Ornithological Observations and Reflections in Shetland. 387 
This would have been very interesting to see, but it was denied 
me. Mr. Hay says he has often seen the Starlings thus perched 
on the sheep here, but more in the spring, and thinks it would 
be for the loose wool (the old pushed out by the new) to line 
their nests with, since, owing to the dip, the sheep would have 
no insects on them. But the Jackdaw I sew on the sheep’s 
head was certainly searching it and the sheep in that instance 
held its head out in much the same way as did these two with 
the Starlings and had much the same expression. It would 
be interesting if Starlings, having originally thus perched on 
sheep for the sake of the insects upon them, continued the habit 
after they could no longer get these, here, perhaps, using them 
as perches, since there are no trees. In so far as the question 
of insects is concerned, sheep should be as much dipped in 
England as the Shetlands, but there are many more insects in 
the larger Island. Here, at any rate, the dip-theory must, 
I think, be given up, for not only does so large a bird as the 
Jackdaw find it worth his while minutely and laboriously to 
search sheep, but there is, I believe, a veritable commensalism 
between the two species, as evidence of which I make the 
following quotation from my notes above alluded to :— 
‘The amount of intelligent reciprocity on the part of the 
sheep, at least, as shown by its keeping still, and thus facili- 
tating the explorations of the Jackdaw, seems to vary in 
different individuals. For the most part, they do not object, 
but some shake their heads a little, as though bored in a mild 
sort of way. Others, however, or possibly the very same, 
upon other occasions—since even sheep may have their moods 
—show a much higher degree of intelligence, so that very 
interesting scenes may sometimes be witnessed. What, for 
instance, can be more interesting than to see one sheep with 
a Jackdaw on her head, standing still in the midst of a moving 
flock, whilst another one, having come up behind, lays her 
chin amidst the wool above her friend’s tail and patiently waits 
to be operated upon in her turn? Nor does she wait in vain. 
The Jackdaw, having finished what he has had in hand, turns 
as a barber might turn towards a waiting customer, and walking 
sedately down the back of the one sheep, steps from it on to the 
head of the other, which he straightway commences to search. 
This searclr is minute and methodical. First the wool of the 
crown is examined, after which the beak is passed, in a quite 
professional manner, over the short black hair of the face, 
coming close to the ear, then closer till at last you seem plainly 
to see it inserted into the orifice, at least, if not into the deeper 
cavity of this sensitive organ. Of course, in a matter like this, 
where one cannot be very close and where everything must 
be made out through the glasses, it is difficult to be quite sure, 
but I believe myself, that the hairs or bristles inside the ears are 
1916 Dec. 1, 
