Birds of the Water Wood & Waste
The Mountain Duck
The Mountain Duck
The geographical formation of Tutira—conglomerate and limestone superposed on “papa”—is well suited to the “Blue,” or “Mountain Duck.” Throughout the centuries our streams have chafed through the harder limestone and deeply eaten into the soft clay rock. The more open and larger streams are full of immense limestone boulders borne down on land slips, the narrower gorges quite precipitous are mostly pebble paved, their little tumbling streams completely overarched in parts with tutu, koromiko, and fern.page 42
In many of these latter every stretch of three or four miles supports a pair of Blue Ducks, whilst in our largest stream, the Waikahau, there is a far larger carrying capacity, and several pair breed there on a mile or two of water. This species lays early, and there must be many nests in August.
This season our first lot of ducklings were marked on September 27th—a brood of three or four—the young being then about a fortnight old. On October 1st another brood was seen about the same place. On October 8th, some miles up the river, I watched for long a family of four—ten days old, I daresay, the ducklings showing much white about front of throat and breast and side of face.
The two old birds, while the ducklings played and dived and fed, floated motionless, or paddled slowly about the calm, unruffled surface, every now and then one of them in play making hostile feints at the other.
Above the great rock where I lay, a shining Cuckoo hawked for flies, a Warbler trilled at intervals in the tall manuka, and the shadows of great white clouds darkened in patches the whole country side.
On October 13th I got a nest just vacated. There was still one whole egg— addled—and a dead duckling half out of the shell, quite undecayed, and not even flyblown; the nest must have been tenanted within two or three hours of my discovery.
It was situated close to the Waikahau stream, and hidden under an immense rush bush on the very edge of a sandy cliff. There, cosy, warm, and dry, beneath page 44 this natural thatch, was the hollow containing the nest.
On the upper side of this ancient rush bush passed an almost imperceptible trail, which doubtless the duck would follow when entering her nest. Along it she would steal in the dim lights of morn and eve, and just opposite the nest fade herself away and disappear on to the beloved eggs.
On the river side, and just overhanging the cliff was the flight hole from the felted growths of rush. The duck would reach her eggs as I have suggested, by the trail, and leave them on the wing, dropping quietly into the pool below.
Round these eggs there was rather less down than is usually found about the eggs of the Scaup or Grey Duck.
The nest hollow was shallower, too, and close by it was another similar cavity, suggesting that possibly the male had spent part of the period of incubation in close proximity to his mate. Their cliff was of flood sand, built up in past years by the stream, and now again in process of demolition, and its composition just such as the Kingfisher also loves, velvet soft and page 45 warm. These Mountain Duck may use the same nest in recurring years, for on river brim, and directly beneath the nesting site, the tiny bits of broken eggshell that first drew my notice were of last year's eggs.
Immediately after leaving the nest, the young are very carefully hidden by day, and in our streams chance only discovers them.
In these boulder cumbered creeks there are endless harbours and refuges, ceilings of limestone, with only room for the birds to crouch on the water floor, potholes scooped by the action of sand and grit, hollows and arches gouged by the current's force, and everywhere along the banks thickets of water growth and hanging fern.
On October 15th a second Blue Duck's nest was got, and this one also was placed just about, though not above, high-level flood mark. Certain types of this river silt are apparently so great an attraction that the Mountain Duck will risk abnormal floods for its advantages.
These birds had chosen for cover a bush of mountain flax, and beneath old dead blades and on the warm, weset, moist river page 46 drift were deposited the four nearly fresh eggs.
The down about these eggs was largely mixed with particles of soft bark and fibre, perhaps inadvertently picked up in the daily uncoverings of the nest, or perhaps to eke out the rather scanty quantity of down. This nest was deserted, the duck having been badly frightened by the rabbiter's dog that flushed her.
After photography, however, the nest was left undisturbed for twenty-four hours, in the hope that the birds might yet return. The colour of Mountain Duck's eggs is pale brownish cream, and their average weight 1088 grains.
On October 29th I find in my diary another entry of Blue Duck marked on the same river reach as the three already mentioned.
This brood consisted of five birds almost full fledged. Four is about the average, perhaps, but three years ago on a forest stream some miles from the homestead there was one brood of six and another of nine.
On November 2nd we experienced for about the seventieth time seven how many a slip there is between cup and lip in this kind of photographic work.page break page break page 47
Often and often have I gently driven for amusement or to show to friends some family of Mountain Ducks up or down stream to some convenient crossing or open reach. We did this on the 2nd, quite easily driving them down the creek and sweeping them from pool to pool till the selected spot was reached. Then, while the camera was being adjusted, an eye was kept on the parent birds, and we were satisfied from time to time with glimpses of them half hidden in the bastard flax that drooped into the stream. Alas! however, when all was complete, the young were gone, vanished! We never again saw them, and the parents only hung about the spot till they knew their brood was perfectly safe, when they, too, decamped.
Later, an examination of the opposite river bank, where we had forced the ducks to pause, proved that they had been blocked by ill luck exactly at one of their bank refuges. The edges were quite paddled with trampling, and no doubt the young had escaped by some well-known run up the rough cliffs, and dropped again quietly into the stream above or below us.page 48
A similar catastrophe all but occurred again a few days later. Another brood had been marked and gently drifted down stream to the chosen pool, yet, even while the camera was being unpacked and fixed, the birds were gone. After long search, however, I found the two youngsters hidden between great limestone rocks, a strong stream breaking over them, and only their heads visible. It was not until my hands were upon them that any movement was made, then they splashed off, diving like frightened trout.
After their reappearance, however, there was no further attempt at concealment. They never again tried to escape by flight or by diving, and quietly allowed us to photograph them.