The Smithsonian Institution National Museum of Natural History’s Division of Birds features more than 640,000 specimens and is considered to be the world’s third largest bird collection. Identified by the acronym USNM (United States National Museum), the National Collection represents up to eighty percent of the world’s known avifauna species, of which there are around 9,600. The collection is specifically available for scientific research by both resident staff and visiting scientists, with the National Museum of Natural History hosting between 200 and 400 such visitors each year. While the collection is not open to the public, the searchable online database maintained by the USNM contains information on more than 400,000 of the collection’s specimens.
The Bird Division Hall of Fame pays tribute to men who have significantly contributed to the study of birds and the collection since its inception in the mid-1800s. Among the Hall of Famers is Spencer F. Baird (1823-1887) who was the Assistant Secretary of the Smithsonian Institution from 1850 to 1878. His donation of more than 3,600 birds formed the foundation of the collection, and he was also a founding member of the American Ornithologists Union and a member of the National Academy of Sciences.
Another founding member of the American Ornithologists Union was Elliott Coues (1842-1899). Coues was an army physician, naturalist and field collector, as well as a member of the National Academy of Sciences. His various publications on field ornithology and identifying North American Birds were invaluable to ornithologists in those early days and remain valuable as reference works to this day.
Robert Ridgway (1850-1929) served as the first Curator of Birds at the USNM in 1881. He was an artist, a founding member of the American Ornithologist Union, member of the National Academy of Sciences and publisher of the first eight volumes of The Birds of North and Middle America – a reference work still in use today.
As a field naturalist and taxidermist for the USNM, William Palmer (1856-1921) collected specimens from Pribilof Islands, Funk Island, Cuba and Java, among other destinations. Assistant Curator of Birds between 1881 and 1889 Leonhard Stejneger (1851-1943) carried out pioneering ornithological fieldwork on the Commander Islands, Kamchatka, the Alps, Southwestern UK, Puerto Rico and Japan. Pierre L. Jouy (1856-1894) was a field collector who collected specimens primarily in Korea, Japan and China. He also made extensive contributions to the ethnological and zoological collections at Smithsonian.
Various methods of marking birds for identification are believed to go back as far as Roman times and this was generally done to indicate ownership. The first person to ring birds for scientific purposes was Danish ornithologist Hans Christian Cornelius Mortensen (1856-1921) who put aluminum rings marked with unique numbers and an address, first on the legs of European Starlings, and later on storks, herons, gulls and ducks, with the intention of tracking their movements. The first organized banding scheme was established at the Rossitten Bird Observatory by German ornithologist Johannes Thienemann in 1903.
Since those early days bird banding has been invaluable in gathering data for conservation and scientific purposes. But banding has its limitations, as once birds are set free they are very often only identified again when found injured or dead, and then only if the person finding the bird takes the time and trouble to report it. At best, bird banding provides only a few pieces of the puzzle of bird migration and behavior. However, rapidly advancing technology has opened up new avenues of tracking birds, with the most promising being satellite telemetry, which provides information immediately.
In 2005, satellite telemetry was used by the Wildlife Research Institute (WRI) and the United States Forest Service (USFS) to track Southern California’s Golden Eagles, and this was later expanded to include Montana. Tiny transmitters are attached to the birds and their signals are tracked by satellites no matter where they may travel. Working in conjunction with the National Oceanic and Atmospheric Administration (NOAA) the WRI received data via the internet enabling researchers to determine exactly where the eagles have been and when. The information is so detailed that it can be determined how high the eagles flew, and how fast they were flying. In the event of an eagle not moving, it’s location can be pinpointed and the bird rescued if injured, or recovered if dead.
As plans for alternative energy sources in the form of wind and solar farms move ahead in California, data on migration, nesting and hunting patterns of Golden Eagles will be invaluable in ensuring the survival of this already endangered species. On a wider scale, the cost and availability of satellite telemetry is an obstacle that may be difficult to overcome, particularly in developing nations, and so bird banding remains an important activity for conservationists.
The theory that navigational skills in some birds may be influenced by iron particles in their beaks reacting to the magnetic field of the earth, has recently been refuted by scientists at Vienna’s Institute of Molecular Pathology. Acknowledging that the new discovery was somewhat disappointing, molecular biologist David Keays noted that the mystery of how animals detect magnetic fields had become even more mysterious.
Using 3D scanners on slivers of pigeon beak, researchers found that the particles which had previously been thought to react with the earth’s magnetic field were in fact macrophages with normal amounts of organic iron to protect the birds from infection. These cells have no ability to produce electric signals to communicate with brain cells and are therefore unable to influence the pigeon’s behavior. These same cells were also found in other parts of the bird’s body and are found in other animals, particularly in the spleen, lungs, and skin, where they play an essential role in recycling iron from red blood cells and fight against infection. The findings were confirmed by scientists from the University of Western Australia – Jeremy Shaw and Martin Saunders – who were also working on the study.
Keays was reported as saying that the new discovery should not be seen as a set-back as it puts scientists on the right path to finding magnetic cells. The general consensus remains that birds, and a significant number of other animals, detect the magnetic field of the earth and use it for navigation. So it stands to reason that they must have cells facilitating this, although in the case of birds, it has been suggested they may make use of landmarks or sunlight for navigation as well.
Scientists will continue in their quest to understand how migratory birds interact with the earth’s magnetic fields, with the hope of linking their findings to other species with homing habits, including sea turtles, rainbow trout and bees. Although the project has its challenges, Keays believes that learning how nature detects magnetic fields could lead to the creation of artificial magnetoreceptors with the potential of treating human medical conditions, particularly relating to the brain.
It seems that years of sharing space with humans and being forced to adapt to changes in city lifestyles, has taught pigeons a few tricks that are quite remarkable to say the least. They might seem to most people just ordinary birds, but on taking a closer look pigeons are actually highly intelligent and are able to differentiate between humans, not by the clothes they wear, as they have learnt that clothing changes, but by facial recognition, which is extremely remarkable.
The perception capabilities of pigeons were tested previously in a laboratory, but researchers of the University of Paris Quest Nanterre La Defense decided to take their next experiment into the “wild” so to speak, to see how undomesticated pigeons would react. To ensure that the test would be performed as accurately as possible, two researchers were selected who shared the same build and skin color, but wore laboratory coats of different color. These two researchers then went out into the park to feed the pigeons. The first researcher threw out the food and then stood back ignoring them, giving them the opportunity to eat the food without being disturbed. The second also threw out food, but then chased them away, being hostile towards the pigeons.
For the second session, both researchers were told not to chase the pigeons, and allow them to eat, but the pigeons had remembered who the hostile researcher was and avoided her. They decided to repeat the session a few times over, even getting the researchers to swop their lab coats, but still the pigeons would avoid the researcher who was hostile on their first encounter. This confirmed the suspicions of the team, that the pigeons relied on facial recognition to detect hostiles.
Facial recognition is not a new skill in the bird world, and other researchers have discovered in previous years that birds such as magpies and jackdaws are also able to recognize humans according to their facial features. So next time you think about chasing away a bird, think twice about your actions, as you might not remember which bird you were hostile to, but they are more than likely going to remember you!
As scientists and biologists continue to struggle to discover exactly what causes birds to migrate with such accuracy, it seems new breakthroughs continue to be made. A recent discovery reported in the June Biophysical Journal sheds exciting new light on a still relatively misunderstood process of nature.
The discovery was made by Klaus Schulten (Swanlund Chair in Physics at Illinois) and his collaborator Ilia Solov’yov (Frankfurt Institute for Advanced Studies). It seems that Solov’yov did not know that the molecule known as superoxide was toxic and was using it in studies of the biomechanical process of the cryptochrome protein found in the eye of a bird. Superoxide is a toxic molecule that is known to damage cells and cause disease. Now it seems it also plays a constructive role in the process that enables birds to ‘visualise’ the Earth’s magnetic field.
It turns out that superoxide is an ideal reaction partner when paired with the cryptochrome protein. In 2000 it was discovered that this protein plays a key role in the development of a bird’s geomagnetic sense, since chemical reactions can take place in the protein in response to magnetic fields. However magnetic fields interact so weakly with molecules that up until now it was virtually impossible to understand how these reactions could take place. It was thought that changes in the electromagnetic field, such as would occur when the bird changed direction while flying, would have an effect on freely tumbling spins of electrons in the birds eye which would essentially serve as a compass that pointed north or south. Researchers then supposed that the cryptochrome recruited a reaction partner with ‘zero-spin’ and it was proposed that oxygen was that partner.
Now it seems researchers had it backwards. It may not be oxygen, but rather its close cousin superoxide, that serves as the reaction partner in this process. Initially the toxicity of the molecule caused Klaus Schulten to dismiss the idea presented by Solov’yov. But then he realized that the toxicity of the molecule was actually crucial to the role it played in the process. Most living organisms, such as birds, have mechanisms for reducing the concentrations of superoxide in the body to prevent it from damaging the organism. The molecule needs to be present – but only in low concentrations. In birds, it is the presence of this molecule that makes the biomechanical compass work effectively.