Tongues of Some Passerine Birds by Mrs

Vol. 6 MARCH 15, 1975 No.1 Tongues of Some Passerine Birds By Mrs. ELLEN M. McCULLOCH, Mitcham, Victoria. SUMMARY The tongues of five species, of three genera, of passerine birds are depicted, and the feeding of certain brush-tongued birds, on various types of food, placed in hanging pottery feeders, is discussed. Some previous research on brush-tongues is given. During August 1972, the Bird Observers Club arranged for the production of hanging pottery feeders, to hold either a solid food mix, or a sweet liquid "nectar", largely designed to attract honey eaters. Several hundred of these feeders are now in use, and the variation in species attracted to them has proved to be interesting. Many birds are opportune feeders and take advantage of tem porary, readily available food supplies. It was anticipated that honeyeaters, Meliphagidae, and silvereyes, Zosteropidae, would readily find the liquid in feeders, and this has generally been found to be so. Additionally, other quite unrelated species have been recorded. These include Ravens, Corvus sp., Crimson Rosella, Platycercus elegans, Striated Thornhill, Acanthiza lineata, and Superb Blue Wren, Malurus cyaneus. The tongues of ravens and rosellas do not appear to be in any way adapted, particularly to the collection of nectar, unlike those of honeyeaters and silvereyes (Rand, 1967). Examination of the tongues of the thornbill and wren showed that, in each species, the tip of the tongue is to some extent frayed out (Fig. l.a, and l.c). Gardner ( 1925), when writing about passerine birds, states: "In many families the thin horny tongue, slightly curled and frayed at the tip, as described for the robin, is found with but slight differences in length and width. Such a tongue has no outstanding character sufficient to identify the particular family to which it belongs and serves to do no more than to indicate a member of the order". Comparison with numerous tongues figured in Gardner's work indicate that the tongues of the Superb Blue Wren and Striated Thornhill are, apparently, similar to those of many small insect eaters found in America. Presumably, this slight brush-tip helps in collection of the insects, which normally form the bird's diet. Parker (1972) figures brush-tipped tongues of the Australian Chats, Epthianuridae; McKean ( 1969) gives details of those of Woodswallows, Artamidae, and Cooper (197 4) discusses and 2 McCULLOCH [ Bird W atcher illustrates the tongue of the Silvereyes, Zosteropidae. Birds in these groups are predominantly insect-eaters, but some species, at least, have been recorded at flowers. In three different areas White-throated Treecreepers, Climacteris leucophaea, have been recorded at feeders, drinking the sweet liquid mixture. This species was not expected as the literature records them eating only insects. Wilson (1969) records under Feeding: "The species is insecti vorous and feeds as it spirals up the trees, constantly searching the crevices of the bark". Comparatively little has been published on the habits of tree creepers, and nowhere can I find records of them drinking water or taking nectar at flowers. Several species forage on the ground and in ground-litter, as well as on tree-trunks and branches. Water bathing is recorded by E. M. McCulloch ( 1968). G. M. Mathews (1923-24) p. 107, quotes John Gould's remarks on White-throated Treecreepers: "I have never observed this species near the water-holes and I feel assured it has the power of subsisting without drinking". Mathews also quotes, p. 108, Captain S. A. White's intriguing note, "They are almost entirely insecti vorous", but no details are given. Mrs. H. Hunt (pers.comm.) states that White-throated Tree creepers come regularly to a food-table and peck at the soft flesh of apples. Treecreepers usually move quickly when searching for food, and unless they are observed at very close quarters, or filmed so that frames can be slowed down, it would be impossible to see if the tongue is protruded to help in the collection of insects. Additionally, they are normally wary birds and, when observed, often fly off or circle around to the far side of the tree-trunk. They do not appear to probe very deeply, or pause often or for long. Gardner (1925) includes a diagram of the tongue of a North American Brown Creeper, Certhia familiaris. It is fringed at the tip, but it seemingly is not as complex as the tongue of Climacteris leucophaea. It is difficult to make a proper comparison between representations of the tongues of the two species on this material, as that of C. leucophaea is so much more highly magnified. Under magnification the tip of the tongue of C. leucophaea, as shown in Fig. 1.d is divided at the tip, and has fine bristles which tend to turn at the centre and curl in the sides of the tongue to form a channel. (The tongue, from which this drawing was made, was removed from a spirit-preserved specimen, and it is not known if this curling is as apparent in the live bird.) The taxonomic value of the tongue structure is debatable, as similar feeding hablts in species not closely related result in super ficial similarity. Figs. l.e and l.b show the tip of the tongues of the Brown Treecreeper, Climacteris picumnus, and Brown Thornhill, Acanthiza pusilla, respectively, and are included to show the inter esting variation within a genus. March ] Tongues of Passerine Birds 3 1975 As the Climacteridae present problems to the taxonomist, com parison with other groups, such as Certhidae, is of interest. ACKNOWLEDGEMENTS To the Director of the National Museum of Victoria for allowing access to museum specimens, also to Mrs. L. Reid, Assistant, Ornithology Department, for so accurately depicting the tips of the five tongues under magnification, shown in Figure 1. a. b . c. d . e. Figure 1. T ongues of birds, x 11 . a. A canthiza lineata; b. A canthiza pusilla; c. Malurus cyaneus; d. Climacteris leucophaea; e. Climacteris picumnus. REFERENCES Cooper, Roy P., 1974. "The Brush-Tongued Silvereye", Australian Bird Watcher, 5 : 119-127. Gardner, Leon L., 1925. "The Adaptive Modifications and the Taxonomic value of the Tongue in Birds", Proceedings U.S. National Museum, 67 : 1-49. McCulloch, Ellen M., 1968. "Treecreeper Bathing", Geelong Naturalist, 5 : 62. · McKean, John L., 1969. "The Brush Tongue of Artamidae", Bulletin British Ornithologists Club, 89 : 129-130. Mayr, Ernst, 1963. "Comments on the Taxonomic Position of some Australian Genera of Songbirds", Emu, 63 : 1-7. Parker, S. A., 1973. "The Tongues of Epthianura and Ashbyia", Emu, 73 : 19-20. Rand, Austin L., 1967. "The Flower-Adapted Tongue of a Timaliinae Bird and its Implications", Fieldiana, Z oot., 51 : 53-61. Wilson, S. J., 1969. Birds in the Australian High Country, Ed. H. J. Frith. .

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