Tuesday 12 January 2016

Puff adders have some sort of scent camouflage to stop them being detected.

The African Puff adders, scientifically known as Bitis arietans, hunt by ambushing their prey. When annoyed, they often emit a hiss or puff sound – hence their name. The snake's main predators include honey badgers, warthogs, some larger birds and other snakes.

Puff adders catch prey by remaining motionless until it approaches within striking range. They can stay still for days. Since they are in this position for a long time above ground it should make them easy for predators to find using their sense of smell.  

However, researchers from the University of the Witwatersrand  discovered that the snakes have evolved an impressive visual and chemical camouflage that makes them virtually impossible to detect. They spent three years radio tracking 30 puff adders to see how effective their scent camouflage is in combination with their natural markings.

When dogs and mongooses, which have no problem in smelling other types of snakes, were released near the puff adders they were almost completely unaware of them, on occasion actually stepping on them and walking over them.

The puff adders, surprisingly, remained motionless, relying on their colouration and lack of obvious smell to protect them. This appears to be an adaption as a result this habit of keeping still, even when threatened.

Puff adders are usually only aggressive when they are on the move, presumably because they have given their presence away at that stage.

I wouldn't recommend testing it out though.

Tuesday 5 January 2016

New marine reserve around Ascension Island in the Atlantic ocean

The UK government is to create a marine reserve almost as big as the UK in the  waters of Ascension Island in the middle of the Atlantic ocean.

Just over half of the protected area will be closed to fishing. It is the latest marine reserve to be declared around remote islands, which will increase marine conservation zones to about 2% of the ocean. This is still much less than  the 30% recommended by scientists to preserve species and expand fish stocks, but is a step in the right direction.

Various governments have designated marine parks at Palau in the North Pacific, Easter Island
and Pitcairn in the South Pacific, and New Zealand's Kermadec islands, in what has become a
landmark year for ocean conservation.

The latest reserve at Ascension Island is said to hold some of the largest marlin in the world, one of the largest populations of green turtles, which breed there, big colonies of tropical seabirds and the Ascension frigate bird. The bird has brownish-black plumage and a deeply forked tail. It has a wingspan of around 2 m (6.6 ft). The male has a striking red gular sac which it inflates to attract a mate. They feed mainly on Flying fish.

The reserve totals 234,291 sq km, slightly less than the size of the United Kingdom. It could
be ready by 2017, once further data has been collected and analysed.