Smith. — 0)i the Birds of Lake Brunner District. 207 



other. As the supply of insect-food lessens, some species of 

 birds chiefly depending on it decrease according to the supply 

 and rate of reduction. From peculiar habits in the economy 

 of such species, they appear incapable of changing their food, 

 habits, or environment, and ultimately become extinct. The 

 extirpation of other species again is due to the ravages of in- 

 troduced predaceous animals. 



The cold winter of 1883, followed in the spring by severe 

 late frosts, and the continuous cold wet summer of 1883-84, 

 produced a wide-spread failure of the food of many species of 

 birds. In the winter and spring followed the irruption of 

 parakeets, extending over the whole of the east coast of the 

 South Island, and the irruption or "plague" of rats on the 

 west coast, which swarmed into some of the towns and villages. 

 The tui and korimako left their home in the bush and migrated 

 across the open country to procure food. All were in mise- 

 rable condition and on the verge of starvation. They daily 

 visited the flower-borders, and eagerly probed with their brush- 

 tongues the scarlet and yellow tube-flowers of Tritomia uvaria. 

 The same season the wood-pigeon was miserably lean, being 

 compelled to feed on the leaves of the kowhai and other trees, 

 which cannot nourish and fatten like the fleshy nutritious 

 berries of the miro and others. The bush-rats {Mus rattus), 

 w^hich depend for food during a part of the year on the ripe 

 berries falling from the trees, were likewise compelled to 

 migrate in search of food. In the same year the habits of the 

 kaka [Nestor meridionalis) and the silver-eye {Zosterops late- 

 ralis) were affected in a similar manner and from the same 

 cause. I collected several specimens of the former in a planta- 

 tion of English trees near Oamaru, all in a wretchedly weak 

 and lean condition. Their presence was a rare occurrence in 

 the district, wdiich is about thirty-five miles from the nearest 

 native bush. The silver-eye or " blight bird " frequented the 

 gardens in the settled districts in unusual numbers, and 

 attacked the ripe fruits, nothing coming amiss to them. All 

 the species affected were in wretched plumage, and their bodies 

 w^ere infested with a species of Acartis. 



The New Zealand quail {Coturnix novm-zealandice) is often 

 cited as showing how rapidly a species will become extinct. 

 Frequently we hear the old colonists speaking of the great 

 numbers of quail inhabiting the grassy plains in the early days 

 of Canterbury. In a few years, however, without any appa- 

 rent cause, they vanished, until at the present time not a 

 single living quail exists in the islands. Their disappearance 

 is generally attributed by ornithologists to the burning of 

 sheep-runs or native-grass lands. Probably this is the princi- 

 pal cause which has effected the extirpation of this useful and 

 beautiful gallinaceous bird. 



