Eavesdropping Moths Predict Bats Next move: Deploy Countermeasures…

In a North Carolina laboratory, a live moth was clamped tight in a box with a microphone and made to panic. Through the panic, its powers of prediction were probed. The moth, a species of tiger moth called Bertholdia trigona, isn’t psychic. Instead, the moths’ hearing is the key. It’s one of two weapons it uses to stymy a deadly predator: the big brown bat. The panicking, if moths can truly be said to panic, may even tell us something more broadly about how, and when, animals respond to the threat of predators. Tiger moths have a peculiar response to the presence of bats, and B.trigona especially. When they hear them approaching, using ears just behind their wings, the moths start making ultrasonic clicks. The clicks—the reason for the microphone in the box— are made by an organ on their sides called a tymbal. For some species of tiger moth, ...(Read More)

An Unlikely Traveler In The ‘Death Zone’…

It’s called the ‘death zone’. The area above 8,000 meters where humans can no longer acclimatise to the effects of altitude; the oxygen is too low, the air too thin. We can only venture there briefly if we want to survive*. Yet despite the thin air and low oxygen there are reports of an unlikely visitor: geese. The geese in question are bar-headed geese. Normally residents of areas in China and Mongolia that migrate to over-winter in India. Unfortunately, slap-bang in the middle of their migration route lies the home of Everest, the highest mountain range in the world: the Himalaya. How bar-headed geese travel at such altitudes is something of a puzzle for physiologists. Flying for any distance in the death zone is remarkable; it takes 50% more power to fly and with only 40% of the oxygen available (60% reduction in the partial pressure) than at sea level the metabolic costs ...(Read More)

Ancient whales, secret passages and diversity

Getting to see the relatives can be a chore for most, especially if they’re a long way away. Now imagine your relatives live in a different ocean, separated by a continent, and the only way there is frozen solid all year long. This is the problem that the Atlantic Bowhead whale populations face if they wish to meet their Pacific dwelling relatives; presumably separated millennia ago as the arctic froze, slamming shut the door of the Northwest Passage until recently. Or so it was thought. Sadly, the whale’s problems didn’t stop there; subsistence hunting by man resulted in some loss of numbers, and then as commercial whaling began they were put on the track of an endangered species. Fortunately, now commercial whaling has (mostly) stopped, they are recovering. Both the separation of populations and hunting have forced the whales through something of bottleneck; an event thought to impact on the ...(Read More)

Fall Fashions: Red or dead…?

 “Autumn is a second spring when every leaf is a flower.” – Albert Camus This is certainly true of the autumn here in Ontario. It’s spectacular. Parks and woods are alive with colour; yellows, oranges, golds and reds so impossibly deep it’s like a new kind of black. Some trees are a near uniform gold, others are a tortoiseshell mottling of all the hues of the autumnal palette. As the daylight hours dwindle and temperatures drop the trees respond; these are the signals to make ready for the coming winter. Veins in the leaves start to close, reducing the flow of sap, and production of the green pigment chlorophyll halts as trees reclaim nutrients and energy from leaves before finally shedding them. As it does so, the veil of chlorophyll is lifted; the tree line turns yellow, orange and gold. And red. For years the reds and purples—due to a ...(Read More)