Parasites

Many sharks and rays are known to breach, leaping fully or partly out of the water. In a recent study, colleagues and I reviewed research on breaching and ranked the most commonly hypothesized functions for it. We found that removal of external parasites was the most frequently proposed explanation, followed by predators chasing their prey; predators concentrating or stunning their prey; males chasing females during courtship; and animals fleeing predators, such as a ray escaping from a hammerhead shark in shallow water. We found that the highest percentage of breaches, measured by the number of studies that described it, occurred in manta rays and devil rays, followed by basking sharks and then by eagle rays and cownose rays. However, many other species of sharks, as well as sawfishes and stingrays, also perform this behavior. A breaching white shark surprises researchers off Cape Cod, Massachusetts. Why it matters It takes a lot of ene...

The extreme weather that has battered much of the U.S. in 2022 doesn’t just affect humans. Heat waves, wildfires, droughts and storms also threaten many wild species – including some that already face other stresses. I’ve been researching bee health for over 10 years, with a focus on honey bees. In 2021, I began hearing for the first time from beekeepers about how extreme drought and rainfall were affecting bee colony health. Drought conditions in the western U.S. in 2021 dried up bee forage – the floral nectar and pollen that bees need to produce honey and stay healthy. And extreme rain in the Northeast limited the hours that bees could fly for forage. In both cases, managed colonies – hives that humans keep for honey production or commercial pollination – were starving. Beekeepers had to feed their bees more supplements of sugar water and pollen than they usually would to keep their colonies alive. Some beekeepers who had been in busines...