Nightingale Island Research Articles

The fauna of the mid-Atlantic islands

Tristan da Cunha, Nightingale, Inaccessible, and Gough Islands are the only Atlantic oceanic islands lying within the southern cold temperate zone. Their relative positions, and the situation of the group as a whole, are shown in figure 49. All of them are volcanic, and probably initially of Tertiary age (Dunne 1941; Le Maitre 1959). There is no historic record of activity but Tristan retains a central cone and well-preserved lateral cinder cones which appear of recent origin. Undated ash bands occur in the peats of this island, and a small, rather broken cone (Edinburgh Peak) on Gough Island may have been the source of an ash band in peat dated by the radiocarbon method as 2345 ± 130 years old (Hafsten, this Discussion). The other two islands show no trace of recent volcanicity. All the members of the group rise steeply from deep water, and there is no sign of previous land links between them

A review of some ticks (Acarina: Ixodidae) of sea birds. Part II. The taxonomic problems associated with the Ixodes auritulus-percavatus group of species.

1. Ixodes auritulus group of ticks and Ixodes percavatus group of ticks are both characterized by having the palpal article I drawn out to a horn anteriorly, but in the percavatus group there is a strong meso-dorsal ‘spur’ on this article, which is lacking in the auritulus group.2. The mutilated types of I. auritulus and I. percavatus sp. revocata are re-described and electotypes established for both.3. Variations from I. auritulus sensu stricto are described from Peru and Guatemala, and a revised description given of the male, female and nymph from Snares Island.4. I. percavatus and I. zumpti sp.nov. have been diagnosed from material from Nightingale Island, Tristan da Cunha. Ticks from Marion Island are identified as a new species, I. pterodromae. Female and nymphs from the Paris Museum originally identified by Neumann as I. auritulus now fall into the percavatus group and are named I. cornuae sp.nov.

THE GREATER SHEARWATER PUFFINUS GRAVIS AT‘ ITS BREEDING GROUNDS.

Summary. An account is given of the breeding cycle of the Greater Shearwater, with speciat reference to the colony (estimated at 4,000,000 breeding birds) at Nightingale Island in the Tristan da Cunha group. The birds arrive at the breeding grounds during late August and September. There is a brief laying season during the second week of November and the chicks hatch early in January. In April the adults desert their young, when they are full–grown but still in down. Fully feathered juveniles are found at the beginning of May and start flying towards the end of the first week of May. As far as is known the juveniles have all left the breeding grounds by early June. Special points of interest relating to the breeding cycle are:.‐(a) The presence of Greater Sheanvaters at the breeding grounds in large numbers at least one–and–a–half months in advance of the laying season. (b) The overcrowding of the breeding grounds at Nightingale. (c) The courtship ceremonies. (d) A strongly developed diurnal habit during the breeding season, although the birds are most active after 4 p.m. (local time) and at night. (e) The presence of large numbers of juveniles at the breeding grounds during May. (f) The apparent absence of adults from their burrows. from mid–April onwards. The occurrence of the Greater Sheanvater at the north–easterly limits of its range at the time breeding IS beginning suggests that a proportion of the population fails to breed each year, and that the main return from the north takes place in mid–ocean, and down the west side of the Atlantic, mainly in August. Flight and locomotion are described. Data collected on the exploitation of this species by the Tristan islanders show that the annual depletions are not more than l% of the estimated Shearwater population at Nightingale.

A New Land Nemertean

IN January 1938, Yngvar Hagen, zoologist of the Norwegian Scientific Expedition to Tristan da Cunha (1937–38), discovered a new nemertean species on Nightingale Island. The animal was found attached to the underside of boulder stones situated on a beach, though far above the high-water mark. The fauna of the area was quite a terrestrial one, as land snails, mites and spiders were also found there. The worm was later handed to me for a closer examination, and this investigation has now been finished. Publication of the paper must wait until after the War, but I should like nevertheless to place this interesting find on scientific record now.

Positions in the Tristan d'Acunha Group

IT has recently been discovered that certain positions in the Tristan d'Acunha group are in correctly quoted in vol. 1, Part 1 of the “Report of Scientific Results of the Exploring Voyage of H.M.S. Challenger 1873–76”. The principal effect of these errors is to place Inaccessible and Nightingale Island in incorrect positions relative to Tristan Island. A full account of the origin of these errors, with a description of the sequence of events which led to their discovery, has been published in the Empire Surveyors Review (vol. 2, No, 13, July 1934).

THE ISLANDS OF THE TRISTAN D'ACUNHA GROUP

AbstractIn January, 1934, a report was received from the Royal Research Ship Discovery II that the positions of Inaccessible and Nightingale Islands in the Tristan d'Acunha group were incorrectly shown on British Admiralty chart No. 1769. The report originated from local information, and was to some extent confirmed by patent log distances run by Discovery II, and by sea sights, but no really definite evidence as to the correct position of the two islands was received. In effect, the report merely stated that both Inaccessible and Nightingale Islands were considerably nearer to Tristan Island than as charted.

XXXIII.—The Alcyonarians of the Scottish National Antarctic Expedition

The Aleyonarians collected by Mr W. S. Bruce on the Scotia voyage represent nine species—six of which are new, namely:—Primnoisis ramosa, n. sp.Thonarella brucci, n. sp.Amphilaphis regularis, Wright and Studer.Primnoella scotiæ, n. sp.Primnoella magellanica, Studer.Paramuricea robusta, n. sp.Gorgonia wrighti, n. sp.Gorgonia studeri, n. sp.Umbellula durissima, Kölliker.Apart from the six new species, the collection is of interest in extending our knowledge of the geographical distribution of previously recorded forms. Thus Amphilaphis regularis, Wright and Studer, previously collected off Inaccessible Island, Tristan da Cunha, and off Nightingale Island, was got in abundance off St Helena; Primnoella magellanica, Studer, previously collected off Monte Video and in the Magellan Straits, was obtained at Burdwood Bank 54° 25′ S., 57° 32′ W.; while Umbellula durissima, Wright and Studer, previously obtained by the Challenger from the North Pacific Ocean, south of Yeddo, was found by the Scotia at 48° 06′ S., 10° 5′ W.

XI. Note on the Structure of Rhabdopleura

The specimens investigated were attached to a colony of Lophohelia , obtained by the “Challenger” Expedition at Nightingale Island, from a depth of 100—150 fathoms. I owe to Mr. John Murray my thanks for his courtesy in allowing me to publish my notes on the structure of this interesting form, in which I hoped that the improved methods of microscopical research introduced in recent years might reveal points which had, perhaps, escaped the two observers to whose study of the living animal we owe our present knowledge of Rhabdopleura .

The “Challenger” Expedition *

V.INACCESSIBLE AND NIGHTINGALE ISLANDS THE first of these islands, the area of which is about four square miles, is situated about twenty-three miles W. by S. of Tristan d'Acunha. The cliffs rise to the height of about 1,000 feet in a perpendicular range on the north-east side. The tract beneath the cliffs is covered with debris of fallen rocks. On the cliffs themselves the plants are similar to those found in the same situation in Tristan. On the lower land are dense thickets of Spartina arundinacea Carm., a tall, reed-like grass, which here forms an extensive penguin rookery; patches of Phylica arborea Th. also grow on the summits of slight elevations; and under the shelter of the cliffs the trees attain a height of twenty feet, or even more. The trunks are seldom or never straight, but mostly lean over, or become partly procumbent, starting upright again towards the top. The largest trunk seen by Mr. Moseley measured a foot in diameter, but the trees on the upper plateau are said to measure 18inchesacross,theydonot,however,growso high, being stunted by the force of the gales. The wood of the Phylica, though brittle, is said to be useful when properly dried, but in exposed situations it rapidly decays. Underneath the trees are ferns, mosses, and sedges, also Acana sanguisorbce Vahl., the leaves of which are used in New Zealand both as a tea and as a medicine, Chenopodium lomeutosumTh.,_ the tea-plant of Tristan, also grows in abundance, forming bushes with woody sterns. A species of Sphagnum, Carex insularis Carm., and Hydrocotyle cap! tata Th. grew in a swamp near the penguin rookery. From the two Germans who were discovered on the island a goo i deal of information was obtained about the vegetation, more especially of that of the higher land, to which it was found impracticable to ascend from the side of the mountain where the ship anchored. The plants found there were similar to those which grewbelow, but in addition grew the species of Empetrum, found on the other islands, Lomaria boryana Willd., which in some instances attained a height of four feet, Lycopodium insulare Carm., and Lage-nophora commersonii Cass., a small Composite plant with a daisy-like flower. The Tussock grass, which appears closely similar to Daclylis ccespitosa Forst., of the Falk-lands, grows in patches of considerable size on the upper plateau, and straggles up the cliffs to the summit. Nertera depressa Banks also grows on the plateau, and its berries form a favourite food of the Nesocichla eremita, the native thrush of the Tristan group; while the Bunting {Emberiza brasiliensis) feeds on the fruits of the Phylica.