The grey squirrel is a familiar creature in our parks and gardens. This fluffy-tailed mammal has been making mischief in the UK for a while now, overwhelming our native reds since being introduced here from North America in the late 19th century. Before the greys arrived, the UK was home to about 3.5 million reds; today, only 120,000–160,000 remain.
Reds have suffered at the paws of greys. Their larger, non-native cousins outcompete them for food and also carry the squirrel pox virus, which is often fatal to reds but not to greys. Scientists have worked to develop a vaccine to protect red squirrels from the disease, but inoculation isn’t much use when it comes to a ransacked larder.
Currently, attempts to control the grey squirrel population involve poisoning or trapping and shooting. But conservationists are exploring more humane ways of keeping their numbers in check. One idea is to use pine martens, which prey on squirrels. Research has shown that woodlands with higher numbers of pine martens host fewer greys and more reds; scientists think that the smaller reds can escape predation by perching on thinner branches that can’t support the weight of greys or martens. However, some conservationists are concerned that increased numbers of pine martens would have an impact on bird populations, too.
A proposal to suppress the grey squirrel population using a contraceptive has also received Government backing, but there are concerns that this approach wouldn’t be species-specific – that food laced with drugs could be consumed by other animals, too.
Clearly, current strategies are largely failing to control numbers of grey squirrels – aliens that cost the UK £40 million a year from damage to broadleaved forest. So eyes are turning to other methods.
Esta historia es de la edición September 2021 de BBC Wildlife.
Comience su prueba gratuita de Magzter GOLD de 7 días para acceder a miles de historias premium seleccionadas y a más de 8500 revistas y periódicos.
Ya eres suscriptor ? Conectar
Esta historia es de la edición September 2021 de BBC Wildlife.
Comience su prueba gratuita de Magzter GOLD de 7 días para acceder a miles de historias premium seleccionadas y a más de 8500 revistas y periódicos.
Ya eres suscriptor? Conectar
Flightless birds
Our pick of 10 curious birds that have lost the ability to fly
ALL YOU EVER NEEDED TO KNOW ABOUT THE Shoebill
THIS PREHISTORIC-LOOKING BIRD IS affectionately known by some as 'king of the marshes' as it is huge (up to 1.5m tall with a 2.4m wingspan) and resides in the freshwater marshes and swamps of East Africa.
Slime: protector, lubricant and glue
GOO, GUNGE, GUNK... WHILE THERE are many names for the stuff that makes things slippery or sticky, slime isn't a single material but a label for a variety of substances with similar physical properties. Those qualities are desirable to many living things, which is why slime is made by such a wide range of organisms.
How do parrots learn to swear?
THERE ARE FEW THINGS AS GLORIOUSLY entertaining as the effing and blinding of a potty-mouthed parrot.
Why are walruses so chubby?
AS A GENERAL RULE, TERRESTRIAL mammals are furry, while aquatic ones are fat. It doesn't work across the board: sea otters rarely leave the water but have the densest fur of any mammal.
What is the lotus effect?
WHEN YOU FIND YOURSELF WATCHING the clock on the wall of a dentist's waiting room, you can always pass a bit of time with a rummage through the bowl of fragrant botanical wonders next to the leaflets about expensive cosmetic work.
Are there any plants in Antarctica?
CONTINENTS DON'T COME ANY MORE inhospitable than Antarctica, where life must contend with the longest, darkest, coldest winters and a year-round blanket of snow and ice.
LANDLORD OF THE WILD
The humble aardvark is seldom praised for its work digging out homes for other animals
CRACK DOWN
As the new Amazon drama Poacher hits our screens, we take a look at the fight to end ivory poaching in India
Wild words
Spending time observing and writing about the natural world can be transformational