Random reflections on aspects of Avian life

Ducks

The duck family is known as Anatidae; it is therefore not surprising that the term for someone who suffers from the belief that somewhere, somehow a duck is constantly watching them is anatidaephobia. It is important to note that the quacking noise made by mallards, while sounding like laughter, is not, and even if it were, they are not laughing at you. As a potential source of food for humans and other predators, Mallard ducks are particularly vigilant – they are alert even when they’re sleeping. While sleeping in a group, there are ‘guard’ ducks that sleep on the outside of the group with one eye open. Collective nouns for ducks are a raft or a paddling of ducks.

Crows

Corvids, such as crows, ravens, rooks, jays and magpies, are the only non-primates that make tools; some scientists compare the intelligence of crows to that of a seven-year-old human child. Moreover, crows are capable of abstract reasoning, complex problem-solving, and group decision-making. More alarming is the fact that they can remember people wo have harmed them, and will hold a grudge...

Singapore’s crows have had a hard time. The government decided that they were too dirty and not in keeping with the country’s self-image and so a crow-culling team was formed.

It remains to be seen if, when and how they will get their own back.

Chats

The first time I saw a chat, in this case a stonechat, (Saxicola rubicola) I thought that it was a mechanical bird. This observation had more to do with the fact that I was quite young rather than anything else, but it must be said that the bird’s movements are somewhat fitful and this, combined with its metallic-sounding utterances, might well lead one to surmise that its origins were in a factory. It might be of interest, to those interested in such things, that some chats, notably the Siberian stonechat, have been recently validated as members of the flycatcher family (Muscicapidae, naturally); they are often located taxonomically amongst the thrushes (Turdidae) and are sometimes referred to as ‘thrush-flycatchers’. In South East Asia, I have only had one sighting of a bird belonging to this family – a white crowned forktail – foraging in a small drainage dyke.

The stonechat depicted above is shown with another bird (below) that the casual observer might surmise is the female of the species. It is in fact another species of the chat family, the whinchat (Saxicola rubetra). However, as noted in the original title of the work, they can be collectively known as ‘furzechats’, as both haunt furze (gorse)-covered heathland. The ‘whin’ in whinchat is derived from the middle English word for furze. Stonechats on the other hand are so called because they utter a sharp loud call that sound like two stones being tapped together.

Hornbills

Since I am rudely awoken every morning at 6.45 by the raucous chattering and screeching of Hornbills alighting on my air conditioning unit, I though they deserved some attention. Hornbills are characterised by a long, down-curved bill and they sometimes have what is known as a casque on the upper mandible. Both the common (English) name and the scientific name of the family (Bucerotidae) refer to the shape of the bill - 'buceros' is derived from the Greek for cow horn.

Several species, including the impressive Rhinoceros hornbill (Buceros rhinoceros), possess a brightly coloured beak and casque. This striking coloration is the result of the bird in question rubbing its beak and casque against a 'preen gland' beneath the tail; this action stimulates the production of an oily orange-red fluid that adds a red hue to the bill. My dawn alarm call is facilitated by the less striking but still impressive Oriental Pied Hornbill (Anthracoceros albirostris). As with other hornbills, in addition to the large toucan-like (no relation) bill, it has clearly visible eyelashes.

I observed the male Hornbill daintily passing a small fruit to his mate (they are monogamous) prior to courtship. Hornbills are known as secondary cavity nesters, in that they do not excavate their own nesting sites but use those created by other birds or some naturally occurring hole or crevice. When females have selected and entered their nest, they seal the cavity with a mixture of vegetation, saliva, mud and droppings, leaving only a small opening through which food may be passed in. I am of the opinion from my observation that they have found a home in the external boxing of my air conditioning unit.

On Crepuscularity

(from the Latin crepusculum: twilight)

Crepuscularity is a feature of geographical locations above and below the tropics. The effect of the sun’s rays through the atmosphere at these times has been captured over the years by northern European painters. The equatorial zone is characterised by the rapid rising and setting of the sun. While the sun in Britain, especially in winter, creeps slowly along the horizon, the sun in Singapore drops almost vertically throughout the year, with sunrise and sunset occurring at approximately 7am and 7pm.

Oil on board 35 X 25 cm Richard Hickman (c1990)

Celestial observations

Some basic things pertaining to the sun, moon and earth

1. A full moon is seen as such everywhere around the world

2. The hours of daylight over a year are much the same everywhere around the world

3. At the equinox, the hours of daylight and night-time are the same everywhere around the world.

4. The gravitational pull of the moon causes the oceans to move about – hence tides.

Both the Sun and the Moon exert a gravitational pull on the Earth's water. The force of the Moon's gravity creates two tidal bulges on opposite sides of the Earth. Depending on the relative position of the Sun, the tidal bulges will change slightly as the Moon experiences its phases; the fact that it is a full moon or new moon in itself does not affect tides, it is the interplay between the sun, moon and earth. At both full moon and new moon, tides are at their highest, with high tides being very high, and low tides very low. At full moon, the Moon and Sun are in a straight line on opposite sides of the Earth and their gravitational forces combine to create larger tidal bulges. At new moon, the Moon and Sun are in a straight line on the same side of the Earth and their gravitational forces combine to create large tidal bulges; these are called spring tides. At quarter moons, the Earth's tides are at their least dynamic. During its quarter phase, the moon forms a right angle with the Sun, so with the gravitational forces from each body acting at perpendicular angles, the overall tidal bulge is less. The tides at these times are known as neap tides.

A few words on ‘shooting stars’…

They are of course not stars – these are the streaks of light you can sometimes see in the night sky and are caused by tiny bits of dust and rock called meteoroids. The light from them is a result of their falling into the Earth's atmosphere and burning up through friction. If any part of the meteoroid survives burning up and actually hits the Earth, it is called a meteorite. At certain times of year, you are likely to see a great number of meteors in the night sky. These events are called meteor showers and they occur when the Earth passes through the trail of debris left by a comet as it orbits the Sun. These showers are given names based on the constellation present in the sky from which they appear to originate. For example, the Geminid Meteor Shower, visible in the UK in December, appears to originate in the constellation Gemini. It is important to understand that the meteoroids (and therefore the meteors) do not really originate from the constellations or any of the stars in the constellations, however. They just seem to come from that part of the sky because of the way the Earth encounters the particles moving in the path of the comet’s orbit. 

Bathwater, the moon and other issues

While I had been apprised of the possibly spurious notion that antipodean bathwater  empties ‘the other way round’ compared to emptying bathtubs in the northern hemisphere, I had not anticipated that the moon is, to a European, upside down in Australia – the man in the moon of London is more like a rabbit in Sydney. On the subject of bathwater, the thinking behind the notion of differing directions according to hemispheres is due to what is known as the Coriolis force. This force accounts for why cyclones rotate anti-clockwise in the Northern Hemisphere, while those I in the Southern Hemisphere rotate clockwise. The circulation directions result from interactions between moving masses of air and air masses moving with the rotating earth. Because the effects of the rotation of the earth are much stronger when the circulation covers a larger area than would occur inside a bathtub, variables such as any small asymmetry of the shape of the drain will determine which direction the circulation occurs, but even in a perfectly symmetric bathtub, the circulation direction will be influenced primarily by currents in the bathtub left over from the time when it was filled.

Some notes on how fast we are moving

The circumference of the earth around the equator is approximately 24,898 miles. On the assumption that a day is 24 hours long, dividing the circumference by the length of the day produces a rotational speed at the equator of about 1,037 mph; the speed decreases more as one journeys farther north or south. The Earth orbits the sun at around at about 67,000 mph – this can be calculated by figuring out how far Earth travels around the sun. Earth takes about 365 days to orbit the sun in an elliptical fashion. If we work on the basis of it being a circle and Earth's orbit is the circumference of a circle, we can work it out: The distance from the Earth to the sun is about 92,955,807 miles - the radius. The circumference of a circle is equal to 2 x π x r, so in one year, Earth travels about 584 million miles. As speed is equal to the distance travelled over the time taken, Earth's speed is calculated by dividing 584 million miles by­­ 365.25 days and dividing that result by 24 hours to get miles per hour. Therefore, the Earth travels about 1.6 million miles a day, or 66,627 mph. Further to this, the sun and galaxy move too, with the sun having an orbit of its own in our galaxy, the Milky Way. The sun is about 25,000 light-years from the centre of the galaxy, and the Milky Way is at least 100,000 light-years across; we are thought to be about halfway out from the centre. The sun and the solar system appear to be moving at an average speed of 448,000 mph. It should be noted that the galaxy is so vast that even at this speed, the solar system would take about 230 million years to travel all the way around the Milky Way. Not surprisingly, the Milky Way, too, moves in space relative to other galaxies and in about 4 billion years, the Milky Way will collide with Andromeda, the nearest galaxy - the two galaxies are rushing toward each other at about 70 miles per second. Undoubtedly, all of this is happening at a nano level too, with sub-atomic particles – protons, electrons and the like - echoing the movement of galaxies. It occurs to me that, relative to distant stars, we can never be in the same place twice.

Planets

The word ‘planet’ comes from the Greek πλανητης, meaning ‘wandering’, as it referred to the observation that planets, unlike stars, appear to wander about the sky. You may notice that the visible planets move across the night sky along a particular path, together with the sun and moon. This path is called the ecliptic; it is the mean plane of the apparent route in the sky that the sun follows over the course of a year. It seems that when the planets of the solar system were formed, they spread out at various distances on the same plane, probably due to the gravitational effect of the sun.

A note on the precession of the equinoxes

In the year 129 BCE the Greek astronomer Hipparchus noticed that the positions of the stars did not match with the records made centuries earlier by the Chaldeans. According to these Chaldean records, the stars had systematically shifted - this indicated to Hipparchus that it was not the stars that had moved but the Earth itself. This systematic shift is called ‘precession’ and consists of a cyclic wobbling in the orientation of Earth’s axis of rotation. Currently, this annual motion is about 50.3 seconds of arc per year or 1 degree every 71.6 years; a full precession occurs after 25,772 years. During a precession, the equinoxes could be seen moving westward along the ecliptic relative to the stars that were believed to be motionless from the perspective of astronomers – and opposite to the motion of the Sun along the ecliptic. The precession of the Earth’s axis has a number of noticeable effects. Firstly, the positions of the south and north celestial poles appear to move in circles against the backdrop of stars, completing one cycle every 25, 772 years. Thus, while today the north pole star, Polaris, lies approximately at the north celestial pole, this will change over time, and other stars (e.g. Vega) will become the pole star. Secondly, the position of the Earth in its orbit around the Sun during the solstices, equinoxes, or other seasonal times slowly changes. The cause of this was first discussed by Sir Isaac Newton in his Philosophiae Naturalis Principia Mathematica where he described it as a consequence of gravitation. It is now known that precessions are caused by the gravitational source of the Sun and Moon, in addition to the fact that the Earth is a spheroid and not a perfect sphere, meaning that when tilted, the Sun’s gravitational pull is stronger on the portion that is tilted towards it, thus creating a torque effect on the planet. If the Earth were a perfect sphere, there would be no precession. I have appropriated a pertinent diagram to elucidate the matter further:

The Earth's gravitational pull is slightly weaker at the equator due to what is known as the 'equatorial bulge.' This, together with the momentum of the spinning earth makes equatorial regions ideal places for space launches. If measured from the centre of the earth, Mount Chimborazo, Ecuador, rather than Mount Everest is the highest point on earth. This is because of Earth's equatorial bulge which pushes Mount Chimborazo, near the equator in the Andes, further from the centre of the Earth. However, elevation is measured from sea level, not the centre of the Earth. Mount Everest is 29,035 feet above sea level, while Mount Chimborazo is just 20,702 feet above sea level.

Notes on equatorial flora

For the purpose of these notes, I define the equatorial zone as the area 10 degrees north and 10 degrees south of the equator. The circumference of the earth along the equator is said to be 24,901.92 miles; there being 360 degrees in a circle means therefore that each degree of latitude is equivalent to a little under 70 miles. My observations are further focused upon the rain forests of the Malay peninsula, namely from Bangkok to Bali, and some of the introduced species.

Trees

For me, the most impressive equatorial species are those that have the large buttress roots that are needed to support the trunk, which can probably grow as much as 200 feet tall. Two that I pick out are the Jelawi (Terminalia subspathulata) and the Kapok (Ceiba pentandra). The Jelawi Tree can grow up to 165 feet tall. This tree has large spreading buttress roots and a wide conical and flat-topped crown. Its bark is pale, ochre-brown and narrowly cracked. Its fruits are small, flattened and double-winged to aid dispersal by the wind.

The forests, jungles if you will, of the Malay Peninsula are characterised by these kinds of trees, known as dipterocarps (di=two; ptero= wing; carp= seed). These jungle areas, while fascinating are not for casual strolling, even if one finds a well-trodden path, the heat and humidity (usually about 95 degrees F and 75% humidity) militates against both exertion and calm contemplation. These conditions are exacerbated by the presence of mosquitoes (which can carry dengue fever) and leeches. The large crown of the Kapok tree gives an umbrella of shade in the forest. Its seedpods, when mature, will split and release hundreds of seeds that float on fluffy parachutes of white fibre. This water-resistant fibre, called kapok in Malay, was commonly used to stuff pillows, mattresses and life-jackets. My joy at seeing siamang gibbons swinging through the trees at one time was tempered by the presence of leeches on my legs and insect bites on my elbows. The siamang (Symphalangus syndactylus) is a black-furred primate native to these forests. The largest of the gibbons, the siamang can reach 3 feet tall. A feature that distinguishes the siamang from other gibbons is that the second and third toes are partially joined by a membrane, hence the name ‘syndactylus’, from the Ancient Greek syn-, ‘united’ + daktylos, ‘finger’.

Tembusu (Fagreia fragans)

Tembusu is a long-living, evergreen tree that can grow up to a hundred feet tall. It is recognisable by its deeply fissured bark and conical shape when young. During flowering, its creamy-white flowers open during sunset and give off a sweet perfume, hence the tree's name fragrans. The lower branches of the Tembusu when mature sag to the ground and turn up at the ends.

Rain Tree (Samanea saman)

This is a large and majestic tree with a big umbrella-shaped crown. When it blooms, its crown is covered in clusters of pink-white flowers, like small upturned brushes. Its name refers to the fact that its leaves fold up before rainy weather; they also close just before sunset (it is called the Pukul Lima in Malay, which means ‘five o’clock’. The sunset hour in Malaysia used to be 5 pm, before changes were made to Standard Time in 1982.

Yellow Flame (Peltophorum pterocarpum)

When the tree flowers, its fragrant brilliant yellow blossoms cover the entire crown. These flowers are about an inch in size, and have wavy, crinkled petals that resemble tissue paper. After flowering, the flowers develop into woody purple-brown fruit pods that develop on the tree. These pods remain in the crown for several months before dropping off.

Angsana tree (Pterocarpus indicus)

The Angsana is a large deciduous tree that can grow to over 130 feet tall. It can be recognised by its drooping, dome-shaped crown. This tree has yellow flowers that are faintly fragrant. They bloom for only a day, then rain down the next morning, creating yellow carpets on the ground. The fruits are flattened pods with disc-like papery wings

Flame of the forest

This name is given to several tropical trees around the world, namely Butea monosperma, Delonix regia (bean family), Mucuna bennettii and Spathodia campanulata. My favourite is the Butea, which has amongst other names, the unfortunate nomenclature of  ‘bastard teak’. The photograph shown below of Delonix regia was actually of a collared kingfisher which is now in the cropped portion. I couldn't get near enough to a Butea monosperma specimen.

Jacaranda

Although not common in the equatorial belt and being indigenous to South America, I include the jacaranda as I like the sound of the name and admire its lilac flowers. Interestingly, in Singapore, it is thought by some to be ‘potentially invasive’, with some concern over its spread into the primary rain forest of the central catchment area (Lok, AFS; Tan, KX; Giam,X; Ng, TP and Tan, HTW. (2008). The spread of Jacaranda obtusifolia humb. & bonpl. (bignoniaceae) into the central catchment nature reserve, Singapore. NUS: Singapore). Tan et al’s short paper includes some beautiful images of Jacaranda flowers – it reminds me of a British photographer’s efforts to portray the invasive Grey Squirrel as an obnoxious rodent pest, but all of the images turned out to be of delightful, playful furry creatures.

Frangipani

The national flower of Laos and personal favourite in terms of its fragrance, Plumeria rubra has a common name of ‘dead man’s fingers’, owing to its stark, knobbly grey branches. I took the liberty of picking the flowering parts from one to do the drawing below. I felt rather like those early naturalists who shot exotic birds in order to take them back to their study for examination. The drawing will not substitute for the real thing but will last somewhat longer. So, all is right with the world.

And here’s the promised photo (as well).

Not trees

Elephant ears (Colocasia gigantea)

This large fibrous plant grows at the side of the roads throughout Malaysia and much of Southeast Asia. The enormous leaves of this relative of the taro grow larger than 5 feet.

Heliconias

Otherwise known, crudely in my view, as ‘lobster claws’, this exotic group of plants (at least exotic to westerners) is quintessentially tropical. As with many other plants found in south east Asia, they were introduced and are now to some extent naturalised.

It is interesting to note that some spices such as chilli, a staple of Asian food, were introduced by the Europeans in the late 15th century.

Finally, it would be remiss of me not to mention the national flowers of both Indonesia and Singapore... the orchid:

Fin