Tuesday 25 September 2018

Nautilus


The nautilus (Nautilus pompilius) is a remarkable creature that is regarded as a “living fossil” because it closely resembles animals that lived in the oceans between 400 and 65 million years ago. Six species of nautilus have survived to the present day, with that in the photo living in the western Pacific Ocean and in open waters around Indonesia and southeast Asia. It is found at depths up to 500 metres (1,650 feet).
The shell protects the nautilus from predators and buoyancy is provided by gas trapped in the inner chambers. It swims by using jet propulsion – water is taken into the shell cavity and expelled through a tube which can be directed to propel the nautilus in the required direction.
The head sticks out of the shell and has up to 90 tentacles that are used to trap prey that includes shrimps. The eyes of the nautilus are very primitive, being without lenses and working like pinhole cameras.
The nautilus only becomes sexually mature after about ten years, and then produces as few as twelve eggs per year. Having survived for so long, the species has clearly found an environmental niche that presents few dangers and allows for a slow rate of reproduction.
© John Welford

Monday 24 September 2018

Box jellyfish



You would not want to get too close to a box jellyfish (Chironex fleckeri). It is thought to be one of the most venomous creatures to exist in the oceans and it can kill a person in only a few minutes. 

Fortunately for most of us, it is mainly confined to waters to the north of Australia and eastern Indonesia, but it is plentiful enough at certain times of the year (November to April in northern Australia) to make it necessary to close beaches to the public. 

It is only a small creature – up to 25 cms (10 inches) in size – but its tentacles can extend up to three metres (10 feet) in length. It is possible to be stung without even seeing the jellyfish itself. Its prey is prawns and small fish that swim in shallow water. 

The name comes from the box-shaped transparent body, from each corner of which hangs a bunch of 15 tentacles. The flattened sides of the box contain sense organs that include remarkably complex eyes. 

Should a swimmer be unfortunate enough to be stung, and not be able to get hold of antivenom, the least he or she can expect is excruciating pain and skin damage that can leave permanent scars. Heart failure is entirely possible, as is drowning following loss of consciousness. 

Despite the extreme dangers presented by contact with this animal, some sea turtles are able to eat box jellyfish without suffering any harm.

© John Welford

Wild liquorice




Wild liquorice (Astragalus glycyphyllos) has the alternative name of milk-vetch, from the former commonly held belief that goats that ate the plant would yield more milk.

It grows in scattered location in Great Britain, in rough grassy places on chalk and limestone, but is absent from Ireland. It is a temperate plant that is also found across much of northern and central Europe as far east as the Caucasus.

Wild liquorice is difficult to spot because it often grows among tall grasses and its greenish-cream flowers blend with the colour of its foliage. 

It is a straggling plant that can grow up to 40 inches (100 cm) in height. It has smooth, trailing stems and many hairless leaflets. The stems bend each time they give rise to a leaf, which makes them zigzag. 

The plant flowers in July and August, many flowers being carried on stalks that are shorter than the leaves. The pods are smooth and curved, with a central division such that several seeds are produced on each side of the “wall”.

Wild liquorice is not the plant from which laxatives and food flavourings are produced. However, the root stems of both wild and true liquorice can be chewed – the botanical name glycyphyllos means “sweet stem”.

© John Welford

Monday 10 September 2018

Water monitor lizard




The water monitor is one of the largest lizards that ventures into salt water. It inhabits low-lying coasts, rivers and estuaries in south-east Asia, Indonesia and The Philippines.

It grows up to 2.7 metres (9 feet) in length and weighs up to 35 kg (75 lbs). It has a long neck, strong legs and a flattened tail that it lashes from side to side in the water.

The water monitor is a predator with a wide-ranging diet, feeding on anything that it can overpower, either onshore or in the water. In common with other monitors, the water monitor will also feed on carrion.

Water monitors are sometimes seen near human habitations, where they scavenge on discarded food waste.

The water monitor lays eggs which the female places at the end of a burrow.

© John Welford

Blackfin icefish



The blackfin icefish is a remarkable creature that is able to live in the coldest waters to be found on Planet Earth. It inhabits the coastal seas on the Atlantic side of Antarctica, where the temperature can fall to -2°C (28°F). It is found at depths of up to 770 metres (2,500 feet) below the surface.

These conditions would freeze the blood of most fish, but the blackfin icefish has its own natural antifreeze. It appears to be ghostly white, which is due to not having any red blood cells. This makes the blood thin enough to flow in very cold temperatures.

The blackfin icefish grows to 72 cms (28 inches) in length and weighs up to 3.5 kg (7.5 lbs). 

It is a sluggish swimmer that needs little oxygen. Its food consists of krill and small fish.

© John Welford

Friday 7 September 2018

Sainfoin



Sainfoin (Onobrychis viciifolia) is often seen on chalk and limestone grassland in southern England, although it is almost certainly not a native plant, having been introduced from central Europe where it was traditionally used as fodder for cattle. The name comes from French – “sain” meaning “wholesome” and “foin” meaning “hay”. It has also been thought that a mythical Saint Foyne might have been responsible for the name.
Sainfoin was mentioned by Nicholas Culpeper, the 17th-century herbalist, as an aid for nursing mothers, based on the plant’s supposed effect on increasing the milk yield of cows. 
Another former medical use for sainfoin was to treat “stranguary” – a painful bladder disease. The leaves were sometimes used as a poultice for reducing boils or they could induce sweating if pulped and mixed with oil.
Sainfoin is an upright, often branched, plant, growing to a height of up to 32 inches (80 cms). The leaves consist of 6-14 pairs of leaflets with a terminal leaflet. 
The flowers appear from June to August. They are bright pink or red, often with purplish veins, carried in conical spikes. Sainfoin is sometimes called “cock’s comb” or “cock’s head”, which refers to the plant’s spiny toothed seed pods. Each pod contains a single seed and it does not split open.
© John Welford

Thursday 6 September 2018

Kidney vetch



Kidney vetch (Anthyllis vulneraria) favours dry grassland habitats, either on chalk downland or close to coasts. It is common throughout Great Britain. It is a plant that has many local names, including “fingers and thumbs” and “lamb’s foot”. In Yorkshire, East Anglia and Dorset it is known as “lady’s finger” after its silky, finger-like bracts – small leaves that appear just below the flower-heads.

In the Middle Ages the plant was regarded throughout Europe as a medicinal herb, particularly for healing wounds – hence the botanical name “vulneraria”, from the Latin “vulnus”, meaning a wound. 

It was called kidney vetch due to the old superstition that a plant that looked in part like a part of the human body must have been so designed by God as a hint that it had a beneficial role in treating ailments of that part of the body. In this case the kidney-shaped flowers were a clue to the plant’s supposed ability to cure kidney diseases.

Kidney vetch grows more or less upright to a height of up to 24 inches (60 cms). The stems and leaves have a silky feel. On each leaf stem the terminal leaflet is much larger than the rest. 

The flower-heads, which appear between June and September, are carried on long stalks with leaf-like bracts beneath them. The kidney-shaped flowers, which can be yellow, orange, red or purple, are a rich source of nectar but the stiff petals are too heavy for many small insects to open, so the rewards are mainly on offer to bumble bees.

The flowers go brown as they fade, after which the seed pods are enclosed by the purple-tipped woolly sepals.

Kidney vetch is a food plant of the small blue butterfly.

© John Welford

Tuesday 4 September 2018

Common pipistrelle bat



The common pipistrelle (Pipistrellus pipstrellus) is the smallest and commonest bat found in the United Kingdom. 

The pipstrelle weighs between 3 and 10 grams and has a wingspan of 15-25 cms. 

The body is covered in brown fur. They have large black ears and narrow wings that are actually membranes stretched between elongated fingers. Strong claws on the feet enable them to hang upside down when roosting. 

During summer months, pipistrelles can often be seen swooping and diving in a characteristically jerky flight during the late evening over gardens as they feed on flying insects such as moths. A single bat can eat as many as 3,000 insects in one night. 

Pipistrelles roost in buildings, being able to squeeze through narrow gaps to find dry and sheltered spots. 

Female pipistrelles give birth in Autumn. In the UK it is usual for them to raise only one young, but twin births are more common in continental Europe.
 


© John Welford

Scorpion fly



There is no surprise about how the scorpion fly (Panorpa communis) got its name. However, this little monster presents no danger to any living creature, with the swollen scorpion-like tail – which only males possess – only being used during mating.
Scorpion flies are found in gardens, hedges and woodland, where they feed mainly on dead insects. They have strong mouthparts that enable them to bite through tough skins.
They are about 1.5 cm ling with a 3 cm wingspan. Their long thin wings have dark markings. They also have long antennae.
The larva of the scorpion fly resembles a caterpillar.
Although the scorpion tail might give the impression that the female fly is at risk during mating, it is actually the male whose life is at stake, given the female’s predilection for eating her mate given half a chance. A male scorpion fly will offer the female a gift of a drop of saliva in the hope of living to tell the tale.
© John Welford

Sunday 2 September 2018

Bird's-foot



Bird’s-foot (Ornithopus perpusillus) gets its name from its slightly curved, pointed pods, which could be seen as resembling bird’s claws. 

It is common throughout Britain, apart from the far north, preferring well-drained sandy or gravelly soils. Although it is a native British species, bird’s-foot is more common in continental Europe as far east as Poland and as far north as southern Sweden.

Bird’s-foot grows up to 18 inches in height (45 cms). 

The stems, some of which sprawl along the ground, have fine hairs. The leaves are split into pairs of leaflets, with a single leaflet at the tip. The first leaflets are often close to the stem and curved backwards.

Bird’s-foot flowers from May to August, with each flower-stalk carrying several small blossoms. The flowers, which are white with red veins, normally pollinate themselves. A characteristic feature of bird’s-foot is a leaf-like bract that grows immediately below the cluster of flowers.

Bird’s-foot is a member of the pea family and produces its seeds in curved pods. However, the pods are segmented with one seed per segment. When ripe, the pods break apart one segment at a time.

 © John Welford