Male Blackbird "Sunning"
Article by RSPB
Blackbird indulging in behaviour known as sunning. This usually involves the bird adopting an unusual posture and deliberately positioning itself in sunlight. It may spread or raise its wings, fan its tail feathers, sit down, fluff the feathers on the head and back, and hold the head to one side, looking directly into the sun with one eye. In this country, sunning has been observed in blackbirds more often than any other species (Simmons, K.E.L. The Sunning Behaviour of Birds, Bristol Ornithologists Club, 1986).
No-one knows for certain the reasons birds do this and several theories have been proposed. However, sunning would appear to perform two separate functions: maintaining the bird's feathers in good condition, and helping to regulate it's temperature. There is even a suggestion that they do it simply because they enjoy it!
Precisely how sunning assists with the maintenance of feathers is not known, despite being widely studied. All birds have a gland on the rump, called an oil gland. The 'preen-oil' that this gland produces helps to keep the feathers flexible and hygienic. It has been suggested that the sun affects the preen-oil in the feathers in some beneficial manner, or that it helps to synthesize the Vitamin D from the preen-oil. This preen-oil also aids with waterproofing the birds' feathers. Additionally, the heat from the sun may stimulate activity in parasites within the feathers, making them more accessible when the bird starts to preen. Preening usually occurs directly after sunning.
Male Blackbird "Sunning"
Article by RSPB
Blackbird indulging in behaviour known as sunning. This usually involves the bird adopting an unusual posture and deliberately positioning itself in sunlight. It may spread or raise its wings, fan its tail feathers, sit down, fluff the feathers on the head and back, and hold the head to one side, looking directly into the sun with one eye. In this country, sunning has been observed in blackbirds more often than any other species (Simmons, K.E.L. The Sunning Behaviour of Birds, Bristol Ornithologists Club, 1986).
No-one knows for certain the reasons birds do this and several theories have been proposed. However, sunning would appear to perform two separate functions: maintaining the bird's feathers in good condition, and helping to regulate it's temperature. There is even a suggestion that they do it simply because they enjoy it!
Precisely how sunning assists with the maintenance of feathers is not known, despite being widely studied. All birds have a gland on the rump, called an oil gland. The 'preen-oil' that this gland produces helps to keep the feathers flexible and hygienic. It has been suggested that the sun affects the preen-oil in the feathers in some beneficial manner, or that it helps to synthesize the Vitamin D from the preen-oil. This preen-oil also aids with waterproofing the birds' feathers. Additionally, the heat from the sun may stimulate activity in parasites within the feathers, making them more accessible when the bird starts to preen. Preening usually occurs directly after sunning.