Russel Wallace : Alfred Russell Wallace (sic)
With a Synopsis of the Described Species of Collocalia (S84: 1863)
It is, therefore, with great pleasure that I bring before the Zoological Society specimens of this long-lost bird; for the description of Rumphius and the character of Linnæus are so clear and precise, that there can be no doubt whatever about the identification of the species. The whole bibliography of the subject has been so well worked out in Messrs. Horsfield and Moore's 'Catalogue of the East India Company's Museum' (Birds, i. pp. 99, 100) that I need do no more now than quote what is essential to prove my point. The oldest description of the bird, quoted by Linnæus, is that of Rumphius (Herb. Amb. vi. p. 183), who says, "Ipsarum color plerumque niger est cum cæruleo fulgore, sique caudæ plumæ separentur, in quavis penna alba conspicitur macula." Linnæus says only, "rectricibus omnibus macula alba notatis," which short character is, however, sufficient to distinguish the bird even now from the other species of the genus, all of which have the tail immaculate. My specimens all have these white spots on the tail; and they were obtained in various localities in and around the Moluccas, north, south, [[p. 383]] east, and west of Amboyna, where Rumphius obtained his specimens. It is to be observed that these white spots are quite concealed, both on the upper and under view, by the overlapping of the feathers and the tail-coverts; so that, as Rumphius accurately describes it, "only when the feathers are separated, the white spots become visible." This circumstance, and the close general resemblance of the bird to the allied Collocalia linchi, Moore, which has no tail-spots, has led to this striking character being overlooked. It would appear that these two species are restricted to the Australian and Indian regions of the archipelago respectively, C. linchi extending from Java westward to the Nicobar Islands, while C. esculenta is found in Celebes and through the Moluccas to Timor and the shores of New Guinea.
It seems extraordinary that a bird which ranges over nearly half of the Malay Archipelago, and is by no means uncommon there, should not have been hitherto identified with the Linnæan species, as it is almost certain that specimens of it must exist in the museums of Leyden and other Continental cities. The fact may, however, probably be accounted for by the circumstance of one of the authorities most relied upon having been himself deceived in what he supposed to be the constructor of the edible nest of Java. M. Poivre furnished Buffon with a figure and description of a bird obtained at the place where nests were found on an island in the Straits of Sunda. This figure and description have been copied by Brisson, and have been mixed up with the description of the true esculenta by Gmelin and other naturalists. The locality, however, from which M. Poivre obtained his nests would show that they must have belonged to C. linchi or C. fuciphaga, and not to C. esculenta; while his figure proves that the bird he obtained was not a Collocalia at all--not even a Swift or a Swallow, but a short-winged, long-legged, straight-billed bird, agreeing in dusky colouring with Collocalia fuciphaga, but having the tail-feathers white-tipped. These extraordinary discrepancies, however, seem to have been generally overlooked; and the character given by Brisson, "rectricibus nigricantibus, apice albis," has been taken as agreeing with that of Linnæus, "rectricibus omnibus macula alba notatis;" whereas Rumphius (who is quoted by Linnæus) says that the feathers must be separated in order to see the white spots, clearly proving that they were situated towards the base, and not at the tip of the tail1.
In the British Museum collection there is a very beautiful species from the New Hebrides, having the white tail-spots as in C. esculenta, but with a narrow band of pure white across the rump.
I add a synopsis of what appear to me to be the well-authenticated species of this genus hitherto described.
[[p. 384]] 1. Collocalia esculenta (L.), Rumph. Herb. Amb. vi. p. 183.
2. Collocalia leucopygia.
3. Collocalia linchi, Horsf. & Moore, Cat. Mus. E. I. Comp. I. p. 100.
4. Collocalia spodiopygia, Peale, U. S. Expl. Exped. i. p. 176.
5. Collocalia troglodytes, G. R. Gray, Gen. of Birds, t. 19 (sine descr.).
6. Collocalia fuciphaga, Thunb. Act. Holm. xxxiii. p. 151. t. 4.
Remarks.--This species has a very wide range, and varies much in size and a little in coloration. The females have a whitish band on the rump, which in old and worn specimens becomes more conspicuous. If that character exists in both sexes of C. francica, it may be considered a distinct species; but a specimen collected by Mr. E. Newton in Mauritius does not perceptibly differ from one of my females from the archipelago. The sexes differ in size, the females being the largest. I have both sexes from Macassar: wing of the male 4 1/10 inches, of female 4½ inches. The Indian specimens seem a little larger than this; those from Java smaller; while the Pacific Islands specimens, collected by the United States Exploring Expedition, are the largest of all, the wing being given as 5 1/3 inches. But as some Indian specimens which I have seen measure 5 inches, there is such a regular gradation that this character will not serve to divide the specimens. In accordance with the views of Bonaparte, I retain the original name of fuciphaga for this species, since, like that of Paradisea apoda, it is rather useful than otherwise, as indicating the erroneous opinions which were so long held as to the origin of the celebrated edible nests.
1. Since reading this paper, I have found that the late Prince Bonaparte had made the discovery of Hirundo esculenta, L. (Comptes Rendus, xli. p. 977), in 1855, from a Timor specimen in the Paris Museum, collected by Maugé in 1820. He notices the white spots towards the base of the tail. With this independent confirmation of my opinion, there can remain no doubt that the species is now satisfactorily determined. [[on p. 383]]