Edgar Chance

Edgar Percival Chance (born March 30, 1881 in Birmingham , † 1955 ) was a British industrialist and ornithologist who amassed a bird egg collection of more than 25,000 eggs in a period when collecting bird eggs was still legal. Today he is best known for his pioneering studies on the brood parasitism of the Eurasian cuckoo . His attempt to collect the largest number of eggs from a single female cuckoo during a breeding period worldwide led to a large-scale and carefully carried out field study of the behavior of individual female cuckoos between 1918 and 1925. Because of his longstanding occupation with the behavior of the cuckoo, he was also known in Great Britain under the name Cuckoo Chance .

Life and Science Contribution

Chance was born in Birmingham and educated at Trinity College of the University of Cambridge . He was a wealthy businessman who ran the chemical company Chance and Hunt, which manufactured chemicals for glass production. He was married and had a daughter, whom he named Cardamine after the so-called cuckoo flower.

Chance collected bird eggs as a hobby and was increasingly fascinated by the parasitic cuckoo. Among other things, he had heard that the ornithologist Eugene Rey had collected more than 20 eggs from a single female cuckoo in one breeding season and he went to great lengths to break this record. The collecting of eggs from individual female cuckoos had been practiced more frequently since the end of the 19th century, because the aim was to clarify whether a single female cuckoo is able to adapt the color of its eggs to the egg color of different host birds or whether it lays eggs like other female birds that are always the same in their shell color. To find out, ornithologists such as August Carl Eduard Baldamus collected specific series of cuckoo eggs, which one could be sure that they each came from a female because of the territorial behavior of the species. Since this showed that the eggs of a female were similar to each other, it was already assumed at the end of the 19th century that the cuckoo specialized in one host bird. However, this has not yet been proven.

In 1918, together with four assistants, Chance began to observe a 400-meter-wide and 600-meter-long meadow plot on which there were also hedges and which bordered the forest on three sides. On the surface bred among other meadows and tree pipit , skylark , yellowhammer , Stonechat and Linnet in the hedges. In 1918 they found a total of 14 eggs which, due to their different colors, could be assigned to two female cuckoos. Female B laid four eggs exclusively in the meadow pipit's nests, while female A laid 10 eggs in the meadow pipit and one in a skylark.

In 1919 both females returned to the property again. Eighteen eggs were collected from female A, but only two eggs from female B. All found are in the nest of meadow pipiters, although a large number of skylarks, tree pipits and other species have been breeding on the property. Edgar Chance was able to set Eugene Rey's record back in 1920. In order to induce female A to lay eggs as large as possible in the observed area, he had artificial pipit nests installed. Since female cuckoos only lay every other day and eggs are only laid in nests where there are already eggs, he had eggs from beeps or larks laid in empty nests on days when the females he observed were ready to lay. This year he collected 21 eggs from female A, 20 of them in meadow beeper nests and one again in the nest of a skylark.

Chance was able to prove that females actually prefer to seek out the nests of a host bird species, that they observe the nests of their host bird beforehand and that the eggs are laid directly in the host bird's nest within a few seconds. Since one observed again and again female cuckoos with an egg in their beak, it was previously thought possible that the female lays the egg sitting on the ground, then takes it in the beak and lays it in the nest of the host bird. Chance was able to prove that the eggs carried by the female cuckoo in their beak are eggs from the clutch of the host bird and that the female only needs about 10 seconds to lay eggs. Chance was also able to clarify that the preferred time for the cuckoo to lay eggs is the period from late afternoon to dusk.

Chance and his staff were so familiar with the behavior of female A that they began filming the female cuckoo's egg-laying in 1921. Chance was able to predict with some degree of reliability when the female would lay and which nest she would go to. A hiding place was set up for the cameraman near the nest, Chance stood near the tree from which the female cuckoo was watching the nest of the planned host bird. As soon as she flew away in the direction of the nest, he whistled the cameraman to signal to start filming.

Female A returned one last time to the property that Chance was observing in 1922. Together with his assistants, Chance ensured that the female had a very large number of possible nesting sites. This year the female laid 25 eggs, although Chance also admitted that this was only possible because of the additional host nests offered.

classification

Following the example of the field study conducted by Chance, several field studies were conducted that confirmed the results of Edgar Chance's investigation. Chance, who removed eggs from complete clutches of meadow pipit and skylark in order to motivate female A to lay eggs, underestimated the nest-robbing activity of female cuckoos. In a field study carried out near Hamburg in 1981, Karsten Gärtner was able to show that 30 percent of marsh warbler nests were robbed by female cuckoos. These nests either contained complete clutches or even young nestlings. Only females show this behavior, so the reason for such activities is not a need for food, but aims to motivate the songbirds to have a second clutch. In a previous study it had already been shown that female cuckoos lay a quarter of their eggs in clutches that are laid by the host birds as a second attempt at breeding after the first clutch has been lost.

Publications

Non-fiction

• 1922 - The Cuckoo's Secret . Sidgwick and Jackson: London.
• 1940 - The Truth About the Cuckoo . Country Life: London.

items

Edgar Chance published several articles including

• Edgar P. Chance, Harry W. Hann: The European Cuckoo and the Cowbird . In: Bird Banding . XIII, No. 3, July 1942, pp. 99-103. doi : 10.2307 / 4509742 .

Movies

• 1922 - Secrets of Nature: The Cuckoo's Secret . Producer: Edgar Chance. Director: OLIVER PIKE . Published by British Instructional Films (BIF). 'The Cuckoo's Secret' is available on the BFI DVD 'Secrets of Nature', published in 2010.

literature

• NB Davies: Cuckoos, Cowbirds and Other Cheats . T & AD Poyser, London 2000, ISBN 0-85661-135-2 .

Web links

• Cuckoo and host eggs, from the collection of ornithologist Edgar Percival Chance . In: NHM picture library . Natural History Museum. 2008. Retrieved July 16, 2016.
• Secrets of Nature: The Cuckoo's Secret (1922) . Wild film history. Retrieved July 16, 2016.
• BBC UK: Birdwatcher gave 1922 cuckoo clue , accessed 16 July 2016

Single receipts

1. ↑ BBC UK: Birdwatcher gave 1922 cuckoo clue , accessed July 16, 2016
2. ↑ BBC UK: Birdwatcher gave 1922 cuckoo clue , accessed July 16, 2016
3. ↑ ^{a b} Davies: Cuckoos, Cowbirds and Other Cheats. P. 30.
4. ↑ Davies: Cuckoos, Cowbirds and Other Cheats. P. 29.
5. ↑ ^{a b} Davies: Cuckoos, Cowbirds and Other Cheats. P. 31.
6. ↑ Davies: Cuckoos, Cowbirds and Other Cheats. P. 31 and p. 32.
7. ↑ Davies: Cuckoos, Cowbirds and Other Cheats. P. 33.
8. ↑ ^{a b} Davies: Cuckoos, Cowbirds and Other Cheats. P. 34.