Crocodiles like to lurk in the shallows, preparing to pounce. They are not, as a general rule, strong enough swimmers to go on extended ocean cruises whenever they feel like it. Despite this, these creatures managed to reach islands across the South Pacific. How?
A group of scientists led by Craig Franklin, and including the late “Crocodile Hunter” Steve Irwin, studied saltwater crocs from the Kennedy River area of Northeastern Australia for about a year for a study forthcoming in the Journal of Animal Ecology. The team tagged 20 animals with receivers to give both their position and body temperature.
They found that eight crocodiles undertook a total of 42 long-distance journeys of more than 10 kilometres [6.2 miles] per day. In 96% of these trips, the reptiles traveled with the current flow. In contrast, the crocodiles were equally likely to travel with and against the current flow when making short journeys [Nature].
The body temperature reading gave the scientists another way to verify this, besides matching croc travel habits to changing ocean currents. When the tide went against the crocs, they just hung out on the beach and their body temperature rose to 90 degrees F as they soaked up the sun. However, when the current became favorable and they went traveling, their temperatures descended to more like 77 degrees.
A thrilling set of ancient crocodile fossils have been unearthed in northern Africa. A “saber-toothed cat in armor” and a pancake-shaped predator are among the strange crocodile cousins whose bones have been found beneath the windswept dunes of the Sahara, archaeologists say [National Geographic News].
At a news conference organized by the National Geographic Society, which sponsored the research, scientists announced that the fossils represent 5 species; 3 new species and 2 that were previously known. These ancient croc ancestors, known as crocodilyforms, are unlike any crocodiles encountered in the Northern Hemisphere, according to the research team. Their findings are detailed in the journal ZooKeys.
The crocs were spectacularly diverse, and included a species that ate dinosaurs, two that grew up to 20 feet long, and two that had long legs for quick movement on land but also had long tails for swimming. The three new species are:
• BoarCroc (Kaprosuchus saharicus), a 20-foot meat-eater. It used its snout for ramming and three sets of dagger-shaped fangs for slicing dinosaurs it ate.
• PancakeCroc (Laganosuchus thaumastos): a 20-foot-long, squat fish-eater with a 3-foot long flat head with spike-shaped teeth.
• RatCroc (Araripesuchus rattoides), a 3-foot-long plant and grub eater with buckteeth used for digging [Chicago Sun-Times].
The two previously known species are nicknamed DuckCroc, a three-foot long, long-legged croc that feasted on fish and frogs, and DogCroc, another small and lanky croc that mostly ate plants and grubs.
Who knew that baby crocodiles are such tender little creatures? According to researchers, they start crying out for their mothers before they’ve even cracked their shells and poked their long noses out into the world: The little crocs make an “umph! umph! umph!” sound right before they hatch [Reuters]. Now a study has shown that the noises they make from within their shells aren’t just idle chatter, but instead play an important role in the hatching.
A team of French researchers studied Nile crocodiles, and found that the calls prompted mother crocodiles to dig the eggs out of the dirt. The cries also seemed to alert all the babies inside their shells that it was time to hatch, leading to a neatly synchronized hatching that could have an evolutionary benefit, researchers say.