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The yellow and black Common Magpie in Sømna, Norway, in 2014. Photo: Magne Husby
Source publication
Two yellow and black Common Magpies Pica pica were observed in Sømna, Norway, in 2014. The normally white parts of these birds were all evenly coloured yellow, while the black parts looked normal. Carotenoids are normally responsible for yellow colours in feathers, but Magpies are not among the bird species for which carotenoids have been identifie...
Contexts in source publication
Context 1
... my surprise, I received pictures and information about a Magpie that had the customary black feathers, but all the typical white parts were brown-yellow. All the yellow feathers were evenly coloured on this beautiful bird (Figure 1). The aim of this work is to find the reason for this colouration, and to investigate how common this phenomenon is. ...
Context 2
... picture I received from Sømna in 2014 showed a Magpie that was black on all the typical black parts, and yellow-brown on all parts that are normally white. During my investigation in the area, I found two adult Magpies with yellow and black feathers (Figure 1). The yellow colour seemed to have faded relative to the pictures I received. ...
Context 3
... and black Magpies are not common, and only two were found among the more than 4000 Magpie pictures on the Internet, one of a single bird in Denmark (July 2009), and my picture of one of the two birds from Sømna, Norway (Figure 1). In addition, I was informed about four additional observations in Norway between 1990 and 2015; one bird in Jaeren (July 1990), two birds in Skiptvet (May−June 2013), two birds in Grue (June−July 2015), and one bird in Baerum (June 2015). ...
Citations
... Comments: 1: Fledgling, a: Yellow instead of white (seeHusby 2015), b: Pink on the white feathers ...
Information about the relative frequency and geographical variation of colour aberrations in birds is rare. By entering the word Magpie Pica pica in 37 European languages into an Internet search engine, I was able to trace 3,974 photographs in 2015 and 3,672 photographs in 2016 in more than 40 countries. By analysing the photographs, I found a significant difference in the frequency of aberrant Magpies, with the frequency increasing northwards and decreasing eastwards. Leucism was the most common aberration, followed by brown (brown and ino) and dilute. Despite some changes in the number of Magpie pictures found for each language between the two years, the numbers correlated strongly. The percentage of aberrant Magpies found for each language in 2015 correlated significantly with the percentage in 2016. While using pictures obtained from the Internet has inherent biases and limitations, it is also a useful new tool revealing patterns in geographical variation in aberrant colouration in several bird species, and allowing us, eventually, to understand the differences.
