ancel johnson (6 risultati)

Paperback. Condizione: New. Print on Demand. This book, a collaboration of two experienced wildlife biologists, examines the growth, replacement, and characteristics of the northern fur seal's pelage throughout its lifetime. The authors identify distinct stages of molt and provide estimates for their duration. They also detail the progression of these stages with age, sex, and season. The text is supported by numerous tables and figures presenting data collected from an extensive study involving the examination of hundreds of individual seals. Through analysis of samples taken from the back and belly of the animals, the authors provide insights into the variation in pelage characteristics across different body regions and between sexes. The findings presented in this book not only contribute to our understanding of the fur seal's biology but also have practical implications for the timing of seal harvesting to ensure the pelts are of the highest quality and value. This book is a reproduction of an important historical work, digitally reconstructed using state-of-the-art technology to preserve the original format. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in the book. print-on-demand item.

Paperback. Condizione: New. Print on Demand. This book delves into the extensive research conducted on fur seals on the Pribilof Islands in 1965. It provides critical data on the population dynamics, reproduction, and other aspects of these marine mammals. The author examines the age structure of male seals killed for commercial purposes, along with the reproductive rates and mortality of females. Tagging and tag recovery techniques are discussed in detail, as they contribute to population estimates and understanding of seal migration patterns. Additionally, the book explores the effects of tagging and marking on pup mortality, emphasizing the importance of minimizing tag-induced fatalities for accurate population assessments. Through comprehensive analysis, this book advances our knowledge of fur seal ecology and provides valuable insights for the sustainable management of these iconic animals. This book is a reproduction of an important historical work, digitally reconstructed using state-of-the-art technology to preserve the original format. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in the book. print-on-demand item.

Paperback. Condizione: New. Print on Demand. This book delves into the fascinating world of fur seal research and population management on the Pribilof Islands, Alaska, during the pivotal year of 1964. The author meticulously documents the intricate methods employed to study and regulate the seal population, offering a comprehensive analysis of age classification, reproduction rates, and mortality trends. Set against the backdrop of the North Pacific Fur Seal Convention of 1911, the narrative explores the delicate balance between conservation efforts and economic interests. Readers will discover the challenges faced by researchers as they sought to understand the complex dynamics of the fur seal population and implement sustainable harvesting practices. The book delves into the ethical considerations and scientific rationale behind population control measures, shedding light on the controversial decision to reduce the number of female seals. Through detailed data analysis and insightful observations, the author examines the impact of these measures on the overall health and stability of the fur seal population. Ultimately, this book underscores the importance of scientific research and adaptive management strategies in ensuring the long-term survival of vulnerable species. The insights gleaned from the Pribilof fur seal studies offer valuable lessons for wildlife conservation efforts worldwide. This book is a reproduction of an important historical work, digitally reconstructed using state-of-the-art technology to preserve the original format. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in the book. print-on-demand item.

Paperback. Condizione: New. Print on Demand. This book compiles the findings of various scientific studies on Alaskan fur seals inhabiting the Pribilof Islands during the 1963 expedition. Conducted by the US Fish and Wildlife Service, these studies aimed to enhance understanding of fur seal population dynamics and forecast their returns based on mortality, reproduction, and tagging efforts. The authors present their findings alongside historical kill and count data, providing a valuable perspective on the species' population trends and overall health. Through meticulous observations, the authors shed light on the fur seal's age classification, reproductive patterns, mortality causes, and population estimates. They also explore innovative approaches to predict future returns and discuss the implications of their findings for managing fur seal populations sustainably. This book is a reproduction of an important historical work, digitally reconstructed using state-of-the-art technology to preserve the original format. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in the book. print-on-demand item.

Paperback. Condizione: New. Print on Demand. This book looks at the influence of the commercial fur seal industry on the Pribilof seal population for the years 1958-1962. It details methods used by the author and their team for estimating the number of pups born annually to assess the impact of hunting on the sustainability of the seal population. Techniques used to monitor the population included bull counts, herd and idle seal differentiation, and the tagging of pups and yearlings with physical checkmarks or Soviet tags. The insights gained from the research within contribute to an understanding of the cyclical nature of the seal population, and the impact that commercial hunting can have on the overall health and survival of the species. This book is a reproduction of an important historical work, digitally reconstructed using state-of-the-art technology to preserve the original format. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in the book. print-on-demand item.

geheftet. 48 Seiten 160 gr. Einband leicht bereieben und beschriftet, Prägung, Seiten leicht nachgedunkelt.