VICUNAS BREATHE EASY IN THE MOUNTAINS

 

Vicuñas live high in the Andes  mountains of South America yet are never short of breath. At about 4,000 m (13,000 ft) above sea level humans would suffer breathlessness, but vicuñas can sprint effortlessly up rocky slopes, and on level ground they can run at nearly 50 km/h (30 mph).

These graceful cinnamon-coloured relatives of camels have normal mammalian lungs, but they have about three times as many red blood cells a litre of blood as humans. Their red cells last twice as long and because these cells contain an unusual form of

the red blood pigment haemoglobin, they are better at collecting oxygen. Altogether, it adds up to an ideal high- altitude breathing system.

HIGH-FLYER MAKES USE OF PANORAMIC VIEW

Soaring above the open plains of Africa, Rüppell's griffon flies higher than any other bird. In 1973, a griffon collided with an aircraft finest flying at more than 11,000 m (36,000 ft) which is high enough to fly over Mt Everest. At these heights, the bird has a vast panoramic view, and it can easily cover more than 150 km (95 miles) a day in search of food. But at altitude even the long-sighted griffon has difficulty picking out tiny details on the ground, so it watches other vultures flying beneath and is quick to follow them if they spot a meal.

To survive at such altitudes the griffon vulture needs some of nature's  finest engineering. Its ultra-efficient lungs allow it to get enough oxygen to ugh to breathe, and its giant wings provide it with lift in the thin air.

GIANT WINGS A griffon vulture's wings can be 2.8 m (9 ft) from tip to tip. This huge wingspan is supported by a lightweight bone structure.

MARMOTS SETTLE IN FOR THE BIG SLEEP

MARMOTS SETTLE IN OR THE BIG SLEEP

IN America, northern Europe, and central Asia, mountain-dwelling marmots spend most of their time pported in hibernation. They sleep for up to nine months each year. By hibernating in winter, animals avoid futile foraging trips when nature's larder is bare. For most animals, this dormant period lasts for three to five months,

Where marmots live, however, winters can be hard and very long Rather than wake up prematurely, they sleep on until May or June, tucked away in long networks of underground burrows. They survive on fat reserves, which make up a fifth of their body weight. When summer finally arrives, marmots have to collect food, raise a family, and fatten up for their next hibernation, all within three months.

SUMMER HARVEST Marmots need to put on weight in summer because food is so scarce during their record. breaking hibernation.