Friday, 5 October 2012

Land of Many Enigmas



Wanderlust bites the laptop
In continuation of our ongoing Kenya park tours, we decided on Amboseli, an around 400 sq. km sized park located at Kajiado District in Rift Valley Province, for our New Year holiday. Being the holiday season for all including the housekeeper, travelling definitely sounded more appealing than washing dishes at home! As scheduled on Saturday the 31st, a roof open travel van with a smiling Andrew at the helm was waiting to pick us up in the morning. He was kept waiting for quite some time as the son and the father got ready – both doing some catching – the son on some sleep and the father on elusive annual sales target (not sure how much catching can one possibly do on the last day of the year)! It was past ten when we started out on “our jungle adventure”, as Barney the dinosaur would say, to “see what we can see”. The laptop accompanied us (like on the Christmas trip) and Aamir chased the sales target along the way. After the half way point, the land turned increasingly arid and dusty and when after nearly four hours we reached the park gate, I knew we would experience the Kenyan summer in the real sense for the first time.

Like Maasai Mara, Amboseli was Maasai land and knick knack sellers in brilliant red shukas circled our van as we arrived. As it always happens, their interest waned soon after, as they realized their energies were better invested on Mzungu fellow tourists rather than on resident Wahindi. Ticket formalities over and Andrew was immediately off - ignoring secretary birds and herons on the way – as he speeded to reach the hotel within the lunch window. I was crestfallen at missing this opportunity of a longer look at secretary birds and their crests – we had this good fortune only once before at Mara. So far I had thought the crests of long quill-like feathers are what give the birds their names, as they lend the bird the appearance of an old fashioned secretary with quill pens tucked behind ear. A more recent hypothesis is that "secretary" is borrowed from a French corruption of the Arabic saqr-et-tair or "hunter-bird". It was not long after when we were inside Serena Safari lodge – an enchanting island of soothing green cleverly hidden from the dusty surroundings by bushes and acacias.

A fabulous lunch on a hot day, a brief splish-splash game at a sprinkler in the resort lawn and Adi was drowsy with sleep, with Aamir only too keen to give him company. So we all went back to our bright red room that had the facade of a Maasai manyatta or homestead, complete with a circular opening that serves as a tiny aperture in a real hut. Unlike the real hut of course our room had many other much larger openings. Like in a real hut, the room and window had wooden sticks as fences and grills for protection; thankfully in our case there were no threats like rival groups or animals that we needed to be protected against.
Rooms with Maasai manyatta facade, complete with circular windows, wooden fences and grills

The animals at Amboseli enjoy their afternoon siesta as well; hence Andrew had suggested that we start at four for our evening safari. I spent my time idling away at the lawn, watching superb starlings and bulbuls, wondering how the under tail colour in the latter varies from red (what I had seen in India) to yellow (what I had seen in Kenya) – completely shattering what I had learnt in my childhood about the red vent being an indisputable identification mark of a bulbul!
 
It was a case of wanderlust biting the laptop for evening safari as well – it seemed there was some more catching required to be done on an increasingly slipping 2011 sales target! We were back at the open expanses of a savannah again – its immensity leaving me breathless like every time. The sky and the land embracing at the horizon, the splattering of whites, greys and oranges on the blue, the hazy outlines of rolling hills through a cloudy mist – it was indeed a grand karibuni awaiting us. 
Clouds, grass lands and the rolling hills
The fauna adventure started with sightings of Grant’s gazelles, the largest in East African gazelle family with their beautiful long ringed horns - no two pairs curving alike – and pale fawn bodies with white under-bellies. African savannah animals are notorious for practically having no fat deposits, and right in front of us were live examples - muscles standing out - lean and mean in the truest sense. An interesting feature about Grant's gazelles is that they are not dependent on water and, consequently, they migrate in the opposite direction of water-dependent species such as wildebeests, zebras, topis and Thomson's gazelles (the last one being the most water-dependent of all gazelles), i.e. against the great migration. In doing so, Grant’s gazelles avoid competition and are able to survive on vegetation found in semi-desert environment. Gazelles are able to extract the moisture that they need from their food; and the smooth, sleek coat is adapted - through colour and hair structure - to reflect heat. 
Grant's gazelle
Most amazing, however, is the gazelle's ability (similar to that in camels) to use the technique of forcing air through nasal passages in order to cool it. A capillary network surrounds the carotid arteries (carrying blood to the head and neck), and blood passing through is rapidly cooled before it reaches the animal's brain! A predator like the cheetah must stop running when its body and brain temperature reaches 40.5° C but the gazelle can keep running as its body temperature rises above 43° C without its brain temperature exceeding 40.5° C - it just pants in order to survive! Very soon we could spot Grant's gazelles grazing next to their smaller brighter cousins, Thomson’s gazelles – the black prominent horizontal stripe across the white belly and all black tail in Tommies helping us to mark them out easily.
Lean and mean with every muscle standing out

Heat, dust and oases
Not withstanding few savannah-like stretches, our primary impression was that of travelling through a huge dusty desert (that explains the presence of Grant's gazelles). The omnipresent volcanic ash from Mount Kilimanjaro eruptions a millennium ago gives the park its name - empusel which means a 'salty, dusty place' in Maa language. In fact the loose surface of soil on the roads which we felt to be dusty can make the way impassable in the wet season. Being in the rain shadow of Mt. Kilimanjaro, the resulting climate is hot and dry, with average day temperature ranging from 33°C to 27°C throughout the year. A few months of rain bring lush grasses, hordes of insect larvae and tree blossoms; only to be quickly replaced by a long dry season of dust, bare earth and grass stubble - the dry, volcanic ash can support little more than scrub and fragile saline grass. Lying at an altitude of nearly 4,000 feet at the foot of Africa’s highest mountain also means the glaring heat of mid-day in the Amboseli basin is followed by a 20°C temperature drop during the cool night.

All of a sudden we saw something unbelievable, on one side of the road there was a lush green swamp with palm trees; on the other side of the road, the same old brown, dusty desolate desert! We shared the same feelings as Joseph Thompson, who as the first European to penetrate the feared Maasai region in 1883, was astonished by the contrast between the arid areas and the swamp oases. And there were not just one or two swamps, we saw quite few of them on our way. Unfortunately the swamps were all off the road and hence we were not allowed to get close to them; what a pity – I tried to imagine what all birds and animals would have taken refuge in the oases.

The contrasting landscape
The desiccation...

And the swamp land
What causes the contrasting terrain – Google comes to my aid as I try to find out later. Though the park lies in a closed drainage system where no major surface streams flow into the basin; the arid landscape belies the reality - believe it or not Amboseli has an endless water supply from Kilimanjaro's ice caps! Snowfall, which occurs on the upper elevations of the mountain’s landmass, feeds the age-old glaciers on the summit. On the lower forested slopes, the snowfall turns to rain, and the porosity of the soaked volcanic soil combined with the structure of the rocks beneath, act like a drainage bed allowing the water to percolate through the soils, converging sometimes as underground streams, to appear at the base as springs around the foothills. The flowing water rise in two clear springs at the centre of the park that provide a permanent water supply, even in drought. At Amboseli, where the country is so level, the water from these springs also ooze out at several points giving birth to (in many cases permanent) swamps. The swamps could also be formed when rains fall directly on the plains and the fine wet soil creates a surface seal to trap the water in pools. Since these wetlands contain water tolerant wooded trees, they are called swamps instead of marshes (marshes have no trees, but contain only grasses, reeds and sedges). Since recorded history, Maasai have used these swamps to water their livestock. And I thought oases are to be found only on sand deserts!

Death by salt, pachyderm or simply age catching up?
As we travelled through this weird landscape of dusty nothingness, savannah grasslands, swamps and an occasional tree, we saw two zebras standing under a desiccated tree in donkey like meditating stance (the Kiswahili word for zebra punda milia means a streaked punda or donkey). What was striking about the scene was not the zebras but the weakened tree – one mighty branch had already broken away and was lying at its foot. As we noticed more and more, there were scores of trees which seemed to have uprooted all by themselves. Andrew affirmed it was nature itself that was causing this havoc and it was quite a common phenomenon with trees at Amboseli.
Weakened tree
The enigmas of the land required some probing and I set out on the internet to unravel the mystery (or probably mysteries - there seems to be more to the land than can be fully understood). The land is witnessing more than one change. The rains are failing, unpredictably, approximately one year out of five causing short-term climate changes. These are occurring against a backdrop of larger scale ecological changes accumulating over decades – daily temperature increases (in the past 30 years, the daily high temperatures have increased by more than 7ยบ C) and the water table rises due to shrinking ice caps in Mt. Kilimanjaro. Over the past half century, the number and size of swamps and pools in the Amboseli basin have increased, previously widespread acacia woodlands have been dramatically reduced and replaced by grassland and halophytic vegetation (plants growing naturally in very salty soil). From what I could gather, there is a big paradox here – the desert is increasing and the swamps are increasing! With climate change, habitat change for fauna is bound to happen – as has been observed in baboons and elephants that are responding to the change by moving to more wooded areas of the park.
Tree die-off is a common feature of the land
What is causing this massive tree die-off? There is no one clear answer. Some believe that the numerous elephants in Amboseli, as elsewhere, may be killing these large yellow barked acacia trees, also known as fever trees. Strangely the fever tree is so-called because of its association with damp areas where mosquitoes, and therefore often also malaria, thrive. Early visitors to Africa were sure these trees were the cause of malaria!

Many do not agree that the deaths can be attributed solely to pachyderms. The closed basin, extremely flat topography and the fact that the area acts like a sink for both surface and ground water causes salt in the water to be concentrated, making the soil saline (and hence the saline grass growing on it to herbivores’ delight). Increased soil salinity, associated with a period of higher rainfall (which further disperses the salt) and a rising ground water-table causes partial drowning of established root systems in the case of trees (whereas grasses survive), producing a killing stress for them. Elephants then accelerate the process, as they feed in the groves of dead and weakened trees.

There is a third view as well. Rapid die off of trees in the Amboseli basin as well as in other African woodlands may be due to natural synchronous senescence of even-age stands. Woodlands in Africa are often even-aged as a result of synchronous seedling establishment after a fire or during a series of favourable years! Consequently all trees in the stand reach maturity at approximately the same time and also die at the same time - in a synchronous dramatic fashion. Like everywhere else, as plants senesce, they lose their ability to survive stress, and environmental stresses then act as enhancers of senescence. As compared to an old tree, a young fever tree may not be as heavily impacted with rising water table because its root system will be better distributed above the table. So are tree die-offs here simply a case of age catching up together on the similar aged trees?

The water sniffers and their air conditioned mansions
A conspicuous feature of the land was big termite mounds rising from the ground, the brown clay hills often mistakenly referred to as 'ant hills' by many (including myself till I started writing this piece). Though termites go by the common name of ‘white ants’, ants and termites are only distant cousins (cockroach is the closer cousin to termite); and ant colonies often invade termite mounds. It is incredible that a drab looking termitary (that's the correct word for it) - sealed and devoid of vegetation - conceals such a complicated structure inside. Built with fine grained soil and saliva, it is a full scale mansion with underground nest, consisting of numerous gallery chambers, and complete with even a nursery to keep eggs! There could be thousands (or even millions) inside a colony silently doing the job they have been entrusted with, being such unwavering followers of the caste system (like ants, bees and wasps). I imagined how one such bustling colony would have started one quiet night with the queen and king taking off, surviving the flight (most rarely do) and burrowing there, the enormous queen in the royal nest now producing more and more offspring (thousands of eggs per day) to add to the team of blind wingless workers and soldiers; the workers busy grooming and feeding others, digging tunnels, locating food and water, building and repairing the nest - and the soldiers ready with their glue-like secretion to bite at any opponent.

Termite mounds can be as high as 9 m or 30 ft - if this was scaled up to human terms, that would be like building a structure 2 km or 1.25 miles high. The mounds are built with a long tube at the top that looks like a small chimney or smokestack. They are sturdy, too. When termite mounds are found to be in the way of building projects, dynamite is often needed to remove them!

In some parts of Africa, there may be as many as 10,000 termites to a square metre of soil surface; and in the savannah, they have a super critical role to play. Acting as highly efficient decomposers; they return the plant nutrients of wood, bark, straw etc to the soil through their faeces and saliva, in the process clearing away leaf and woody litter and reducing the severity of the annual bush fires. The termite's exquisite tunnelling ability aerates soil and loosens up compacted soils in areas where plant life is no longer viable. They can live symbiotically with certain bacteria that are able to fix atmospheric nitrogen and may play a role in enhancing soil fertility locally. And that's not all - the chewed woody material from which termite nests are made supplies nourishment to an edible mushroom species which have specific, binding associations with termites. The termites cultivate them in fungus gardens and termite young sometimes graze on these gardens like miniature sheep - the mansions have their private gardens too!

The U.S. Department of Energy is looking at termites to help come out with breakthroughs on renewable sources of cleaner energy. They may produce up to two litres of hydrogen from digesting a single sheet of paper, making them one of the planet’s most efficient bioreactors. They are able to digest cellulose in woody fibres (as many know by the extensive building damage that the insects have caused) by exploiting the metabolic capabilities of about 200 different species of microbes that inhabit their hindguts.

The mansion extraordinaire has one more marvel hidden inside - a well planned HVAC (heating, ventilation and air conditioning) system with an extensive network of tunnels, conduits, columns and shafts; generating complicated air flow patterns somewhat similar to those by a human lung! Termite ‘cities’ found in arid climates remain moist in the underground nest all year round. The termites have the ability to move their colony up and down in the soil to find the optimal temperature and moisture conditions. They construct long tunnels, often tens of metres long, down to the water table to access water. Varaha Mihira (505 AD- 587 AD), the famous astronomer, mathematician, and astrologer of India, in his treatise "Brihat Samhita," refers to dakargala (Sanskrit word meaning “science of underground water exploration”), wherein the role of termite hills, as an indicator of underground water has been elaborately explained. As he had said, “a well-developed, active, permanent colony of mound-building termites can be taken as an indication of underground springs in proximity”, the termite mounds in Amboseli amply testify to its underground water reserve. And little wonder then that the mounds are valued even after they are abandoned - usually only after the fertile queen dies or is killed - by plants and animals alike; for their moistness, temperature control, soil fertility and elevation (the last one offers protection from flooding and forest fires).

Imagine for a moment a termite mound on the African savannah, where temperatures swing between 40°C (104°F) during the day and 1°C (34°F) at night. Termites survive only if their environment has a constant temperature of 30°C (86°F) and that is the temperature at which their fungus farms survive as well. Both not only manage to survive but thrive - have been thriving since the days of the dinosaurs. That raises the question why we, with all our intellect and wisdom, can only create houses with fans, air blowers, and air conditioners; and buildings that use 40% of all energy consumed by us. It is time that we learnt the science and art of energy efficient housing from the master architects.

References:

As always Wikipedia
A Traveller’s Guide to Wildflowers and Common Trees of East Africa by David J Allen

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