Natural History Notes

Compound eyes consist of numerous ommatidia. Most insects have compound eyes, which upon closer inspection have many an array tiny lenses. They are the most visible part of the subunits of the compound eyes known as ommatidia. Each ommatidium comprises of the lens, light gathering unit and light absorbing cells. A dragonfly's compound eyes can have thousands of ommatidia. Because the lens is not flexible like ours, an insect cannot focus properly resulting in less detailed view of their surroundings. However, an insect vision is very efficient when it comes to detecting movement. As an object moves across their field of vision, it turns each corresponding ommatidia on and off making them highly sensitive to movement. This adaptation of the insect eyes is important because it helps insects evade predators, hunt potential prey and avoid collision when flying. Compound eyes help this fly catches its prey. The numbers of ommatidia varies among insects. General...

Oriental Garden Lizard

- March 11, 2013

The Oriental Garden Lizard ( Calotes versicolor ) is one of the common species of reptiles in parks, gardens, villages and cultivations. It is readily seen sunning on exposed low branches, fences and rural roads. When one comes too close, it habitually runs for cover or dive into the undergrowth. Because it can change colour, it is also call the Changeable Lizard, and can be mistaken for a chameleon. Male Oriental Garden Lizard Typical of Agamid lizards, it has a series of upward pointing triangular scales on its head, which become smaller as it runs down its back. Numerous variable sized, backward pointing scales cover the body of this small reptile. Surrounding the eyes are movable eyelids, visible up close. The body is somewhat triangular in cross-section: the underneath being flattened and the sides compressed toward the top. Generally, the male are larger than female, reaching one foot in length. Oriental Garden lizards fight over territory. In breeding season, th...

Water Striders

- January 20, 2014

In the rainforest, water strider, which belongs to the family Gerridae in the order Hemiptera , inhabits damp habitat like streams especially near the banks. Most water striders are large insects with elongated body, long and slender legs, and large eyes visible up close. The middle legs mainly help the water strider move on the water surface and the front ones are use to handle prey. A water strider can "walk " on water. Aside from visual cues, water strider or also known as water skater, detects prey in the water via vibration. It feeds on its prey tissues fluid using piercing-sucking mouthparts with the help of strong digestive enzyme. However, water striders are themselves food for other animals like fishes, birds and frogs. For this reason, they have drab coloration that helps them avoid predators. Rainforest streams are suitable habitat for water striders. Scientists have long known that water tension partly explains how water striders walk on water. How...

Mimosa pigra: A Notorious Invasive Tree

- November 17, 2011

Mimosa pigra growing in river bank Mimosa pigra or also known as Catclaw Mimosa is a widespread non-native invasive species that grows gregariously in many parts of the tropics. This invasive tree native habitat is in South America, but have since spread to other topical areas. Indeed Mimosa pigra is a notorious foreign tree that is very difficult to control as it is easily dispersed via its hardy seeds that can survive for many years. Mimosa pigra also grows rapidly especially in sandy soil besides large rivers. As a result, local ecosystem would be altered and the relatively rich native vegetation would become a homogenous stand of only several species of trees, and in turn some local animals like birds have to leave because of decline in fruiting trees or nesting site. Mimosa pigra flowers Mimosa pigra tree bears some resemblance to its close relative the Mimosa pudica or the Sensitive Plant, but it is much larger in size. It is a thorny plant that can gr...

Durian Fruit

- November 10, 2011

Durian, the king of fruit Durian fruits is one of the most popular Asian fruits especially in South-east Asia to the extent that it is regarded as the king of fruits. Locals like the the taste, smell and texture of Durians. On the contrary, many westerners in particular dislike the smell of Durians. The unmistakable capsular fruit of Durian ( Durio zibethinus ) is green and spiky, and when it is opened it reveals the seeds which are covered with yellow pulp. The pulp is usually eaten raw or cook to make porridge, for example. A full grown Durian tree. Like many tropical fruits of Asia, Durians originated from the rainforest and has been cultivated by man for a very long time. It is not unusual to find a Durian tree inside the rainforest whereby it can be identified by its conical crown and greyish-green leaves.

Fishtail Palm

- August 17, 2013

The Fishtail Palm ( Caryota mitis ) derives its name from its delta-shaped, fishtail-like leaflet with ragged ends. It has the characteristics monocot leaf with parallel veins readily seen in many other palm species as well. Additionally, like all palms, it also lack wood, bark and side branches often seen in dicot trees. Leaflets of Fishtail Palm A palm tree native to Southeast Asia, this quick growing palm can reach a height of up to 12 meters. The slightly curved leaves can measure up to three meters and the leaflets usually range from 10-20 centimeters. It has been used in landscaping quite extensively as a screening, tall hedges and even interiorscape. Flowers and fruits of Fishtail Palm are borne on dense cluster of string. The rounded fruits are borne on long hanging stalks. Although they might appear edible, the fruits contain highly irritating calcium oxalates crystals. When this crystals puncture the skin, it cause intense itching, and highly irritating to th...

Types of Insect Antennas

- May 18, 2012

The antennas or commonly called feelers are one of the most characteristics features of insects’ parts. They are elongated appendages in various length and shape projected from the insect’s head. Essentially a sensory organ, the insect antennas give them the ability to detect chemical and movement. The simplest type of antenna is the filiform which consist of many more or less the same sized subunits. This beetle of the Anobiidae family displays a pectinate antenna A wide array of antenna forms is found as a result of different modification of the subunits. A pectinate antenna, for example, has each subunit prolonged at one side, giving rise to a comb like appearance. In many insects of the order Lepidoptera which include moths and butterflies, the antenna gradually becomes broader at the tip making it looks like a club or knob ( clavate ). The clavate antenna of a butterfly ended in a knob

Clidemia hirta (Koster's Curse)

- October 21, 2010

The white flowers of Clidemia hirta Clidemia hirta or also known as Koster's Curse is a locally widespread invasive species that originated from the Central and South Americas. A number of factors contributed to its successful dispersion. For example, the fruits of Clidemia hirta contain numerous tiny seeds and they are produced throughout the year; it also has broad habitat preference from edges of the rainforest to plantations. Besides that, there are many dispersal agents which feed on its fruits and then disperse the seeds including birds such as bulbuls and flowerpeckers. Ripe fruits of Clidemia hirta Clidemia hirta usually grows not more than 2 meters tall. It is a hairy shrub - the stems, leaves and fruits are covered with fine hairs. Like many members of the Melastomataceae family, the leaves are opposite in arrangement, and the veins arise from the base of the leaves, running parallel with each other toward the apex. The white flowers, with five pe...

Animal Pollinated Flowers

- November 30, 2014

Because pollination requires suitable pollinator to be successful, animal pollinated flowers have developed a variety of colors, scent and sizes; thus, restricting the kind of animals that visit them. Consequently, only animals with the right characteristics can feed on the nectar, and in return pollinate the flowers. A butterfly uses its proboscis to feed on nectar. Insects generally has keen sense of sight, hence they tend to visit colorful flowers. Butterflies, for example, often visit red, orange and yellow flowers, including those with long tubular tube for they can easily reach the nectar using their long sucking mouthparts . In contrast, bees cannot see red but they can see blue. This explains why many bee flowers are blue or violet. Bees are attracted to blue, purple and violet flowers. Time of opening also played a crucial part in attracting the right pollinators. Some flowers open at night like those of durian , which are pollinated by bats. Strongly...

Banana Flowers

- January 20, 2013

Banana flowers The banana tree ( Musa sp.) is essentially a large herb most notable for its fruits. The large flowers are in many cases dioecious, that is the female and male flowers are present in the same plant. The inflorescence initially starts out at the tip of the plant. In the beginning, it is erect but eventually bends downwards. At first, only the female banana flowers develop in cluster around the thick long stalk. They are often referred as hands, and each finger will eventually become the fruit. As the fruits develop, the stalk continues to grow, and the male flowers will appear near the end, at the axil of the conspicuous bracts.