Oology

Oology (or oölogy) is a branch of ornithology studying bird eggs, nests and breeding behavior. Oology can also refer to the hobby of collecting wild birds' eggs, sometimes called egg collecting, birdnesting or egging, which is now illegal in many jurisdictions.

As a science
Oology became increasingly popular in Britain and the United States during the 1800s. Observing birds from afar was difficult because high quality binoculars were not readily available. Thus it was often more practical to shoot the birds, or collect their eggs. While the collection of the eggs of wild birds by amateurs was considered a respectable scientific pursuit in the 19th Century and early 20th Century, from the mid 20th Century onwards it was increasingly regarded as being a hobby rather than a scientific discipline.

In the 1960's, the naturalist Derek Ratcliffe compared Peregrine Falcon eggs from historical collections with more recent egg-shell samples, and was able to demonstrate a decline in shell thickness. This was found to cause the link between the use by farmers of pesticides such as DDT and Dieldrin, and the decline of British populations of birds of prey.

As a hobby
Egg collecting was still popular in the early 20th century, even as its scientific value became less prominent. Egg collectors built large collections and traded with one another. Frequently, collectors would go to extreme lengths to obtain eggs of rare birds. For example, Charles Bendire was willing to have his teeth broken to remove a rare egg that became stuck in his mouth. He had placed the egg in his mouth while climbing down a tree.

As a crime
Legislation, such as the Wild Birds Protection Act 1954 and  Wildlife and Countryside Act 1981 in the United Kingdom, has made it impossible to collect wild bird's eggs legally. In the United Kingdom, it is only legal to possess a wild-bird's egg if it was taken before 1954; selling wild–bird's eggs, regardless of age is illegal.

However, the practice of egg collecting, or 'egging', continues as an 'underground' or illegal activity in the UK and elsewhere. In the 1980's and 1990's, the fines allowed by the law were only a moderate deterrent to some egg collectors. However, the Countryside and Rights of Way Act 2000, allowed for six months imprisonment for the possession of the eggs of wild birds. and, since it came into force, a number of individuals have been imprisoned, both for possessing and for attempting to buy egg collections.

Despite this, some of those who engage in egg collecting show considerable recidivism in their activity. One, Colin Watson, was convicted six times before he fell to his death in 2006, while attempting to climb to a nest high up in a tree. Another individual has been convicted nine time and imprisoned twice and a third has been convicted 51 times, imprisoned four times and barred from entering Scotland during the bird breeding season.

The Royal Society for the Protection of Birds has been particularly active in fighting illegal egg collection. At one point, RSPB staff were being trained by soldiers from the Brigade of Gurkhas in camouflage skills and in surveillance, map and radio techniques, to better enable them to guard nests of rare birds.

In the United Kingdom, owners of old egg collections must retain proof that the eggs pre-date 1954 in order to avoid the possibility of prosecution.

Methods
When collecting eggs, normally the whole clutch of eggs is taken. Because eggs will rot if the contents are left inside, they must be 'blown' to remove the contents. Although collectors will take eggs at all stages of incubation, freshly laid eggs are much easier to 'blow', usually through a small, inconspicuous hole drilled with a specialized drill through the side of the eggshell. Egg blowing is also done with domestic bird's eggs for the hobby of Egg decorating.

Major research collections

 * Natural History Museum (610,000 eggs), UK
 * Delaware Museum of Natural History (520,000 eggs), USA
 * H. L. White Collection, Melbourne, Australia
 * National Museum of Natural History (190,000 eggs), Washington DC, USA
 * Muséum de Toulouse (150.000 eggs), Toulouse France
 * San Bernardino County Museum (41,000 clutches with 135,000 eggs)
 * Western Foundation of Vertebrate Zoology (190,000 clutches with >800,000 eggs), California, USA

Oologists and egg collectors

 * Charles Bendire
 * Colin Watson
 * Francis Charles Robert Jourdain

Oology related publications
Numerous books, and at one point a journal, have been published on egg collecting and identification :
 * Thomas Mayo Brewer, (1814–80), an American ornithologist, wrote most of the biographical sketches in the History of North American Birds, by Baird, Brewer, and Ridgway (1874–84). He has been called "the father of American oölogy". He wrote North American Oölogy which was partially published in 1857.
 * William Chapman Hewitson, Illustrations of Eggs of British Birds, (third edition, London, 1856).
 * Alfred Newton, Dictionary of Birds, (New York, 1893–96).
 * Oliver Davie, Nests and Eggs of North American Birds, (fifth edition, Columbus, 1898).
 * Oliver Davie, Nests and Eggs of North American Birds, (fifth edition, Columbus, 1898).
 * Oliver Davie, Nests and Eggs of North American Birds, (fifth edition, Columbus, 1898).