FIRST LIST OF THE BIRDS OF THE SOUTH KONKAN. 41 



species A. melanosUrnus, Legge, in Ceylon. Careful observation 

 will, no doubt, disclose scores of similar instances. 



[The above quotation shows, 1 think, how entirely even 

 the greatest authorities have failed to grasp the point I have 

 so often urged, viz., that the variation in depth and intensity 

 of colour has nothing to do with latitude and longitude, but 

 depends on rainfall. If they could (or would) only realize 

 this, they would perceive that it explains at once an enormous 

 number of the variations in tint, which have puzzled ornitho- 

 logists. 



It is not a question of east or west, north or south ; 

 it is the average rainfall and average humidity that 

 mainly determine intensity of color, in the adults of 

 non-migratory, but widely extended species. 



To return, however, to this particular species. This 

 Glaucidium is a very good instance of the variation in color 

 due to differences in the amount of rainfall. Take a specimen 

 from Allahabad, where the rainfall is under 40 and the 

 atmosphere normally dry, and you have radiatum without 

 a trace of rufous. Take another from Anjange in Travancore, 

 where the rainfall is very heavy and the atmosphere always 

 humid — painfully so to my feelings — and you have malabaricum 

 with the entire head and upper back densely overlaid with 

 chestnut rufous, and with the rest of the plumage, especially 

 the wing-lining, tinted in many places with the same hue. 



Between these two forms, almost exactly mid-way as regards 

 coloration, lie all these Ratnagiri birds, of which Mr. Vidal 

 has procured me a huge series. Precisely similar to these are 

 specimens from Kalodoongi, at the foot of the Kumaon Hills, 

 where the average rainfall and humidity are almost precisely 

 the same as in Ratnagiri. 



But one point has to be noticed. It would appear that it is 

 only, as time runs on, that moisture operates to darken and 

 intensify plumage to its fullest extent ; the birds of the year, 

 whether of Scops malabaricus, Glaucidium brodii (in Sikhim), 

 Syrnium nivicolum, (in Sikhim), or Glaucidium malabaricum, are 

 invariably much paler, and less rufous than the adults, and 

 the older the birds grow the more deeply colored they become 

 in the heavy rainfall tracts, while in the scanty rainfall, and 

 a fortiori desert regions, they become paler as they advance in 

 years. 



Wallace says : " Dark colored birds are said to become blacker 

 towards the south/' and so they do, if that south happens to 

 be a well-watered region ; but it is just the contrary if it be 

 a dry and desert locality. Greater southing, greater heat, per se 

 in no way affect color — dry heat pales, damp heat intensifies. 



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