If you’ve ever passed by a field of horses at night, you’ve probably noticed that they rarely lie down to sleep. So why do these mammals sleep standing up?
The answer is one of survival: Horses slumber while standing to balance their need for sleep against the ever-looming threat of predators.
Horses come from a long line of prey animals in the family Equidae, and sleeping on their hooves is an adaptation against predation. “Standing gives them a literal jump on predators and a better chance of getting away than if they were [lying] down,” Karen Waite, an equine specialist at Michigan State University, told Live Science in an email.
Simply put, horses are big animals, and it takes time and energy for them to get off the ground. A standing horse is therefore much better able to run away when roused from sleep. According to BBC Science Focus, the same goes for other large prey herbivores, such as zebras, bison, elephants and giraffes, all of which are capable of sleeping on their feet.
Related: Why do horses wear shoes?
Horses have specialized anatomical features that enable them to stay on their hooves while catching some z’s. These features, known as a “stay apparatus” include a series of tendons and ligaments — soft tissues that connect muscle to bone, and bone to bone, respectively — that run throughout both the forelegs and hind legs, according to Waite. When a horse relaxes its leg muscles, the stay apparatus ligaments and tendons act as tension bands that stabilize the shoulder, knee and ankle joints in the legs. This enables the horse to remain standing without having to maintain much tension in their muscles.
These horses feel safe enough to lie down. (Image credit: mokuden-photos via Getty Images)
But while horses do most of their sleeping while standing, they do need to lie down for more restorative sleep. “Horses will spend most of their time sleeping standing up, but they don’t actually reach full REM sleep when they’re standing,” Sarah Matlock, a senior instructor of equine behavior at Colorado State University, told Live Science. During rapid eye movement (REM) sleep in humans — when a sleeping individual’s eyes move rapidly under closed eyelids — dreaming can occur, and so muscles become temporarily paralyzed so we don’t act out our dreams. During REM sleep,the brain also consolidates and processes new information for long-term memories. People who don’t get enough REM sleep may experience problems with mental concentration and mood regulation, a weakened immune system and less cell growth.
Adult horses are often able to get by on as little as 5 hours of sleep per day, and they can get most of it while standing up. And while standing horses can achieve “slow-wave,” or deep, dreamless sleep, but an adequately rested horse requires at least 25 minutes of REM sleep per day, which can only happen while lying down, Matlock said.Related mysteries—Why do we still measure things in horsepower?
—Can any animal survive without sleep?
—How long can you go without sleep?
Because of this, horses must lie down every day. If they don’t, they may experience sleep deprivation, which can be a serious health risk for a horse. For instance, putting it at risk of injury from falling, according to the American Association of Equine Practitioners. “Horses that don’t get enough REM sleep can be misdiagnosed with narcolepsy,” Matlock said. “Like, they might fall over while you’re riding them.”
Because standing while sleeping is an adaptation to avoid predators, horses need to feel comfortable and safe before they are willing to lie down and sleep, Matlock said. In feral horse populations, if multiple horses lie down to get REM sleep at the same time, there will always be at least one horse that remains standing, likely to watch for potential predators.
“If they don’t feel safe in their environment, or they don’t have other horses with them, or if they’re isolated, then they’re less likely to feel safe enough to lay down to sleep,” Matlock said.
Nissan is set to announce a leap in its cost-cutting plans that will see 20,000 jobs go globally, according to reports in Japan.
The carmaker, which employs around 6,000 workers at its sprawling manufacturing operations in Sunderland, had already let it be known last November that 9,000 roles would be going amid weak sales and rising costs.
But Japanese broadcaster NHK said on Monday it expected that total to more than double.
Nissan, which was yet to comment on the claim, is due to reveal full year results covering the 12 months to March on Tuesday morning.
They are expected to show a net loss of up to £3.8bn due to a series of writedowns on the value of its operations.
They will be the first results Nissan has declared since the appointment of a new chief executive last month.
More on Nissan
Related Topics:
Ivan Espinosa issued a “significant” downgrade to Nissan’s outlook just three weeks ago.
If the job cuts report is true, it would amount to a 15% reduction in the company’s worldwide workforce.
Image: New models of the Nissan Juke being assembled at the Sunderland plant. Pic:PA
It is not known if the Sunderland production facilities form part of any planned job cuts or production reductions, of up to 20%, that were reported.
Nissan has, on several occasions since Brexit, called the plant’s future into question before proceeding with investment plans.
It has invested £2bn in Sunderland since 2023 alone.
The company secured UK government money this year for a new electric powertrain manufacturing facility in Sunderland.
But a senior Nissan executive, Alan Johnson, warned more aid was needed just last month, arguing that the UK was “not a competitive place” to build cars.
Nissan, like rivals, is facing challenges on many fronts.
Sir Keir Starmer has promised to bring down migration numbers by tightening up the rules on those allowed to come to the UK.
The prime minister promised his new plan will reduce net migration – the difference between immigration and emigration – by the end of this parliament in 2029.
Details of the plans have been published in a white paper, a government document that outlines policy proposals before being introduced as legislation.
Sky News has combed through the white paper to bring you the details.
Language requirements
All visa routes will require people to have a certain level of English proficiency.
More from Politics
People coming with the main visa holders – dependents – will also have to have a basic understanding of English, which they currently do not.
The level of proficiency needed depends on the visa, with a skilled worker visa requiring at least upper intermediate level. Currently, it requires just an “intermediate” level.
To extend visas, people will have to show progression in their English.
Image: Keir Starmer announced the changes at a podium with ‘securing Britain’s future’ on the front. Pic: PA
Settled status
Currently, people have to live in the UK for five years before they can gain settled status.
Under the new plan, they will have to live in the UK for 10 years.
However, “high-contributing” individuals such as doctors and nurses could be allowed to apply for settled status after five years.
A new bereaved parent visa will be created so those in the UK who have a British or settled child that dies can get settled status immediately.
Settled status gives people the right to work and live in the UK for as long as they like, and provides them with the same rights as citizens, such as healthcare and welfare and the right to bring family members to live in the UK.
People with settled status can then choose to apply for British citizenship.
Please use Chrome browser for a more accessible video player
1:51
Sky’s Sam Coates questions PM on migration
British citizenship
People can qualify sooner for citizenship by contributing to UK society and the economy, like settled status.
The Life in the UK test will be reformed.
Social care visa
This visa, which allowed care workers to come to the UK due to a shortage, will not exist anymore.
There will be a transition period until 2028 when visa extensions and switching to the visa for those already here will be allowed.
Please use Chrome browser for a more accessible video player
2:09
‘We risk becoming an island of strangers’
Skilled worker visa
People wanting to come to the UK on a skilled worker visa must now have at least an undergraduate university degree. The minimum was previously A-levels.
There will also be tighter restrictions on recruitment from overseas for jobs with “critical” skills shortages, as well as strategies to incentivise employers to increase training and participation rates in the UK.
Very highly skilled people, in areas the government identifies, will be given preferential access to come to the UK legally by increasing the number of people allowed to come through the “high talent” routes such as the global talent visa, the innovator founder visa and high potential individual route.
A limited pool of refugees will be allowed to apply for employment through the skilled worker route.
Image: Skilled worker visas will now require at least a university degree, with preferential access for highly skilled people. Pic: PA
Study visas
People on graduate visas will only be allowed to remain in the UK for 18 months after they finish their studies.
Currently, students finishing degrees can stay for two years if they apply for the graduate visa, or those finishing PhDs can stay for three.
Institutions sponsoring international students will have their requirements strengthened, with those close to failing their sponsor duties placed on an action plan and limits imposed on the number of new students they can recruit.
Sponsors, who can cover tuition fees and living costs, include overseas governments, UK government scholarships, UK government departments, UK universities, overseas universities, companies and charities.
Humanitarian visa
The Ukraine, Hong Kong and Afghanistan humanitarian visa routes will remain.
However, the government will review the effectiveness of sponsorship arrangements for those schemes so businesses, universities and community groups can “sustainably” sponsor those refugees.
Image: The government will continue to support humanitarian visas, such as the Afghanistan one after the Taliban took over Kabul in 2021. Pic: AP
Domestic worker visa
To help prevent modern slavery, the government will reconsider this visa, which currently allows foreign national domestic workers to visit the UK with their employer for up to six months.
Businesses
Companies wanting to bring people from abroad to work for them in the UK will have to invest in the UK first.
To prevent exploitation of low-skilled workers on temporary visas already in the UK, the government will look at making it easier for workers to move between licensed sponsors for the duration of their visa.
The right to family life
A growing number of asylum seekers have used the “right to family life” – Article 8 of the Human Rights Act – to stop their deportation.
Legislation will be introduced to “make clear it is the government and parliament that decides who should have the right to remain in the UK”.
It will set out how Article 8 should be applied in different immigration routes so “fewer cases are treated as ‘exceptional'”.
Image: A group of migrants was brought into Dover by Border Force as the PM announced immigration changes. Pic: PA
Foreign national offenders
The Home Office will be given powers to more easily take enforcement and removal action, and revoke visas in a much wider range of crimes where people did not serve jail time in other countries.
Deportation thresholds will be reviewed to take into account more than just the length of their sentence, with violence against women and girls taken more seriously.
Enforcement
Sir Keir said the immigration rules – at the border and in the system – will be more strongly enforced than before “because fair rules must be followed”.
People who claim asylum, particularly after arriving in the UK, where conditions in their home country have not materially changed, will face tighter controls, restrictions and requirements where there is evidence of abuse of the system.
Other governments will be made to play their part to stop their nationals coming to the UK, or from being returned.
Sponsors of migrant workers or students abusing the system will have financial penalties or sanctions placed on them, and they will be given more support to ensure compliance.
People on short-term visas who commit an offence will be deported “swiftly”.
Scientific and tech methods will be explored to ensure adults coming to the UK are not wrongly identified as children.
eVisas, which have now replaced physical documents, will help tackle illegal working and support raids on those overstaying their visas or on the wrong visa.
Major banks are legally obligated to refuse current accounts to individuals suspected of being in the UK illegally and to notify the Home Office. This will be extended to other financial institutions.
Hamas has released Edan Alexander, an Israeli soldier who holds American citizenship, as part of ongoing efforts to achieve a permanent ceasefire with Israel.
The 21-year-old was believed to be the last living American hostage in Gaza.
In a statement, Hamas said: ” The Izz ad-Din al-Qassam Brigades released the captured Israeli soldier, Idan Alexander, a US citizen, a short while ago, following contacts with the US administration. This comes as part of the efforts being made by mediators to achieve a ceasefire, open the crossings, and allow aid and relief to reach our people in the Gaza Strip.
Image: Edan Alexander. Pic: Hostages and Missing Families Forum via AP
“This step comes after important contacts in which Hamas demonstrated positivity and high flexibility.
“We affirm that serious and responsible negotiations achieve results in the release of prisoners. However, continuing the aggression prolongs their suffering and may kill them.
“We affirm the movement’s readiness to immediately begin negotiations to reach a comprehensive and sustainable ceasefire agreement, including the withdrawal of the occupation army, the end of the siege, a prisoner exchange, and the reconstruction of the Gaza Strip.
“We urge the Trump administration to continue its efforts to end this brutal war waged by the war criminal Netanyahu against children, women, and defenceless civilians in the Gaza Strip.”
Mr Alexander was transferred to Israel Defence Forces via the Red Cross.
Image: A sign outside a Jewish community centre in Edan Alexander’s home town of Tenafly, New Jersey. File pic: Reuters
An IDF statement said: “The returning hostage is currently being accompanied by IDF special forces on his return to Israeli territory, where he will undergo an initial medical assessment and meet with his family.
“The commanders and soldiers of the Israel Defense Forces salute and embrace the returning hostage as he makes his way home to the State of Israel.
“The IDF Spokesperson’s Unit asks everyone to respect the privacy of the returning hostage and his family.”
Mr Alexander’s parents, who live in the US, made the journey to Israel ahead of the expected release.
The family said they were deeply grateful to US President Donald Trump and his administration for its work to secure the release – and have urged the Israeli government to continue efforts to free all hostages.
Mr Alexander, who is from New Jersey, was 19 when he was taken from his base on the border with Gaza in southern Israel during the Hamas attacks on 7 October 2023.