Feather Atlas Useful for Identification of North American Birds

A unique resource for identification of flight feathers of North American birds is now available at the online Feather Atlas.

“The Feather Atlas is the first widely-available resource to provide species identification tools for detached feathers,” said Pepper Trail, the ornithologist with the National Fish and Wildlife Forensics Laboratory, a division of the U.S. Fish and Wildlife Service. He is the coordinator for the atlas website project.

“Until the Feather Atlas, there was no widely-available image database of detached flight feathers of North American birds,” Trail said in an email interview. “These scans will be useful in terms of illustrating feather structure and function (compare, for example, the outer primaries of buteos, accipiters, and falcons), as well as documenting plumage variation."

“The primary intended use is for species identification, but there are many other possible uses, including by researchers (as a source for feather measurements), artists (to reference fine details of plumage when they lack access to specimens), and educators (to show examples of feather shape and appearance). There will likely be other uses for these scans that have not even been imagined."

Groups represented by the atlas thus far are hawks, eagles, vultures, falcons, pigeons and doves, cuckoos, owls, and woodpeckers, with 64 species currently illustrated.

Tail fathers of the Red-bellied Woodpecker. Image courtesy of the Feather Atlas.

“We began with raptors, with particular emphasis on the different plumages of Bald and Golden Eagles,” said Pepper Trail, a biologist in the Laboratory. “The feathers of birds of prey, including hawks, eagles, and owls, are the most commonly encountered by FWS agents, both in partial carcasses (for example, electrocuted bird remains) and in crafted items (such as feather fans). Flicker feathers are also frequently used in crafted items, which led us into the woodpeckers.”

For each species, examples of wing and tail feathers are shown on a background that provides a scale for referencing the size of each feather. Precise measurements – to the nearest millimeter – are also given in a data table found beneath each scan. “The measurements are an important additional resource for making identifications,” Trail said.

Further details for each image provide the bird’s sex, age and where it originated.

Also provided with the atlas is a glossary of terms used to describe parts of a feather, illustrated with annotated figures. Coming soon to the web site will be options to zoom in to view feathers in a greater detail, print an image or create a portable document file with the image.

Details on the legal issues related to feather possession are presented, including a link to the complete list of protected species. There is also information about special rules which are applicable to Native Americans, which often use bird material in tribal ceremonies.

The Forensics Laboratory created the atlas since it provides “identification resources to the field officers of the Office of Law Enforcement,” Trail said. “Much of our work at the laboratory involves making species identifications from partial remains, including loose feathers,” Trail said. “Therefore, we have both the expertise and the specimen reference collection needed to undertake this effort.

“Law enforcement personnel will find the scans useful in identifying flight feathers in crafted items and bird carcasses. Field biologists will be able to use the scans to identify feathers encountered during field work. For example, I am often asked to identify molted feathers picked up during field surveys, where the goal is to distinguish Great Gray versus Great Horned Owls or Northern Goshawk versus other raptors.

“The Feather Atlas marks an expansion of our identification resources onto a widely accessible web-based platform that will be useful not only to Fish and Wildlife Service agents, but to refuge officers, state game departments, researchers, and the general public.”

The laboratory already provides a variety of bird “Identification Notes” for use by agents and researchers.

The web site has already undergone a review by “various Fish and Wildlife Service personnel and museum-based ornithologists,” Trail said. “Their comments were very helpful in refining our search tools and in developing the information presented on the homepage. We are still working toward implementation of some of their suggestions, for example, making thumbnails of the scans available.”

The ultimate goal of the atlas is to present images of the flight feathers of all species of North American birds – a project that will take years.

Trail stated that the strategy is to scan as many members of a bird family as possible before adding that group to the atlas, thus allowing comparisons between similar species. As a result, he explained, “the availability of specimens influences which groups we work on. We are currently scanning the feathers of upland gamebirds (quail, grouse, and relatives) and nightjars. After that, we plan to begin work on waterfowl. And on an ongoing basis, we will add new species and scans to existing groups as additional specimens become available.”

Feathers scanned for the website are from specimens in the reference collection of the Forensics Laboratory, Mr. Trail said. “Almost all these are salvaged carcasses that have been donated by our wide network among wildlife rehabilitation centers, National Wildlife Refuges and other FWS offices, bird-banders, and state game departments. No birds are killed to provide specimens.”

The actual scanning is done by a Laboratory volunteer, Sue Polich, and the specimen preparation and website design are done by Laboratory staff when time is available, Trail said.

The website emphasizes that it is illegal to possess birds or parts of birds protected by the Migratory Bird Treaty Act, which covers almost all native North American species.

“This includes molted feathers and feathers that may have come from road- or window-kills,” Trail explained, noting that the Feather Atlas offers a legal way to study and appreciate the beauty of the feathers of protected native species: “Appreciate the images, but don’t collect feathers unless you have a permit to do so!”

Opportunities for close examination of feathers may be available at museums, zoos, and wildlife rehabilitation centers.

“Education about feathers can be done using the feathers of non-native birds such as Ring-necked Pheasant, Indian Peafowl, Rock Pigeon, European Starling and House Sparrow, Trail concluded. “The feathers of all these species can be legally possessed without permits.”

“Feathers represent a supreme combination of beauty and functionality, Trail said. “The variety of their patterns and shapes is an endless source of fascination, and I never tire of the challenge of making species identifications based on feathers alone. This project has required a sustained focus on the details of feather appearance that has been very rewarding. The response so far has suggested wide interest in this resource, which is certainly encouraging.”

National Forensics Laboratory Feather Atlas

National Forensics Lab bird “Identification Notes”