154 Food of Cuckoos 



10. Argyllshire ; male, imm. 



A mass of insect remains, consisting of one small spider, one 

 centipede, five empty skins of a small smooth larva (not 

 identified), the remains of a beetle and an entire beetle. 



11. August ; female, imm., Suftolk. 



Filled with the skins of the larvae of one of the Noctuse — I 

 counted just 40 — and a few smooth green larvse. 



12. May ; male, ad., Argyllshire. 



A semi-digested mass of insects, including a fragment of a black 

 beetle. 



To draw any relialble data concerning the food of the Cuckoo, 

 it would be necessary to collect a large number of specimens from 

 various parts of the country, at least 100 for each of the six months 

 during which they are more or less abundant. My dozen skins are 

 of no service for general conclusions. 



An analysis of the twelve examples tabulated above shows that 

 they were obtained in the following months : — 



May (3), June (2), July (i), August (3), September (2), 

 October (i). 



Those shot at the end of August, throughout September, and 

 early in October, all contained hairv larvae ; with one exception, 

 the larvae chosen were of the Buff-tipped moth, whereas those 

 obtained in May, June, July contained principally coleopterous 

 insects. 



One bird (July 27th, Ranworth) contained a number of larvae 

 of the Swallow-tailed butterfly. This is worth specially noting, 

 for the Norfolk Broads are one of the few remaining strongholds 

 of this fine butterfly ; they are particularly plentiful about the 

 Ranworth marshes bordering the river Bure. In this ornithological 

 paradise I have seen Garganey Teal, Bearded Tits and Swallow- 

 tailed butterflies on the wing at the same time. The range of all 

 three species (so far as their British status is concerned) is being 

 reduced year by year, and I don't know that even in the Broad 

 district you would often see the three in one day, except at Ranworth. 



Cuckoos are exceedingly plentiful here. They are distributed 

 in greater numbers over the Broad district than in any other locality 

 with which I am acquainted. Here one finds acre upon acre of 

 reedy swamp. The great reed-beds are full of reed warblers, and it 

 is their nest that the Cuckoo selects, in almost every instance, for 

 introducing its own egg. 



The larva of the Swallow-tailed butterfly is probably distasteful 

 to most insectivorous birds. It is naked, it is true, and green, but 

 it is ornamented with velvety black rings spotted with red, and has 

 a fork-like tentacle on the neck of a red colour. When alarmed, 

 the beast is said to emit a strongly-scented fluid, which keeps off 

 the ichneumon flies (Westwood). But no diet seems to come amiss 

 to the Cuckoo, and no larvae appear to be immune from their 

 attack. 



