288 SPOLIA ZEYLANICA. 
Again, how are we to class Jerdon’s Imperial Pigeon, Ducula 
insignis cuprea, which occurs all over South India? It has 
only once been recorded from Ceylon, but was on that one 
occasion found breeding. 
However, at least half of our casual visitors are species 
which perform regular migrations, but whose usual winter 
quarters do not extend so far south as our Island. Nearly all 
the members of this class belong to families which include our 
common winter visitors. If we look at the 12 species of duck 
which occur in Ceylon, the gradation is well seen. The 
Smaller Whistling Teal, the Quacky Duck or Goose Teal, and 
the Comb Duck are resident, but also in all probability partial 
migrants ; the remainder are all migrants, which visit us in 
varying numbers. The Common Teal and Garganey are 
fairly abundant in some years, but scarce in others. The 
Brahminy Duck and the Shoveller visit the lagoons in the 
north of the Island in small numbers, which vary from year 
to year. The same may be said of the Spotted-billed Duck 
and the Pintail. Two more species, the Larger Whistling 
Teal and the Gadwall, have only been recorded once or twice, 
and should, therefore, be put down as casual visitors, while the 
Red-crested Pochard is on the doubtful list ; it is said to have 
been seen near Jafina by Layard. 
We have now arrived by the process of elimination at our 
regular migrants. These vary from birds which visit us every 
year in enormous quantities, such as the Pintail Snipe, to 
species which are extremely scarce, but fairly regular in their 
visits, such as the Woodcock. At the lower end of the scale, 
as I have said, it is difficult to draw the line between them and 
the casual visitors. We may, however, say roughly that the 
regular migrants number between 60 and 70 species, all of 
which visit us during the north-east monsoon. 
The number of species is thus only just over one-sixth of 
those on the Ceylon list, but the number of individuals is so 
large that the bird population is swelled enormously by their 
arrival. This is especially the case on our lagoons, paddy 
fields, and tanks, which teem with bird life during the north- 
east monsoon, and presenta comparatively deserted appearance 
during the south-west. In fact, im Ceylon we have the 
