I was intrigued by an unusual Cape Bulbul I saw feeding with a variety of birds on some rusk crumbs that I had thrown out into our garden in Stanford on Friday 27 June. The bird had a broad white stripe on its tail and white stripes on its wings.
Unfortunately I do not have a big lens for my camera so these were the best shots that I could get from the kitchen doorway. I did not wish to frighten the birds away by approaching them more closely. Rob Little of the Percy Fitzpatrick Institute of African Ornithology at UCT kindly answered my queries about the bird, describing it as a partially leucistic Cape Bulbul. He commented that there has been “unusually high reporting of leucistic birds across the country over the past few months”
Leucism is a genetic defect resulting in a reduction or an absence of melanin pigment cells causing white or washed out plumage. It is rare in birds but more instances have been seen in recent years. Leucistic birds are more vulnerable that their normal counterparts.
In his informative article which appears in African Birdlife, Rob speculates that the more frequent occurrences of such birds may be a result of there being more birders out in the field or more people willing to report unusual occurrences but also “is tempted” to speculate that the increase in sightings may be due to the increasingly polluted and stressful environment in which we live.
( Little, R. 2014. Bright white: Leucism and albinism in birds. African Birdlife July/August 2(5): 14-15)
He has given permission to link the article on the Scenic South.