Bøger af Frederick R. Gehlbach

Mountains rise like islands from deserts and grasslands along the US-Mexican border. The stunningly varied borderlands offer a laboratory for studying historical trends and ecological cycles. This work describes the stability and changes in the Borderlands' climate, landforms, and natural communities and in its distinctive plants and vertebrates.

A Texas naturalist shares an intimate record of the wooded ravine near his home in this almanac based on decades of journal entries. In the mid-1960s, naturalist Fred Gehlbach and his family built a house on the edge of a wooded ravine in Central Texas. On daily walks over the hills, creek hollows, and fields of the ravine, Gehlbach has observed the cycles of weather and seasons, the annual migrations of birds, and the life cycles of animals and plants that also live there. In this book, Gehlbach draws on thirty-five years of journal entries to present a composite, day-by-day almanac of the life cycles of this semiwild natural island in the midst of urban Texas. Recording such events as the hatching of Eastern screech owl chicks, the emergence of June bugs, and the first freeze of November, he reminds us of nature's daily, monthly, and annual cycles, from which humans are becoming ever more detached in our unnatural urban environments. The long span of the almanac also allows Gehlbach to track how local and even global developments have affected the ravine, from scars left by sewer construction to an increase in frost-free days probably linked to global warming. This long-term record of natural cycles provides one of only two such baseline data sets for North America. At the same time, it is an eloquent account of one keen observer's daily interactions with his wild and human neighbors.

The eastern screech owl, widespread over the eastern half of North America and noticeably tolerant of human activity, is one of America's most familiar birds. Residing naturally in wooded environs with tree cavities, this owl lives well in suburbia and can be found nesting in mailboxes, porch columns, and purple martin houses. Based on a twenty-five-year study, biologist Frederick R. Gehlbach tells the life story of the eastern screech owl, focusing on case studies of suburban and rural study plots in Central Texas. This is the first thorough study of major life-history, behavioral, and ecological features of the species. Indeed, it is the first concurrent, comparative study of an urban and a rural population of any New World animal. Told in a personal voice, the story of these birds will interest all who have not lost touch with their ancestral world. However, Gehlbach has also included quantitative data and analysis of interest to ecologists, wildlife biologists, and ornithologists. Photographs (including color shots of the gray and rufous phases), figures, and tables provide further detail. Gehlbach's investigations have been those of not only an academic ecologist, but a suburbanite curious about his natural surroundings. The result is a model of research on species population dynamics and adaptation, yielding an emerging picture of what the eastern screech owl needs for successful coexistence with human neighbors.