Dr Abe V Rotor
Blackbird Martinez (Turdus merula), Drynaria fern and towering acacia tree make an
ecological sanctuary, together with a host of other organisms that depend on them.
Tagudin, Ilocos Sur.
This is one for the biologist and ecologist. I say, it's one for the Book of Guinness record.
Up high in a dozen centuries old acacia trees, reaching up to 10 storeys high, their boughs and branches clothed with epiphytic ferns, I found the long lost blackbirds, we call martinez in Ilocano.
I was then in the grade school in San Vicente (Ilocos Sur) when I saw the last martines bird. But here on a Black Friday on top of these towering trees, there is the lost bird, in fact several of them in pairs and families. It is like the Coelacanth, a primitive fish thought to have long been extinct, suddenly rising from the depth of the craggy Madagascar sea. Its fossil in rock tells us it is 40 million years old. And here it is - alive and has not changed! The fossil fish is alive! So with the Martinez!
The blackbirds have made the towering acacia trees their home and natural habitat, building their nests on the Drynaria fern. The fern grows on the branches, reaching the peak of its growth during the rainy season when the host tree sheds its leaves, in effect allowing sunlight to nurture the fern.
The fern has dimorphic leaves. The primary ones are long and shaped like stag horn and bear sori or spore sacs, while the other kind is shaped and arranged like shingles, enclosing the fern's rhizome. Like all ferns, Drynaria undergoes alternation of generations - the spore-forming phase and gamete-forming phase. It is the sporophytic or asexual generation that the fern plant is familiar to us. It is typically made of roots, stems and leaves - but never flowers and fruits. It is for this that ferns are classified separately from seed-forming and flowering plants. They belong to Division Pterophyta.
Blackbird Martinez (Turdus merula)
In the dry season, the fern becomes dormant, appearing dry and lifeless from the outside, but shielded by the shingles the fleshy rhizome waits for the rain and sunlight - and the shedding of the host tree. Then almost at an instant the fern springs to life, carpeting entire boughs and branches.Now it's the tree's turn. In summer, while the fern is dormant, it builds a new crown, and together with those of the adjoining trees form a huge canopy that makes a perfect shade. This could be one reason the friars in the 15th century thought of introducing the acacia (Samanea saman) from Mexico to be planted around churches and convents.
Not only that the acacia is the biggest legume in the world; it is self-fertilizing and self supporting, and sharing its resources to countless organisms from earthworm to humans. How is this possible?
The acacia harbors in its roots symbionts - Rhizobium bacteria that convert the element Nitrogen (N) into Nitrate (NO3). Only then can N that comprises 78 percent of the air we breathe can be used by plants to manufacture food by photosynthesis.
And with the deciduous character of the tree, dead leaves form a litter on the ground that makes a good mulch and later becomes compost - a natural fertilizer for the tree, surrounding plants, microorganisms and animals. Then as the pods of the tree ripen and drop to the ground, animals like goats come around to feed on them and in effect enrich the ground. The tree's efficient physiology and symbiotic potential with other organisms make it not only one of the most self-reliant trees in the world, but a miniature ecosystem in itself.
We see today very old acacia trees in these places, just like those around the old St Agustine church in Tagudin built in the 16th century where I found the blackbirds among the Drynaria ferns at their tops. Tagudin is the southernmost town of Ilocos Sur, some 330 kilometers north of Manila - a good five-hour drive. It continues to attract northbound tourists to have a stopover and see this spectacle, among other attractions of this old town, such as its native handicrafts, pristine seashore and progressive upland agriculture.
Going back to the blackbirds, why do we give much importance to them? Well, the blackbirds protect both tree and fern from insects and other pests, and fertilize them with their droppings. They too, are gleaners and help keep the environment clean. Unlike the house sparrow, ground fowls and the crow, they are not nuisance to the place; their presence is barely felt except for their occasional calls which sound quite sonorous but nonetheless pleasant, and their display during flight of a queer pair of white spots on their wings. I developed the liking to watch them for hours - their gentle movement, familial ways, although they do not as gregarious as pigeons, and their glossy black bodies distinct from the surrounding and against the sky. They make a good specimen for bird watching and photography.
Beyond the aesthetics about the bird, I learned from my good friend Dr. Anselmo Set Cabigan, a fellow biologist and science professor, that the martinez was introduced from Guam on instruction of a Spanish Governor General to control locust infestation in the Philippines. This is the first case of applying the principle of biological control in the Philippines - and perhaps elsewhere - which was then too advance in its time. Today, biological control is practiced worldwide as part of Integrated Pest Management (IPM), a holistic approach in dealing with all kinds of pests which include pathogens.
Locust (Locusta migratoria manilensis) is a scourge to agriculture in many countries since prehistoric times. I have witnessed how a swarm of locust devour complete fields of rice and corn, and other crops overnight. During swarming the sky darkens as sheer numbers of these flying insects block the sky. And as they ride on the wind they produce a deafening hissing sound that adds terror to farmers and inhabitants.
And why was the martinez bird the chosen nemesis of the locust? It clearly shows the efficiency of this predator. Actually predation is most effective when the locust is still in its non-migratory phase, specifically during the congegans - more so when it is in the solitaria phase. The bird immediately checks the pest before it develops into enormous population - and reach its swarming stage.
I believe that the triad formed by the acacia tree, Drynaria fern and the blackbirds is the beginning of an emerging ecosystem where wildlife and human settlement meet in cooperation and harmony. It is a zone where Nature re-builds spent environments and creates intermediate types, in which the role of man is basically to let nature's laws and rules to prevail. For example, doves and pigeons in public squares and plazas in many parts of the world are learning to trust people, and many people are just too happy to share their homes and other resources with them. They are planting trees and setting up more and wider parks for the wildlife.
For one, Japan now requires the greening of rooftops of buildings through gardening dubbed aeroponics, and by putting up ecological sanctuaries to attract wildlife to settle in them. In Europe on the other hand, miles and miles of hedges have evolved into a unique ecosystem, that one can no longer differentiate a well-established hedge from a natural vegetation. Also in Europe, woodlands which are actually broad strips that serve as boundaries of fields and pastures, are gaining through time higher biodiversity levels, and moving towards dynamic stability, called in ecology as homeostasis.
The Philippines is not behind. We have multi-storey orchards in Cavite, Batangas and Laguna that simulate the structure of a tropical rain forest long before the term ecology was coined. And many basins of ricefields and sumps of irrigation systems have become natural ponds.
The 38th parallel dividing the whole length of warring North Korea and South Korea – a strip of no man’s land, twenty kilometers at its widest – has developed, since the armistice in 1958, into a natural wildlife sanctuary. Today it has a very high level of biodiversity and distinct from any reservation on either side of this highly restricted boundary.
These neo-ecological zones are sprouting from backyards, parks, submerged coastlines, denuded mountains, and the like. Even contiguous idle lots – and abandoned fishponds, farms and settlements - are slowly but steadily becoming bastions of wildlife.
Truly, the case of the centuries old acacia trees where the Drynaria and the martinez birds, and man living with them in peace and in harmony - is a manifestation of Nature's triumph. It is triumph to us and the living world. ~
Grotesque looking acacia tree clothed with Drynaria ferntowers over church and convent in Tagudin, Ilocos Sur.
Photographs taken with an SLR Digital Camera with 300 mm telephoto lens.
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