49 
Jaegers make good recognition marks. This characteristic tail is so conspicuous as to have 
suggested to sailors the colloquial names of “Mason” (referring to the trowel-like 
tail), “Bos’n” (from the tail like a marlin-spike, the special tool of a boatswain), or just 
“Marlin-spike.” 
Nesting. On the ground. 
The occurrence of the two colour phases, as well as every possible 
intermediate plumage, makes the identification of some of the Jaegers a 
difficult matter. Skuas and Jaegers are pirates of the air; they pursue 
successful fishing birds and force them to disgorge the fish they have 
swallowed. Eggs and young birds in the nest are never safe from them. 
Three Jaegers occur in western Canada and one Skua — the latter very 
rare. 
Economic Status. The Jaegers are not very numerous and except in 
far away, wild localities, where numbers give them local importance, they 
are of no economic influence. 
35. 1. Chilean Skua. Catharacta chilensis. L, 20-22. A large, dark brown, Jaeger- 
like bird with a rounded tail. With or without scattered lanceolate feathers of a dull 
golden hue down the back of the neck and upper shoulders. A conspicuous white bar at 
base of primaries (Figure 90). 
Distinctions. As above. 
Figure 90 
Wing of Jaeger, showing white at base of primaries; 
scale, about 1. 
Field Marks. Would probably be seen in fife as a large, nearly black bird with round 
tail and conspicuous white spot at base of primaries. Disregarding the elongated tail 
feathers of the Jaegers, the Skua is considerably larger than any of them. 
Distribution. Both shores of South America, wandering north in theTacific occasion- 
ally. Breeds in the Fuegian Archipelago. 
Nesting. Probably similar to the other members of the family. 
A Skua taken off southern Vancouver island in 1917 was originally 
identified as the Atlantic Skua Catharacta skua , but has recently been 
assigned to this species. This is the only record of this bird in Canada. 
The Skuas are typically birds of the Antarctic where they occupy the same 
place in the natural economy as do our birds of prey. Too rare on our 
coast to be recorded except by specimens authoritatively identified. 
36. Pomarine Jaeger, bos’n. (boatswain) bird. Stercorarivs pomarinus. L. 22 
(Tail 9*25 maximum). Projection of centre tail feathers beyond outer ones 4-25 inches. 
Occurs in two phases and intermediate stages. In the dark phase, the general colour 
is dark brown, slightly lighter below and on cheeks, with a black cap. In light phase, 
the underparts, breast, neck, and face are white; cheeks mostly, and throat in some cases, 
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