in one foraging site within the PCFG's foraging range. I approach this study by examining site fidelity to Clayoquot Sound in increasing detail at different time scales. Using the variability recorded in 17 field seasons of whale census surveys (1997-2013) as a proxy for fluctuations in prey, I suggest that the combination of physical properties of the study area and the life history characteristics of the primary prey species type enable Clayoquot Sound to persist as a foraging site through time.
Download or read book Population Assessment of Western North Pacific Gray Whales Eschrichtius Robustus written by Amanda L. Bradford and published by . This book was released on 2003 with total page 230 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Eye of the Whale written by Dick Russell and published by Simon and Schuster. This book was released on 2001 with total page 696 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Eye of the Whale focuses on one great whale in particularthe coastal-traveling California gray whale. Gray whales make the longest migration of any mammal - from the lagoons of Baja California to the feeding grounds of the Bering Strait between Alaska and Siberia (nearly 6,000 miles). That the gray whale exists today is nothing short of miraculous. Whaling fleets twice massacred the species to near extinction - first during the nineteenth century and again during the early part of the twentieth century."--BOOK JACKET.Title Summary field provided by Blackwell North America, Inc. All Rights Reserved
Download or read book Factors Influencing the Acoustic Behavior and Nearshore Residence of the Gray Whale Eschrichtius Robustus Along Their Migration Route written by and published by . This book was released on 2009 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: Our long-term goal is to quantify the acoustic behavior of gray whales in the coastal waters of the Northeast Pacific Ocean and to characterize the link between coastal residency patterns of these migratory mammals and the distribution of hyperbenthic swarms of their primary prey, mysids.
Download or read book Anthropogenic Disturbance of Western Gray Whale Behavior Off Sakhalin Island Russia written by Glenn Andrew Gailey and published by . This book was released on 2013 with total page 283 pages. Available in PDF, EPUB and Kindle. Book excerpt: The western North Pacific population of gray whales (Eschrichtius robustus) is critically endangered of extinction. The population size is estimated to be 131 individuals with 31 reproductive females. Throughout their potential home range, the western gray whale population face several threats to their future survival. On their only known feeding grounds off the northeastern coast of Sakhalin Island, Russia, anthropogenic activity has increased in the past decade due to oil and gas exploration and platform/pipeline construction. This dissertation examines the influences of geophysical seismic surveys (pulse sounds) and platform/pipeline installation (continuous sounds). Each chapter progressively improves upon behavioral models that assess changes in gray whale movements and respirations relative to anthropogenic activity. Theodolite tracking and focal follow methodologies were employed to collect gray whales' movement and respiration information during and in the absence of anthropogenic activity. Spatial, temporal, environmental, and acoustic (pulse and/or continuous) sound levels and non-sound related anthropogenic variables were included as explanatory variables to examine their influence on movement and respiration response variables, such as speed, orientations, dive/surface time, breathing rates, etc. During the 3-D seismic activity, gray whales traveled faster, changed directions of movement less, were recorded farther from shore and stayed underwater longer between respirations as the received sound level exposure increased. During platform/pipeline installations, western gray whales increased their distance from shore with indicators of stress (rapid breathing) and observed to be sensitive to close distance of approach by vessels. No acoustic influence on western gray whale behavior was found during a 4-D seismic survey; however, sample sizes were small in this study to sufficiently detect more subtle to moderate changes in gray whale behavior. These studies illustrate short-term influences anthropogenic activity had on western gray whale behavior which could lead to longer-term responses that may be detrimental to the survival of certain individuals and/or the population. A comprehensive analyses are proposed to increase sample sizes to identify subtle to moderate behavioral changes as well as examine alternative hypotheses to the null hypothesis of no impact used in this dissertation. With the potential to displace individuals/population out of critical feeding habitats needed for their annual survival and the expected increase of anthropogenic activity in the future, this dissertation highlights the importance to monitor and identify problems and suggest alternatives to development/activities that may be impacting this endangered population of gray whales. The electronic version of this dissertation is accessible from http://hdl.handle.net/1969.1/149559
Download or read book Impacts of Sakhalin II Phase 2 on Western North Pacific Gray Whales and Related Biodiversity written by and published by Iucn. This book was released on 2005 with total page 123 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Assessment of Population Structure in the Eastern North Pacific Gray Whale Eschrichtius Robustus written by Anna Maria D'Intino and published by . This book was released on 2011 with total page 88 pages. Available in PDF, EPUB and Kindle. Book excerpt:
