How some animals use the Earth's magnetic field to navigate

COME wintertime thousands of garden warblers, pied flycatchers, and bobolinks—all tiny songbirds—will cross the equator heading south for sunnier climes. It is an epic trip. For guidance they will rely on the position of the sun and stars, as well as smells and other landmarks. They may also use the Earth's magnetic field, thanks to a sense known as magnetoreception. Theories about it have long attracted quacks. Franz Anton Mesmer, a German doctor working in the late 1700s, argued that living things contain magnetic fluids, which, when out of balance, lead to disease. His idea of “animal magnetism” was debunked and similar ones viewed with scepticism. But magnetoreception has drawn more serious attention in the past half-century. A pioneering study in 1972 demonstrated that European robins respond to magnetic cues. The list of animals with a magnetic sense has since grown to include species in every vertebrate category, as well as certain insects and crustaceans. Some may use it simply to orient, such as blind mole rats. Others—salmon, spiny lobsters, thrush nightingales—may use it for migration and homing, alongside other sensory cues. How do they do it?

Think of the Earth's magnetic field as shaped by a bar magnet at the centre of the planet. From the southern hemisphere, magnetic field lines curve around the globe and re-enter the planet in the northern hemisphere. A few features of the field vary predictably across the surface of the Earth. Intensity is one variable—the Earth's magnetic field is weakest at the equator and strongest at the poles. Another is inclination. The angle between the field lines and the Earth changes with latitude, so an animal migrating northwards from the equator encounters steadily steeper inclination angles on its route.

Animals can potentially derive two types of information from the geomagnetic field: the direction in which they are facing, and where they sit relative to a goal. Directional information is the more basic, as polarity lets animals orient north or south as if using a compass. But this has limited utility over long distances. A strong ocean current can sweep turtles off track; winds can do the same for migratory birds. Determining latitude relative to an end point is more useful, and magnetic cues like intensity and inclination may help. Take loggerhead sea turtles (pictured). They swim from the coasts of Florida into the North Atlantic gyre, circling it for years before returning to their natal beaches to breed. Straying from the course can have deadly consequences. One study put hatchlings in test sites that simulated the magnetic fields at three points on the outer edge of the gyre. In all three cases, the turtles reoriented to stay within its confines. Another study, published in April, showed that turtles nesting on far-off beaches with similar magnetic properties (like two on either side of the Florida peninsula, at similar latitudes) had more in common genetically than with those nesting closer by. Turtles, it would seem, can get lost while searching for their natal beach. They may swim to one farther afield but more magnetically familiar and breed there.

Questions still abound. The evidence for a magnetic sense is mostly behavioural; researchers have yet to find receptors for it. Part of the problem is that the cells could be located anywhere inside an animal, since magnetic fields pass freely through tissue. (By contrast, cells that enable the other senses, like sight and smell, make contact with the external environment.) Two theories of magnetoreception dominate. One says animals have an intracellular compass. Another suggests that chemical reactions influenced by the geomagnetic field produce the sense. For researchers, this means more questions than answers.

Crowd was 'Out Here With Animals' Saturday

Twin Towns Area residents and visitors were "Out Here With Animals" Saturday, Aug. 25.

From 10 a.m.-3 p.m., Tractor Supply Company, Wahpeton, hosted animal adoptions, a pet supplies drive, live music and more in its parking lot. All proceeds benefit Chahinkapa Zoo and 4-H of Richland and Wilkin Counties.

"We're very grateful to have Mike (Rosley) and TSC as a great community partner," Zoo Director Kathy Diekman said. "It's fun to see the other animals from different places. This is outstanding and we're really looking forward to continuing this partnership."

Youth of all ages enjoyed petting and playing with the livestock provided by Brad Abel. The petting zoo included five goats, a donkey, a pig, three ducklings and three guinea chicks.

Guests also viewed the 11 antique tractors on site and a vendor fair. Everything from canned goods to glass works was available for purchase.

"We've got vendors from as far as Fergus Falls," Rosley said. "There's 100 racks of ribs (to eat)."

Throughout August, Tractor Supply Company is accepting new sealed food, toys, cleaning supplies, bed, scratching posts, leashes and bowls. They'll be donated to area animal rescue facilities and shelters.

"The supplies drive is an important component to Out Here With Animals because it allows our customers who don't have the ability (to adopt) to still give back in a much needed way," stated a TSC press release.

If all of the activities weren't enough, Out Here With Animals included music from Mike Morris of The Roosters, nail trimming and checkups for animals and a dunk tank sponsored by Heritage Insurance Services. Eric Issendorf, head coach of the North Dakota State College of Science Wildcats football team, was among the community members who volunteered to be dunked.

"It slipped," joked Sarah Abel of the Wahpeton Breckenridge Area Chamber of Commerce as she helped a youth send Issendorf into the water.

Dozens of animals saved thanks to new animal sanctuary in Jonesborough

JONESBOROUGH, TN (WJHL)- It's a place where every animal has a heartbreaking story but where they all get to live happily ever after. Tilted Tavern Animal Sanctuary opened this year in Jonesborough.

The goal is to rescue and provide care for farm animals who have been abused or neglected. It's a unique mission the Jones family said never expected to take on.

About a year ago, in her role as a veterinarian, Brooke Jones took a phone call from someone looking for a place to take a hen in bad shape. "They asked if we know anyone that would help and so I said sure," Tilted Tavern co-owner Brooke Jones said with a laugh.

After the hen, "We rescued one cow and a chicken and now we have around 50 animals," Tilted Tavern co-owner Robert Jones said. "We would've never thought we would be here."

The husband and wife team have turned their historic 50-acre farm into Tilted Tavern Animal Sanctuary.

"Right now we have chickens, ducks, cows, horses, a goat, and a pig, and two roosters," Robert Jones said.

He said animals like Skittles the goat and Dumbleboar the pig have come along way since they first arrived. Like most of the animals here they have a heartbreaking story.

"We've had neglect, we've had animal cruelty, our pig is from an animal fighting ring," Robert Jones said.

Without the animal sanctuary, "Some animals would've just died at where they were at the beginning before we got there, others would've been euthanized," Robert Jones said.

Once an animal is rescued, if they are not fit for adoption they come here where they are rehabilitated, loved, and safe.

"The fact that I can not only help the community out but also help animals and have something for them is really wonderful for me personally," Brooke Jones said.

Now after living through nightmare situations, the animals get to to live out their days on this peaceful Jonesborough farm.

Alpacas to aquariums and beyond: Jennifer's passion for animals fulfilled

To Jennifer Vandenbergh, the phrase 'all creatures great and small' is more than a line from a well known hymn or a recognisable RSPCA advertising hook – it's a way of life.

The TAFE NSW Orange Animal Studies student has used her training to involve animals as varied as fish and alpacas in both her professional life.

In addition to working at Second Nature Aquarium, Ms Vandenbergh played a crucial role in setting up and running her brother Scott's stud farm, Kienella Aplacas, at Springside.

According to the stud's website it breeds “show-quality alpacas … for sale as pets, stock guards, and breeding females; their fleece is also available for hand spinners”.

For Ms Vandenbergh, the operation allows her to pursue her passion for animals while lending a hand to family.

“I love everything about animals, particularly the unconditional love, loyalty and companionship they provide,” she said.

“Since starting our stud, my brother, who is disabled, has been a different person. He just loves being with the alpacas.”

The former Orange High School student also uses her free time to visit nursing homes with a qualified therapy dog, Chevy.

“It's rewarding to see how happy she makes the residents,” Ms Vandenbergh said.

Enrolments are now open for semester two at TAFE NSW Orange, with a range of courses on offer.

What We Get Wrong About Animals

Humans have long trapped animals in cages, nets and snares, but the tangled webs of vanity, curiosity, cruelty and fear we cast over other creatures may be even more perilous. We see our virtues and vices reflected in animals — hardworking beavers, indolent sloths, innocent lambs, greedy vultures — through a glass darkly. But these well-worn clichés blind us to a world far more dazzling and varied, according to Lucy Cooke, the acclaimed zoology-trained author and documentary filmmaker, in her new book, "The Truth About Animals." As she writes, "Painting the animal kingdom with our artificial ethical brush denies us the astonishing diversity of life, in all of its blood-drinking, sibling-eating, corpse-shagging glory." (Yes, corpse shagging. The penguin portion is not for the faint of heart.)

In 13 breezy chapters, each devoted to a misunderstood creature, Cooke collects some of our most crackpot notions (and the equally startling truths) about animals. She nimbly pings between arcane, medieval and modern sources, assembling a cast of characters that includes unhinged aristocrats, ill-fated adventurers, Thomas Jefferson, Julius Caesar, Sigmund Freud, the Colombian drug lord Pablo Escobar, the Danish astronomer Tycho Brahe and more than a few mad scientists.
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Aristotle believed the courage of animals corresponds to the heat of their blood; European scientists contended that frogs hatch from wet clay, caterpillars from cabbage and eels from drops of dew. Others theorized that migrating swallows spend winters underwater or on the moon. The real animal behavior Cooke reports is often even more extraordinary. Researchers have recently observed chimpanzees dancing in the rain, fashioning spears to hunt bush babies and playing with sticks they cradle and put to bed like dolls.

Cooke unearths old beliefs and debunks modern-day myths with humor and panache. Pandas, we learn, are not bumbling fluff balls too busy being cute to breed in captivity. Elaborate matchmaking efforts at zoos say more about us and our obsessive meddling than the bears, which are known to mate more than 40 times in a single afternoon in the wild. And bats — popularly believed to be blind, bloodsucking, disease-bearing rats with wings — are more "Buddha than Beelzebub." They see perfectly well, are very rarely rabid and share more DNA with us than they do with rodents, and only three species are vampiric. They are also among the few animals to engage in oral sex, a fact Cooke presents as one of their "porn-star credentials."

The book is big on bawdy humor, and while it's not that weird mating habits and giant genitalia aren't funny, Cooke describes the "ins and outs" of animal sex with a glee normally found among middle schoolers. (Gonads inspire some of the most blindingly painful puns and rhymes; a debate over beaver testicles becomes the "fluster over the beaver's cluster.")

Cooke's appetite for the salacious sometimes overwhelms her sensitivity, as it does in her account of Maurice K. Temerlin, an American psychology professor who reared a chimpanzee named Lucy in his suburban home. At first Lucy is a model "daughter" who uses silverware and raises a kitten. Temerlin, disturbingly, then begins to fix her cocktails. Soon Lucy is fixing herself cocktails. When she takes to masturbating with the vacuum cleaner, Temerlin responds by buying her Playgirl and even participating in one of these sessions to "see what would happen." (Nothing, mercifully.) When Lucy eventually grows too unruly, Temerlin offloads her in Gambia, where she is flayed and butchered by poachers. A story like this is worth analyzing for what it might reveal about anthropomorphism at the edge. Cooke, however, plays it for laughs.

The fraught history of humans and animals has lately been the focus of expanding scholarship, insightful meditations such as John Berger's influential essay "Why Look at Animals?" and environmentalist critiques. Cooke, however, attempts neither to probe its complexities nor to sound apocalyptic alarms (though she does, dutifully, note the impact of human carelessness and mass consumption on other species). She is not plumbing the depths; she is riding the thermals. Her pace is quick, her touch is light, and through her wealth of research we can reach new heights of wonder.