252 TONGATABU. 



very abundant. These Fruit-bats appear on the wing in the 

 early afternoon in full sunlight, and at the time of our visit 

 were feeding on the bright red flowers of one of the indigenous 

 trees. Flowers form an important proportion of the food of 

 Fruit-bats. In New South Wales, at Botany Bay in May, 

 numbers of Fruit-bats were to be seen feeding on the flowers of 

 the gum-trees. The bats must probably often act as fertilizers, 

 by carrying pollen from tree to tree, adherent to their fur. 



As dusk comes on, the Fruit-bats on the wing become more 

 and more plentiful. It is probably only those specially driven 

 by hunger that come out before dusk. Besides these large 

 bats, there are small Insectivorous bats in Tonga, which dart 

 about amongst the cocoanut trees, but we obtained no speci- 

 mens. The heavy flap flap of the Pteropus is as strongly 

 contrasted with the rapid motion of the true bats, as is the 

 flight of a goose with that of a swallow. There are plenty of 

 horses and cattle in Tonga, and the high ground of Eua is 

 occupied as a sheep run. 



A small Heron {Demiegnthi sacra) wades about on the coral 

 reefs at Tonga, and catches small fish, and is also to be seen 

 frequently inland all over the island. This bird changes its 

 plumage from pure white to uniform grey, and all stages of 

 parti-coloured plumage were to be seen during our visit. 

 Contrary to the usual rule, the bird is white when young, and 

 dark in the mature state. Hence the ancestors must have 

 been white, and the race is assuming a darker plumage for 

 protection. 



In the groves, the most abundant bird is one about the size 

 of a sparrow ; brown with yellow wattles {Ftilotis carunculata). 

 It has a sweet and very loud song, and fills the woods 

 with its melody. A Kingfisher {^Hakyon sacra) is .constantly 

 to be seen sitting on dead twigs, ready to dart on its prey. 

 Amongst the cocoanut trees a beautiful little Swift {Collocalia 

 spodiopygia)^ of the same genus as the species by which the 

 edible birds' nests, the well known Chinese luxury, are made, 

 and which is a Swift, and not a Swallow, as it is commonly 

 called, skims about with a constant twittering. These Tree- 

 swifts are especially abundant about the villages, though they 

 nest in the crowns of the cocoanut palms.* 



In the thickest masses of foliage, a most beautiful small 

 Fruit Pigeon, of a bright green, with a patch of the purest 

 purple on its head {^Ptilinopus poiphyraceus), is to be heard 



* For an account of the nesting of Collocalia, see Bernstein, " On 

 the genus Collocalia." Acta Societatis Scientiarum Indo-Nederlandicae, 

 Vol. II. For the nesting of the closely allied '' Tree-swift," Dciidrocliclidon, 

 see Bernstein, "Habits of Javan Birds," Ibid., Vol. III. 



