A carob tree is either male or female and when it flowers the male tree needs an insect to transfer the pollen to the flowers of a female tree. Nothing unusual in this because the majority of flowering plants make use of insects to ensure that pollination takes place. 

Carob trees rely on flies. They attracting by producing a strong scent of rotting vegetation which can be smelt from several metres away. Flies are probably equipped to detect the odour from further away than we can.

When a fly lands on a male flower it starts walking about and in the process ends up with the carob’s pollen attached to its body. If it visits the flowers of a female tree some or all the pollen grains on its body are detached and if they are in the right spot fertilise the flower.

Not all plants rely on animals for pollination. About ten percent of all flowering plants rely on physical factors such as wind. Wind pollination is mainly used by grasses and conifers. Most aquatic plants depend on the surrounding water to transfer their pollen.

Together plants make use of at least 200,000 species of animals to pollinate them. They cannot rely on chance for an insect to land on them so they have evolved special traits to attract them.

Most flowers have coloured petals that make the flowers more visible to insects.

Many petals have patterns which are only visible under ultraviolet light. Humans cannot see UV light and what looks like a mono-coloured petal to us looks like an airport runway to an insect with lines which lead the bees to their nectar and pollen.

Night-flowering plants usually have large white flowers which are shaped like a funnel. They are usually strongly scented flowers to attract bats and moths.

Plants that are pollinated by birds are usually red and do not produce any scent as most birds have a weak sense of smell.

Plants that are visited by a wide variety of insects often risk wasting their pollen as after visiting a flower of a particular species an insect might visit the flower of another species. Some plants, such as the orchids, have become specialised to attract just one species of insect.

Bees, of which the honey bee is but one of thousands of species, are the most important pollinators of cultivated plants. It has been estimated that thirty percent of the food that we need depends on honey bees for pollination and if honey bees were to disappear we would find it very difficult to find produce enough food.

This article was published on 4 December 2014, 

In search of mushrooms

This is the best time of the year to visit the countryside in search of fungi. Armed with a simple camera one should be able to find a good number of species especially in wooded areas such as Buskett Gardens and Wied il-Luq.

Mid-autumn is a good time to find mushrooms because the soil is wet and the air is still relatively warm.           

                                                                                      

About 100,000 fungi have been identified although it is estimated that there can be up to five million species most of which are still to be identified.

About three hundred species of fungi can be found in the Maltese islands. They grow on a wide range of substrates both in the countryside and on man-made objects.

Most people assume that fungi are members of the plant kingdom. Fungi are sessile, they have what look like roots and reproduce by means of spores. In fact this was the belief until in the late sixties it was discovered that fungi are closer to animals than to plants which led to them being assigned a kingdom of their own.

The cell wall of fungi is composed of chitin. Chitin is the main component of the external skeleton of arthropods such as insects and lobsters and is also found in some mollusc structures. Plants do not produce chitin.

Fungi consist of an array of tiny filaments that look like plant roots, known as hyphae. The hyphae are hidden in soil, wood or other organic material on which the fungus can feed.

The hyphae produce acids and enzymes which digest the food outside the cells. The organic material is broken down into simpler compounds which are then absorbed into the cells.

Fungi can live on a very wide range of living or dead organic material. Fungi play an important role in the recycling of nutrients breaking down dead plants and animals into compounds that can be absorbed and utilised by plants. On the other hand fungi that feed on living plants and animals often cause disease or death.

The mushrooms with which we are familiar are nothing but a fruiting body whose function is solely to produce spores and to release them in air so that they drift as far as possible from the parent fungus. 

This article was published in The Times of Malta on 26 November 2014. 

Beautiful Flamingos

The Għadira Nature Reserve is again open to the public. Those visiting the reserve last weekend had the pleasure of watching two juvenile flamingoes feeding and flying around the protected wetland.

The two flamingoes are the ones that were saved by BirdLife in early September. The two birds were migrating south but probably could not keep up with the rest of the flock and had to land. The first bird landed at Paradise Bay on September 4^th. The second bird was found in a private garden at Birżebbuġa five days later.

In the past few years flamingoes made it several times to the headlines usually because one or more were shot while migrating over the Maltese islands. Flamingoes used to be rare migrants in the central Mediterranean but now we are seeing several flocks every year especially in early autumn.

What we are seeing is the result of new flamingo colonies which are establishing themselves in various wetlands just to the north of Malta in Sicily.

Italian ornithologists, monitoring the island’s birds have, after an absence of many decades, found flamingos breeding again in saline marshes along the south-eastern coast of Sicily.

The ornithologists said that within a year of stricter bird protection laws coming into force and better enforcement the number of species of birds breeding in Sicily increased tenfold.

In Italy hunting is permitted as long as it does not conflict with the needs for the conservation of wildlife and does not cause actual damage to agricultural production. Hunting for most birds is allowed only from the first of October until the end of December. A few species can be hunted from the last Sunday of September and for a small number hunting is allowed till the end of January. No hunting is allowed in spring when the birds are preparing to breed.

Italian legislation, as stipulated by EU Directives prohibits all forms of bird trapping.

Furthermore the law allows the prohibition of hunting of certain species if their populations are declining or if they are threatened by sudden environmental conditions such as bad weather or disease.

In spite of what Maltese hunters say local bird protection legislation is too liberal and furthermore enforcement still leaves much to be desired. Spring hunting and bird trapping are presently the two main threats to Maltese birdlife and the rest of nature. Hunting in spring kills birds returning to breed and every bird shot in spring is a nest less. Moreover the presence of hunters disturbs birds attempting to breed even if these are not shot at.

This article was published in The Times of Malta on 6 November 2014. 

Solid as a rock

In a few localities around the Maltese islands it is possible to find what looks like mounds of reddish-brown soil with stones and pebbles embedded in it. On close inspection one realises that what looks like soil is a solid structure as hard as the surrounding rocks. 

These geological features were formed after the Maltese islands emerged from beneath the surface of the sea were they were formed. One can find such structures among other places at Wied Magħlaq and Pembroke.

The Maltese islands are made up of five layers of sedimentary rock. The oldest layer started to be deposited thirty to thirty five million years ago making the Maltese islands relatively young in geological terms.

The topmost layer, therefore the most recent layer to be formed is known as upper coralline limestone is usually more 150 metres thick. The second layer which is made up of Greensand is absent from many areas and which is nowhere thicker than thirteen metres. This is followed by the blue clay layer underneath which one finds the globigerina limestone which can be as thin as 20 metres in some places and thicker than 100 in others. The oldest layer is the lower coralline limestone which is very similar to the upper coralline limestone and which like it is very thick.

Beneath these five layers are even older layers which cannot be seen without drilling through the lower coralline limestone.

 The emergence of the Maltese islands above the surface of the sea did not mean the end of rock formation.

The rocks which formed after the emergence of the islands from the sea are known as quaternary deposits because they were formed during the quaternary period. This period started just over two and a half million years ago. It s defined by a number of ice ages with warm periods in between. This period is divided into two - the Pleistocene which ended about twelve thousand years ago and the Holocene, the period in which we are living. The Holocene is considered as the most recent interglacial warm period.

During the Quaternary sea levels went up end down depending on the temperature. During Ice Ages evaporated water precipitated as snow and ice and formed thick glaciers leading to lower sea levels. In higher temperatures the glaciers melted and sea levels became higher. The low water level uncovered the sea bottom between Malta, Sicily and the Italian mainland creating a large continuous landmass. T

he weather was also characterised by heavy precipitation and the creation of several valleys which were formed by large amounts of flowing water which carry with them large quantities of sediment and debris including soil, pebbles rocks as well as small and large organisms.

The quaternary deposits were carries down such valleys although it is possible that many of them were formed during the Holocene period. 

This article wsa published in The Times of Malta on 30 October 2014.

The common grass eggar

The grass eggar is a common moth. It can be seen from October to November especially in areas where grasses and plants of the pea family grow. In Maltese it is known as baħrija tas-silla.

The grass eggar belongs to a family of moths known as Lasiocampoidea in which we also find the oak eggar, which is known in Maltese as baħrija tal-ballut and the rare lackey moth which is known in Maltese as malakosoma.

In this family the females are generally noticeably larger than the males a characteristic we find in all three species found in the Maltese islands.

The grass eggar is found throughout Europe, North Arica, and the Near East as far as southern Russia but is missing from high altitudes. In some parts of its range, particularly in Central Europe, it has become endangered because of eutrophication, agricultural intensification, abandonment of grazing areas and fragmentation of habitat. In other parts of its range especially around the Mediterranean it is still common.

In colder countries the moths are seen in the warmer months especially in August and September. Wherever it occurs it prefers nutrient-poor habitats with low-growing grass especially in dry limestone area and thus finds a good habitat in the Maltese islands.

The female lays its eggs on the ground before winter. The eggs hatch when the days start getting warmer and the caterpillars form a cocoon before summer to hatch in autumn.

Like that of the oak eggar, the caterpillar is covered in protective hairs. It feeds on a variety of grasses and plants of the pea family. When the caterpillar is older it tends to change its diet to eat more plants of the pea family.

The closely related oak eggar has a similar life cycle but the adults can be seen flying in August and September. It is common only in the Buskett area.

This article was published in The Times of Malta on 23 October 2014. 

Digging their way out of soil

Autumn marks the appearance of large numbers of fairly large brown beetles with a noticeable horn like that of a rhinoceros on their head. The beetles appear after sunset and disappear before dawn. In some areas these insects concentrate in such large numbers that anybody passing by would find it difficult not to notice them.

This beetle, which belongs to the scarab family known scientifically as Phyllognathus excavatus. This species is found in southern Europe and North Africa and to the east in Asia all the way to Crimea.

They emerge from beneath the soil surface usually in the days following the first rains of the season. After mating they dig their way back into the soil using their shovel-like front legs to dig their way in. by dawn they all disappear except for those which find themselves on a hard surface such as roads and tiled areas.

Once back in the soil the female lays its eggs in rotting vegetation. The eggs hatch after about two weeks and the soft-bodied white larva which emerges grows slowly in the soil taking about two and a half years to reach a length of five centimetres. When it is fully grown it is ready change into a pupa inside which the body of the larva breaks down completely and rebuilds itself into a six-legged winged adult. The whole process is known as metamorphoses.

The scarab family is represented in the Maltese islands by more than thirty species. These include the rhinoceros beetle, known in Maltese as buqarn kbir, the dung beetle known as ħanfusa barri tad-demel  and the chafer called the għawwar dehbi because of its golden coloured body.

In Maltese the general term for beetles is ħanfus. Over the years entomologists have coined descriptive names for the many species that did not have a common name but they seem to have missed giving a name to this species of beetle for which the name ħanfusa tal-qarn seems to be very appropriate.

This article was published in The Times of Malta on 16 October 2014. 

The Painted Lady

The painted lady is a common butterfly. It is found on all continents except South America and Antarctica. It is a notable migrant and in some years tens or hundreds of thousands appear suddenly in the Maltese countryside only to disappear some days later.

In the USA this species is known as Cosmopolitan. In Maltese it is known as farfett tax-xewk.

When resting on the ground with its wings closed the painted lady can be very well camouflaged and difficult to see but it often spends time sunbathing with its dark orange wings open in full view of any predator that happen to be in the vicinity as well as to potential mates.

Adult lives from two to four weeks but during their brief life some manage to travel from North Africa to northern Europe. Spring migration takes place every year but we do not see it annually because the exact route taken is determined by weather and wind direction.

Until recently it was believed that the movement is in one direction only but research is indicating that in autumn there is another migration to the south. The southern movement takes place at very high altitude and is being studied by means of entomological radars. Research has shown that these butterflies use the sun to orientate themselves so as to be able to keep a straight-line path.

The caterpillars can be found feeding on mallow plants (ħobbejż), wild artichoke (qaqoċċ tax-xewk) and borage (fidloqqom).

The painted lady is related to the red admiral (farfett tal-ħurrieq), another common butterfly. It also has other close relatives namely the Australian painted lady, the American painted lady which is usually found in mountainous areas of North America and the west coast lady which can be found throughout much of the western US and south western Canada.

This article was published in The Times of Malta on 2 Ictober 2014.