Tabla de contenidos para April 2026 en What on Earth! Magazine

IN THE SLOW LANE This little brown-throated three-toed sloth was snapped by a photographer after it slowly crossed a road in Costa Rica, causing a traffic jam! Sloths are the world's slowest-moving mammals. This species of sloth is about the size of a small dog and moves at about 0.15 mph. GO WITH THE FLOW This spectacular photo shows the Tasman River flowing into Lake Pukaki from the mountains of Aoraki/Mount Cook in New Zealand. The blue colour of the water is caused by silt particles. TRUNK AND DUNK What a leap! Former circus performer René Casselly regularly performs tricks with his elephant companions. The first winner of the German version of the TV show Ninja Warrior, Casselly now lives at Kimba Elephant Parkin Hungary, a shelter for retired circus…

Castles were designed to keep danger out, but they also featured clever ways for defenders to fight back. Both castle design and the weapons and tactics used to attack castles evolved over time as each side tried to outsmart the other. Read on to discover some of the most important ways castles were attacked and defended. Key: Attack | Defence Archer A skilled bowman could fire a crossbow quarrel (heavy arrow) straight through a castle's arrow loop. But even the best archers would need five or six shots to be sure of hitting their target. Battering ram Battering rams were built from tree trunks. Soldiers used their weight and strength to push or swing them hard into the castle gates. The rams were often suspended from wooden roofs that also…

★ Turtles have been around since the time of the dinosaurs, for over 200 million years! ★ There are more than 350 different species of turtle and tortoise in the world today. ★ Turtles and tortoises can hide inside their shells, but they can never come all the way out. Their shells are made up of 50 bones and include the spine and rib cage. ★ Sea turtles use Earth's magnetic field to help them navigate the oceans over huge distances. ★ Nearly half of all turtle and tortoise species in the world today are vulnerable or endangered. ★ Turtle eggs are regularly stolen by predators. As a result, fewer than 1 per cent of all turtle hatchlings survive to adulthood. ★ It is very hard to determine how old…

letters@whatonearthmag.com Which is your favourite World Book Day costume? Here are just some of the fantastic fancy-dress photos sent in by readers. From a giant peach to a pair of Artful Dodgers, the brilliant What on Earth! readers went full fancy-dress to celebrate World Book Day. Here is a selection of our favourite costumes - every reader featured in the magazine will receive a copy of Gross FACTopia! as a special prize. And don't worry if you can't see your photo here. We received so many great entries we'll be featuring more in future issues. Congratulations to everyone who entered - and happy reading!…

T. rex could outrun Usain Bolt! New research has revealed that towering Tyrannosaurus rex was not as stompy as previously assumed. Scientists studying T. rex footprints have found that the dinosaur moved on tiptoe - and was pretty quick, too! In fact, the latest study suggests that T. rex was up to 20 per cent faster than previously thought. The top speed of a small T. rex would be about 25 miles per hour, which is much faster than most humans can run. In fact, the fastest recorded human, Usain Bolt, ran 100 metres in 9.58 seconds. A small T. rex, in comparison, would win the 100-metre dash with a time of 8.77 seconds! Why a horse's whinny is an unusual sound Imagine what a horse sounds like. Is it…

1 Windsor Castle Built: c.1070 Built by William the Conqueror, Windsor Castle is the oldest and largest occupied castle in the world - and it has been home to British monarchs for nearly 1,000 years. 2 Bodiam Castle Built: 1385 Bodiam Castle in Sussex, England was built at a time of fears of French invasion during the Hundred Years’ War (1337-1453). It is surrounded by a large, impressive moat. 3 Mont-Saint-Michel Built: 966 CE At high tide, the sea can cut off Mont-Saint-Michel from the French coast. This helped protect the rocky island stronghold - including throughout the Hundred Years’ War. 4 Pena Palace Built: 1854 Built in Portugal on the site of a former monastery, Pena Palace was designed to look like a fairy-tale castle, with bold colours and…

Mushrooms are the reproductive part of some fungi. They sprout from the mycelium, often forming an umbrella shape. The world's biggest fungus! A mycelium network in Oregon in the USA spreads across nearly 10 square kilometres, making it the largest fungus ever discovered. It is about three times bigger than Central Park in Manhattan, New York. Its nickname is the ‘humongous fungus’! DID YOU KNOW? If a tree is attacked by disease or insects, it can send a chemical warning signal to other trees through the web! Encyclopedia Infographica, by Valentina D'Efilippo and Andrew Pettie, is out now.…

DID YOU KNOW? The largest-known prairie dog town was 25,000 sq mi across. It was home to around 400 million prairie dogs!…

Castles are still some of the most dramatic buildings on Earth today - so imagine how awe-inspiring they must have seemed to the people who built, lived in and attacked them hundreds of years ago. In Europe, castles began to spread from the 9th and 10th centuries and remained central to war and power throughout the Middle Ages. They were built as both homes and fortresses: places where rulers could live, store supplies and defend their land. But castles did not stay the same. Over time, builders kept redesigning them to meet new threats, from surprise raids to ever more powerful siege weapons. Here, you can follow how castle design evolved from simple early forts to mighty stone keeps and increasingly sophisticated strongholds with thicker walls and more elaborate defences.…