Tawny frogmouth
Credit: © feathercollector, Shutterstock

Australia is famous for its unique culture, metropolitan cities, and unusual wildlife, among other things. Each week, this seasonal feature will spotlight one of Australia’s many wonders.

The tawny frogmouth is not actually a frog. It’s actually a bird of Australia known for its wide, froglike mouth and heavy, triangular bill. The tawny frogmouth has a stout body. With round, striking, yellow eyes, it is sometimes mistaken for an owl. It is actually a member of the nightjar family. The tawny frogmouth is found throughout Australia, including Tasmania. It prefers open woodlands but lives almost anywhere there are trees, including urban and suburban parks and gardens.

The tawny frogmouth measures 13 1/2 to 21 inches (34 to 53 centimeters) in length, with males larger than females. The bird has silver-gray feathers streaked and mottled with black and reddish brown. Its bill is dark, and its eyes are yellow. During the day, the tawny frogmouth perches on low tree branches and blends into the bark. If one is startled out of sleep, it straightens its body to resemble a branch. This is called stumping. 

The tawny frogmouth is nocturnal (active at night). During the daytime, it perches on low branches, relying on its coloration for camouflage. At night, it hunts insects and other small invertebrates (animals without backbones), snatching up its prey in its big mouth. The bird is also known to eat small mammals and reptiles, frogs, and other birds. Such animals as carpet pythons and foxes eat tawny frogmouths.

Tawny frogmouths mate for life. They breed from August to December, often following seasonal rains. The female lays 2 to 3 eggs in a nest of loose sticks. The eggs take about 30 days to hatch. Both the male and the female incubate the eggs and feed the young. The young are ready to leave the nest after about a month. Tawny frogmouths can live up to 14 years in the wild.

August 26, 2019

In New Zealand, a newly identified species of ancient giant penguin—or “monster” penguin as dubbed by the Canterbury Museum in Christchurch—has added to the southwest Pacific island nation’s roster of extinct oversized animals. The leg and foot bones of Crossvallia waiparensis, a 5-foot, 3-inch (1.6-meter) tall, 180-pound (80-kilogram) penguin, were found in Waipara, North Canterbury, on New Zealand’s South Island.

This illustration shows the ancient giant penguin Crossvallia waiparensis alongside a modern human. Credit: © Canterbury Museum

The ancient “monster” penguin bones were discovered in 2018 at Waipara Greensand, a geological formation that has produced significant penguin fossils before. Researchers from the nearby Canterbury Museum and the Senckenberg Natural History Museum in Frankfurt, Germany, studied the penguin fossils, and they named C. waiparensis as a new species in the Aug. 12, 2019, issue of Alcheringa: An Australasian Journal of Palaeontology.

C. waiparensis, which lived during the Paleocene Epoch between 66 million and 56 million years ago, was roughly four times larger than the emperor penguin, the largest of all modern penguins. During the time of C. waiparensis, New Zealand was still attached to Australia, which was once connected to Antarctica. A related prehistoric giant penguin, Crossvallia unienwillia, was discovered in Antarctica’s Cross Valley in 2000. The leg bones of both giant penguins suggest their feet were more adapted for swimming than those of modern penguins, and they may not have stood upright as modern penguins do.

Emperor penguins, seen here in Antarctica, are the largest living penguins. They stand about 3 feet (1 meter) tall and weigh as much as 100 pounds (45 kilograms). (Credit: © Shutterstock)

Prior to the discovery of C. waiparensis, New Zealand’s legacy of ancient giant critters already included the world’s largest parrot (Heracles inexpectatus), a massive eagle (Hieraaetus moorei), a dog-sized burrowing bat (Vulcanops jennyworthyae), the more than 6-foot (2-meter) tall moa, and other giant penguins.

February 1, 2018

Bird watchers in Australia were recently surprised as several species of predatory birds appeared to be spreading bushfires as a novel hunting technique. For many years, wildlife biologists have documented raptors that fly around the edges of wildfires, practicing what the scientists call “fire-foraging.” The birds pounce on small mammals and reptiles flushed from the bush by advancing flames. A new report in the Journal of Ethnobiology, however, details how birds also seem to be intentionally spreading wildfires to new, unburned areas of grassland to increase their hunting chances. The report suggests that birds, like humans, have learned to use fire both as a tool and as a weapon.

Bushfire smoke darkens Sydney in New South Wales, Australia. A recent scientific report has backed up Australia’s age-old stories of “firehawks” that spread bushfires to catch prey. Credit: © AP Photo

Bushfires are wildfires common throughout Australia due in part to the country’s hot and dry climate. Many wildfires start in the remote countryside known to Australians as the bush. Bushfires can be extremely destructive, especially if they reach urban areas. The fires damage forests and farmland and can kill animals and people and destroy property. In recent years, as global warming has helped make drought conditions worse in Australia, bushfires have been an increasing threat.

Bird watchers have long reported witnessing black kites (Milvus migrans), whistling kites (Haliastur sphenurus), and brown falcons (Falco berigora) hunting prey on the edges of wildfires. Recently, however, birds were seen picking up smoldering twigs with their beaks or talons. The birds then carried the twigs to other areas of dry bush up to a half mile (1 kilometer) away, where they dropped the sticks like lit matches, igniting a new blaze. The birds then began feasting on the animals trying to escape the new flames.

Australian “firehawks” could potentially spread bushfire damage (seen at left) to areas the fire might not naturally reach (at right). Credit: © Julian Smith, EPA/Landov

In the past, Aboriginal people in Australia also used fire to flush animals from the bush. They also say that so-called “firehawks” have been doing the same for thousands of years. The birds’ behavior is not new, then, but has been long known to local people of the Northern Territory, Western Australia, and Queensland. Firehawks are even mentioned in stories of the Dreamtime, an ancient time when the first beings existed.

Despite the dangers posed by bushfires, forest rangers in Australia regularly light controlled fires for the benefit of the environment. Small occasional fires can rid an area of underbrush. If an area goes unburned for a long time, the accumulated underbrush can fuel a much larger and more dangerous fire. However, rangers must now take into account the risks posed by raptors that may spread controlled burns into new areas where the fires could grow out of control.

July 19, 2016

Late last month, paleontologists (scientists who study fossils) announced an amazing discovery. Researchers led by Lida Xing at the China University of Geosciences in Beijing had discovered two bird wings preserved in amber. They published their findings in the journal Nature Communications.

Amber preserved this 100 million-year-old wing tip featuring bones, feathers, and soft tissue.
Credit: © Ryan C. McKellar, Royal Saskatchewan Museum

Amber is a hard, yellowish-brown fossilized resin. It comes chiefly from the resins of pine trees that grew millions of years ago. These resins were gummy materials mixed with oils in the trees. When the oils oxidized (combined with oxygen), hard resins were left. These pine trees were then buried underground or underwater, and the resins slowly changed into lumps of amber. These lumps often contain insects trapped as the resins flowed from the trees. But finding larger animals such as small vertebrates (animals with backbones) is incredibly rare. In the 1993 science fiction film Jurassic Park, dinosaur DNA (deoxyriboneucleic acid) is discovered in the blood of an ancient mosquito fossilized in amber. Movie scientists then used the DNA to recreate dinosaurs—an improbable, yet intriguing, plot line.

The wing fossil subjects of last month’s report were formed about 100 million years ago, in the Cretaceous Period, in what is now Myanmar (also called Burma). Two birds apparently became stuck in the sticky resin of a tree and died. The amber preserved the three-dimensional structure of the birds’ wings, as well as the wings’ feathers, skin, and bones—even the color patterns!

Xing and his team think the wings came from a group of birds called enantiornithines, which means opposite birds in Greek. These birds had claws and teeth, and they went extinct along with the nonflying dinosaurs about 65 million years ago. The fossils showed that the wings were from young birds and that the birds hatched as miniature adults, ready to fly. This is different from modern birds, which must develop for weeks or months before they can leave the nest.

The structure of the wings and the arrangement of feathers are similar to modern bird wings. Birds evolved (developed over time) about 150 million years ago from meat-eating dinosaurs, so they must have quickly developed modern-looking wings, before enantiornithines and the ancestors of modern birds split.

Unlike science fiction, these fossils won’t resurrect the extinct enantiornithines, even if they do contain DNA. The technology to create entire animals from bits of ancient DNA does not yet—and might never—exist. The fossils do, however, offer paleontologists a treasure trove of information that will help us better understand early birds and their world.

December 4, 2013

Mice laced with a common painkiller parachuted into a United States Air Force base on Guam recently as part of an ongoing attempt to kill off invasive brown tree snakes that have caused enormous ecological damage on that South Pacific island. For the helicopter drop, the dead mice were attached to tiny paper streamers that deposited them in the forest canopy, where the snakes live. Each mice is dosed with 80 milligrams of acetaminophen, an amount scientists consider harmless to other animals and humans. (Acetaminophen tablets used for pain relief in humans commonly contain about 500 milligrams.) No mouse drops were made over populated areas. Guam is an American territory in the Mariana Islands.

Brown tree snakes, which are native to Australia and Papua New Guinea, entered Guam in the late 1940′s or early 1950′s, probably by traveling with military cargo. The snake is a fierce predator of small animals, including birds and lizards. Animals native to Guam had no experience of the snakes. Nor were there predators to control the snake’s numbers. In addition to destroying native bats and other animals, the snakes have wiped out 9 of the island’s 12 native bird species. An estimated 2 million of the snakes currently live on the island. Brown tree snakes slithering into electric power substations on Guam cause about 80 power outages each year, at a cost of up to $4 million in repairs and lost productivity.

Mice bombs attached to cardboard and paper streamers are being dropped on parts of Guam to combat destructive brown tree snakes. (USDA/APHIS)

The recent mouse bombardment was the fourth official aerial drop in the new snake eradication effort, which began in Sepember. Wildife experts on the island also employ snake traps, snake fences, snake-sniffing dogs, and human hunters. A study by the U.S. Department of Agriculture (USDA) suggests that the snakes are taking the tasty but lethal bait. Scientists worry a brown tree snake invasion of nearby islands, including Hawaii, in cargo planes or ships could cost billions in damage.

In a blog on the Anderson Air Force Base website, Marc Hall, the supervisory wildlife biologist of the USDA at the base wrote, “Before the snakes arrived, Guam’s ecosystem was very different. Numerous birds could be seen and heard when walking through the northern limestone forests. Without the birds to disperse seeds and the fact that nonnative pigs and deer tear up the ground and eat sapling plants, the native limestone forest has been severely degraded and will require extensive help in order to recover.”

 Additional World Book articles:

• Invasive Species (a Special Report)
• New Top Predator? Pythons in the Everglades (a Special Report)
• Trees Under Threat (a Special Report)

April 9, 2012

After devastating the mammal population of Everglades National Park in Florida, Burmese pythons are targeting the park’s birds. They are not only eating area birds but also taking their eggs straight from the nest.

Researchers from the Smithsonian Museum of Natural History have monitored the invasive snake’s diet by examining the stomach contents of captured pythons. They found that the diets of some 300 captured snakes consisted of more than 25 species of birds. They also found eggs inside the snakes, proof that they are attacking nests. Most snakes that eat eggs puncture the shells with fangs and suck out the contents. However, the researchers found shell fragments inside the snakes, suggesting that they eat the eggs whole. “This finding is significant because it suggests that the Burmese python is not simply a sit-and-wait predator, but rather is opportunistic enough to find the nests of birds,” noted Carla Dove, a researcher with the Smithsonian study. “Although the sample size is small, these findings suggest that the snakes have the potential to negatively affect the breeding success of native birds.” The study was reported in the March 2012 issue of the journal Reptiles & Amphibians: Conservation and Natural History.

An earlier study, published in March 2012 by two Florida university researchers, revealed that pythons were battling alligators for the position of top predator in the Everglades. That study was the first to provide evidence linking a sharp decline in populations of medium- and large-sized mammals in the park to an explosion in the number and range of the large snakes.

Egrets are among the most beautiful birds in the Everglades. (World Book illustration by Trevor Boyer, Linden Artists Ltd.)

Native to Southeast Asia, the Burmese python is classified as an invasive species in North America. From 1999 to 2004, pet exporters met a growing American demand for Burmese pythons by shipping more than 144,000 baby snakes to the United States. However, new owners were frequently unprepared or unwilling to care for the grown snakes, which can measure 23 feet (7 meters) in length and weigh 200 pounds (91 kilograms). Many owners dumped their snakes into the wild. Pythons released into the Florida Everglades, a region with a climate similar to that of the snakes’ native habitat, flourished. Pythons also have escaped into the wild during hurricanes.

Researchers surveyed native mammal populations over 313 nights during an eight-year period by counting live and dead animals along a road that runs to the southern tip of the park. They then compared their tallies to population surveys done in 1996 and 1997. In areas of the Everglades where pythons have lived the longest, populations of raccoons had fallen by 99.3 percent. The number of opossums had dropped by 98.9 percent, and bobcat populations had fallen by 88.5 percent. The researchers were unable to find any rabbits or foxes. Populations of native animals were larger in areas more recently or not yet invaded by the snakes.

The U.S. Association of Reptile Keepers disputed the findings of the study. The organization contended that mercury pollution in the Everglades has played a major role in the disappearance of the mammals.

Young Indian pythons hatch from eggs outside the mother's body. (AP/Wide World)

Wildlife experts agree that eliminating the secretive and hard-to-hunt snakes from the park would be impossible. They are unsure if the spread of the snakes, which have no natural predators in North America, can be halted. In January, the federal government outlawed the import and interstate commerce of Burmese pythons, two other pythons, and the yellow anaconda. Reptile importers are still allowed to trade in reticulated pythons and boa constrictors.

Additional World Book articles:

• Ecology
• Invasive Species (A Special Report)
• Reptile