动物奇葩睡眠习惯：海獭睡觉手牵手

From sleeping standing up to shutting down half of their brain, animals have some strange sleeping habits.
动物们有一些奇特的睡觉习惯，有的站着睡觉，有的一半大脑休息。

Now some of these more unusual habits, from napping giraffes to birds that sleep while flying, have been revealed in an infographic.
现在一些更不寻常的睡觉习惯已经用信息图表展示出来了，从打瞌睡的长颈鹿到边飞边睡的鸟类都有记录。

The chart maps the liveliest to the idlest creatures to reveal that Little brown bats are most lethargic, sleeping for around 19.5 hours a day.
图表展示了从最活泼的动物到最懒惰的动物，其中小型棕蝙蝠是最嗜睡的，一天大概睡19.5小时。

This long period of sleep is thought to be a way of conserving energy and means they only hunt for a few hours each night when their insect prey are available.
这样长时间的睡眠被认为能够保存能量，这意味着每天晚上它们只有几个小时在捕捉昆虫。

In contrast, giraffes can go weeks without sleep and when they do grab some shut eye, it’s never for more than five minutes.
相比之下，长颈鹿可以几个星期不睡觉，它们真正闭上眼睛的时间也不会超过5分钟。

This is because being large and slow moving giraffes are constantly vulnerable to attacks from predators, and therefore can’t sleep for long periods.
长颈鹿因为体积大，移动不方便，所以容易受到食肉动物的攻击，因此睡眠时间不长。

Adult giraffes sleep standing up in short bursts, but keep watch on their young which lie down to sleep, tucking their long legs underneath their bodies and curling up like a cat.
成年长颈鹿站着小睡时也会照看躺下睡觉的幼崽。幼崽把长腿弯曲在身子下面，像猫一样缩成一团。

However, other animals are experts at multitasking and can swim or fly while sleeping.
还有其他一些动物擅长同时进行多项活动，边游边睡或者边飞边睡。

As well as exotic beasts, the chart features pets such as domestic cats (shown above) which sleep for approximately two thirds of their lives and take extra naps when it's raining or if they're bored
除了一些奇异的野兽，图表也突出展示了一些宠物，例如家猫，它们一生中大约三分之二的时间都在睡觉，下雨或者无聊的时候也会睡一小觉。

For example, dolphins and whales sleep while keeping half of their brain alert, so they don’t drown, with dolphins typically dozing for around 10 hours a day.
例如，海豚和鲸鱼睡觉时会保持一半大脑清醒，所以它们不会淹死，海豚通常一天会睡10个小时左右。

The method is known as ‘logging’and it has been observed in bottlenose dolphins, which keep half of their brain a low level of alertness.
这种方法称为“运行记录”，在宽吻海豚身上就能观察到这一点，它们能使一半大脑保持较低的警觉性。

This allows the dolphin to retain enough consciousness to carry on breathing through its blowhole.
这使海豚能保留足够的意识去通过喷水孔呼吸。

While sea otters aren’t alert while they sleep, they form rafts to they don’t drift away from each other.
然而海獭睡觉时并不警觉，他们彼此手牵手，这样就不怕在睡梦中被海浪冲散了。

The creatures sometimes hold hands, or paws, when they sleep and typically eat, sleep and rest while floating in groups called rafts.
这种动物睡觉时有时手拉手，有时爪牵爪，通常成群结对像竹筏一样漂在水上吃、睡和休息。

These can range in numbers from a handful to hundreds of otters.
海獭的群体数量从几只到几百只不等。

Migrating birds can sleep while flying, with some drinking and napping during epic journeys that last for six months.
候鸟能边飞边睡，在持续六个月的迁徙过程中伴随着饮水和小睡。

Scientists recently have found that migrating birds, such as the Alpine swift, can fly for 200 days without stopping.
科学家最近发现了高山雨燕等候鸟能够在空中持续飞行200天。

The bird’s activity appeared to rise and fall during flight in a 2011 study, leading experts suggest that they control their wings while flying.
2011年的研究显示这种鸟飞行期间忽高忽低，由此，专家表示它们飞行时能够控制翅膀。