A saltwater crocodile attacks a feral pig in Australia
Credit: © Adam Britton, Media Drum World/Alamy Images

Normally invasive species get a bad reputation. They take over ecosystems, reproducing unchecked by predators and eating the native species’ food. The cane toad, native to Central and South America, has dominated regions of Australia, the Caribbean Islands, Florida, Hawaii, Japan, New Guinea, and the Philippines. Zebra mussels hopped aboard a ship in the Caspian Sea and have since clogged up the Great Lakes in the United States. Asian tiger mosquitoes, Burmese pythons, stink bugs, and Japanese beetles also wreak havoc in their new neighborhoods. However, in Australia, there is a plot twist in the invasive species narrative.

The feral pig was taking over Australia beating out livestock for food, damaging fences and water sources, and eating crops before harvest. The pigs were brought by European settlers in the late 1700’s. They soon took over and bred throughout the country. Scientists were beginning to worry the feral pigs would put the ecosystems past the brink of return. Then, the saltwater crocodile stepped in.

Saltwater crocodile
© Firepac, Shutterstock

The saltwater crocodile is the largest living reptile and one of the most fearsome predators on Earth. Adults can reach lengths of 23 feet (7 meters) and weighs of over 1 ton (0.9 metric tons). The saltwater crocodile has a long, low, sausage-shaped body; short legs; and a long, powerful tail, which it uses to swim. It also has a tough hide, a long snout, and sharp teeth to grasp its prey. Saltwater crocodiles have lived on the coasts of northern Australia and Southeast Asia, and on the islands between for millions of years. The saltwater crocodile is also called the estuarine crocodile and the Indo-Pacific crocodile. In Australia, it is informally called the “saltie.”

A saltwater crocodile’s diet depends greatly on its age and size. Young individuals eat crustaceans, insects, rats, and small fish. As saltwater crocodiles grow, they take increasingly larger prey, including sharks and water buffalo. Large adults may attack humans if an opportunity presents itself. The crocodile has had a menu change in recent years, giving a new meaning to the term “piggy bank.” They have recently taken to feral pigs, snatching them up when they go to the water to drink. Pork is on the menu and seems to be a permanent a-la-carte item.

Adult saltwater crocodiles have one of the strongest bites in the animal kingdom. They can close their jaws with approximately 3,700 pounds per square inch of force. In contrast, human bite force is only about 200 pounds per square inch. Those pigs do not stand a chance if the crocodiles hit the mark on the first bite!

Because they present a danger to humans, saltwater crocodiles are sometimes feared and hated by people. In northern Australia, they were hunted almost to extinction before a 1970 hunting ban enabled populations to recover. Like most other crocodiles, saltwater crocodiles are threatened by hunting, invasive species, habitat loss, and pollution. Governments across the saltwater crocodile’s range work to educate people on how to avoid attacks. Scientists in Australia studied the carbon and nitrogen isotopes in bone samples of crocodiles comparing today’s crocodiles to those from almost one hundred years ago. The study found that feral pigs had become the primary food source in the last 50 years. This finding reveals that although crocodiles used to mainly eat aquatic prey, they have adapted to eat mostly prey that lives on land! The crocodiles seem to be making a comeback with their new diet. This invasive species helped out an endangered species! You will be here for a while, crocodile!

Illustration of a Megalodon shark and great white shark shown for scale
Credit: © Christian Darkin, Science Source

Arriving at the tail end of a long de-bait, scientists have figured out what happened to the megalodons that used to swim in our oceans. Megalodons were the largest sharks that ever lived, reaching an estimated 52 feet (16 meters) long. Megalodon, which means big tooth, lived from about 17 million to 2 million years ago. The fate of the megalodon has stumped scientists and enthusiasts for ages. How did such a powerful and monstrous shark die out?

The megalodon was a powerful predator (hunting animal). Its jaws may have reached about 6 1/2 feet (2 meters) across. Scientists believe it had an exceptionally strong bite. Megalodon’s largest teeth measure about 7 inches (17 centimeters) along their edges. They rank as the largest shark teeth known. A new finding made a splash in the headlines, revealing just how this monster shark became extinct. Extinction occurs when every member of a species (kind) of living thing has died.

The great white shark, shown here, is one of the most dangerous sharks. It has many sharp, triangular teeth. The great white shark can grow to more than 21 feet (6.4 meters) in length.
Credit: © Shutterstock

A new study has shown that maybe those big teeth didn’t help these large predators out much. After studying zinc isotopes in fossils of teeth from great white sharks and megalodons, the scientists reported that great white sharks and megalodons competed for food. Zinc isotopes in teeth reveal where the animal lies on the food chain. When teeth have low levels of zinc, that means the animal is higher on the food chain. The great white shark and megalodon tooth fossils had the same range of zinc isotopes. The two sharks were not chums, they were biting into the same prey! In a feeding frenzy, the great white sharks won, leaving the great big megalodons hungry.

While the great white shark is one of the most dangerous sharks, they can only grow to a little more than 21 feet (6.4 meters) in length. So the megalodon had about 30 feet (9 meters) on them! Unlike most other sharks, great white sharks have warm blood and warm muscles. These characteristics make them faster and stronger than most other sharks. Great white sharks have sharp, triangular teeth with jagged edges. They can rip chunks of flesh from seals and sea lions, two of their favorite prey. It looks like baby shark beat out the bigger shark!

Dogs are playful animals that have lived with people as pets for more than 10,000 years, longer than any other animal. 
Credit: © Jean Frooms, Shutterstock

Today, May 20, is National Rescue Dog Day! You probably know a rescue dog in your neighborhood. Dogs are considered rescue dogs when they are adopted from shelters, humane societies, or found in unfortunate situations. The American Society for the Prevention of Cruelty of Animals (ASPCA) reports over 3.3 million dogs enter shelters in the United States every year. They take in dogs of all sizes, breeds, ages, and colors.

Dogs have lived with people as pets for more than 14,000 years, longer than any other animal. During that time, breeders have developed about 400 dog breeds to perform various tasks, provide companionship, and please the human eye.

Pets depend on their owners
Credit: (c) Ariel Skelley, Corbis

If you are looking to get a dog, you have many options. You can find a breeder and buy a purebred or designer dog. You can also adopt a dog from a shelter! The chief advantage of selecting a purebred pup is that you know how the dog will look when it is grown. Purebred dogs, however, suffer from many inherited diseases. For this reason, you should buy a purebred dog only from an experienced breeder with a good reputation. You should also find out as much as you can about the dog’s parents and their ancestors. A veterinarian may also recommend good breeders and help you choose a healthy dog. Be careful where you look for a puppy, because you might end up supporting a puppy mill. Puppy mills are breeding facilities that can cause suffering to dogs through overbreeding and neglect. Overbreeding and neglect are considered animal cruelty.

If you aren’t committed to a certain breed, you can find a companion in a mixed-breed dog. The best thing about mixed-breed dogs is that each one is unique. Mutts come in every size, shape, and color. However, it may be difficult to predict the adult size and appearance of a mixed-breed puppy. Humane societies and animal shelters have good selections of mixed-breed dogs. Adopting an adult or senior dog can save the dog’s life. You can offer the dog a safe and loving home for the rest of its years.

Rescue dogs have sometimes gone through traumatic situations and may take time and patience to calm down. National Rescue Dog Day was founded by Lisa Wiehebrink after she rescued her dog Cooper from a shelter in Los Angeles, California. Before he was adopted, Cooper was found in an abandoned lot. Under Wiehebrink’s care, Cooper became a loving, fun, and loyal pet. She decided more people should know how many rescue dogs need a caring home. It is estimated that more than 1 million rescue dogs are euthanized in the United States every year because shelters become overcrowded. You can save a dog’s life by heading to your local shelter to adopt a tail-wagging rescue dog!

If you want to help out a rescue dog today, check out your local animal shelter. You can volunteer, donate supplies such as dog food or dog beds, adopt a dog, or foster a dog. When you foster a dog, you take care of it in your home until someone adopts it, making sure the shelters have enough room to care for all the abandoned dogs in a safe, healthy, and loving manner. If you rescue a dog, you might end up asking yourself “Who rescued who?”

Disney and Pixar’s animated movie Turning Red (2022)
Credit: © Walt Disney Studios Motion Pictures

What’s red, fluffy, and loves boy bands? Pixar’s newest movie Turning Red is a big hit shining a spotlight on red pandas. Turning Red is an animated motion picture released by Pixar Animation Studios and the Walt Disney Company in 2022. It tells the story of a young Chinese-Canadian girl who discovers she can shapeshift into a red panda. The movie is set in Toronto. It was the first Pixar movie created by an all-woman leadership team.

Turning Red tells the story of the Chinese-Canadian 13-year-old Meilin “Mei” Lee, who lives in Toronto. Mei’s family includes her mother, Ming, and father, Jin. They maintain a Chinese temple dedicated to their ancestor Sun Yee. Mei works to balance pleasing her mother and being herself with her friends Abby Park, Miriam Mendelsohn, and Priya Mangal. Mei and her friends obsess over a boy band called 4*TOWN. After Ming embarrasses her daughter, Mei has a nightmare about red pandas and wakes up transformed into a giant red panda. Mei hides her transformation from her parents. But, she cannot keep her newfound ability hidden for long, and its discovery leads her to secrets in her family’s past.

The Lee family is voiced by Rosalie Chiang (Mei); Sandra Oh (Ming); Orion Lee (Jin); and Wai Ching Ho (Mei’s grandmother Wu). Mei’s friends are voiced by Hyein Park (Abby); Ava Morse (Miriam); and Maitreyi Ramakrishnan (Priya).

The film was directed by the Chinese-Canadian animator and screenwriter Domee Shi and the American playwright and television writer Julia Cho. The American actor and producer Lindsey Collins produced the film.

The film’s soundtrack, also released in 2022, features original songs written and composed by the Swedish composer Ludwig Göransson. The American singer-songwriter siblings Billie Eilish and Finneas O’Connell wrote three original songs performed by 4*TOWN in the film.

In real life, red pandas are adorable and unique creatures. A red panda is a medium-sized mammal with a red coat and a long, ringed tail. The red panda is also called the lesser panda, in reference to the much larger giant panda. Red pandas are not closely related to giant pandas or any other living animal. Red pandas live in bamboo forests on upper mountain slopes. Red pandas are arboreal—that is, they live in trees. A red panda has adaptations that allow it to climb trees easily including its tail for balancing and flexible ankles which allow it to climb headfirst down trees. They are found in parts of Bhutan, China, India, Myanmar, and Nepal.

Human population growth in the Himalayan region threatens the habitat of the red panda. Deforestation has reduced the area where red pandas live in the wild. Red pandas are in danger of dying out completely. They are protected by national and international laws. Scientists and wildlife officials have worked to help ensure the pandas’ survival by protecting their habitat and breeding them in zoos.

Ham, chimpanzee sent into space
Credit: MSFC/NASA

When thinking of Project Mercury, students likely point to the first astronauts. Mercury was the first National Aeronautics and Space Administration (NASA) project to send humans into space. They were some of the first beings to traverse the stars aboard a rocket and orbit the Earth, but that’s not all. Primates are the group of animals that includes monkeys, apes, and human beings. The first primate in space wasn’t cosmonaut Yuri Gagarin—it was a brave chimpanzee named Ham.

Ham was one of several animals used in Project Mercury. The Mercury capsule was tested with chimps and other primates before launching humans into space. Chimpanzees were used because they are intelligent and closely related to humans, with the ability to be trained to perform simulated spacecraft operations. Ham helped to prepare the U.S. space program for human space flight.

Ham was born in the 1950’s in a forest in Cameroon (then French Cameroon). The U.S. Air Force had chimps captured from the forest and sent to the United States. In 1959, 40 chimps were enrolled in the “School for Space Chimps” on the Holloman Air Force Base in Alamagordo, New Mexico. They were given the nickname astrochimps and trained for spaceflight. Another astrochimp, Enos, later became the first and only chimpanzee to orbit Earth.

At just 3 years old, Ham, also known as Subject 65, excelled at his tasks. The nickname Ham stood for Holloman Aerospace Medical Center, where the chimps were trained. Ham learned to pull levers when cued by a blue light. The chimps were trained to spend long periods in a chair and were subjected to extreme acceleration forces and microgravity, the sensation of weightlessness experienced by astronauts in space. After 18 months, Ham and five other well-performing chimps were sent to Cape Canaveral, Florida, in 1961 for an experimental flight. The brief suborbital flight was to test the environmental controls, life support, and recovery systems of the Mercury spacecraft in weightless conditions.

On Jan. 31, 1961, a Mercury-Redstone 2 rocket took off with Ham as its passenger. He was strapped into a “couch” in the small, pressurized capsule. The craft briefly lost air pressure during the flight, but Ham’s capsule saved him from harm. The rocket traveled 400 miles (640 kilometers) and peaked around 160 miles (250 kilometers) above Earth’s surface. It went higher and faster than NASA’s plan, which called for a peak of 115 miles (185 kilometers) altitude and a top speed of 4,400 miles (7,000 kilometers) per hour. The rocket actually reached speeds of 5,800 miles (9,300 kilometers) per hour.

The flight lasted about 16 ½ minutes. Ham experienced 6 ½ minutes of weightlessness. Ham was dressed in a spacesuit and waterproof pants. He was hooked up to sensors that recorded his body temperature, breathing, and heart rate. The flight was probably extremely distressing to Ham. Despite the stress of weightlessness and crushing acceleration forces, Ham was able to pull levers in response to flashing blue lights. He proved that astronauts could perform motor functions under the stresses of spaceflight. His capsule splashed down in the ocean and was recovered 130 miles (210 kilometers) from its target. The capsule was taking on water, and Ham had been waiting in distress for hours.

After the flight, Ham was relocated to the National Zoological Park in Washington, D.C., in 1963. After 17 years living alone there, Ham joined other chimps at the North Carolina Zoo in Asheboro in 1980. Ham died on Jan. 18, 1983, at the age of 25, young for a chimp. His remains were buried by the U.S. Air Force at the International Space Hall of Fame in the Museum of Space History in Alamogordo. His skeleton was kept for scientific study at the National Museum of Health and Medicine in Washington D.C. NASA eventually stopped sending non-human primates into space in the 1990’s, in part due to pressure from animal rights groups.

The killer whale, shown in this photograph, has a glossy black back, a white underside, and a white patch near each eye. Its powerful, swift body helps make it an effective predator.
© Brandon Cole, Alamy Images

Australian scientists reported in January 2022 their observations on three instances where a pod of orcas viciously attacked, killed, and consumed a blue whale—the largest of all animals. The scientists described the attacks as “the biggest predation event on Earth,” the likes of which may not have occurred since the age of the dinosaurs. The titanic battles also settled a long-standing debate among scientists on whether gigantic blue whales could be vulnerable to the ocean’s top predators.

The blue whale is the largest animal that has ever lived. An adult reaches up to 100 feet (30 meters) long and can weigh over 150 tons (135 metric tons)—larger than even the largest dinosaur. Orcas, also known as killer whales, are apex predators at the top of the food chain in every ocean of the world. Adult males typically measure from 19 to 27 feet (6 to 8 meters) long and weigh 4 to 10 tons (3.6 to 9 metric tons). Females are usually somewhat smaller. They often travel in groups, called pods, up to dozens of animals, usually led by an adult female. Orcas feed on a wide variety of ocean animals, but some pods are known to specialize in hunting large whales.

The scientists reported their observation of three separate orca attacks on blue whales that took place from 2019 through 2021 off Bremer Bay in Western Australia. In two of the attacks, a large pod of orcas was seen to attack, kill, and consume blue whale calves up to about 60 feet (12 meters) in length. A third attack was observed on a fully grown adult blue whale about 72 feet (22 meters) long. Up to 12 orcas cooperated in a gruesome hour-long attack led by 8 adult females as dozens of juvenile orcas circled about. The orcas attacked as a pack, biting and ripping flesh from the enormous whale as it desperately tried to flee. The scientists watched as one orca forced its way into the dying giant’s mouth to tear away and eat its massive tongue. Once the blue whale expired, about 50 orcas surrounded the great beast to feast on the carcass.

Orcas have been observed hunting every kind of large whale in coordinated packs, much like wolves. However, orcas are almost always observed preying on calves, rather than fully grown adults. More than three times their body size, an adult blue whale poses a formidable and dangerous challenge to any orca that dares attack. Scientists also believed that taking such large prey must have relied on attacks led by the larger males in the pod.

Now, scientists have observed that orca attacks against adult blue whales are successful and are often led by females. They believe that such predation by orcas may have been more common in the past before the blue whale population was decimated by whaling in the past 150 years. Such attacks may be led by mature females who have learned coordinated pack techniques to take down large prey.

The white tiger has chalk-white fur with chocolate-brown or black stripes. It also has distinctive blue eyes.
© Shutterstock

True or false: the white tiger is white in order to blend in with its snowy habitat.

False! Tigers can live in almost any climate. So why are they different?

White tigers are not a separate species of tiger, nor are they albinos. Rather, these individuals carry two copies of a specific gene that causes their white appearance. Genes are the units of inheritance that determine which characteristics living things receive from their parents.

The white tiger is a tiger with chalk-white fur and chocolate-brown or black stripes. White tigers also have distinctive blue eyes. All other tigers have yellow eyes.

White tigers are extremely rare in the wild. Wild tigers are found only in Asia, and only a few remain in most countries. More than 100 white tigers live in the world’s zoos. They are all descendants of a white cub caught in India in 1951.

Whiteness in tigers is a recessive trait—that is, a tiger will only be white if it inherits two copies of the gene for whiteness, one from each parent. The gene for whiteness is quite rare.

To provide the best chance of white cubs, breeders often cross tigers that are closely related. This practice, an example of inbreeding, has led to many cubs being born with serious birth defects.

The red-tailed hawk lives in open areas throughout North America. This illustration shows a red-tailed hawk in flight. The hawk uses its powerful beak to tear open prey, such as rodents. The red-tailed hawk reaches about 2 feet (0.6 meter) in length.

The red-tailed hawk is a large, stocky bird of prey. The red-tailed hawk is one of the most common hawks of North America. It lives throughout the continent and the Caribbean Islands. Red-tailed hawks prefer open spaces with places to perch, but they can adapt to almost any habitat. The red-tailed hawk has a distinctive, piercing call that sounds like “keeeeer.”

Adult red-tailed hawks measure 18 to 26 inches (45 to 66 centimeters) long. The average wingspread of an adult red-tailed hawk is about 50 inches (130 centimeters). Adults may weigh between 1 ½ and 3 pounds (700 and 1,400 grams). Females are larger than males.

Red-tailed hawks vary in coloration. Most adults have a rust-red tail. They usually have brown plumage on the top side of their bodies. The underside of the body is lighter and often mottled with dark colors. The wing undersides are also lighter in color and often have brown, black, or red markings.

Red-tailed hawks are soaring hawks. Such hawks use their excellent eyesight to spot prey from high up in the air. They then swoop down to catch it. Red-tailed hawks feed primarily on small mammals, such as mice and rabbits. They will eat just about anything they can catch or find, however, including other birds, fish, large insects, reptiles, and fresh carrion (dead animals).

Red-tailed hawks mate for life. A female red-tailed hawk lays one to five eggs per clutch. Chicks hatch in 28 to 35 days. The female usually incubates the eggs and stays at the nest with the hatchlings while the male hunts for food. Parents continue to care for their young for as long as 13 weeks after hatching.

Many species of hawk have become threatened with extinction, largely due to the destruction of their natural habitats. However, red-tailed hawks have adapted well to environments changed by human activity. They often patrol for prey in areas cleared by humans, such as farms or roadsides.

Humpback whale mother and calf
Credit: © Shutterstock

A study published in November 2021 reported more accurate measurements of just how much giant whales eat—and just how much they defecate (eliminate solid wastes)—which has surprising effects on the ocean ecosystem and even global climate. The research demonstrates that ocean food webs are more complex and intertwined in surprising ways, more surprising than simple predator-prey relationships.

Baleen whales, including the blue whale, bowhead whale, fin whale, and right whale, are among the largest animals that ever lived. These gigantic beasts feed mainly on millions of tiny shrimp-like krill and other zooplankton that they filter out from huge gulps of seawater. Calculating exactly how much they eat has always been a difficult exercise.

A gray whale filters food from water by squeezing the water out of its mouth through thin plates called baleen.
Credit: © Shutterstock

In the latest study, scientists used Global Positioning System (GPS) tags to follow more than 300 baleen whales as they swam and ate their way through the oceans. This tracking enabled the scientists to record each time a whale lunged to gulp a mouthful of krill. Sonar and drones flown overhead were used to determine the dimensions of the krill swarm swallowed, providing the most accurate measure yet of how much each whale was consuming. The results were surprising. The baleen whales were routinely eating three times or more the amount of food previously estimated. Across all species studied, baleen whales consume an average of 5 to 30 percent of their body weight each day. A single average-weight adult blue whale can consume about 40 million krill a day, equaling about 4 tons (3.6 metric tons). Of course, what goes in must come out. So equally astonishing was the amount of feces (solid bodily waste) that baleen whales produce as measured by the study. A blue whale can excrete more than 50 gallons (190 liters) of waste in one go.

The populations of many kinds of whales collapsed in the 1900’s because of excessive whaling. Whalers killed so many blue, bowhead, humpback, and right whales that these species nearly became extinct. The researchers estimate that before the 1900’s, baleen whales in the Southern Ocean consumed 430 million tons (390 million metric tons) of krill annually. That’s twice as much krill than exists today. With so many krill-eating whales removed from the ecosystem, researchers expected krill populations to increase. But krill populations dropped after most of their predators were killed off—a fact known among ocean scientists as the krill paradox.

How could this have happened? Researchers know when whales feed on krill, a good amount of nutrients are excreted in their feces afterward. In the nutrient-poor Southern and Pacific oceans, this cycling of nutrients is especially important. The nutrients excreted are rapidly taken up by blooming populations of simple one-celled algae in the oceans called phytoplankton. The phytoplankton in turn serve as food for more krill, which are then food for whales. More whales mean more whale poop—fertilizer in the ocean—which means more krill.

When living things grow, they add carbon to their bodies, removing some carbon from the atmosphere. In another unexpected finding, the researchers estimate that restoring baleen whale populations to 1900 levels could foster plankton blooms that would remove 235 million tons (215 million metric tons) of carbon from the atmosphere, helping to combat global warming.

A dog show is a competitive event in which judges evaluate dogs on their physical appearance and condition. In this photograph, a woman parades a doberman pinscher for the judges’ review.
© Shutterstock

The National Dog Show, presented by the Kennel Club of Philadelphia and the American Kennel Club, took place over the weekend at the Greater Philadelphia Expo Center in Oaks, Pennsylvania, fully returning for the first time since 2019 due to the COVID-19 pandemic. In 2020, the show went on without spectators. Instead, cardboard cutouts sat in the audience and the dogs competed without applause.

The National Dog Show has aired on television every Thanksgiving Day after Macy’s Thanksgiving Day parade for 20 years. This year the show was open to vaccinated spectators as well as well-behaved dogs. While the judges announced best in breed winners, the “Best in Show” winner will not be announced until the show airs on Thursday, Nov. 25.

The bichon frise is a popular show dog. This photograph shows bichons frises lined up for judging at a dog show.
AP Photo

The American Kennel Club (AKC), the best-known dog registry in the United States, classifies dog breeds into seven major groups for exhibition in dog shows. The seven groups are (1) sporting dogs, (2) hounds, (3) working dogs, (4) terriers, (5) toy dogs, (6) nonsporting dogs, and (7) herding dogs. The AKC also has a miscellaneous category for dogs that are growing in popularity but that have not yet been accepted for registration.

This weekend over 1,500 dogs made their way to the Philadelphia area to compete with their owners, handlers, milk-bones, and hair dryers. There are 209 registered breeds in the show this year competing in the 7 group competitions. Each breed competes to be “Best of Breed.” Those winners participate to be “First in Group” in each of the seven groups. From the seven dogs named “First in Group,” the judges name the overall champion as “Best in Show.”

The American Kennel Club added a new breed to the registry this year. The Biewer terrier, a German toy breed, is making its debut on the show. The breed, pronounced like“beaver,” is a relative of a Yorkshire terrier with white, tan, and brown fur. They are known as friendly and athletic companions.

Last year, Claire the Scottish deerhound, a type of hound, won “Best in Show.” In 2019, a bulldog named Thor won after taking the non-sporting group. A whippet, a hound breed, named Whiskey won in 2018. This year perhaps a Biewer terrier will take home the blue ribbon.