Birds from North Borneo.

by Max C. Thompson.

INTRODUCTION

The major part of this report is an account of birds collected by the expedition of the Bernice P. Bishop Museum of Honolulu, Hawaii, to North Borneo, from June 24, 1962, through January 14, 1963. Most of the time spent in the then British Colony was devoted to collecting in lowland habitats. The chief collecting localities were in the vicinity of Quoin Hill on the Semp.o.r.na Peninsula, and near Kalabakan. Approximately two weeks were spent in surveying the Tenom area. Additional work was done by the North Borneo Department of Agriculture after my departure, mainly by Antonio D. Garcia.

ACKNOWLEDGMENTS

I am indebted to J. L. Gressitt of the Entomology Department of the Bishop Museum for providing the opportunity for me to work on the expedition and to examine and report on the material collected. Without the help of the North Borneo Department of Agriculture, the success of our expedition would have been restricted. The Entomologist of North Borneo, G. R. Conway, was of great help with our logistic problems as was the Director of the Department, Mr. E. J. H. Berwick, and the Agronomist of Cocoa Research Station, Ed Wyrley-Birch. The Bombay Burmah Trading Corporation, Ltd., provided facilities and transportation at Kalabakan. Mr. Dai Rees of that corporation should be especially mentioned. Others who helped are: J. A. Comber, Ronnie Young, Mr. and Mrs. Horace Traulsen, Maureen Wyrley-Birch, and the Resident, Tawau, Mr. Peter Edge. The Conservator of Forests kindly provided the necessary permits for collecting.

Authorities of the United States National Museum and The American Museum of Natural History generously permitted me to work at those inst.i.tutions, using their specimens for comparative studies. Other specimens were borrowed from the Museum of Comparative Zoology, Rijksmuseum Van Natuurlijke Historie, British Museum (Natural History), and the Yale Peabody Museum. Dr. Alexander Wetmore, Herbert Deignan, and Charles Vaurie helped with some of the more difficult taxonomic problems. Specimens cited in this report are in the Bernice P. Bishop Museum, The University of Kansas Museum of Natural History, The University of Michigan Museum of Zoology, and the U. S. National Museum.

Richard F. Johnston and Robert M. Mengel kindly read the ma.n.u.script and made many helpful suggestions. The latter re-read it and a.s.sisted with the editing.

The most recent comprehensive work published previous to my preparation of ma.n.u.script for the present account was Smythies (1960) "The Birds of Borneo."

This report is a partial result of field work supported by a grant from the United States Army Medical Research and Development Command, Department of the Army, to the Bernice P. Bishop Museum for research on ectoparasites of vertebrates. The contract numbers were DA-MD-49-193-62-G47 and G65. The Chapman Fund of The American Museum of Natural History met part of the cost of transporting, to and from the United States, specimens from North Borneo collected after I left there.

METHODS

While collecting at Quoin Hill, we used only guns in taking birds. At an area 12 miles north of Kalabakan, we supplemented the guns with mist nets in the primary forest. This method was excellent for taking rarely seen species. For example the thrush _Zoothera interpres_ was never seen in the field but was taken several times in mist nets.

Another method of collecting was the use of native snares. Such snares were made of heavy nylon string tied to a sapling, held down by a nylon string attached to a treadle. When a bird stepped on the treadle, it tripped the snare and a loop closed about its feet, hoisting it aloft.

To divert large ground birds and mammals into the snare, natives placed brush barriers along the top of a ridge for one or two miles. Animals were diverted by these barriers until they came to an opening; if they went through they usually tripped the trap. Pheasants and the large ground cuckoo were taken in this manner.

NOTES ON ZOOGEOGRAPHY

The avifauna of Borneo is of Indo-Malayan affinities. The number of birds endemic to Borneo is relatively small; most species are shared with the Asian mainland. Only 29 birds are known to be endemic to the island and 17 of these are montane. The large proportion of montane endemics is not surprising, because Borneo has been connected with the Asian continent in recent geological time; lowland isolation, and differentiation, has been less extensive than the montane. The Sunda Shelf, on which Borneo is situated, lies in a shallow sea generally less than 300 feet deep. Beaufort has shown that the Malay Peninsula, Sumatra, and Java were connected until early historic times (Darlington, 1957:488).

The endemic species in Borneo are members of four, possibly five, genera that are also endemic. Four of these five genera are montane in distribution. The only endemic for which the geographic history cannot be adequately explained is the monotypic _Pityriasis gymnocephala_. Its affinities seem to be with the Cracticidae of New Guinea and Australia.

The species has been found throughout Borneo. Since _Pityriasis_ is endemic to Borneo, it probably was detached from the parent stock at an early period. The Australasian affinities of _Pityriasis_ emphasize its zoogeographical peculiarities. A more detailed discussion of this species appears in the annotated list below.

COLLECTING LOCALITIES AND COLLECTORS

[Ill.u.s.tration: Fig. 1. Localities from which collectors from the Department of Agriculture or I saved specimens in North Borneo.]

1. Cocoa Research Station, Quoin Hill, elevation 750 feet, Tawau. Max C. Thompson (MCT) and Antonio D. Garcia (ADG).

2. Tawau. Max C. Thompson.

3. Twelve miles north of Kalabakan, elevation 600 feet. Max C.

Thompson.

4. Kalabakan, elevation 50 feet. Max C. Thompson.

5. Tiger Estate, 20 miles northwest of Tawau. Max C. Thompson, Antonio D. Garcia.

6. Ulu Balung Cocoa Estate, Mile 27, Quoin Hill, elevation 750 feet, Tawau. Antonio D. Garcia.

7. Karindingen Island. Max C. Thompson.

8. Siamil Island. Max C. Thompson.

9. Lahad Datu. Antonio D. Garcia.

10. Kuala Sumaw.a.n.g, 25 miles west of Sandakan. Antonio D. Garcia.

11. Agricultural Station, Mile 17, Sandakan (Gum-Gum). Antonio D.

Garcia.

12. One-fourth mile east Gum-Gum, Sandakan. Antonio D. Garcia.

13. Lamag, Kinabatangan River. Antonio D. Garcia.

14. Pintasan Agriculture Station, Kinabatangan River. Antonio D.

Garcia.

15. Kampong Kuamut, Kinabatangan River. Antonio D. Garcia.

16. Kampong Maluwa, Kinabatangan River. Antonio D. Garcia.

17. Ka-Karis, Kinabatangan River, elevation 200 feet. Antonio D.

Garcia.

18. TonG.o.d, Kinabatangan River, elevation 300 feet. Antonio D. Garcia.

19. Tuaran. Max C. Thompson, Antonio D. Garcia, S. F. W. Chong (SFWC).

20. Telipok. Antonio D. Garcia, G. R. Conway.

21. Mt. Rumas, 5 miles northwest of Tuaran, elevation 75 feet, Antonio D. Garcia.

22. Five and one-half miles southwest of Tenom, elevation 4,000 feet.

Max C. Thompson.

23. Tenom, elevation 600 feet. Max C. Thompson.

24. Kampong Banjar, Mile 29, Keningau. Antonio D. Garcia.

25. Oil Palm Research Station, Mile 32, elevation 40 feet, Sandakan.

Antonio D. Garcia.

ECOLOGY OF THE COLLECTING LOCALITIES

QUOIN HILL.--At this locality I recognized five habitat types as follows:

_Primary forest._--We were fortunate to be able to work at Quoin Hill because it had been opened to cultivation (of Cocoa, _Theobroma cacao_) for only a few years. Thus the primary forest here started at the edge of the Cocoa Research Station. This was in marked contrast to areas on the west coast, where one would need to travel many miles inland to find virgin forest. The forest at Quoin Hill was typical tropical rain-forest, composed mostly of dipterocarps (Dipterocarpaceae). These comprise an essentially Indo-Malayan family, members of which are so conspicuous that we commonly referred to it as Evergreen Dipterocarp Forest. The lowland forests of Borneo are composed of approximately 3,000 species of trees (Browne, 1955). At Quoin Hill, as in most of the tropical rain-forest of Borneo, the forest canopy is stratified in three layers, a distinct and easily recognizable top story and less easily separable middle and lower stories. The top canopy is composed of foliage of giant trees that may tower to heights of 200 feet and have trunks three to seven feet in diameter. The trunk is usually unbranched for 50 to 100 feet and the whole tree is supported by b.u.t.tresses jutting out from the main trunk. Some of the most important plants in the tropical rain-forest are the strangler figs (_Ficus_ sp.). These plants, when in fruit, draw birds in large flocks to feed upon them. Such figs were common about the edges of the research station and some birds taken from these trees were never taken elsewhere. The birds seemed to wait for a certain degree of ripeness of fruits; on one day the figs were unmolested and the next day the trees would be swarming with birds.

Strangler fig trees reach tremendous size and help form the upper forest canopy.

The middle and lower forest canopies are not easily separable and I shall speak of them together. The trees forming these varied from 10 to 60 feet in height. The ground surface beneath the trees was usually bare except for leaf litter and dead branches. Sunlight penetrates only where the big trees have been removed or where the larger trees are otherwise widely s.p.a.ced. At Quoin Hill the large trees of species affording lumber of commercial quality had been taken out, modifying somewhat the character of the forest. Such forest actually contained many of the animals characteristic of primary forest, and I refer to it as badly disturbed primary forest.