156 THE SCOTTISH NATURALIST 
Buack TERN, Hydrochelidon nigra nigra.—See p. 108. 
SANDWICH TERN, Sterna sandvicensis sandvicensis.—First seen 
Elrig shore (Wigtownshire) on 23rd April, and Largo Bay on 28th 
April. Autumn movement was apparent by mid-August. Last 
seen Largo Bay on 9th October. 
Common TERN, Sterna hirundo.— Terns” are recorded from 
the Little Ross lantern on 14th February (1. 1920, 146), and during 
the winter of 1919-20 several were received from near Aberdeen by 
Dr Collinge. On 16th April an arrival is noted at Cochno Loch 
(Kilpatrick Hills), and one near Kirkcaldy on 28th April. Thereafter 
there are many notes of arrival up to 4th June. Departures from 
nesting-places are reported as early as 24th July; there were 
enormous numbers about the Isle of May from roth to 18th 
September—last seen there 23rd September. Several were sent to 
Dr Collinge from about Aberdeen during the winter of 1920-21. 
Arctic TERN, Sterna paradisea.—First recorded from Vallay 
(O.H.) on roth May, Auskerry and Lerwick on 15th May, and 
arrivals at breeding-places up to 22nd May. Departure had begun 
by 28th July, and they were last seen at Lerwick on 15th September. 
LittLe TERN, Sterna albifrons albifrons.—Arrivals are noted at 
Tentsmuir on 1st May, and Vallay on roth May. Last seen in 
autumn, Isle of May, 17th September. 
BLACK-HEADED GULL, Larus ridtbundus.—Arrivals are recorded 
at Largo on roth January, and Lerwick on r7th March. By 22nd 
July old and young birds were returning to the shores; great flocks 
arrived in Largo Bay on rath August, and on the same day they 
left the moors at Hareshawmuir (Ayrshire). 
LrEssER BLACK-BACKED GuLL, Larus fuscus. — Birds of this 
species were seen at Cathcart (Clyde) on 21st February, and 
between Burntisland and Kinghorn on 28th February. Arrivals, 
doubtless of our breeding Z. f. affinis, are reported from Glasgow 
on 8th March, and Erskine Ferry on 13th March—thereafter many 
notes till 25th April. Last seen at Lerwick on 22nd September, 
and on the Kilpatrick Hills (Clyde) on roth and 16th October, 
27th November, and 11th December. 
Ivory GULL, Pagophila eburnea.—See p. 109. 
GREAT Skua, Stercorarius skua skua.—First seen about Lerwick 
on 1st April, and Foula on 15th April; last seen Girlsta, Tingwall, 
Shetland, 4th September. 
Arctic Skua, Stercorartus parasiticus.—First seen at Foula on 
28th April and Lerwick on 12th May, while one was seen in Largo 
