Topic: Birds (Page 2)

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πŸ”— Crop Milk

πŸ”— Birds

Crop milk is a secretion from the lining of the crop of parent birds in some species that is regurgitated to young birds. It is found among all pigeons and doves where it is also referred to as pigeon milk. Crop milk is also secreted from the crop of flamingos and the male emperor penguin, suggesting independent evolution of this trait. Unlike in mammals where only females produce milk, crop milk is produced by both males and females in pigeons and flamingos; and in penguins, only by the male. Lactation in birds is controlled by prolactin, which is the same hormone that causes lactation in mammals. Crop milk is a holocrine secretion, unlike in mammals where milk is an exocrine secretion. Crop milk contains both fat and protein, as with mammalian milk, but unlike mammalian milk, it contains no carbohydrates.

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πŸ”— Alex

πŸ”— Biography πŸ”— Psychology πŸ”— Cognitive science πŸ”— Neuroscience πŸ”— Birds

Alex (May 1976 – 6 September 2007) was a grey parrot and the subject of a thirty-year experiment by animal psychologist Irene Pepperberg, initially at the University of Arizona and later at Harvard University and Brandeis University. When Alex was about one year old, Pepperberg bought him at a pet shop. The name Alex was an acronym for avian language experiment, or avian learning experiment. He was compared to Albert Einstein and at two years old was correctly answering questions made for six-year-olds.

Before Pepperberg's work with Alex, it was widely believed in the scientific community that a large primate brain was needed to handle complex problems related to language and understanding; birds were not considered to be intelligent, as their only common use of communication was mimicking and repeating sounds to interact with each other. However, Alex's accomplishments supported the idea that birds may be able to reason on a basic level and use words creatively. Pepperberg wrote that Alex's intelligence was on a level similar to dolphins and great apes. She also reported that Alex seemed to show the intelligence of a five-year-old human, in some respects, and he had not even reached his full potential by the time he died. She believed that he possessed the emotional level of a two-year-old human at the time of his death.

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  • "Alex" | 2021-07-09 | 17 Upvotes 1 Comments

πŸ”— Silkie Chickens

πŸ”— Agriculture πŸ”— Food and drink πŸ”— Birds πŸ”— Agriculture/Livestock

The Silkie (also known as the Silky or Chinese silk chicken) is a breed of chicken named for its atypically fluffy plumage, which is said to feel like silk and satin. The breed has several other unusual qualities, such as black skin and bones, blue earlobes, and five toes on each foot, whereas most chickens only have four. They are often exhibited in poultry shows, and also appear in various colors. In addition to their distinctive physical characteristics, Silkies are well known for their calm, friendly temperament. It is among the most docile of poultry. Hens are also exceptionally broody, and care for young well. Although they are fair layers themselves, laying only about three eggs a week, they are commonly used to hatch eggs from other breeds and bird species due to their broody nature.

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πŸ”— Brood parasite

πŸ”— Birds

Brood parasites are organisms that rely on others to raise their young. The strategy appears among birds, insects and fish. The brood parasite manipulates a host, either of the same or of another species, to raise its young as if it were its own, using brood mimicry, for example by having eggs that resemble the host's (egg mimicry).

Brood parasitism relieves the parasitic parents from the investment of rearing young or building nests for the young, enabling them to spend more time on other activities such as foraging and producing further offspring. Bird parasite species mitigate the risk of egg loss by distributing eggs amongst a number of different hosts. As this behaviour damages the host, it often results in an evolutionary arms race between parasite and host as the pair of species coevolve.

The strength of defenses and counter-adaptation rely on the host/parasitic species' ability to evolve; some host species have very strong rejection defenses resulting in the parasitic species evolving to have very close mimicry. In other species, hosts do not show rejection defenses and as a result, the parasitic species will show no evolved trait (example: egg mimicry).

πŸ”— Tromelin, the Island of Forgotten Slaves

πŸ”— France πŸ”— Birds πŸ”— Overseas France

Tromelin Island (; French: Île Tromelin, pronouncedΒ [il tʁɔmlΙ›Μƒ]) is a low, flat island in the Indian Ocean about 500 kilometres (310Β mi) north of RΓ©union and about 450 kilometres (280Β mi) east of Madagascar. Tromelin is administered as part of the French Southern and Antarctic Lands, a French Overseas Territory, but Mauritius claims sovereignty over the island.

Tromelin has facilities for scientific expeditions and a weather station. It is a nesting site for birds and green sea turtles.

πŸ”— Abnormal Behaviour of Birds in Captivity

πŸ”— Birds πŸ”— Animal rights πŸ”— Veterinary medicine

Abnormal behavior of birds in captivity has been found to occur among both domesticated and wild birds. Abnormal behavior can be defined in several ways. Statistically, 'abnormal' is when the occurrence, frequency or intensity of a behaviour varies statistically significantly, either more or less, from the normal value. This means that theoretically, almost any behaviour could become 'abnormal' in an individual. Less formally, 'abnormal' includes any activity judged to be outside the normal behaviour pattern for captive birds of that particular class or age. For example, running rather than flying may be a normal behaviour and regularly observed in one species, however, in another species it might be normal but becomes 'abnormal' if it reaches a high frequency, or in another species it is rarely observed and any incidence is considered 'abnormal'. This article does not include 'one-off' behaviours performed by individual birds that might be considered abnormal for that individual, unless these are performed repeatedly by other individuals in the species and are recognised as part of the ethogram of that species.

Most abnormal behaviours can be categorised collectively (e.g., eliminative, ingestive, stereotypies), however, many abnormal behaviours fall debatably into several of these categories and categorisation is therefore not attempted in this article. Abnormal behaviours here are considered to be related to captive housing but may also be due to medical conditions. The article does not include behaviours in birds that are genetically modified to express abnormal behaviour.