S98 JNSESSORES. CUCULUS. CUCKOO. 



tail (Motacilla alba), and the Meadow-Pipit (Antlius praten- 

 sis), answer its purpose. 



In Northumberland, constant experience tells me, that the 

 nest of the last mentioned bird is the one almost always cho- 

 sen. Taking advantage of the absence of its dupe, during 

 the time of laying (which generally occupies four or five 

 days), the Cuckoo deposits its egg among the rest, abandon- 

 ing it, from that moment, to the care of the foster-parent. 

 As the same period of incubation is common to both birds, 

 the eggs are hatched nearly together, which no sooner takes 

 place, than the young Cuckoo proceeds instinctively to eject 

 its young companions, and any remaining eggs, from the 

 nest. To effect this object, it contrives to work itself under 

 its burden (the back, at this early age, being provided with 

 a peculiar depression between the shoulders), and shuffling 

 backwards to the edge of the nest, by a jirk rids itself of the 

 incumbrance ; and this operation is repeated, till the whole 

 being thrown over, it remains sole possessor. This particu- 

 lar tendency prevails for about twelve days, after which the 

 hollow space between the shoulders is filled up ; and when 

 prevented from accomplishing its purpose till the expiration 

 of that time, as if conscious of inability, it suffers its compa- 

 nions to remain unmolested. The egg of the Cuckoo is very 

 small in proportion to the size of the bird, which circum- 

 stance is in close connection with the instinct, that directs it 

 to choose for its depository the nest of a smaller species. If 

 it selected that of a larger bird, the offspring that its young 

 one would have to contend with, being its equal, perhaps its 

 superior, in size and weight, would consequently frustrate 

 the design, and the young Cuckoo would perish in the vain 

 endeavour at the sole possession of the nest. It is an opinion 

 very commonly entertained, that this bird sucks the other 

 eggs in the nest, where it deposits its own, but there appears 

 to be no reason for supposing this to be the case ; the belief 

 has, without doubt, arisen from the fact of the young Cuc- 

 koo being so often found sole tenant, after the expulsion of 



