Fearsome and fast, sharks occupy the top spot in the food chain, but are also the most vulnerable to ecosystem changes. Public attitudes to these apex predators is changing, and scientists are beginning to understand their biology, behaviour and contribution to the environment—but will we be quick enough to save them?
Turning over the soil to prepare it for planting is a fixture of the agricultural calendar, but it’s also devastating for earthworms. Conventional tillage uses a plough to invert the soil and bury weeds and leftover crops, but it also exposes earthworms to predators and harsh weather, compacts the soil, and destroys organic matter rather than leaving it to decompose. Afterwards, earthworm numbers take up to ten years to recover. By contrast, in land planted without tilling—usually by drilling seeds into the soil—earthworm numbers are 137 per cent higher, according to research published in Global Change Biology, which looked at 215 field studies from 40 countries, from as far back as 1950. Organic matter in the soil was also up 196 per cent. No-tillage is becoming more popular around the world, because it conserves soil structure and reduces erosion, although more herbicides are generally used to kill weeds. Anecic worms, which take food from the surface but dive deep between soil layers and set up permanent burrows, were particularly affected by conventional tillage, as were epigeic worms, which live in surface mulch. While earthworms found in cultivated land in New Zealand are non-native, these guests now have a critical ecosystem role, recycling organic matter, making nutrients more available to plants, and improving soil structure.
Beneficial gut bacteria may be killed by global warming, according to a study conducted on British lizards by researchers at the University of Exeter and University of Toulouse—to the reptiles’ great detriment. Scientists put viviparous lizards (Zootoca vivipara) in enclosures that were two and three degrees warmer than the average temperature to simulate predicted climate change. Lizards made ideal subjects as, being cold-blooded, they are unable to internally regulate their temperature. While some types of bacteria died over time and some flourished, the overall biodiversity of the warmer lizards’ gut bacteria plummeted 34 per cent compared with the control group. Afterward, the lizards were kept in a common garden for a year, where more of the ‘warmed’ lizards died. Study author Elvire Bestion says while discussion about climate-driven biodiversity loss tends to focus on charismatic animals, there’s a risk to forgetting about what’s on the inside.
Scientists are now spying on bird colonies via satellite.
An unlikely crew is given the assignment of catching birds in butterfly nets on a weather-beaten subantarctic island.
Get up close and personal with red snapper, a common predators at Astrolabe Reef.
Fish life abounds in the coraline shallows.
Life takes on a new hue 30 metres down a coral reef wall.
Welcome to the shark capital of the world.
Somewhere, maybe, the South Island kōkako is calling in the bush. One avid pursuant reckons he's recorded it.
Bryce McQuillan specialises in the tiny, the nocturnal and the cryptic.
Of all the world’s amphibians, the most evolutionarily unusual and critically endangered is the Archey’s frog. The smallest of New Zealand’s four native frogs, this ‘living fossil’ hasn’t changed much in 150 million years. It didn’t evolve ears or a voice, prefers the forest floor to water, and can’t leap without landing in a bellyflop. Why are Archey’s frogs so strange, and what makes them so important?
At a group of tall rock stacks south of the Poor Knights is a huge cavern at a depth of 25 metres, choked with fish and rays, and wallpapered in colourful sponges.
Blue Maomao Arch, tucked into a corner of South Harbour at the Poor Knights hosts huge aggregations of maomao. But can you see the demoiselles?
At the northern extent of the Poor Knights Islands is a gash in the rock, cutting through a promontory to a depth of more than 40 metres. Pink maomao and rays parade through it, day in day out.
Protected from fishing for 35 years, the waters of the Poor Knights Islands abound with life. Diver and conservationist Wade Doak called this place a "wet library", a sort of reference section for marine life unfettered by human activity, and an image of hope for the future of our coasts.
Natural History New Zealand producer and cameraman Max Quinn on decades of documentaries.
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