Download Free Status Of The Double Crested Cormorant Phalacrocorax Auritus In North America Book in PDF and EPUB Free Download. You can read online Status Of The Double Crested Cormorant Phalacrocorax Auritus In North America and write the review.

The final report to the U.S. Fish and Wildlife Service regarding the Status of the Double-Crested Cormorant (Phalacrocorax Auritus) in North America
"The geographic area included in this updated status assessment of the Western Population of double-crested cormorants extends from the Pacific Coast east to the Continental Divide, north into southern British Columbia (following the breeding range of the species), and south to the international border with Mexico. The current size of the entire western breeding population is estimated to be about 29,240 breeding pairs. The estimate for the current breeding population in British Columbia, Washington, Oregon, and California, which support the great majority of the Western Population, is approximately 26,390 breeding pairs."--From Executive Summary.
This is the story of the survival, recovery, astonishing success, and controversial status of the double-crested cormorant. After surviving near extinction driven by DDT and other contaminants from the 1940s through the early 1970s, the cormorant has made an unprecedented comeback from mere dozens to a population in the millions, bringing the bird again into direct conflict with humans. Hated for its colonial nesting behavior; the changes it brings to landscapes; and especially its competition with commercial and sports fishers, fisheries, and fish farmers throughout the Great Lakes and Mississippi Delta regions, the cormorant continues to be persecuted by various means, including the shotgun. In The Double-Crested Cormorant, Dennis Wild brings together the biological, social, legal, and international aspects of the cormorant's world to give a complete and balanced view of one of the Great Lakes' and perhaps North America's most misunderstood species. In addition to taking a detailed look at the complex natural history of the cormorant, the book explores the implications of congressional acts and international treaties, the workings and philosophies of state and federal wildlife agencies, the unrelenting efforts of aquaculture and fishing interests to "cull" cormorant numbers to "acceptable" levels, and the reactions and visions of conservation groups. Wild examines both popular preconceptions about cormorants (what kinds of fish they eat and how much) and the effectiveness of ongoing efforts to control the cormorant population. Finally, the book delves into the question of climate and terrain changes, their consequences for cormorants, the new territories to which the birds must adapt, and the conflicts this species is likely to face going forward.
The bestselling natural history of birds, lavishly illustrated with 600 colorphotos, is now available for the first time in flexi binding.
The Double-crested Cormorant (Phalacrocorax auritus) is a widespread, colonial, North American waterbird with bicoastal and inland distributions. Four subspecies have been described within North America corresponding to five geographic breeding regions: Interior and North Atlantic cormorants (P. a. auritus); Southeastern cormorants (P. a. floridanus); Alaskan cormorants (P. a. cincinnatus); and Pacific cormorants (P. a. albociliatus). Management strategies vary widely across the species' range according to local perceptions rather than relative population status. An understanding of population genetic structure is necessary for delineating appropriate management units. We examined the genetic structure of Double-crested Cormorants across their range in the United States and Canada to quantify variation within and among breeding sites and to assess the status of traditional geographically defined subspecies. Sequences (700bp) from domains I and II of the mitochondrial control region were analyzed for 234 Double-crested Cormorants from 23 breeding sites. Variation was also examined at 8 microsatellite loci for 395 cormorants from the same 23 breeding sites. The mtDNA and microsatellite data provided strong evidence that the Alaskan subspecies is genetically divergent from other populations in North America (net sequence divergence = 6.72%; [Phi]ST for mtDNA control region = 0.738; FST for microsatellite loci = 0.05). Our data also suggested strong genetic divergence in the southwestern U.S.; southern California may represent a zone of introgression resulting from a northward expansion of a unique lineage from the species' range in northwestern Mexico. In contrast, there was little support for recognition of subspecies within the conterminous U.S. and Canada, outside of Alaska. Rather than genetically distinct regions corresponding to the putative subspecies, we observed a distribution of genetic variation consistent with a pattern of gradual isolation by distance. This pattern implies that genetic differences across the range are due to geographic distance rather than discrete subspecific breaks. Although three of the four subspecies were not genetically distinct, potential demographic separation, habitat differences, and recent declines at some colonies within the regions, suggests that the Pacific and possibly the North Atlantic breeding regions may still warrant consideration as distinct populations. This thesis provides the first species-wide assessment of the phylogeography and population genetic structure of the Double-crested Cormorant. It further resulted in the first microsatellite markers developed specifically for a North American pelecaniform. The mitochondrial and microsatellite data provide a comprehensive assessment of the four putative subspecies described for the species. Given the highly varying conservation status of Double-crested Cormorants throughout their range, results of this study provide guidance for conservation and management practices on their behalf in North America.
Explores the roots of the human-cormorant conflict and assesses the federal policies that have been developed to manage the bird's population in the twenty-first century.