Monthly Archives: August 2017

The mistletoe bird

It is one of those little plants that you hardly notice in the rainforest. It perches on tree branches, like a sea fan on a coral boulder, like a Christmas decoration. At a glance, it seems like another tassel of twigs and leaves emerging from the tree. But look closer and you see that its leaves are smaller and a paler green, tinged with coppery yellow, unlike the tree’s longer, parrot-green leaves. On the tree’s brown branch powdered with white lichen, the little plant arises out of a swollen bulb-like base, holding out dark brown twigs dusted with white spots, like chocolate sprinkled with sugar. Clusters of pinkish-red berries and buds line the smaller plant’s twigs, on the tree bereft of fruit or bud.

The clutch of leaves, berries, and flowers are on the tree, but are not of the tree itself. The little plant is an epiphyte: a plant that grows on other plants. It is a mistletoe.

In the company of mistletoes lives an unassuming little bird that you hardly notice in the rainforest. A tiny bird, small enough to hide behind a leaf or to hold in a closed fist, and drab enough to escape the attention of anyone but an ardent birdwatcher. An undistinguished little bird, dull olive brown above, rather dingy white below, with sharp eyes, glinting dark and attentive, and a sharp beak, gently curved to a point to poke among the flowers. A metallic, fidgety tick-tick-tick call announces her presence as she darts through the boughs. You have to be quick to spot her before she disappears. In keeping with her modest appearance, birdwatchers call this species the plain flowerpecker.

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Small enough to hide behind a leaf, a Plain Flowerpecker, in Dampa Tiger Reserve, Mizoram

I’ve traveled far from my home in the mountains of the Western Ghats in southern India to see this flowerpecker. And not just any plain flowerpecker, but a particular one: a bird flitting among the mistletoes on the same trees where I had seen the species two decades earlier. I am seated on the steps of the Dampatlang watchtower in Dampa Tiger Reserve in Mizoram, northeast India. Twenty years ago, I had spent many quiet, contented hours watching birds around me from the same steps while camping here for fieldwork. To the south, steep cliffs plunge to Tuichar valley. An evergreen forest with many trees adorned with mistletoes surrounds me on three sides.

Alongside the watchtower grow two small orange trees and a straggling Holmskioldia holding bunches of scarlet cup-and-saucer blooms. Against the wild forest backdrop, the planted orange and cup-and-saucer plant marked what seemed a very human temperament to cultivate and ornament the lands we live in.

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Pale-billed Flowerpecker with a fruit of the Singapore cherry Muntingia calabura in southern India.

Seated two stories high, I am almost eye-to-eye with the flowerpecker. The bird flits from branch to branch, dives into each mistletoe cluster, peeking, probing, seeking with eye and beak. Flowerpeckers remain closely tied to the mistletoes on the trees within their territories spanning a few hectares at most. The birds consume mistletoe flower nectar and fruits, but this is a two-way relationship. The plant, too, gains when the birds pollinate its flowers and disperse its seeds.

Many mistletoes have tube-like flowers that, when probed by a flowerpecker beak, part like a curtain or pop open furling the petals down and thrusting the stamens out to dust the bird’s head and face with pollen. After the bird sips the sugary nectar with a special tube-like tongue (who needs a straw when your tongue itself is rolled into one?) and flies over to probe other flowers of the same mistletoe species, some of the carried pollen may rub off on receptive female parts, triggering the latter plant’s reproduction.

Despite this penchant for flowers and the bird’s name itself, the flowerpecker remains, at heart, a fruit-lover. Mistletoes often have long and overlapping flowering and fruiting seasons so there is always food for a hungry flowerpecker to find. Ripe mistletoe fruit never fails to attract flowerpeckers.

Mistletoes represent a group of over 1300 plant species worldwide belonging to five families, chiefly the Families Loranthaceae and Viscaceae. As the latter name suggests, the fruits are viscid, the usually single seed surrounded by a sticky pulp, often enclosed in a rind-like peel.

The plain flowerpecker and its close cousin in southern India, the Nilgiri flowerpecker, manipulate mistletoe fruits in their beaks to gently squeeze the seed from the pulp. They swallow the sugary, nutritious pulp and wipe their bills on twigs to remove the sticky seed. If the flowerpecker swallows the fruit, the seed passes rapidly through the bird’s gut to be excreted out. To remove the still sticky seed, the birds wipe their rears on twigs or tree branches. In either case, these actions have the same result, which biologists call ‘directed dispersal’: the mistletoe seed gets planted where it is likely to germinate.

Nilgiri flowerpecker planting a mistletoe seed. Photos by Kalyan Varma (http://kalyanvarma.net).

Mistletoes are also partial parasites. They synthesize their own food through photosynthesis, but their special roots draw water and nutrients from the host tree on which they are perched. Extreme infestation of trees by mistletoes is rare in natural forests, occurring more often in degraded or managed forests and monoculture plantations. Still, foresters and others concerned with production of timber or fruits from trees sometimes call for mistletoes to be removed or eradicated.

Recent research suggests that this may be unwarranted. In forests, falling mistletoe leaves add vital nutrients to soil under the trees where they grow. Experimental removal of mistletoes causes a cascade of harmful impacts including declines in soil nutrients and populations of other species. Besides flowerpeckers, mistletoes sustain a large number of other species worldwide. The barbet-like tinkerbirds of Africa, the mistletoebird and honeyeaters of Australia, the sunbirds and white-eyes of Asia, mouse lemurs and sifakas of Madagascar, tyrant and silky flycatchers and colocolo opossums of the Americas, the eponymous mistle thrush of Europe, myriad insects and other creatures—all find food and spaces for hunting or nesting in mistletoes.

Plain flowerpecker with a mistletoe fruit in Dampa Tiger Reserve, Mizoram.

Back at the watchtower, I watch the feisty flowerpeckers defend their mistletoes, darting at intruders who entered their territories, chasing after them zipping between branches with rapid ticking calls. Fighting flowerpeckers have been known to fall to the ground while grappling fiercely with each other. One imagines their raging little hearts beating furiously, as they flay and peck at each other to defend what they perceive as their own.

Together, the flowerpecker and mistletoe epitomise an irreplaceable vitality of the forest.

An hour later, as I leave the watchtower, I sense that there is more to it than just a symbiotic evolutionary link between bird and mistletoe in a forest webbed with ecological connections. Perhaps, behind the gleam of that flowerpecker’s eye, there resides, too, a temperament to cultivate and protect what she consumes and an aesthetic to adorn the trees in her forest with the prettiest little plants she can find.

An edited version of this article appeared on 19 August 2017 on Scroll.in.