He enquires whether this phenomenon is a usual one and how it is that the comparatively weak raven can vanquish so powerful a bird as the golden eagle.
The above statement and its attendant queries are the result of faulty observation.
Such a thing as a battle between ravens and golden eagles has probably never happened. If it did take place it could have but one ending—the victory of the golden eagles.
Battles rarely, if ever, occur in nature between different species. In order that a battle may take place it is necessary that each of the opposing species should want the same thing and be ready to fight and, if necessary, to sustain serious injuries in order to obtain that thing.
Now these conditions are rarely fulfilled except at the breeding season, when males of the same species fight for the females.
The only other things over which fighting is likely to arise are food and nesting sites.
It frequently happens that birds of different species want the same food. But this rarely leads to anything in the nature of a battle. In such contests the weaker almost invariably gives way to the stronger without any fighting.
A familiar instance of this is afforded by the behaviour of the white-backed (Pseudogyps bengalensis) and the black vultures (Otogyps calvus) when they gather round a carcase.
Jesse writes, and my experience bears out what he says: “Often I have been watching the vulgar white-backed herd, with a disreputable following of kites and crows, teasing and fighting over a body, when one of these aristocrats (i.e. Otogyps calvus), in his red cap and white waistcoat, has made his appearance. Way is immediately made for him, the plebeian herd slinking back as if ashamed or afraid, and I cannot remember the last comer ever being obliged to assert his authority.”
If the smaller vultures, which are the more numerous, chose to combine, they could drive off the black vultures, but in doing this some of them would run the risk of sustaining injuries. Now, it seems to be a rule in nature that no creature will willingly run such a risk. Rather than do this an animal will flee before a comparatively puny adversary.