The Plumbeous Water Redstart

The Plumbeous Water Redstart is the most "action-packed" of any aquatic stream bird in defending its territory.

A study of the bird's ecology and living habits published by the Biology Department at National Taiwan Normal University points out that males have a clear sense of territoriality and will quarrel with each other across a commonly recognized border. The squabbles often get started when one male finds that a neighboring male has approached too close to the border. He will fly up to his side of the border at once and let out a series of sharp, rapid cries. The other will respond with a similar cry and fly towards the other, and that's the way the quarrel begins.

Both birds will squawk and hop towards the other with their wings pressed against their bodies. And sometimes one will stand quiet and motionless while the other goes through his routine as though they were taking turns.

Fortunately, it's extremely rare that they exhibit violent behavior toward birds of their own kind. Both sides usually carry out a "no-contact" but also "no-compromise" war across a DMZ of about twenty centimeters.

How does this battle between noncombatants come to a halt? While putting on their intimidating exhibitions, the birds gradually draw apart until one side simply gives up and leaves.

So what determines who wins and who loses? Birdwatchers have no answer. But it's clear that territorial disputes occur only between males. The rest of the family just stands by and watches, providing moral support perhaps.

The birds' territories are normally less than 190 meters in diameter because a larger area would entail the expenditure of too much energy in border patrol work, taxing the bird's strength and giving his antagonist an advantage.

The Plumbeous Water Redstart (Rhyacornis fuliginosus affinis) is found at an altitude of around 2,000 meters above sea level among creeks and ravines on the lower slopes of Taiwan's mountains, in what are more or less closed-off little worlds in the greater natural environment. Because the banks have been eroded and are poor in nutriments, NTNU biology professor Wang Ying says, the variety and quantity of life in the ravines are limited and the food chain is simple.

That limited space has its advantages for birdwatchers. "As long as you find a place with the right kind of topography, you can just sit back and wait," says Liu K'e-hsiang, a birdlover who believes that stream birds are the easiest kind of birds to observe.

And the feisty little Redstart is considered the stream bird most fascinating to watch. Besides threatening and intimidating members of their own species, Redstarts are quite merciless in attacking other birds that infringe on their territory and sometimes scare even the bigger ones off. Birds from up the mountain that pass through without knowing the situation may find themselves short of feathers.

Despite the occasional tussle, Redstarts actually don't like to spend a lot of energy fighting over territory because finding food is their biggest job.

Their main foodstuff is the insects that glide along the surface of the stream. In Chinese the saying goes, "The early bird catches the bug," but in this case it's not true because the insects are most active in the afternoon. That's when the birds do most of their catching--up to one hundred in an hour, although the top mark recorded is 340 in 50 minutes, about seven bugs a minute.

Redstarts are monogamous, and they mate and reproduce each year from February to July. They build their nests in the morning, when the insects are less active. The female picks the spot, usually in a crack or crevice in the creek bank. Each female lays from two to four eggs, which hatch in five to eight days, depending on the temperature.

Although they live in a small world with few natural enemies, their habitat is not a shangri-la unaffected by the outside world. On the contrary, just because the food chain is so simple, a change in the outside environment that disturbs a single link can destroy the whole chain.

Think about it: a mother bird, exhausted from sleepless nights and the travails of labor, forces herself to pick up her spirits and look cheerful. She has no idea that what she's worked so hard to bring into the world are just "rotten little eggs" that won't develop into healthy chicks....

Do you want this kind of a scenario to come true?

[Picture Caption]

Cleaning up after making a "pit stop" on a convenient rock. Shown is a male. (photo by Kuo Chih-yung)

The female's plumage, not as brilliant as the male's, looks leaden-gray from a distance. (photo by Wang Chia-hsiung)

The chicks have speckled bellies and breasts. (photo by Wang Chia-hsiung)

The female's plumage, not as brilliant as the male's, looks leaden-gray from a distance. （photo by Wang Chia-hsiung）

The chicks have speckled bellies and breasts. （photo by Wang Chia-hsiung）