Pamela C. Rasmussen

Rasmussen is a visiting assistant professor of zoology, and assistant museum curator of mammalogy and ornithology, at Michigan State University (MSU), having formerly been a research associate for the eminent American ornithologist S. Dillon Ripley at the Smithsonian Institution in Washington, D.C. She is a member of the American Ornithological Society (AOS) Committee on Classification and Nomenclature, a scientific associate with the bird group of the British Natural History Museum zoology section at Tring, and an associate editor of The Ibis, the scientific journal of the British Ornithologists' Union. She is a scientific affiliate for the Field Museum of Natural History and the founder and editor of AVoCet, MSU's avian vocalizations center. In 2020 she replaced the ornithologist Frank Gill as an editor of the IOC World Bird List, an online list maintained on behalf of the International Ornithologists' Union.

MSUM has regular exhibitions; those featuring Rasmussen's projects include "Land of the Feathered Dragons: China and the Origin of Birds" in 2015, “They Passed Like a Cloud: The Passenger Pigeon and Extinction” in 2014, “Echoes of Silent Spring: 50 Years of Environmental Awareness” (for the Silent Spring 50th anniversary in 2012), “Avelution: Birds in the Development of Darwin’s Theories of Evolution,” in 2010 and "Birds of South Asia: History vs. Mystery," in 2003–2004. The last was also shown at the Detroit Zoo Wildlife Interpretive Gallery in 2005–2006.

A 2008 paper saw a return to white-eye taxonomy with the formal description of the Togian white-eye Zosterops somadikartai, an endemic species of the Togian Islands of Indonesia, which, unlike most of its relatives, lacks the white ring around the eye which give this group of birds its name. Rasmussen noted that the Togian white-eye is distinctive not only in its appearance, but also in its lilting song, which sounds higher pitched and is less varied in frequency than the songs of its close relatives.

Many allopatric forms previously regarded as conspecific are treated by Rasmussen and Anderton as full species. Most of these had previously been proposed elsewhere, but the book introduced a number of innovations of its own. Experts on Asian birds, Nigel Collar and John Pilgrim, in 2008 analysed Rasmussen and Anderton's proposed changes, indicating which had previously been proposed by other authors, and which were novel, and required further justification.

Other studies by Rasmussen and her international colleagues looked at the importance of energy availability, and a 2007 paper showed that global patterns of spatial turnover are driven principally by widespread species rather than restricted ones. This complements other work, and helps to establish a unified model of how terrestrial biodiversity varies both within and between the Earth's major land masses.

In 2005, Rasmussen was part of a large multi-institutional collaboration investigating biodiversity hotspots, which have a prominent role in conservation. The study assessed locations quantitatively for three criteria of bird diversity – species richness, the level of threat, and the number of endemic species. The results demonstrated that hotspots did not show the same geographical distribution for each factor. Only 2.5% of hotspot areas are common to all three aspects of diversity, with over 80% of hotspots registering on only one criterion. Each criterion explained less than 24% of the variation in the other factors, suggesting that even within a single taxonomic class, different mechanisms are responsible for the origin and maintenance of various aspects of diversity. Consequently, the different types of hotspots also vary greatly in their utility as conservation tools.

Rasmussen considered in a 2005 paper whether the revised taxonomy of the book, with its many species splits, had significant conservation implications, but felt that the effect on species richness in South Asia was limited, and would have only a moderate conservation impact, increasing the number of potentially threatened species in the region from 6% of the total avifauna to about 7%.

Rasmussen described four new Asian bird species from her study of museum Specimens. The Nicobar scops owl Otus alius, the Sangihe scops owl Otus collari, and the cinnabar hawk owl Ninox ios, a Sulawesi endemic, all in 1998, and the Taiwan bush-warbler Bradypterus alishanensis in 2000. She rediscovered the forest owlet Athene blewitti, which had not been seen since 1884, in western India, previous searches by S. Dillon Ripley, Salim Ali and others having failed because they relied on fake documentation from Richard Meinertzhagen. In November 1997, Rasmussen and Ben King of the American Museum of Natural History spent ten days unsuccessfully searching two east Indian locations before driving west to the site of another old specimen, where King spotted a small, chunky owl with short, heavily white-feathered legs and huge claws, which Rasmussen confirmed as the target species whilst the owl was videotaped and photographed.

In 1992, Rasmussen took the position of assistant to S. Dillon Ripley, the former secretary of the Smithsonian, who was planning to produce a definitive guide to the birds of South Asia. When he became ill shortly after beginning the project, Rasmussen took over the project, and with artist John C. Anderton, produced Birds of South Asia: The Ripley Guide, a two-volume bird guide for the Indian subcontinent which was the first field guide for the area to include sonograms. Volume 1 contains the field guide with over 3400 illustrations in 180 plates, and more than 1450 colour maps. Volume 2 (Attributes and Status) gives specimen measurements, data about identification, status, distribution and habits. Vocalizations are described from recordings, and there are over 1000 sonagrams.

She took her M.S. in 1983 at Walla Walla University, an Adventist-affiliated university in southeast Washington, and her Ph.D. at the University of Kansas in 1990, where she studied blue-eyed shags, and was introduced to evolutionary theory, which had not been taught at her alma mater.

Rasmussen revealed the true extent of the major fraud perpetrated by the eminent British soldier, ornithologist and expert on bird lice, Colonel Richard Meinertzhagen. Meinertzhagen, who died in 1967, was the author of numerous taxonomic and other works on birds, and possessed a vast collection of bird and bird lice specimens; he was considered to be one of Britain's greatest ornithologists. However, British ornithologist Alan Knox had analysed Meinertzhagen's bird collection at the Walter Rothschild Zoological Museum in Tring, UK in the early 1990s, and uncovered significant fraud involving theft of Specimens from museums and falsification of the accompanying documentation.

Pamela Cecile Rasmussen (born October 16, 1959) is a prominent American ornithologist and expert on Asian birds. She was formerly a research associate at the Smithsonian Institution in Washington, D.C., and is based at the Michigan State University. She is associated with other major centers of research in the United States and the United Kingdom.

1508 species that have occurred in India, Bangladesh, Pakistan, Nepal, Bhutan, Maldives, the Chagos archipelago and Afghanistan are covered, including 85 hypothetical and 67 'possible' species, which are given only short accounts. Notable aspects of Birds of South Asia are its distribution evidence-base – the book's authors based their distributional information almost completely on museum Specimens – and its taxonomic approach, involving a large number of species-level splits. Its geographical range was also greater than that of older works, notably in the inclusion of Afghanistan.