1 92 1.] tlte Near East and Tropical East Africa. G-il 



Galerida theklae Brehm. 



At Solium I wag surprised to find birds belonging to this 

 species. la all, twelve sjiociincns were collected. I have 

 not been able to compare them with specimens o£ Galerkla t. 

 cyreiiaica from the type-locality, but they agree perfectly 

 with the description of that race. This is the most easterly 

 point in northern Africa at which these birds have been met. 



Wing of five males 94 to 100 mm., culmen 16-17. Wing 

 of four females 91-95 mm,, culmen 15-17. 



Note on the influences which tend to differentiate plumage 

 colour am07i<j the Crested Larks. 



The Crested Larks of the Near East afford interesting 

 evidence regarding the influences which tend to differentiate 

 plumage colour. 



Beebe, when conducting experiments on some American 

 Doves in captivity, found that artificial humidity produced 

 darker plumage.d and more variegated birds. 



Ogilvie-Grant found that rainfall seemed to be a factor 

 among Bustard-Quail in south-eastern Asia in determining 

 the darkness or otherwise of plumage. Similarly, the darker- 

 plumaged Robins, Song-Thrushes, etc., of the British Islands, 

 and the still darker Hebridean Song-Thrush, seem to be 

 influenced by the greater rainfall in their homes. 



Through the kindness of the Egyptian Meteorological 

 Department, I have been supplied with the following fioures. 

 I would point out that the percentage of humidity is the 

 amount of moisture in the atmosphere, and has nothing to 

 do with lainfall. Thinking that perhaps birds might be 

 influenced by conditions during their actual breeding-season, 

 I also worked out conditions for those months durin"- which 

 they breed, and the following are the results. 



The races of Galerida cristata are arranged, beginning 

 with the darkest-plumaged birds and ending with the palest- 

 plumaged birds ; — 



