Mason Bees

The mason bee is common in spring. It can easily be identified by the thick layer of reddish brown hair that covers its thorax, the hairless blackish brown abdomen and reddish legs. Females have an abdominal broom. This is a structure formed by fringes of hair which is used to collect pollen.

This species is found in western counties of the Mediterranean including Portugal, Spain, France, Italy and Malta as well as North African counties as far east as Libya. In Italy it is restricted to southern Italy, Sicily and Sardinia.

In Maltese the mason bee is known as naħla tal-koppla because of the rounded structure of its nest which looks like a church dome.

Mason bees are solitary bees but at this time of the year several can be seen close together on the ground especially in rocky areas, collecting gravel and small stones which they use to build their nests.

Females the building material collected from these places and cement it by mixing it with a secretion from their labial glands to form a mud. The mud is used to build rounded nests which are attached to walls or rocks. The labial secretion makes the dried mud impervious to water and the nest can last for many years.

The internal structure of the nest consists of several elongated cells which are filled with honey and pollen. An egg is laid in each cell. The larva forms a pupa which overwinters inside the nest. The adult bee emerges in early spring to start nest building and to collect pollen from flowers

The mason bee belongs to a family known as megachilid. Most bees belonging to this family are known either as mason bees or leafcutter leaves depending on the material they use to build their nests. A small number of species which collect plant or animal hairs and fibres are known as carder bees.

About fifteen species of megachiclid bees are found in the Maltese islands.

Megachiclid bees are inefficient pollen collectors. They have to visit several plants to collect sufficient pollen for their needs and this makes them very important pollinators. 

This  article was published in the Times of Malta on 16 April 2015. 

The tadpole shrimp

Tadpole shrimp - Triops cancriformis 

Tadpole shrimps are small crustaceans that were already alive 300 million years ago. They are living fossils that have outlived the trilobites, dinosaurs and mammoths and millions of other species.

They live in ponds and pools, an unstable habitat because they often dry up during parts of the year.

The tadpole shrimp found in the Maltese islands, which goes by the scientific name of Triops cancriformis, has existed unchanged for the past 200 million years or so. It is the oldest living species known.

Triops cancriformis is found in Europe, the Middle East and Japan. In many parts of Europe it has lost its habitat and has decreased considerably. In some areas it is endangered and strictly protected. Only two populations are known in the UK.

The tadpole shrimps I have seen in the Maltese islands have been about six centimetres in length although it is not unknown for members of this species to grow up to eleven centimetres long.

In Malta it has become very rare mainly because of destruction of its habitat. Many of the sites in which it used to be found have disappeared and it has also disappeared from most of its old but still existing sites.

Like the frog which shares the pools in which it lives, the tadpole shrimp has a very fast life cycle. It becomes a mature adult within two or three weeks of hatching. This allows it to complete its life cycle before the rain pools in which they live dry up.

The eggs are very resistant to drought and extreme temperatures and can survive for many years in the dried mud or dust at the bottom of a pool waiting for the right hatching conditions. They can even survive digestive juices and can pass through the digestive system of a bird unharmed. It is probably the ability of the eggs to survive under very difficult conditions that has enables the various species of triops to survive for so many millions of years.

Tadpole shrimps feed on small invertebrates, microscopic particles and plants. They absorb oxygen through their legs and can be seen moving their legs rhythmically all the time to move the water around them. They usually swim with their shield upwards but when oxygen is scarce they swim upside down with their feet close to the surface of the water where there is usually more oxygen.

The name Triops is derived from two Greek words meaning three and eyes. It got its name because these species have a pair of compound eyes and a third eye known as the ‘naupliar eye’ in between. 

This article was published in The Times of Malta on 3 April 2014.

The stream of life

The Maltese islands have very few permanent freshwater streams.

Found on the west side of Malta and in Gozo, these streams are an important habitat to a number of species and plants.

These streams occur in places where the clay is still intact. The Maltese islands are made up of five layers of sedimentary rocks. Rain water can percolate through all these layers except clay. 

In areas where no clay is present rain water percolates through the rock strata until it reaches sea level and forms a layer on top of salty water. This is the water that is extracted through boreholes and galleries for domestic and commercial use.

In areas with a layer of clay percolating water is unable to continue moving down as clay does not allow water to pass through it. The water on top of the clay moves horizontally until it finds a way out, usually a fisure in the rocks and here it forms a stream.

At Baħrija Valley we find one of the most important fresh water streams in the Maltese islands. It provides habitat for the rare fresh water crab, which is known in Maltese as qabru, a species that requires water throughout the year. 

It is an important species in need of protection. Its conservation is of utmost importance because the local race is endemic to the Maltese islands, that is, it is not found anywhere else in the world.  

It is already legally protected and nobody can pick it up or kill it but what is required is more protection of the fresh water habitat where it lives. 

The water must be allowed to flow and any form of pollution, especially by pesticides and herbicides must be strictly controlled. 

This article was published in The Times on 1.08.2012.

Bees make the world buzz!

For many, a bee is just the honey bee, which is just one species of more than 20,000 recorded bee species. 

Bees are closely related to wasps and ants and are important pollinators. They evolved from wasps which are predatory insects and can nowadays be found wherever insect-pollinating flowers manage to live.

Insect-pollinated flowers, before the appearance of bees, were pollinated by other insects such as beetles, flies and butterflies. The appearance of bees probably led to a greater diversity of flowering plants.

Bees became specialised nectar and pollen feeders which put them at an advantage over other insects. Nectar is the source of energy which allows these insects to fly tirelessly in search of flowers and nectars provides the proteins for the growing larvae.

More than sixty species of bee have been recorded in the Maltese islands and more are likely to be found as this group of insects has not been thoroughly. 

Some bees live in colonies while others are solitary. Bee communities may semisocial. These consist of colonies of sisters living together in which there is division of labour. 

More advanced communities are called eusocial. These are more complex organisations consisting of a queen bee, female workers and male drones.

Solitary bees do not live in colonies although in some species the individual nests are built close to each other giving the impression of a colony. The largest of the solitary bees is the large carpenter bee which is known in Maltese as bomblu iswed.

The bumble bee, known in Maltese as bomblu, is a social bee of great benefit to humans because of its pollinating activities.

A close look at indigenous flowers including species which flower during the summer months such as the pennyroyal (plejju), fennel (busbies), caper (kappar) and squirting cucumber (faqqus il-ħmir) can lead to the discovery of the interesting world of bees. 

This article was published in The Times on 13.06.2012

The yellow-legged wader

The wood sandpiper is a wading bird seen in the Maltese islands during migration. It is one of the smaller waders with a short fine bill and yellowish legs. 

Several species of waders visit the Maltese islands. To the uninitiated they might all look the same but with a little practice and experience identifying these birds becomes second nature.

The best place to see migrating wood sandpipers and other waders in Malta is at the Għadira Nature Reserve near Mellieħa which is open t the public on weekends but to see them breeding you would have to travel north at least as far as Scandinavia. 

The nests are built on the ground in open swampy areas in northern forests, but as the summer season so far north is very short you would have to be there between May and mid-July. 

The start and finishing dates of the breeding season depends on how far north they are. In northern Russia for example breeding does not start before June.

Some adult green sandpipers start migrating south as early as late June. 

Young birds remain behind for longer and usually leave in late August. 

This gives them time to become fully grown and to build up their fat reserves which will provide them with the energy required to fly south. 

European and many Asian wood sandpipers spend the winter in Africa. 

On their way south they stop to feed and replenish their fat in suitable places. 

Wetlands north of the Mediterranean are of great importance for these birds as the reserves they build make it possible for them to cross the Sahara desert without the need to refuel.

When stopping to feed, migrating sandpipers keep themselves busy walking continuously along the water’s edge or in shallow waters, picking up tiny aquatic insects from the mud or from the water’s surface.

Wood sandpipers have a very large breeding range and they are not considered as being endangered although climate change is seen as a threat as this could result in their specialised habitat shrinking in area.

 As the earth warms up these birds might have to travel further north to find suitable breeding sites. 

This article was published in The Times on 18.04.2012

How the wild rabbit was tamed

The wild rabbit is not indigenous to the Maltese islands but it has been here for so long that it is now considered as part of the Maltese fauna. 

The rabbit originated in the Iberian Peninsula.  

From there it was taken to other countries and is now found throughout Europe. I

t was probably introduced in Malta by the Romans or possibly by the Phoenicians. 

Malta was one of the stops of the Phoenicians as they sailed across the Mediterranean their western colonies and their homeland and they could have released rabbits on the Maltese islands to ensure a supply of fresh meat during their journeys. 

The rabbits survived in the Maltese countryside and eventually provided meat for the local population. 

The Knights of St John issued several edicts to restrict or prohibit the local population from hunting rabbits.

In 1773 the restrictions even resulted in a revolt known as the Rising of the Priests.

It is not known when rabbits started to be domesticated in the Maltese islands. 

Some farmers used to keep a doe enclosed with four stone walls each between 80 and 100 cm high. 

The doe was well fed and was too heavy or too lazy to jump out. Males on the other hand would jump inside at night to mate. 

This provided the farmers with a supply of meat close at hand. 

These rabbits were probably the progenitors of the local domestic rabbit known as ‘tax-xiber’.

Wild rabbits are usually a pale sandy brown or greyish with white underparts and different colour varieties can be found in the same area.

Wild rabbits are still relatively common in the Maltese countryside but they are rarely seen because they emerge to feed at dawn and dusk and are very timid as a result of centuries of hunting. 

At the Għadira Nature Reserve, where hunting has been prohibited since 1980, many rabbits have become tame and active during the day and can be seen regularly by those visiting the reserve which is open to the public on weekends. 

This article was published in The Times on 04.04.2012

The rat that lacks pigment

Some time ago I photographed a strange looking rat that was so tame that it came to within two or three metres of me and allowed me to take many pictures of it before it walked calmly away. 

The rat had white markings on the face showing that it was an albinoid rat.

Albinism is characterised by complete or partial absence of pigment in the skin. It can occur in all vertebrates including humans. The lack of pigment can be partial or complete and can also effect the hair and eyes.

Albinism is not often seen in nature. The lack of pigment results in loss of camouflage and albinistic animals are easily spotted by predators. In areas with no predators albino animals can have a normal life expectancy. A Spanish sparrow (għammiel tal-bejt) with large patches of white on its wings used to breed in a ventilator close to where I live and managed to survive for many years.

Several albino animals have been purposely bred for particular characteristics. The best known are albino rabbits and rats. Albino rabbits are said to have a better taste while albino rats are used extensively in laboratories for biomedical studies and experimentation.

It is said that these rats are the descendants of rats caught around 1800 by English rat-catchers for ratting, a blood sport in which trained dogs were lowered in pits full of rats to kill as many as possible in the shortest time possible. Rats which exhibited any albinism, instead of being thrown in the pits, were kept for breeding and exhibition and these became the stock from which today’s laboratory rats are descended.

Two species of rat are found in the Maltese islands; the brown rat (far tal-kampanja) and the black rat (far iswed). Both species of rat can by found in urban and rural areas. 

They are very common animals that can be carriers of disease and can cause a lot of damage to crops and stored food. 

This article was published in The Times on 12.10.11

The amazing praying mantis

Last Sunday I was photographing a dragonfly resting on top of a dry plant when out of the corner of my eye I saw a brown praying mantis. 

Praying mantises are amazing insects. They are long and as thin as a stick with a pair of large eyes on the sides of a flexible head. The head can swivel in many directions which allow the mantis to scan its surroundings for predators and prey. The most unusual feature of these insect is that the front legs have been modified into very effective hunting instruments.

The praying mantis is known in Maltese as debba tax-xitan , devil’s mare in English. Mantis is derived from the Greek word for prophet. Three species of praying mantises are found in the Maltese islands. 

This is a very small number when compared to the approximately 2,200 species found in the world. Some of the larger species are capable of catching larger animals including lizards, frogs, fish rodents and even birds.

Most species are diurnal, that is, they are active during the day, but the males of some species fly at night to visit females which they detect by means of pheromones. 

By flying at night they can avoid day-flying predatory birds and to avoid bats some have organs capable of detecting the echolocation sounds of bat which allows them to take evasive action when bats are hunting in the vicinity. 

After all the effort and risks incurred to find a female, most male praying mantises make the ultimate sacrifice by allowing the female with which they had just copulated to eat them and so providing her with nutrients to produce the eggs. 

This article was published in The Times on 5.10.11

Flesh flies breed on living or dead organic material

Flesh flies, as their name implies, breed on living or dead organic material, mainly flesh. Their maggots live in dead animals, dung or decaying vegetable matter and sometimes in open wounds of mammalian species. 

Some species are internal parasites especially of beetles and grasshoppers while others live in bees and wasps’ nests.

About 30 species are found in the Maltese islands. Most are dark with light stripes but in many cases it is difficult to tell species apart unless they are studied microscopically. 

In many species the female is larger than the male. The most common species, known in Maltese as dubbiena tal-laħam, is larger than the common house fly. It can be found on decomposing organic material as well as on flowers.

These insects which are found throughout most of the world are not only a nuisance but can also be important vectors of diseases including leprosy. Sometimes they are also important as pest control agents and can be beneficial in fruit tree orchards and in forestry plantations.

Flesh flies have been extensively studied especially because of their importance in forensic science. Flesh flies do not lay eggs. The eggs hatch inside the female fly which then ‘gives birth’ to the maggots. 

Different species place their young in animals that are at different stages of decomposition ranging from freshly dead to bloated or decaying. This makes it possible for entomologist to accurately give the date or sometimes even the time of death of a corpse.

There is a tendency to classify insects as being either good or bad. Flies are automatically deemed as bad and therefore to be annihilated. But the living world is not that simple. 

Many species of flies can cause problems but at the same time they also help to break down organic matter and help to recycle it. 

Flies reduce the time required for a corpse to decompose and without them we would see more dead animals lying around. 

This article was written in The Times on 28.09.11

The lappet moth family

Lappet Moth (Gastropacha quercifolia)

The lappet is a large moth that is found in all of Europe as well as in northern and eastern Asia. It belongs to a large family of about 2,000 species known as the eggars, snout moths or lappet moths. 

The family is characterised by having feather-shaped antennae, and an atrophied proboscis. The caterpillars are covered in short hair which is used as a defense mechanism as well as to build the cocoon in which they turn into a pupa. Four members of this family have been recorded in the Maltese islands.

The lappet is very common throughout the islands between May and June and from August to October. The caterpillar has decorative skin flaps on some of its legs hence the name lappet. 

It feeds on the leaves of fruit trees and is sometimes considered as a pest. When fully grown the caterpillar descends to the ground and builds a cocoon in which to pupate. The caterpillar is covered in short hair. This hair, together with silk which the caterpillar itself produces is used to build the cocoon.

Female lappet moths are larger than males. They produce a pheromone which smells of charcoal or burnt wood to attract males. When resting, lappet moths are very well camouflaged. They fold their wings in the shape of a tent to look like oak leaves hence its Maltese name werqa niexfa.

In the lappet, the snout, which is a characteristic of members of the snout family, resembles a petiole (the part of the leave attached to the twig or branch). This adds to the resemblance of the moth to a dried leaf and enhances its camouflage.

In the same family as the lappet we also find the oak eggar (baħrija tal-ballut) which is common especially at Buskett and its surroundings, the grass eggar (baħrija tas-silla) which is also common and the lackey moth (malacosoma) which has been recorded in Malta once in 1956. 

This article was published in The Times on 17.08.11

Moths on the Maltese islands

Moths are far more common than most people believe. They are not as familiar as the closely related butterflies because with the exception of a very small number they are nocturnal insects. They spend the day trying to be as inconspicuous as possible. They often settle on a surface with the same colour as their body, they place the antennae close to their body and keep their wings flat and close to the surface to avoid making a shadow.

Several hundred species of moths have been recorded from the Maltese islands. Some of which are endemic to Malta, that is they are found only on the Maltese islands. Some are very common while others have been seen only once or twice and more species will be added the list as this group of insects is still being studied by lepidopterists.

For many Maltese a moth is a baħrija but for others especially country people who learnt about nature from their parents, moths are known as farfett ta’ billejl (butterfly of the night) or just farfett. For them the baħrija is a hawk moth. 

Moreover the baħrija was associated with either good or evil. If a hawk moth entered a house it meant that somebody was about to die. 

There are several species of hawk moths in the Maltese islands but the one which was believed to be the portent of death was probably the humming bird hawk moth which is known in Maltese as ħabbara (messenger). This species is one of the few day-flying moths and often enters houses.

Many species of moths that are plant pests are known as susa a word that is more widely used for the woodworm (susa tal-injam). 

The caterpillar of these moths lives in the branches, leaves or fruit of plants and like the woodworm feeds on the plant inside which it lives. 

This article was published in The Times on 20.07.2011

Butterfly diversity peaks in June

Butterfly numbers and diversity reach their peak in June. After that month, the number of butterflies in the Maltese countryside start to decrease.

By now, many species have disappeared and will not be seen again, until next spring. At the moment the most common species and the one most likely to be seen is the small white butterfly which happens to be one of the most common butterflies during the rest of the year.

Another common species is the large white butterfly which looks very much like the small white but is usually much larger.

These two species are common because they feed on, among other things, on the leaves of wild and cultivated members of the cabbage family such as cauliflowers, kohlrabi and of course cabbages.

Up to 40 or 50 years ago in some villages in Malta children trapped these butterflies using the same methods that adults used to trap birds.

Their aim was not just to catch the butterflies.

They used to catch them by using very crude methods such as hitting them with a piece of cardboard while they were resting on a flower.

The trapping was a serious exercise which taught them the skills required, later in life, when they would start to trap birds.

In their play they copied adult bird trappers.

They prepared a trapping site by clearing it of vegetation, levelled the ground and removed all stones.

They then laid down two pieces of cloth on the ground. The cloth was attached to two thin sticks to which they attached a long piece of string.

When the string thread was pulled the sticks and cloth flipped onto to butterflies preventing them from escaping.

To make the site more authentic they even had a decoy butterfly attached to a stick by a thread. The stick could be moved up and down by means of a string to make the butterfly flutter as if it was flying. Some boys even had decoy butterflies tied to sticks stuck in the ground around their trapping site.

When caught the butterflies were placed in a carton box or tin can as trophies to be shown to their friends who had also been trapping butterflies.

The best trappers enjoyed a high status and would boast and brag about the number of butterflies they caught and recount stories about the ones that got away...

This article  was published in The Times on 03.08.2011

Watching Cory’s shearwaters

Cory's shearwater (Calonectris diomedea)

This weekend I took part for the second year running in a Birdlife Malta boat trip to watch Cory’s shearwaters off Gozo. Seeing the enthusiasm of the participants while watching the shearwaters brought to my mind pictures I have seen of tourists watching whales in other parts of the world.

Whale watching is attracting millions of people worldwide. The first whale watching trips took place in 1955.

During that year 10,000 persons paid US $ 1 per trip to be able to get close to the whales. 

By 2008 the number of persons watching whales had risen to 13 million. It is estimated that these generated US $ 2.1 billion in tourism revenue annually.

Watching shearwaters in Malta offers an unforgettable experience that is probably as exciting as whale watching. The Cory’s shearwater, known in Maltese as Ċiefa, is a large bird that looks like a long-winged gull. It flies just above the water surface keeping its wings open to make the most out of air currents that form just above the water surface. It is well adapted for life at sea and approaches land only to breed. 

The Cory’s shearwater nests in colonies, usually under boulders or in crevices in undisturbed cliffs. During the day the colonies are very quite and one does not realize that hundreds of birds could be present close by. During the night the colony becomes alive with the loud calls of the shearwaters as these birds visit the nests to relieve their partner and after the eggs hatch to feed the young birds.

At least 5,000 pairs of Cory’s shearwater breed in the Maltese islands. The largest colony is found at Ta’ Cenc in Gozo.

Shearwater watching can become more popular in the Maltese islands and can even attract a good number of specialized visitors to the Maltese islands. Furthermore such activities can help to create more awareness about the Maltese natural environment. 

This article was published in The Times on 13/7.2011

The island bluetail damselfly

Island bluetail damselfly (Ischnura genei)

The island bluetail damselfly is a delicate insect known in Maltese as damigella. It is closely related to the more robust dragonflies. 

It lives in valleys with running water and near ponds, pools and reservoirs. 

It is a weak flyer and does not stray too far from aquatic habitats on which it depends throughout its life cycle. Like dragonflies the damselfly lays its eggs in water. The larva spends its entire life under water feeding on smaller organisms.

Two forms of this species are found in two colour forms: green and reddish-brown. Both forms can occur in a particular place and the colour might a result of different environmental temperature during the larval stage of the damselfly. 

In other insect species larvae that are developing later in the season, when the temperature is higher give rise to brown adults which are thus better camouflaged in the dry summer vegetation. As far as I know this has not been investigated in damselflies but a future study might show such a link.

Like dragonflies, it has very interesting courtship and mating habits, quite different from that of other insects.

The genital opening is near the tip of the tail, but before mating the male transfers his sperm to an accessory genital organ on the underside of his abdomen, just behind the thorax. 

He then finds a female and seizes her by the neck with a pair of claspers situated at the hind end of his body. They then fly in tandem and settle, linked together in this way.

When mating takes place, the female bends her body around under the male’s body and the sperm is transferred for fertilization.

Damselflies and dragonflies use different methods to lay eggs. Some insert them in the plants of aquatic plants or in vegetation at the water’s edge. 

Others fly over the water and drop them, while others dip the abdomen into the water to wash the eggs off the tip. Some species remain in tandem whilst the female is laying.

Their larvae or nymphs spend all their time under water hunting smaller animals. A hunting larva stalks its prey to within a centimetre or less, than shoots out the labium and seizes its prey with its claws. 

The victims are mostly insects, but large well-grown larvae can even catch tadpoles and small fish. The labium is a segmented organ, found in all insects below the mouth. In dragonfly larvae this organ bears a pair of pincer-like jaws near the tip and is elongated and hinged so that it can be extended in front of the head.

This article was published in The Times on 20.04.2011

The pomatias

Pomatias sulcatus

I recently took some pictures of an interesting species of snail but although I found its scientific name I could not find a common name for it so as its scientific name is Pomatias sulcatus, I used part of this name for the title of this article.

This species of land snail is found throughout the western Mediterranean. It is common on calcareous soils near the coast and inland. It can be found on soil, in crevices in rocky ground, under stones and among fallen leaves. Sometimes it buries itself in the soil while the specimens I photographed were living on a tree trunk. In the Maltese island it is common on Malta, Gozo and Comino as well as on some of the smaller islands.
There was and probably still is some controversy about this snail in the Maltese islands. Some biologists have listed it as a distinct species endemic to the Maltese island others as a subspecies while others believe that the snails found on Malta are not different enough from the snails found in other parts of the Mediterranean to be considered as a separate species or subspecies.

Pomatias sulcatus is not the only species of pomatias that can be found in the Maltese islands. Another species, Pomatias elegans which is known as the round mouthed snail, can be found at San Anton Gardens at Attard. It probably found its way there on imported plants. This species is common in southern Europe and lives in similar habitats as Pomatias sulcatus.

The pomatias are one of the few groups of land snails that have an operculum. This is a calcareous structure like a small lid that fits neatly in the opening of the shell sealing the soft body inside. The operculum is found in most species of marine and freshwater snails but very rarely in land snails. Its main function is to prevent desiccation especially in those species that live in the intertidal or splash zone of the coast. The presence of an operculum in the pomatias suggests that these snails evolved from marine snails. 

This article was published in The Times on 06.04.10