14 
MUSEUM BULLETIN NO. 28. 
most raptoral species prefer fur to feathers when it can. be obtained 
This is probably more a matter of greater opportunity than taste, but 
eems to be a fact except in a few exceptional and fortunately rare 
species. , . , . 
As these invasions seem to be governed by the rabbit situation more 
than any other factor there seems to be no means of controlling them. 
All that can be recommended is to kill as many of the offenders as 
possible. Probably the crisis of the present cycle is over now. I he 
northern raptores have had two rabbitless seasons and have exhausted 
the grouse. Following the laws of cause and effect their numbers must 
also be considerably reduced through lack of food and the terms that 
they preyed upon will have an opportunity for recovering. . 
The course here recommended of encouraging and protecting the 
useful species of hawks and destroying the harmful ones necessitates 
careful discrimination between the two classes. Unfortunately, the 
knowledge necessary to distinguish the different species is not Widespread 
and to most people a hawk is a hawk and to be killed at every opportunity. 
With so much at stake a farmer or sportsman is no more justified in 
advancing ignorance as an excuse than he is in proclaiming his inability 
to distinguish between crops and weeds or to know the various insect 
pests that he has to fight, or the game that the law allows him to shoot. 
In fact discrimination is a part of his business as farmer or sportsman and 
as such should be studied. f 
Until a better knowledge of the usefulness and harmfulness, of t>ur 
birds of prey is more widely distributed the following rule for action can 
be given for the southern prairie provinces— protect and encourage the 
larger summer hawks, except those actually caught in the act of poultry 
killing, and destroy the winter ones when opportunity offers, in t is 
way a few harmful hawks may escape and a few innocent ones suffer 
but the results on the whole will be a great step in advance oi the present 
practice of indiscriminately killing friend as well as foe. 
