September 1901.SEPTEMBER 1901.
SEPTEMBER 1901.
TheRock has taken on quite a wintry appearance. The vegetation on the more exposed portions has entirely disappeared under the influence of the heavy seas experienced during the greater part of this month. The acorn barnacles with which the higher parts were encrusted are following suit owing to the ravages of the white whelk; the terns have deserted us, and, to complete the prospect, on the morning of the 19th we had the first visit of our winter boarders, the eider duck. A chip of rock covered with acorn barnacles becomes an interesting object when placed in the aquarium. Each conical shell is packed as close as possible to its neighbour, apex upwards. The apex is open, and fitted with a lid composed of four shells. Under water these lid-shells are seen to separate, and a bunch of “fingers” set on a stalk are thrust out, make a clutch, and are withdrawn. The “fingers” have extremely fine hair-like processes fixed at right angles to them, the whole forming a sort of net through which the water is filtered and the minute food-forms retained. It is interesting to know that although now fixed immovably to the rock these animals began life as free swimmers, and, strange to say, closely resembled the young crab. Another object we had under observation at the same time was one of the sea anemones, named the dahlia wartlet. A fleshy-looking disc studded with pieces of broken shell and sand, it appeared anything but attractive; but seen in the aquarium, the connection with its floral namesake was at once apparent. Unfolding itself from an orifice in the centre, as one would “flype” a stocking, rows of beautiful coloured tentacles were disclosed. These tentacles have the property of adhering to any object they come in contact with, and contain within themselves some wonderful mechanism. Placing a fly on the extremity of one of the tentacles, it was immediately held fast. The whole of the tentacles then curled inwards, carrying the fly with them, thus clearly showing their function.
The heavy easterly surf has deprived us for the present of our fishing, forcing the fish off the rock to deeper water. There are evidently plenty about, as the gannets are to be seen busy diving in the vicinity. It is extremely interesting to watch these birds pursuing their prey. Flitting near the surface, they enter the water at an angle of about twenty degrees; again, at a higher altitude, they drop like a plummet, describing an arc of bubbling foam from their entrance to where they emerge with a bounce a few feet further ahead, beating the water with their wings for several yards before being again fairly on the wing. The air cells pervading various parts of the body of a bird, and which contribute to its buoyancy, are probably vested in a greater degree in the gannet, an extremely large one being situated in front of the forked bone, or clavicles. Several instances are recorded where a bird which had its windpipe temporarily obstructed was able, by means of these cells, to carry on the function of respiration through the wing bone, the broken end of which protruded through the skin. The voluntary compression of these cells, by expelling the air, destroys the buoyancy of the bird, and explains the amazing rapidity of its descent. An objectionable method is practised in some places for the capture of these birds. A submerged piece of planking with a herring fixed to its upper surface is set adrift, or towed from a boat, in the vicinity of their fishing grounds. Swooping from an altitude, say, of a hundred feet, they apparently see but the herring alone, with the result that their necks are dislocated by impact with the plank, the impetus of their descent being sometimes so great as to bury their bills to the base in the wood. It is a common sight here, during the breeding season, to see these birds trooping past in Indian file to their home on the Bass Rock, in batches of a dozen or so, each preserving a regular distance from his neighbour. Though I have frequently watched them pursuing their vocation, I have never seen them bring their prey to the surface, nor could I say whether their dive was successful or not; but occasionally they emerge from their dive with a satisfied “honk,” which may be translated “got ’im.” Gifted with an insatiable appetite, they sometimes gorge themselves to such an extent as to be incapable of rising from the water, when they may be easily captured, as they make no attempt to dive. An instance of this was witnessed by a large crowd one Sunday, a few summers ago, in Arbroath Harbour. Some conception of the carrying capacity of these birds may be had when it is known that a sitting mother bird has been seen to insert her bill into the inviting mouth of her returned partner and deftly extract, one by one, as many as six full-grown herring.
A “false alarm” was occasioned at the end of last month by two cormorants or scarts appropriating the signal poles as a roosting-place. One of these poles is fixed on either side of the balcony, and projects horizontally. When a signal is made from the Rock, two-feet discs are suspended from them in pre-arranged positions. A wire stay from the balcony railing supports the extremity of each pole, and on this stay the birds were seated, one at the outer end, the other in the middle. Discs in this position, but pendant from the pole, by our code reads “Send boat,” and this the keeper on shore duty in Arbroath construed it to be and acted accordingly, with the result that we were somewhat alarmed by the appearance of the harbour tug about eleven the same evening. Our impression was that something serious had happened on shore, and that one of our number was urgently wanted. On the tug hailing us, and saying they had been sent out in response to signals shown from the Rock that afternoon, our minds reverted to the birds, and our fears set at rest. Considerable alarm prevailed amongst our families, and not until the tug returned with the news that “All was well on the Rock” were their fears allayed.
On the morning of the 27th the sea round the Rock was seen to be strewn with apples, a few dozen of which we managed to secure. Their presence here is a mystery, and we trust has no connection with the long spell of fog we have had. On the 24th we completed a fusillade of forty hours, a record run of fog.