Melanerpes aurifrons, the golden-fronted woodpecker, is a permanent resident in central Texas. These woodpeckers typically are found in temperate and tropical regions of North American and extend as far north as southwestern Oklahoma and south to the northern region of Nicaragua. Unlike the predominant picture associated with woodpeckers, the golden-fronted woodpecker finds most of its food not by drilling into trees but by scavenging insects and insect larvae from the surface and subsurface of trees and along the ground. Melanerpes aurifrons also eats large quantities of fruits and nuts (Husak and Maxwell, 1998).
Most woodpeckers drum on trees in order to obtain food, and their skulls are functionally designed to withstand this impact. For example the overhang of the frontal onto the upper jaw acts as a mechanical bony stop to prevent the protraction of the upper jaw. The frontal overhang is most important, and thus best developed, in woodpeckers that obtain all of their food by drilling into trees. Without this overhang, the naso-frontal hinge would be damaged (Bock, 1999a, 1999b). Within Melanerpes aurifrons this feature is only moderately developed because it rarely uses its beak to drill into trees for food. It is very well developed in Picoides, but almost nonexistent in Colaptes (flickers, almost exclusive ground foragers). |
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The most striking feature of the skull of the woodpecker is the hyoid apparatus (highlighted in red), which extends from its usual position just ventral to the lower mandible and wraps posteriorly around the skull to end between the orbits immediately dorsal to the base of the upper beak. This bony structure aids the woodpecker in extending its tongue extremely long distances in order to spear insects beneath bark or leaf litter (Bock, 1999b). |
Woodpeckers belong to Piciformes, a taxon that also includes puffbirds, barbets, jacamars, honeyguides, wrynecks, and toucans. The fossil record of modern-type piciforms extends back into the late Oligocene of Germany. The specimen on which this age is based, however, consists only of a fragmentary tarsometatarsus and can not be diagnosed any further than Pici (barbets, toucans, honeyguides, woodpeckers, wrynecks, and piculets; Mayr, 2001).
Literature
Baumel, J. J., A. S. King, J. E. Breazile, H. E. Evans, and J. C. Vanden Berge (eds.). 1993. Handbook of Avian Anatomy: Nomina Anatomica Avium, Second Edition. Publication of the Nuttall Ornithological Club, number 23. Nuttall Ornithological Club, Cambridge, Massachusetts, 779 pp.
Bock, W. J. 1999a. Functional and evolutionary explanations in morphology. Netherlands Journal of Zoology 49:45-65.
Bock, W. J. 1999b. Functional and evolutionary morphology of woodpeckers. Ostrich 70:23-31.
Burt, W. H. 1930. Adaptive modifications in the woodpeckers. University of California Publications in Zoology 32:455-524.
Husak, M. S., and T. C. Maxwell. 1998. Golden-fronted Woodpecker (Melanerpes aurifrons). The Birds of North America, no. 373.
Mayr, G. 2001. The earliest fossil record of a modern-type piciform bird from the late Oligocene of Germany. Journal für Ornithologie 142:2-6.
Parker, W. K. 1875. On the morphology of the skull in the woodpeckers (Picidae) and wrynecks (Yungidae). Transactions of the Linnean Society, London 1:1-22.
Shufeldt, R. W. 1900. On the osteology of the woodpeckers. Proceedings of the American Philosophical Society, Philadelphia, 39:578-622.
Links
Film of Melanerpes aurifrons on the Internet Bird Collection (IBC).
Images of M. aurifrons on the Animal Diversity Web (Univ. of Michigan Museum of Zoology).
Information on the golden-fronted woodpecker on the Patuxent Bird Identification InfoCenter (USGS).
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