Abstract
suppose you confronted a creature with the following description: a disproportionately large head, large glowing yellow eyes, a wide mouth with a short hooked beak; a short body with small twig-like legs, and plumage that resembles tree bark. Although it may appear to be one of Jim Henson's muppets, this is actually a general description of the Tawny Frogmouth Podargus strigoides
Frogmouths are related to nightjars (two better-known species of nightjar are the Whippoorwill Caprimulgus vociferus, and the European Nighthawk C. europaues), All of these birds are classified into the order Caprimulgiformes. The members of this order are characterized by wide gaping mouths, short beaks, cryptic coloration, and nocturnal lifestyles. N ightjars are usually small, have long narrow wings, and feed during flight Frogmouths, on the other hand, are much larger than most nightjars and have short, broad wings. Frogmouths are subdivided into the family Podargidae.
Podargidae consists of 12 species of frogmouths. The Tawny Frogmouth is one of the larger species, weighing from 300 to 600 g. Jn captivity, specimens frequently weigh in excess of 600 g. Average length ranges from 33 to 47 cm, while the wingspan usually ranges from 65 to 100 cm. There are seven known subspecies of Tawny Frogmouth.
The plumage of the Tawny Frogmouth is colored with a variety of browns, grays and rusts arranged in a pattern that gives the bird an appearance of a tree branch or bark. Males and females are similar in appearance. One small difference between the sexes is in eye coloration. Males may have an orange-brown ring surrounding their iris, while this ring has not been known to appear in females.
The Tawny Frogmouth is native to Australia and Tasmania, and can be found throughout the continent. It is also found on several of the larger islands sur-
rounding Australia, including Kangaroo,
Groote and Fraser Islands. There are
also unconfirmed reports in southern
regions of New Guinea. These birds
prefer woodlands and forests in which
they can conceal themselves, even though
adult Tawny Frogmouths are rarely
predated upon. One known predator,
however, is the Barking Owl Ninox
connivens. Larger snakes will also occasionally
prey upon them.
The Tawny Frogmouth has shown a
preference for eucalyptus trees . The camouflaged
plumage of these birds allows
them to blend in with their surroundings.
When startled, they assume an
upright posture by raising their heads
and straightening their backs. This posture
gives the bird the appearance of a
dead branch which is so effective the
Tawny Frogmouth is rarely seen in the
wild , even by well-trained ornithologists.
Many zoo visitors are unable to locate a
bird only a few feet away from them.
The natural diet of the Tawny
Frogmouth consists mainly of insects,
small reptiles, amphibians, mammals and
occasionally includes small fruits .
Frogmouths can catch food while in flight,
like the small nighthawks but they usually
catch prey by chasing it on a branch
or by ambushing it by jumping on it from
an overhead branch. These birds also
scavenge for dead insects on road surfaces
which results in many Tawny
Frogmouths killed by traffic.
References
Bibliography
Hollands, David. Birds of the Night: Owls, Frogmouths and Nightjars of Australia. Reed BooksPtyLtd, Balgowlah,NSW, 1991, pp. 210, 216.
del Hoyo, ]., Elliott, A., and Sargatal, ]., eds.
Handbook of the Birds of the World, Vol. 1, Lynx Editions, Barcelona, 1992, pp. 68, 70.
International Species lnformation Systsm ISIS Bird Abstract, Apple Valley, MN, December 1992, p. 185.
Perrins, Christopher M., PhD and Middleton, L.A., Ph.D., eds. All the World's Animals - Birds:
Owls, Parrots & Waders. Tors tar Books, New York, 1985, pp. 96-101.
Pizzey, Graham. A Field Guide to the Birds of Australia, Princeton University Press, Princeton, NJ, p. 206.
Rutgers, A. and Norris, K.A., eds. Encyclopedia of Aviculture, Vol. 2, Blandford Press, London, 1972, p. 261.
Products Mentioned in Text
D-Ca-Fos Natural Bone Ash with Vitamin D3 Supplement produced by Fort Dodge Laboratories, Inc., Fort Dodge, Iowa 50501.
Nebraska Bird of Prey Diet packed by Central Nebraska Packing, Inc., North Platte, Nebraska 69101.
Vionate Vitamin Mineral Powder produced by Gimborn-Rich Health, 4280 Northeast Expressway, Atlanta, Georgia 30340.
Roccal-D manufactured by The Upjohn Company, Kalamazoo, Michigan 49001.
Isolette manufactured by Regal Plastics, Oklahoma City, Oklahoma 73127.
Heating unit produced by Lyon Electric Company, Inc., Chula Vista, California 92011 .•