Violet fritillary butterfly

The violet fritillary butterfly (Boloria dia) is one of the smallest fritillaries, its wingspan being up to 3.4 centimetres. It is found quite commonly in central and eastern Europe but only in local populations further south. It inhabits forest edges, open woodland and meadows on low hillsides, reaching no higher than 1000 metres.

It is light orange-brown with black spots. The underside forewings are similar but paler, but the hindwings are purple-brown with white spots. Males and females look similar.

The flight period is from mid-spring to early autumn, during which up to three broods may be produced.

The food plants are violets and brambles.

© John Welford

Ostrich dinosaurs

The name “ostrich dinosaur” has been given to a group of creatures that lived during the late Cretaceous period (110-66 million years ago), in what is now North America and Asia. The proper name for the group is Ornithomimosaurs. They acquired their popular name because of their resemblance to modern ostriches in their size and overall shape.

They were tall and slim with powerful hind legs that would have allowed them to run fast. The front limbs worked like arms with fingers and sharp claws that could grasp their food. They had beak-like toothless mouths that would also have made them look like modern flightless birds.

One ostrich dinosaur was Struthiomimus which would have been four metres long and two metres tall. Fossils have been found in Alberta, Canada. Others were Gallimimus (8 metres long), Dromiceiomimus (3-4 metres) and Ornithomimus (4-5 metres, see picture) which could probably run at up to fifty miles an hour.

This class of dinosaurs would have eaten seeds and fruits, plus worms, lizards and other small animals.

© John Welford

Gorillas: nothing like King Kong!

Most people have two persistent images that they bring to mind when gorillas are mentioned. One is the fierce monster swatting planes at the top of the Empire State Building in the 1933 film King Kong; the other is the British naturalist David Attenborough being received hospitably by a family of gorillas in the Rwandan rain forest in his “Life on Earth” series broadcast in 1979.

So which image is closer to the truth? It should come as no surprise to learn that 1970s reality beats 1930s Hollywood every time! The gorilla’s reputation for ferocity is based on very shaky evidence.

The name “gorilla” goes back as far as 480 BC when a Carthaginian named Hanno used it for a human tribe that were noticeably hairy. It was applied to the animal only after 1847 when Thomas Savage, an American missionary working in West Africa, acquired a gorilla skull and heard stories about huge apes from local people. According to them, the skull would have belonged to “a monkey-like animal, remarkable for its size, ferocity and habits”. It would appear that he was treated to some fearsome stories about these creatures, which he had no reason to disbelieve although he never set eyes on a live gorilla himself.

Thus, when Thomas Savage took his gorilla skull back home and the newspapers got to hear about it, popular imagination was fired about the fierce creatures that terrorised the African jungle and were mercifully absent from the fauna of the United States. It was stories about African gorillas – read in childhood – that inspired the film producer Merian C Cooper to create a monster that he named “King Kong” and which only reinforced the public perception of what gorillas were like.

However, real gorillas are very different from King Kong! They are vegetarians that live on a diet of green plants and bark. They have huge stomachs to house the large intestinal tract needed to digest the enormous amounts of food that they need to eat each day, given that jungle grass is not particularly nutritious, and their large heads contain the powerful jaw muscles with which they have to chew their food for many hours every day.

That said, the food is plentiful and gorillas do not need to be in competition with each other for food supplies. A male “silverback” maintains a harem of females who occupy a relatively small territory in which they spend most of their time eating and sleeping.

It is, however, true that male gorillas will challenge each other when it comes to controlling harems of females. When a young male seeks to become “alpha” there will be a lot of posturing and noise from roaring and chest-drumming. However, there is usually little or any fighting, because the male who shouts louder and is physically larger will nearly always win the day by intimidation alone.

A visiting human is far more likely to be in danger if he or she is seen by a female gorilla to be a threat to her young, and that is true of most wild mammals.

Gorillas are gentle giants that deserve to be left in peace.

© John Welford 

Sea snakes

Sea snakes are found in the Indian and Pacific Oceans and are of two quite distinct types. There are aquatic sea snakes and amphibious sea snakes. The former spend all their lives in the sea whereas the latter, which are also known as sea kraits, can come ashore; they have wide scales on their bellies that enable them to slither on land.

Aquatic sea snakes are viviparous, which means that they give birth to live young. Amphibious sea snakes lay eggs on land.

Sea snakes are reptiles, which means that they have to come to the surface to breathe, unlike fish. However, they are able to absorb a certain amount of oxygen from the water they swallow. They also have valves on their nostrils that close when they dive into deeper water.

Sea snakes feed on fish, eels and fish eggs. They are extremely venomous (their venom is ten times as deadly as that of most land snakes) and they use that venom to stun their prey before swallowing it whole.

The illustration is of a banded sea snake, which is one of the amphibious breeds.

© John Welford

Picture credit: Julie Bedford. Licensed under the Creative Commons Attribution 2.0 Generic licence.

Spotted medick

Spotted medick (Medicago arabica) is found in the south and east of England, mainly in grassy environments such as pastures. It is otherwise known as Calvary clover, from an old folk belief that the dark spots seen on its leaves were caused by Christ’s blood falling on a specimen of the plant that was growing at the foot of the Cross.

The plant grows to a maximum height of 24 inches (60 centimetres) although many stems trail along the ground. The leaves grow as sets of three leaflets, which might lead to people mistaking the plant for a kind of clover. The dark spots are seen most easily as the leaves age and start to turn brown.

Small bright yellow flowers appear on stalks between April and August. These are replaced by pods that coil into a spiral that has a double row of spines. These enable ripe pods to be pulled off the plant and carried some distance on the legs and flanks of passing animals.

When on the ground, the pod does not split open to release the seeds. Instead, one of the seeds will germinate inside the pod and send a shoot through the pod’s wall to find soil in which to root itself. The rest of the pod will often remain attached to the new plant as it grows.

© John Welford

Ornitholestes

Ornitholestes was a meat-eating coelurosaur dinosaur that lived around 155 million years ago which is towards the end of the Jurassic period. This was about the time that the first birds were appearing, having evolved from reptiles, and the name Ornitholestes means “bird robber” because it was originally supposed that the animal preyed on early birds and their nests. However, this is unlikely given that birds were evolving in what is now Europe and the very rare fossils of Ornitholoestes have only been found in what is now the state of Wyoming.

Ornitholestes was no great size, being only about two metres (six feet) from nose to tip of tail. It would therefore have relied on its speed for catching its prey and escaping from larger predators. It may also have developed keen senses of sight and smell for the same purposes.

Ornitholestes had small sharp teeth and strong arms that ended in long claws. These suggest that the animal might have preyed on the young of other dinosaur species, possibly grabbing them as they hatched from their eggs and making off at speed when the parents realised what was happening. The “robber” part of the name was therefore quite likely to have been appropriate, although the eggs and young being attacked were not those of birds!

© John Welford 

Lucerne

Lucerne (Medicago sativa) is a plant that grows wild throughout Great Britain although it is a non-native species (of Mediterranean origin) that started off as a “tame” one but escaped.

Lucerne is otherwise known as alfalfa, and it has uses as a fodder crop due to its high protein and vitamin content. Farmers have traditionally used lucerne to improve the productivity of their land, because the roots develop small nodules that “fix” nitrogen. This means that nitrogen is taken from the air and transferred to the soil where it becomes an essential plant food.

Wild lucerne grows as a bushy plant up to 36 inches (90 centimetres) high. The leaves split into three leaflets that are toothed towards the ends. The plant flowers in June and July, with the purple (sometimes yellow) flowers clustered near the stem tips.

The flower has an interesting mechanism for achieving pollination. The stamen (male) and stigma (female) parts of the flower are tensioned such that when a bee (or other heavy insect) lands on a flower, the stigma springs up and hits the bee, thus being able to collect any pollen that the bee was carrying. Likewise, the stamen deposits more pollen on the bee that it then carries to the next flower.

The seed pods coil into spirals, each containing many seeds. It is possible to make a salad garnish from lucerne/alfalfa seeds by allowing them to sprout in a glass jar and eating the seedlings, which have a nutty flavour.

© John Welford