(309) GANNETS BREEDING IN THE CHANNEL ISLANDS: TWO NEW COLONIES BY RODERICK DOBSON AND R. M. LOCKLEY. (Plates 40-42). THE first indication we have of the breeding of the Gannet (Sula bassana) in the Channel Islands came in the summer of 1945, when an Alderney fisherman, Mr. E. Quinain, returning home after an enforced absence of five years, noticed that the eastern side of the rock of Ortac, lying between Alderney and the Casquets, was covered with Gannets. At the same time he discovered that a smaller colony was nesting on the rocks called Les Etacs (also known to the fishermen as the Garden Rocks) which lie off the western end of Alderney. It is unfortunate that, owing to the German occupation of Alderney from 1940 to 1945 and the absence of the native inhabi­ tants of this island during the same period, it is not yet known in which of these years the Gannets first occupied these sites ; but the fishermen of Alderney are quite certain that no Gannets were nesting on Ortac, Les Etacs, or on any other rock in these waters in 1940, though they say.it was common to see Gannets fishing near Alderney in the summer months. Towards the end of 1945, Mr. Quinain supplied the above informa­ tion in correspondence with Mr. H. J. Baal, of St. Helier, Jersey. It was obviously imperative that an expedition be made in 1946 to ascertain the latest facts. Messrs. Roderick Dobson and K. LeCocq visited Alderney on May 2ist, 1946, and were able to land on Les Etacs ; they also approached Ortac by boat and took photo­ graphs. On June 7th,-1946, the writers flew over Ortac and took photographs from the air ; on June 9th they revisited Ortac in a boat and took a series of photographs to supplement those taken from .the air. Ortac is difficult to land upon and very few people have done so, we believe ; on this occasion bad weather with a heavy swell made it impossible to land on Ortac or Les Etacs, but good views of the latter rocks were obtained from the cliffs of Alderney, from which some two-thirds of the Gannets are visible. On June nth, as the writers were leaving Alderney, they were able to take photographs of Les Etacs from the air. From these visits and from the photographs obtained it is possible to compute the number of nesting pairs of Gannets in the Channel Islands in 1946 at a minimum of 450 pairs, divided as follows:— c. 250 pairs on Ortac, c. 200 pairs on Les Etacs. This new colony is of special interest as extending the present breeding range of the Gannet southward by almost 2 degrees of latitude. The nearest existing colonies are those on Grassholm, Wales, and at Bull Rock, S.W. Ireland, 195 miles and 375 miles distant respectively. 310 BRITISH BIRDS. [VOL. XXXIX. ORTAC. The rock of Ortac measures about one-third of an acre in extent and stands in an isolated position, Lat. 490 43' 27" N., Long. 2° 17' 30" W. It is 79 feet above L.W.O.S.T., and is composed, we are told, of a coarse Cambrian sandstone; it appears to have no soil and very little, if any, vegetation. MAP SHOWING POSITION OF THE NEW COLONIES RELATIVE TO NEAREST EXISTING COLONY ON GRASSHOLM. The Gannets' nests appear to be made of seaweed and flotsam and, as will be seen in the accompanying photographs, Ortac has suitable nesting ledges on its crown and its easterly face. The westerly side in unsuitable, being steep and much exposed to the prevailing south-westerly swell and winds. Its east side is protected from excessive wave-action by the not far-distant islands of Burhou < o <-< X X > H as o • 2! W O 03 MAP SHOWING POSITIONS OF ORTAC AND LES ETACS, WITH REFERENCE TO ADJACENT w ISLANDS OF THE CHANNEL ISLAND GROUP. I—1 312 BRITISH BIRDS. [VOL. XXXIX. and Renonquet. The size of the island places a limit on the number of breeding Gannets ; the maximum capacity of Ortac, therefore, might be put down at 500 pairs of nesting birds. It is quite possible that this limiting factor early caused the (surmised) increasing number of Gannets to overflow from Ortac to Les Etacs; but of this, of course, we have no actual proof. Les Etacs, at least, have much more room than Ortac for further expansion and might comfortably accommodate some 1,000 pairs of nesting Gannets. No immature birds were seen on or near Ortac. About 100 pairs of Guillemots and a few Razorbills also breed on Ortac. LES ETACS. Les Etacs consists of two groups of igneous rock some acre and a half in extent. Height, 128 feet above L.W.O.S.T. Lat. 490 42' 20* N., long. 2014' 26" W. The main colony of Gannets has settled on the most westerly and largest islet which has some soil and vegetation (chiefly sea-beet and sea-pink and some atriplex). It has a hog's-back formation with a surface suitable for many more nests ; at present there are some 190 nests on this site, two-thirds on the central northerly slope and one-third on the contingent southerly slope. A further 10 pairs occupy the summit of a pinnacle of about the same height in the eastern group, distant some 100 yards from the main colony. On May 21st, 1946, the majority of nests in the main colony on Les Etacs contained eggs, some of which were freshly laid; many nests near the summit were, however, still under construction and without eggs. No immature Gannets were seen in May or June, but on a visit to Alderney from August 6th to 13th, 1946, R. Dobson saw, from the mainland of the "island, a considerable number of Gannets in first and second year plumages on or flying over Les Etacs ; they were constantly settling on the top of the rock, to one side of the breeding colony. The following birds also breed on Les Etacs :— Great Black-backed Gull {Lams marinus), two pairs. Herring-Gull {Larus a. argentatus), twenty or thirty pairs. Kittiwake (Rissa t. tridadyla), nine nests on northern side. Shag (Phalacrocorax a. aristotelis), at least 70 pairs. British Razorbill (Alca tarda britannica), fifty pairs (?) Southern Guillemot (Uria aalge albionis), several hundreds. Oystercatcher (Hamatopus ostralegus occidentalis), two pairs. Rock-Pipit (Anthus spinoletta petrosus), two or three pairs. Carrion Crow (Corvus c. corone), one nest. British Birds, Vol. xxxix, PI. 40. NESTING GANNETS ON THE WESTERN STACK OF LES ETACS. (Photographed by R. Dobson). British Birds, Vol. xxxix, PI. 41. ORTAC : EAST SIDE, SHOWING MAIN PART OF NEW GANNETRY {Photographed by R. Dobson). British Birds, Vol. xxxix, PL 42. UPPER—LES ETACS, SHOWING SITE OF NEW GANNETRY ; WESTERN EDGE OF ALDERNEY IN FOREGROUND. LOWER—MAIN GANNET COLONY ON NORTHERN SLOPE OF THE WESTERN STACK OF LES ETACS. (Photographed by R. Dobson). .