Jenyns Natural History. 1857 



are generally dispersed over the kingdom, have a tendency to equalize their numbers 

 throughout the different parts of it ; deficiencies from accident, or any other cause, in 

 one locality, being made up by supplies from another, in which there happens to be an 

 excess. It seems also not improbable, that, without a diminution of numbers in any 

 one place to induce strangers to settle there, the numbers in another are not allowed to 

 increase beyond a certain limit, in consequence of the law which impels old birds to 

 drive away their offspring, as soon as they are sufficiently matured to shift for them- 

 selves. If there be convenient space for them in the neighbourhood, without interfer- 

 ing with the old birds, they may be suffered to remain ; but otherwise they are forced 

 to go elsewhere ; and if there is no colony near, allowing of increase, to which they 

 can attach themselves, they found a new colony, wherever circumstances may be fa- 

 vourable to their so doing. In some instances, they may have to traverse long dis- 

 tances before they can effect this object ; or they may be compelled to leave the coun- 

 try altogether, and resort to another; and perhaps this supposition may serve to 

 explain the circumstance of their sudden appearance in some localities, where they had 

 not been previously observed* The well-known fact, too, of old birds driving away 

 their young may, in the case of certain rare species, account for their being young or 

 immature individuals, which alone occur, perhaps, at irregular intervals, in a given 

 country. These individuals are such as have wandered to near the extreme geogra- 

 phical limits assigned to their species. If, from a general excess of numbers in other 

 places, they are compelled to travel so far from central quarters as to overstep these 

 limits, existence is with difficulty maintained, or may be no longer possible. They 

 then perish ; and it may be in this way that the nurnbers of some species are constantly 

 held in check, or at least reduced, in certain seasons, when particular circumstances 

 have led to an undue increase." — p. 107. 



Anecdote of a Tame Barn Owl. — " White has mentioned a tame brown owl, with 

 which he was acquainted.! A friend of mine has sent me the following particulars 

 respecting a tame white one, which was taken, when young, from a nest in the woods 

 at Dilstone, near Hexham in Northumberland, and given by a lady to her children, 

 who brought it up. Great pains appear to have been taken to domesticate this owl, in 

 consequence of which it became very familiar. In imitation of its own call, it re- 

 ceived the name of Keevie, to which it would readily answer when within hearing, fol- 

 lowing the sound from whatever part of the premises it might happen to be in. Its 

 usual place of repose during the day was under the branches of an old Scotch fir, which 

 grew down a steep inaccessible bank, where it would sit apparently asleep, but suffi- 

 ciently awake to endeavour to attract the notice of any one who passed, by its usual 

 cry of keevie, keevie. If the passenger stopped and answered it, it immediately scram- 

 bled up the boughs of the fir, till it brought itself to a level with the walk above, in 

 hopes of being fed ; but if he went on again, unheeding its solicitations, it returned 



* An instance of this kind is mentioned in the volume of * Reports on the Progress 

 of Zoology and Botany,' lately published by the Ray Society. " In April, 1838, a 

 flight of rooks " is said to have " entered into the city of Danzig, and settling upon 

 all the larger trees, in gardens as well as in the most crowded streets, built their nests 

 there and brooded." — Prof. Wagner's Report on Birds, p. 71. 



f Nat. Hist, of Selborne, Lett. XI. to Pennant. 



