Menopause-causing bait is curbing rat populations in New York

5 May 2017

Population halved in three months

By Alice Klein

It is pest control without poison. A new type of bait that stops rats from having babies is helping to tackle infestations in several US cities.

The bait – known as ContraPest – was approved by the US Environmental Protection Agency last August. It makes rats infertile by triggering early menopause in females and impairing sperm production in males. There are no side effects and the rats eventually die of natural causes.

The technique is considered more benign than other control strategies being investigated, such as gene drive, which can be used to spread infertility genes through pest populations. A recent report by the US National Academies of Sciences warned that gene drive could have unforeseen consequences.

The first field trial of ContraPest, conducted in the New York City Subway in 2013, halved the resident rat population in three months. Two more trials have now been completed in the US – one at a large-scale farm and one in an urban area – both in East Coast cities.

Rat numbers at the farm fell by one-third over three months. In the urban area, population growth was suppressed during the peak breeding season so that the population expanded at only one-third the expected rate.

“You’ll never wipe out rats completely – they’re too smart,” says Brandy Pyzyna from SenesTech, the biotechnology company in Arizona that developed the bait.
Fast breeders

“But if you think about it, one breeding pair of rats can produce 15,000 pups in a year,” she says. “Even if you can reduce that by a third in a few months, you’re already talking 5000 fewer rats, and the population will continue to go down.”

Continued

Denmark gets its first wild wolf pack in 200 years

Arrival of a female wolf, that trekked 500km from Germany, means the pack could have cubs by spring

Patrick Barkham

Thursday 4 May 2017 17.29 BST Last modified on Thursday 4 May 2017 17.31 BST

A wolf pack is roaming wild in Denmark for the first time in more than 200 years after a young female wolf journeyed 500km from Germany.

Male wolves have been seen in Denmark since 2012 and the new female could produce cubs this spring in farmland in west Jutland after two wolves were filmed together last autumn.

It is further evidence that the wolf is returning to well-peopled landscapes after centuries of persecution, with wolf packs also re-establishing themselves in France and Germany and individuals sighted in Holland and even Luxembourg. Before the new population, Denmark’s last wolf was killed in 1813.

“We expect that they will have cubs this year or the next,” said Peter Sunde, a senior researcher at Aarhus University.

“People were very surprised when wolves first appeared in Denmark but they are highly mobile and are just as adaptable to cultural landscapes as foxes are. The only problem historically is that we killed them.”

DNA from two faeces samples have confirmed that the female wolf came from a pack 25km south of Berlin in Germany before travelling to north-west Denmark, probably leaving her family group last spring to do so.

There is sometimes speculation that wolves are deliberately released into the countryside by unofficial rewilders but according to Guillaume Chapron, a researcher at the Swedish University of Agricultural Sciences, this female’s trek north was entirely natural. “The wolf went on its four legs, it makes complete biological sense,” he said. Wolves can walk 50km in 24 hours and have been recorded making journeys of more than 1,000km across Europe from Germany, where they re-established themselves in 1998. Germany’s wolf population is currently growing at 25-30% each year, with the young dispersing across central Europe.

 

continued 

In search of the elusive saola - via Richard Freeman

Bill Robichaud fights to save one of the world’s rarest creatures

by Catherine Capellaro

April 6, 2017

When one the most important zoological discoveries of the century was announced in 1992, field biologist Bill Robichaud happened to be sitting in a noodle shop in Vientiane, Laos, reading the Bangkok Post. The article had an inset map showing the location of a Vietnamese village where a set of long, tapered horns — unlike any known to science — were found in a hunter’s shack. “I thought, that thing’s in Laos, for sure,” says Robichaud. “Three days later I was down on a bus to that part of Laos.” By now, we have a name for the mysterious cloven-hoofed creature, the saola (pronounced sow-LAH).

The importance of that discovery still animates Robichaud, who studied zoology at UW-Madison and now lives outside Barneveld. It turns out the saola is the only surviving line of a genus of bovid, a grazing animal related to cattle, bison, goats and antelopes. “This wasn’t a new species of something else; this was an entirely new type of mammal that doesn’t look like anything else, and it had gone undetected,” says Robichaud. “Even the Vietnamese biologists in Hanoi didn’t know about it. And villagers didn’t know it was anything special. I think it was, without doubt, the most surprising zoological find of the 20th century.”

Robichaud assumed some superstar biologists would latch onto the project and make the saola their life’s work. A natural candidate would be George Schaller, who had studied tigers, mountain gorillas, jaguars and giant pandas. The subject of Peter Matthiessen’s adventure tale The Snow Leopard had been a mentor and colleague of Robichaud’s at the Bronx Zoo Wildlife Conservation Society. “I just said, ‘George, you’ve defined your career by being the first guy to do the first-ever field study of large, unknown mammals. Why aren’t you settling down in Laos and making saola your retirement project?’” Schaller’s reply: “How can you study an animal you can’t even see?” So Robichaud seized the opportunity to study the rare and elusive creature. “I just kept waiting for someone to take this over, and nobody did, so I just did it by default.” Robichaud now coordinates a massive international effort to save the saola from imminent extinction.



Continued

'Shocking' levels of PCB chemicals in UK killer whale Lulu

By Rebecca Morelle Science Correspondent, BBC News


2 May 2017

One of the UK's last killer whales was contaminated with "shocking" levels of a toxic chemical, scientists say.

The animal, called Lulu, was found dead on the Isle of Tiree in Scotland last year after becoming entangled in fishing lines.

But tests now reveal her body contained among the highest levels of polychlorinated biphenyls, or PCBs, ever recorded.

The chemicals were banned from the 1970s but are still in the environment.

Researchers now fear that other animals in Lulu's pod also have similarly high levels of contamination. The group, which is found off the west coast of Scotland, is thought to consist of just eight animals.

Dr Andrew Brownlow, head of the Scottish Marine Animal Stranding Scheme and veterinary pathologist at Scotland's Rural College (SRUC), told BBC News that Lulu had "shocking levels of PCBs".

He said: "The levels of PCB contamination in Lulu were incredibly high, surprisingly so. They were 20 times higher than the safe level that we would expect for cetaceans to be able to manage.

"That puts her as one of the most contaminated animals on the planet in terms of PCB burden, and does raise serious questions for the long-term survivability of this group (of UK killer whales)."



Continued

Jurassic animal found on Skye 'fed milk to young'

Palaeontologists believe an animal that lived in what is now Skye 165 million years ago fed milk to its young.

Milk teeth have been discovered in the fossil jaw of a juvenile Wareolestes rex, a species of mammal from the Middle Jurassic.

Scientists suggest adult females secreted milk on to a bare patch of skin for their young to lap up.

Nipples and suckling as seen in modern mammals had still to evolve when Wareolestes rex lived.

The two centimetre-long jaw was found on Skye in 2015 and is one of the most complete fossils of the early mammal to be found outside of China.

Single teeth of Wareolestes rex have previously been found in England.



Read on