Sadie K. Wright | USGS Science

USGS2007

Responses of California Brown Pelicans to disturbances at a large Oregon roost

Numbers of California Brown Pelicans (Pelecanus occidentalis californicus) along the coast of Oregon and Washington have increased sharply in recent years. We identified East Sand Island in the Columbia River estuary as the site of the largest pelican roost within this region. Numbers of pelicans roosting on East Sand Island have increased from less than 100 during 1979-1986 to a high count of 10,852 in 2002. The East Sand Island roost is currently the site of a major non-breeding aggregation of this endangered subspecies. Total numbers of pelicans roosting on East Sand Island increased seasonally from April to September or October, and then declined sharply with the onset of winter storms. Pelicans appeared to forage more during low tides, and return to the roost during high tides; therefore, pelican numbers on the island were positively associated with tide height. Land-based human disturbance was negatively associated with total pelican numbers, whereas water-based human disturbance had no significant effect on total pelican numbers on the island. Natural disturbances, although more frequent than human disturbances, apparently did not influence the total number of pelicans on the island.

Waterbirds↗

USGS2003

[Book Review] Biology of marine birds

A text devoted to the biology and ecology of marine birds has not been published in the last 15 years. Although a number of more taxa-specific texts have been produced during that period, there has not been a single publication that attempted to review our knowledge of all the major seabird orders since the works of Nelson (1979), Croxall (1987), and Furness and Monaghan (1987). Following the publication of those works, a large and impressive body of literature has been produced. Given the rapid expansion of the field in the last two decades, the time was ripe for production of an extensive compendium on the biology, ecology, and conservation of the world's seabirds. E. A. Schreiber and J. Burger are editors of this CRC publication, Biology of Marine Birds . The book consists of 19 chapters that vary in length from 15 to 51 pages. There are also two extensive appendices: (1) a list of seabird species (restricted to the orders Sphenisciformes, Procellariiformes, Pelecaniformes, and Charadriiformes, the latter limited to Stercorariidae, Laridae, Rhynchopidae, and Alcidae) and their IUCN status, and (2) a very useful table of species-specific life-history traits. The 19 chapters were prepared by 26 authors, among them some of the most respected and published seabird scientists in the world. A brief preface introduces the book, its objective (to provide an examination and summary of the research on seabirds), its audience (researchers, conservationists, managers, and policy-makers), and the taxa covered. The editors coauthored the introductory chapter, Seabirds in the Marine Environment. The authors describe distinctive characteristics of seabird life-histories in comparison to other taxa, hypotheses for why those lifestyles evolved and the potential role of energy limitation in the evolution of seabird life-histories. Along with a discussion of other common seabird traits, such as a propensity for colonial breeding, the authors also suggest directions for future research in seabird ecology.

The Auk↗