Notes First record of 'Balearic Shearwater' for the Southern Hemisphere In the skin collection of the Estacion Biologica de Donana, Spain, I discovered two specimens of the Balearic race of Manx (or Yelkouan) Shearwater Puffinus puffinus (oryelkouan) mauretanicus (specimens EBD 2362A and EBD 2363A), reportedly collected at sea between 33°55'S 18°38'E and 34°15'S 18°38'E, off South Africa, on 29th September 1979. The labels stated also that the locality was 'South of Belville—in False Bay', and both individuals had been identified as Manx Shearwaters of the nominate race. Specimen EBD 2362A is female and EBD 2363A is male. They appear to be adults of the pale/intermediate plumage type (cf. Yesou et ai, Brit. Birds 81: in prep.), and their measurements are all within the range given for this subspecies in BWP vol. 1. They are at exactly the same stage of moult, having three old primaries and the rest new or part-grown; the upperparts appear patchy, as would be expected. All available cross-references indicate that the specimens are labelled correctly; and, although the co-ordinates may suggest a locality (33°55'S) on land, the exact location is described as being o/fBelville. The previous southernmost records for this species (cf. Bourne et ai, Brit. Birds 81: 306-319) are two individuals near Madeira on 10th September 1986, and 210 off the Atlantic coast of Morocco down to 30°N during the first week of January 1987. (A record from 10°N in February 1985 remains unproved.) The two South African specimens, therefore, represent a considerable extension of the known range of this form. EDMACKRILL Welton-le-Marsh, Spilsby, Lincolnshire PE23 5SY Canada Geese nesting in tree On 3rd May 1984, J. Ellis and I were shown an unusual nest of Canada Geese Branta canadensis (plate 170) by the head gamekeeper of an estate in Nottinghamshire. The nest was in the stump of an elm Ulmus about 4 m tall on the edge of a clump of tall trees some 200 m from a lake. At 2.7 m up the stump, there was a hollow, measuring 1.2 X 0.6 m, full of wood chippings; to these the goose had added a quantity of down, and she was sitting on five eggs. The gamekeeper thought that the site might have been chosen for protection against foxes Vulpes vulpes. I can find no reference to Canada Geese nesting above the ground. R. A. FROST 66 St Lawrence Road, North Wingfield, Chesterfield, Derbyshire S42 5LL Dr M. A. Ogilvie has commented as follows: 'This is the first time I've heard of tree nesting in Britain, but it is entirely to be expected. In the USA, nesting in crowns of pollarded trees is commonplace, and this habit has been turned to advantage on reserves, where platforms, half-barrels and the like are placed on poles in the water and readily used by Canada Geese, getting them out of reach of raccoons Procyon lotor, which are one of the major nest predators there. There is a report of a nest 30 m up in the old nest of an Osprey Pandion haliaetus, and platforms in trees to 20 m are commonly used. This is widely 322 Notes 323 covered in North American literature, but was left out of B\VP because it was not then known in the Western I'alearctic. However, I covered it pretty thoroughly in Wild Geese (1978), so the information is available on this side of the Atlantic. Canadas also nest on cliff ledges, just like Barnacle Geese B. Uucopsis in the Arctic. There is little evidence for predation by foxes Vulpes vulpes on Canada Goose nests in Britain, so, although the site might have given protection from foxes, it probably also gave shelter from the elements. Nesting under scrub or at the foot of trees is very normal—perhaps for this reason.' El)S 170. Canada Goose Branta canadensis on nest 2.7 m up stump of elm limits, Nottingham­ shire, May 1984 (R. A. Frost) Wigeon diving It seems to be extremely unusual for Wigeons Anas penelope to dive, except when they are pinioned or injured. The only reference we can find is in The Handbook, where it is stated that 'diving for food appears to be quite exceptional, though recorded by Lilford'. It is, therefore, of interest to record the behaviour of two eclipse male Wigeons and one female or immature which we watched on the estuary at Frampton-on-Severn, Gloucestershire, on 12th September 1984. They were near a muddy ridge, which would be covered at high tide, and no vegetation was visible; predators were not present to cause panic. They were diving when we first saw them, and continued to do so at frequent intervals for about ten minutes; the dives were neat, lasting 10-15 seconds, and usually all three ducks were underwater together. There was no preliminary splashing or chasing, and preening was not noticed between dives; there were no other ducks in the vicinity. Eventually, the Wigeons left the water and settled near a pack of Teals A. crecca, where they stayed resting and preening. It seems reasonably certain that they were diving for food. The Handbook gives molluscs (small Cardium) in Scotland and insects in Iceland as the only exceptions to this species' normal diet of vegetable matter, but Bannerman (1958, The Birds of the British Isles, vol. 7) mentioned shrimps, snails and spawn offish and frogs; BWP added no relevant items to this food information. SYBIL M. BUTLIN and KATHERINE M. BURKE Frocester Cottage, Frocester, Stonehouse, Gloucestershire GL10 3TE 324 Notes Talon-locking between Hobby and Kestrel On 28th April 1984, at Lake Mitrikou, northeast Greece, S. H. Holliday, P. Leonard, A. Roadhouse and I observed two Hobbies Falco subbuteo chasing a male Kestrel F. tinnunculus. One of the Hobbies then locked talons with the Kestrel and both raptors tumbled to the ground, calling and still locked together, at only 10 m from us; the Kestrel then flew up to a nearby small bush, but was soon chased off by the Hobby and pursued at low level by both Hobbies until out of sight. Although the Kestrel is known to be aggressive towards other raptors, BWP comments that it is 'usually tolerated or only swooped at playfully and escorted from territory'. The locking of talons with conspecific intruders has been reported, but talon-locking between different species apparently has not. S. J. HAYHOVV 42 Middlefield Road, Grange Estate, Rotherham, South Yorkshire S60 3JJ Winter feeding behaviour of Coot BWP (vol. 2, page 603) states that the Coot Fulica atra 'Feeds, in flocks, on land (normally near water)— particularly late autumn to spring when wind causes high waves.' At Llanishen Reservoir, South Glamorgan, Coots graze the grass banks, predominantly in the period from mid December to March, when aquatic vegetation is in short supply; contrary to BWP, they tend to revert to feeding on the water when winds cause high waves and aquatic vegetation, disturbed from the reservoir floor, floats on the surface. The reason for bank-grazing may be food availability. I thank L. W. Austin for commenting on the above. NIGEL ODIN 4 Y-Goedwig, Rhiwbina, Cardiff, South Glamorgan CF4 6UL Common Gulls successfully nesting on a roof in Aberdeen In 1984, a pair of Common Gulls Larus canus raised two fledglings, from a clutch of three eggs, on a flat office roof at Total Oil Marine, Altens, Aberdeen. The roof has been used as a nest site by Oystercatchers Haematopus ostralegus since spring 1982, soon after the building was completed. In the springs of 1982 and 1983, a pair of Common Gulls prospected the site, and roosted on the roof for most of the day during April and May; no serious attempts at either mating or nesting were made in these years. In April 1984, a pair returned and indulged in nest- building and pairing behaviour, including food-begging and copula­ tion. Nest material was brought to the site and placed in a corner against a low balustrade which surrounds the roof. During this time, a pair of Oystercatchers laid-two eggs on the roof. Little or no aggression was shown by either species towards the other; rather, they seemed both to benefit from the increased protection against Carrion Crows Corvus corone and Herring Gulls L. argentatus provided by the non-sitting birds. The Common Gulls laid three eggs around 12th-13th May, and incubation, undertaken by both sexes, lasted until 8th June, when all Notes 325 three eggs hatched; one chick died at a week old, having become trapped between two pebbles, but the other two fledged successfully and left the nest site about 9th July. This appears to be the first recorded instance in Britain of successful nesting by Common Gulls on a roof, although Cramp et al. (1974, The Seabirds of Britain and Ireland) mentioned a failed attempt in 1971 at Dalcross Airport, Inverness-shire. Common Gulls frequently use man- made sites in Scandinavia (e.g. Haftorn 1971, Norges Fugler), but Dutch and British pairs do not seem to do so. M. A. SULLIVAN 14 Caimside, Cults, Aberdeen Blackbird laying eggs on bare vegetation debris In April 1984, in an area of mixed deciduous woodland near Hamilton, Strathclyde, I saw a female Blackbird Turdus merula fly hurriedly from the thick sprouting base of a lime tree Tilia. As I passed the tree, I peered in to check the nest, which would have been at about waist height. I found, however, that the four eggs had been laid on the flat area of decayed debris which accumulates in this type of tree; there was no nest material, nor even a hollow to receive the eggs, one of which had been tumbled down as the Blackbird left.