Is that a Dead Branch or a Tawny Frogmouth?

by Chris Smith, Animal Technician I Oklahoma City Zoological Park Suppose you confronted a creature and straightening their backs. This pos­ with the following description: a dis­ ture gives the bird the appearance of a proportionately large head, large glow­ dead branch which is so effective the ing yellow eyes, a wide mouth with a Groote and Fraser Islands. There are Tawny Frogmouth is rarely seen in the short hooked beak; a short body with also unconfirmed reports in southern wild, even by well-trained ornithologists. small twig-like legs, and plumage that regions of New Guinea. These birds Many zoo visitors are unable to locate a resembles tree bark. Although it may prefer woodlands and forests in which bird only a few feet away from them. appear to be one of Jim Henson's they can conceal themselves, even though The natural diet of the Tawny muppets, this is actually a general de­ adult Tawny Frogmouths are rarely Frogmouth consists mainly of insects, scription of the Tawny Frogmouth predated upon. One known predator, small reptiles, amphibians, mammals and Podargus strigoides however, is the Barking Owl Ninox occasionally includes small frUits. Frogmouths are related to nightjars connivens. Larger snakes will also occa­ Frogmouths can catch food while in flight, (two better-known species of nightjar sionally prey upon them. like the small nighthawks but they usu­ are the Whippoorwill Caprimulgus The Tawny Frogmouth has shown a ally catch prey by chasing it on a branch vociferus, and the European Nighthawk preference for eucalyptus trees. The cam­ or by ambushing it by jumping on it from C. europaues). All of these birds are ouflaged plumage of these birds allows an overhead branch. These birds also classified into the order Caprimulgi­ them to blend in with their surround­ scavenge for dead insects on road sur­ formes. The members of this order are ings. When startled, they assume an faces which results in many Tawny characterized by wide gaping mouths, upright posture by raising their heads Frogmouths killed by traffic. Their cap- short beaks, cryptic coloration, and noc­ turnal lifestyles. Nightjars are usually ,<; E small, have long narrow wings, and feed Ul (fJ during flight. Frogmouths, on the other ~ u hand, are much larger than most night­ > .D jars and have short, broad wings. o .r:o Frogmouths are subdivided into the fam­ (L ily Podargidae. Podargidae consists of 12 species of frogmouths. The Tawny Frogmouth is one of the larger species, weighing from 300 to 600 g. In 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 ofthe 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 be­ tween 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, Tawny Frop,7nollth, Podargus strigoides, .3 weeks olcl

41' September/October 1995 tive diet usually consists of mice, crick­ separated from its parents, the female In 1990, a young captive-raised female ets, mealworms and Bird of Prey Diet, a began producing eggs again, but many was acquired from the San Antonio Zoo­ commercially packaged food supple­ of the eggs were found broken. When logical Gardens & Aquarium. Again, with­ ment. eggs were found intact, they were pulled in a year, nesting was observed and eggs Breeding season in the wild lasts from for artificial incubation and replaced by were produced. After two eggs were August to December, although captive dummy eggs. Only one chick subse­ found broken, all eggs found subse­ birds have been known to breed through­ quently hatched, but it died shortly after quently were pulled and replaced with out the year. A loose nest of small twigs hatching. dummy eggs. In both May 1991 and April is built and maintained by both the male In 1986, the female died, leaving the 1993, chicks were successfully hatched and female in the crotch of a tree or on male alone again. During her lifetime, and handreared. a nest platform. One or two white eggs, she had laid 10 eggs; two hatched, one The first egg hatched was artificially approximately 45 mm x 30 mm, are survived, three died in the shell, one was incubated at 36.9°C. The wet bulb read­ incubated by both parents. Incubation infertile, and four were found broken. ing was maintained near 29°C. The egg lasts 28 to 30 days. The TawnyFrogmouth was first kept in captivity in 1862 at the London Zoo. They are fairly easy to main­ tain in captivity and wild-caught birds 95M,DWESf A.VIAN usually adjust well to their new sur­ RESEARCH roundings and often will breed readily in E· X· p. 0 captivity. The first captive hatch was at INDIANAPOLIS the Wassenaar Zoological Park in Holland. Again this year... Your personal video series of this year's 6th Annual The Tawny Frogmouth is a popular Midwest Avian Research Expo. Now you, too, can help support Avian exhibit species with zoo visitors and Research by bringing the 95 Conference and Wet Labs into your home. personnel. As of December 1992, 169 Twenty hours of lectures. slides. iabs and shows in a 3 set series. (85.56.28, Le., 85 males, 56 females and Don't miss the great opportunity to be instructed and lectured bysome 28 unsexed birds) Tawny Frogmouths ofthe top veterinarians and aviculturists in the world. were being kept by 51 institutions Each set oftapes is professionally recorded with broadcast quality and clarity. throughout the world. More than 75% of VIDEO SET 1 CONFERENCE LECTURES tSAT Dr. Branson Ritchie - Proventrlcular these birds are captive-born. Of the 12 Dilatation Syndrome. Dr. Jack Gaskin - Human Psittacosis: An Avicultural species of frogmouths, the Tawny is the Nightmare and Avian Bordetellosis • Sally Blanchard - Understanding and only one currently managed in captivity. Working With Phobic Parrots. Dr. Peter Sakas - Avian Toxicoiogy • Mark Hagan, MAg - Nutritional Observations, Hand-feeding Formulas. and Although the Tawny Frogmouth is rela­ Digestion in Exotic Birds. Michael Massie - AVIAN Nutrition. Randal Brue. tively common in its natural state, very MS, PhD - Concepts in Adult and Pediatric Psittacine Nutrition few birds are exported due to Australia's VIDEO SET 2 CONFERENCE LECTURES t SUN Dr. Branson Ritchie - Prevention wildlife protection and export laws. of Avian Polyomavirus infections Through Vaccination. Larry Ring. Attorney The Oklahoma City Zoological Park at Law - Birds and the Law. Sally Blanchard - Avian Behavior Discussion. Trent Swigert - Incubation To Hatch. James Millam PhD - UC Davis Amazon has exhibitedthe TawnyFrogmouthsince Breeding Project. Wanda Elder - Model Avicultural Program. Dr. Nicole 1981, when a pair of captive-hatched VanDerHeyden - Psittacine Pediatrics. Sue Bondelier - ARCUS birds was obtained from the New York VIDEO SET 3 WET LABS t FRI Dr. Nicoie VanDerHeyden - Endoscopy Zoological Society;Wildlife Conservation Techniques. Dr. SUsan Clubb - Handfeeding Techniques. Dr. Rob Porter Society (formerly Bronx Zoo). These - Neocropsy Procedure. Dr. Keven Flammer - Emergency Medical Procedure Demonstration. Dr. Jack Gaskin - Simplified Microbioiogy for birds have been exhibited in a 2.5 m x 2 Aviculturists • Sally Blanchard - Psittacine Behavior. Dr. Keven Rammer­ m x 2 m enclosure, with several medium­ Aviculturists Problem Solving sized perches and plants to offer the birds hiding and nesting areas. The birds 95 Conference Series settled into their new surroundings quickly. Unfortunately, the female died Purchase: Conference (2) each $ 99.95 Purc,hase: Wet Labs...... $139.95 within a year and it wasn't until 1984 that Purchase: 2 sets $ 17.00 off a new female could be obtained. Due to Purchase: 3 sets $ 50.00 off a larger male population in captivity, Includes shipping and handling females are in great demand, often mak­ ing it difficult to acquire them. Our goal is to fund research through the best possible education at every level Within a year of introduction, the pair All Proceeds Donated to Avian Research l4iIii!I!iiJ 1995 Recipients are: Dr. Keven Flammer. ':v'itJ began nesting and soon successfully ~ Dr. Jack Gaskin and Dr. 8I'anson Ritchie - hatched one chick. Supplemental Please allow 3 • 6 _ks for delivery I VISA • MAmR CARDS are accepted feedings were given to the chick two Make Checks Payable to: times a day for the first few weeks, al­ TRIPLE ilL" PRODUCTIONS though the parents were doing a fine job 1715 Dean Road. Suite C- Dept A. Temperance, MI48182 in raising the chick themselves. 1/8()().437-09S2 After the chick had grown and been

afa WATCHI3IRD 49 was hand-turned five times daily until rate measurement of their growth (see Table I Daily Waight Gain of Hand-Raised Tawny Frogmouths the developing chick broke through the Table I), because extra weight from their lin grams) air cell. When the chick pipped, warm diet was not included in the measurements. Day 1991 Hatch 1993 Hatch Notes water was sprayed into the incubator to Newly hatched chicks are covered with 1 12.9 1'.8 temp at 90· F 2 14.6 13.7 increase the humidity and prevent the a white down, with a little light gray 3 14.5 17.4 egg's membranes from desiccating. The down blended in. The chicks' eyes are 4 16.8 23.0 chick hatched unassisted following a 30­ 5 19.2 24.9 open a few days after hatching. They 6 22.2 29.9 day incubation period. grow quickly and, by the second to third 7 21.2 36.3 The same procedure was used for the week after hatching, the flight feathers 8 24.5 39.7 temp at 85" F second egg, however the incubation tem­ 9 26.3 44.1 are clearly visible and much of the white 10 29.9 52.1 perature was 37.5°C because the egg had down has been replaced with brown and 11 33.0 58.3 been placed in a different incubator. gray contour feathers. At four weeks, the 12 39.2 67.1 (The egg was not subsequently moved to 13 52.0 71.4 flight feathers are developed well enough 14 56.0 84.1 discontinued night feedings an incubator at 36.9°C to avoid subject­ for the chick to fly short distances. At this 15 59.5 96.0 ing the developing egg to a sudden tem­ age, the chicks fledge; however, they are 20 72.4 105.8 perature change that could threaten its 25 75.9 110.8 still only about half the size of the adults 30 124.0 162.8 ready to fledge development.) The chick hatched unas­ and still require their parents' care. By 35 167.1 166.5 sisted after 24 days and suffered no ill the sixth week, the young birds have 40 197.9 165.0 effects from the higher-than-normal in­ 45 191.2 195.4 reached adult size. 50 218.5 229.5 cubation temperature. In May 1993, while one chick was After hatching, the chicks were left in being handraised, the adults laid an­ Acknowledgments the incubator to dry for 24 hours before other egg. Since the pair had demon­ I would like to acknowledge the bird being moved to an isolette (infant incu­ strated great care in sitting on dummy department of the Oklahoma City Zoo: bator). The chicks were not fed during eggs, the egg was left with them. The egg Jim Fish, curator; Darcy Henthorn, Ken this time to allow their yolk sacs to be was laid in a nest basket of bromeliads Hovey, Neil Carter, Jeff Papp, any other absorbed. The isolette used was con­ hung at about 2 m high. The male was prior personnel of the department, and structed of a Plexiglas box with a 150­ observed doing most of the incubation Alan West for preparing this article for watt electric heating unit mounted to a throughout the day. A chick was found in publication. removable lid. A small sliding door on the nest 30 days after the egg had first the front was used to remove the chicks been seen. Bibliography during feeding and cleaning. Crickets, with the hind legs removed, Hollands, David. Birds of the Night: Owls, Frogmouths andNightjars ofAustralia. Reed The isolette was initially heated to and waxworms were continuously of­ BooksPtyLtd, Balgowlah,NSW, 1991, pp. 210, 32°C. The temperature was gradually fered through the day. The insects were 216. decreased as the chicks grew and be­ placed in stainless steel bowls. The slick del Hoyo, ]., Elliott, A., and Sargatal, ]., eds. camefeathered out. Acloth-covered bowl surface of the bowls prevented them Handbook ofthe Birds ofthe World, Vol. 1, served as a nest for the first few weeks from escaping. The adults quickly de­ Lynx Edicions, Barcelona, 1992, pp. 68,70. InternationaiSpecies1nformationSystsmISISBird until the chicks could grasp well enough pleted the supply of insects to feed to Asbtract,AppleValley, MN, December 1992, p. to use a small perch. The linens were their offspring. The chick was also given 185. changed and the isolette was disinfected supplemental feedings of chopped pin­ Perrins, ChristopherM., PhD andMiddleton, L.A., Ph.D., eds. All the World's Animals - Birds: daily with Roccal-D, a general disinfectant. kies, crickets and waxworms by the Owls, Parrots & Waders. Torstar Books, New The chicks' diet consisted primarily of keeper staff for the first two weeks al­ York, 1985, pp. 96-101. chopped newborn mice (pinkies) and though the parents were doing an excel­ Pizzey, Graham. A Field Guide to the Birds of crickets with their heads and append­ lent job of raising the chick. Australia, PrincetonUniversityPress, Princeton, NJ, p. 206. ages removed. As the chicks grew, adult As the chick grew, it was closely mon­ Rutgers, A. and Norris, K.A., eds.Encyclopediaof mice (skinned and chopped) were add­ itored, although no problems arose. The Aviculture, Vol. 2, Blandford Press, London, ed. Two vitamin supplements, Vionate chick left the nest after 24 days, but 1972, p. 261. and D-Ca-Fos were lightly sprinkled on continued to stay close to its parents. the diet. D-Ca-Fos is a vitamin D, calcium With the end ofthe mating season, life Products Mentioned in Text and phosphorus supplement. Vionate is returned to normal for the Tawny D-Ca-Fos Natural Bone Ash with Vitamin D3 a general vitamin and mineral supple­ Frogmouths. The success with raising Supplement produced by Fort Dodge Laboratories, Inc., Fort Dodge, Iowa 50501. ment which is used for adult birds as well two chicks in a season gives the bird Nebraska Bird of Prey Diet packed by Central I as hatchlings. department a great deal to look forward Nebraska Packing, Inc., North Platte, Nebraska The chicks were fed four times a day: to next season. We hope to continue our 69101. 0800,1100,1400 and 1700. An addition­ success with the breeding program of Vionate Vitamin Mineral Powder produced by Gimborn-Rich Health, 4280 Northeast al night feeding was also given for the these strange and interesting birds. Expressway, Atlanta, Georgia 30340. first two weeks. The amounts eaten by The next time you visit a zoo and find Roccal-D manufactured byThe Upjohn Company, the chicks were recorded on data sheets yourself standing in front of what ap­ Kalamazoo, Michigan 49001. after each feeding. pears to be a vacant exhibit, take a sec­ Isolett": manufacturedbyRegal Plastics, Oklahoma City, Oklahoma73127. The chicks were weighed before each ond look. You may find what appears to HeatingunitproducedbyLyon Electric Company, early morning feeding for a more accu- be a dead branch staring back at you. Inc., ChulaVista, California 92011.•

50 Septemher/Octohcr 1995