Island Life; Or, The Phenomena and Causes of Insular Faunas and Floras

Animal Life of Formosa.—We are at present acquainted with 35 species of mammalia, and 128 species of land-birds from Formosa, fourteen of the former and forty-three of the latter being peculiar, while the remainder inhabit also some part of the continent or adjacent islands. This proportion of peculiar species is perhaps (as regards the birds) the highest to be met with in any island which can be classed as both continental and recent, and this, in all probability, implies that the epoch of separation is somewhat remote. It was not, however, remote enough to reach back to a time when the continental fauna was very different from what it is now, for we find all the chief types of living Asiatic mammalia represented in this small island. Thus we have monkeys; insectivora; numerous carnivora; pigs, deer, antelopes, and cattle among ungulata; numerous rodents, and the edentate Manis,—a very fair representation of Asiatic mammals, all being of known genera, and of species either absolutely identical with some still living elsewhere or very closely allied to them. The birds exhibit analogous phenomena, with the exception that we have here two peculiar and very interesting genera.

But besides the amount of specific and generic modification that has occurred, we have another indication of the lapse of time in the peculiar relations of a large proportion of the Formosan animals, which show that a great change in the distribution of Asiatic species must have taken place since the separation of the island from the continent. Before pointing these out it will be advantageous to give lists of the mammalia and peculiar birds of the island, as we shall have frequent occasion to refer to them.

List of the Mammalia of Formosa. (The peculiar species are printed in italics.)

1. Macacus cyclopis. A rock-monkey more allied to M. rhesus of India than to M. sancti-johannis of South China.

2. Pteropus formosus. A fruit-bat closely allied to the Japanese species. None of the genus are found in China.

3. Vesperugo abramus. China.

4. Vespertilio formosus. Black and orange Bat. China.

5. Nyctinomus cestonii. Large-eared Bat. China, S. Europe.

6. Talpa insularis. A blind mole of a peculiar species.

7. Sorex murinus. Musk Rat. China.

8. Sorex sp. A shrew, undescribed.

9. Erinaceus sp. A Hedgehog, undescribed.

10. Ursus tibetanus. The Tibetan Bear. Himalayas and North China.

11. Helictis subaurantiaca. The orange-tinted Tree Civet. Allied to H. nipalensis of the Himalayas more than to H. moschata of China.

12. Martes flavigula, var. The yellow-necked Marten. India, China.

13. Felis macroscelis. The clouded Tiger of Siam and Malaya.

14. Felis viverrina. The Asiatic wild Cat. Himalayas and Malacca.

15. Felis chinensis. The Chinese Tiger Cat. China.

16. Viverricula malaccensis. Spotted Civet. China, India.

17. Paguma larvata. Gem-faced Civet. China.

18. Sus taivanus. Allied to the wild Pig of Japan.

19. Cervulus reevesii. Reeve's Muntjac. China.

20. Cervus pseudaxis. Formosan Spotted Deer. Allied to C. sika of Japan.

21. Cervus swinhoii. Swinhoe's Rusa Deer. Allied to Indian and Malayan species.

22. Nemorhedus swinhoii. Swinhoe's Goat-antelope. Allied to the species of Sumatra and Japan.

23. Bos chinensis. South China wild Cow.

24. Mus bandicota. The Bandicoot Rat. Perhaps introduced from India.

25. Mus indicus. Indian Rat.

26. Mus coxinga. Spinous Country-rat.

27. Mus canna. Silken Country-rat.

28. Mus losca. Brown Country-rat.

29. Sciurus castaneoventris. Chestnut-bellied Squirrel. China and Hainan.

30. Sciurus m'clellandi. M‘Clelland's Squirrel. Himalayas, China.

31. Sciuropterus kaleensis. Small Formosan Flying Squirrel. Allied to S. alboniger of Nepal.

32. Pteromys grandis. Large Red Flying Squirrel. Allied to Himalayan and Bornean species. From North Formosa.

33. Pteromys pectoralis. White-breasted Flying Squirrel. From South Formosa.

34. Lepus sinensis. Chinese Hare. Inhabits South China.

35. Manis dalmanni. Scaly Ant-eater. China and the Himalayas.

The most interesting and suggestive feature connected with these Formosan mammals is the identity or affinity of several of them, with Indian or Malayan rather than with Chinese species. We have the rock-monkey of Formosa allied to the rhesus monkeys of India and Burma, not to those of South China and Hainan. The tree civet (Helictis subaurantiaca), and the small flying squirrel (Sciuropterus kaleensis), are both allied to Himalayan species. Swinhoe's deer and goat-antelope are nearest to Malayan species, as are the red and white-breasted flying squirrels; while the fruit-bat, the wild pig, and the spotted deer are all allied to peculiar Japanese species. The clouded tiger is a Malay species unknown in China, while the Asiatic wild cat is a native of the Himalayas and Malacca. It is clear, therefore, that before Formosa was separated from the mainland the above named animals or their ancestral types must have ranged over the intervening country as far as the Himalayas on the west, Japan on the north, and Borneo or the Philippines on the south; and that after that event occurred, the conditions were so materially changed as to lead to the extinction of these species in what are now the coast provinces of China, while they or their modified descendants continued to exist in the dense forests of the Himalayas and the Malay Islands, and in such detached islands as Formosa and Japan. We will now see what additional light is thrown upon this subject by an examination of the birds.

List of the Land Birds peculiar to Formosa

Turdidæ (Thrushes)

1. Turdus albiceps. Allied to Chinese species.

Sylvidiæ (Warblers)

2. Cisticola volitans. Allied to C. schœnicola of India and China.

3. Herbivox cantans. Sub-species of H. cantillaus of N. China and Japan.

4. Notodela montium. Allied to N. leucura of the Himalayas; no ally in China.

Timaliidæ (Babblers)

5. Pomatorhinus musicus. Allies in S. China and the Himalayas.

6. P. erythroenemis.              Do.                  do.

7. Garrulax ruficeps. Allied to G. albogularis of N. India and East Thibet, not to the species of S. China (G. sannio).