voL.xni.] SOME HABITS OF SPARROW-HAWK. 117 



the full strength of the sun for the operation. Preening 

 normally seems to follow a meal as night does day : the 

 usual site selected is a dead and sloping branch, in my experi- 

 ence not so often a horizontal branch : a live branch with a 

 good length free from twigs is also often used both for a 

 feeding place, particularly by the hen during the incubation 

 period, and for preening afterwards. After the main brooding 

 period is over, the hen will select some such site near the 

 nest and the choice of this site appears to depend on the 

 direction of the wind. It is usually up-wind from the nest, 

 probably because the cock brings the food down-wind or 

 across wind to such a position relative to the nest. Another 

 great point in the selection of the site seems to be a clear 

 view of the nest and as much space in other directions as 

 is possible in the wood. The amount of sun power the bird 

 requires appears also to depend on the nature of the wind, 

 i.e., the colder the wind the more likely the bird will be to get 

 in the full sun. This habit on the part of the sitting bird 

 of perching somewhere not far away, when not brooding, 

 makes it necessary to get a friend to relieve one at a stated 

 time. Otherwise the hen will see you getting out of the hut, 

 and that very soon makes her a difficult subject, to put it 

 mildly. I have several peep-holes as a rule, and have learned 

 by experience to look up-wind first, but it is best to investigate 

 all trees in the immediate neighbourhood of the nest for 

 likely perching branches as soon as it is decided to leave the 

 hut. I have many times found a bird using a projecting 

 end of the hut frame as the look-out post. The amount of 

 time a bird can spend without moving on one of these perches 

 is quite astonishing. Except for turning the head occa- 

 sionally and sometimes changing its stance from one foot to 

 both or the other, she may not stir for hours. Last June 

 on one hot day I watched my hen in the same spot for more 

 than three hours, and was very thankful when some children 

 came into the wood and frightened her. At the time the sun 

 had not reached the nest ; it being Sunday morning, and my 

 arrangements having been made chiefly for afternoon watching. 

 Even for their curious flights sun and the wind must not 

 be over a certain mild strength, at any rate low down. It 

 seems useless to watch for these flights if there is rain, fog 

 or much wind. At any rate, I have often got up here before 

 daybreak to watch, on what seemed, at that hour, an ideal 

 morning, but which after dawn turned out wet or windy, but 

 without success. Building, and more especially early building, 

 is spasmodic and seems again to depend on the weather. 

 I have found a new nest as early as February 17th (1918) 



