Jamie Morton is the NZ Herald's science reporter.

Weird Science: How much do spiders eat?

A wandering spider snacks on a rainforest beetle. Photo / 123RF
A wandering spider snacks on a rainforest beetle. Photo / 123RF

Here's a figure to give arachnophobic people the jitters: our planet's spiders wolf down between 400 and 800 million tonnes of food each year.

In the process, these eight-legged carnivores play an important role to keep countless insect pests, especially in forests and grassland areas, in check.

That's according to a new study by Swiss, German and Swedish scientists, who drew on data from 65 previous studies to make the first estimate of how many spiders are currently to be found in seven biomes on the planet.

Their conclusion: altogether there are about 25 million metric tonnes' worth of them around, and most of them are found in forests, grasslands and shrublands, followed by croplands, deserts, urban areas and tundra areas.

The researchers then used two simple models to calculate how much prey all the world's spiders as a whole kill per year.

In their first approach, they took into account how much most spiders generally need to eat to survive, as well as census data on the average spider biomass per square meter in the various biomes.

The second approach was based on prey capture observations in the field, combined with estimates of spider numbers per square metre.

According to their extrapolations, 400 to 800 million tonnes of prey are being killed by spiders each year.

For a sense of just how much this is, take the following into account: all humans together consume an estimated 400 million tonnes of meat and fish annually.

Awesome still massively popular, but say goodbye to tar-rah matey

Lingo in the UK has moved on greatly from the days of the 1990s: but "awesome" remains a popular word. Photo / File
Lingo in the UK has moved on greatly from the days of the 1990s: but "awesome" remains a popular word. Photo / File

The need to communicate with a wider-world coupled with a move away from the cosy, close-knit communities of the 90s has dramatically changed the way British people speak over the last two decades, new research has revealed.

The study, by Lancaster University and Cambridge University Press, looked at the most characteristic words of informal chit-chat in today's Britain.

An earlier study by the team compared existing data from the 1990s to two million words of then newly collected data from the year 2012.

Now, the team have collected more data and compared the same 1990s collection to a bigger collection comprising five million words spanning between 2012 and 2015.

Not surprisingly, the internet age has had a massive influence on the words Britons use.

While in the 1990s they were captivated by "cassettes", today "email", "Internet", "Facebook", "Google", "YouTube", "website", "Twitter", "texted" and "iPad" all topped the bill.

"Twenty-four" reflected the open-all-hours community in which they now live - far away from a world where the "cobbler" and "playschool" were high in their vocabulary, while "permed" and "comb" were headed well and truly for the verbal dustbin, along with "tar rah".

Yet "awesome", which replaced "marvellous" in an earlier study, was still popular and now joined "massively" in the top 15.

The word "croquet" had taken a hit along with expressions such as "mucking", "whatsername", "golly" and "matey".

"Boxer", "crossword" and "draught" were all in the 1990s' top 15; newcomer "yoga" eased itself comfortably into the current top 15.

Identifying Jack the Ripper's last known victim

Scientists have looked at whether Jack the Ripper's last known victim can be identified. Photo / 123RF
Scientists have looked at whether Jack the Ripper's last known victim can be identified. Photo / 123RF

Scientists who led genealogical and demographic research around the discovery of the mortal remains of King Richard III have now been involved in a new project to identify the last known victim of Jack the Ripper - Mary Jane Kelly.

The University of Leicester team was commissioned by author Patricia Cornwell, renowned for her meticulous research, to examine the feasibility of finding the exact burial location and the likely condition and survival of her remains.

This was done as a precursor to possible DNA analysis in a case surrounding her true identity following contact with Wynne Weston-Davies who believed that Mary Jane Kelly was actually his great aunt, Elizabeth Weston Davies.

Now, in a new report, "The Mary Jane Kelly Project", the research team has revealed the likelihood of locating and identifying the last known victim of Britain's most infamous serial killer known as Jack the Ripper, who is thought to have killed at least five young women in the Whitechapel area of London between August and November 1888.

But the research team weren't optimistic - largely because of the challenges of identifying the correct grave sites - and then gaining permission to exhume the body.

Said study co-author Dr Turi King: "As information presently stands, a successful search for Kelly's remains would require a Herculean effort that would likely take years of research, would be prohibitively costly and would cause unwarranted disturbance to an unknown number of individuals buried in a cemetery that is still in daily use, with no guarantee of success."

- NZ Herald

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