Summer Tanager
Piranga rubra (Linnaeus, 1758) (0, 1)
Photo © By Mike's Birds - Summer TanagerUploaded by Magnus Manske, CC BY-SA 2.0, https://commons.wikimedia.org/w/index.php?curid=21097492
STATUS
Nearctic. Polytypic.
OVERVIEW
Record as per BOU, 1971.
1950-57 RECORD
1). 1957 Caernarfonshire Bardsey, first-winter male, 11th to 25th September, trapped 11th, 15th and 20th September, photo.
(R. W. Arthur, British Birds 56: 49-52, plate 12; I. C. T. Nisbet, British Birds 56: 204-217; BOURC (1963), Ibis 105: 290; Lovegrove, Williams & Williams, 1994; M. J. Rogers and the Rarities Committee, British Birds 92: 603; BOURC (1999), Ibis 141: 177; M. Grantham, Birding World 17 (8): 348, 349, photo).
History R. W. Arthur (1963) in British Birds, Vol. LVI. pp. 49-52, says: 'At 7.20 a.m. on 11th September 1957, on Bardsey Island, Caernarvonshire, R. Moss and R. Stjernstedt had brief views of a bird resembling a large, bright male Greenfinch (Chloris chloris) without the wing and tail patches.
Unfortunately it dived into cover and was lost, but at 12.15 p.m. on the same day it was caught by J. D. Gay in the Lane heligoland trap and then examined in the hand by M. R. Buckley, R. V. Collier, E. R. Corte, A. Cumber, R. C. Lee, A. Morley, the three observers already mentioned, and myself.
The following detailed description was taken:
Upper-parts: forehead olive, slightly yellowish, with some rusty-red feathers; crown and nape similar, with two reddish feathers at front of crown; sides of head also similar, but lores appearing darker; mantle, scapulars and upper rump less yellow, with three large red feathers; lower rump similar to head, with four paler reddish feathers.
Under-parts: chin and throat deep yellow mixed with orange feathers; breast, belly and under tail-coverts similar but without orange feathers (these parts were stained with fruit juices, though this possibly happened while the bird was being carried to the laboratory in a bag).
Tail: upper-side olive, darker at tips, outer webs slightly yellowish; under-side dull, tinged olive.
Wings: primaries and secondaries brown-black, broadly fringed olive on outer webs (less distinctly on 2nd primary); inner secondaries with whole outer webs olive; primary coverts similar to primaries but with less distinct fringes; greater coverts similar to inner secondaries; median coverts olive with dark shafts; lesser coverts mainly olive, with one reddish feather among those on right wing; under wing-coverts pale, tinged olive-yellow; axillaries olive-yellow.
Soft parts: upper mandible dark horn on culmen, paler in centre and very pale horn at sides; lower mandible very pale horn; gape-flange yellowish; legs and feet bluish-slate; iris dark brown.
Measurements: wing 99 mm. (primaries straightened), tarsus 20 mm., bill from nostrils 14 mm., bill from hinge 22 mm., bill depth at forehead c. 10 mm.; weight 24.6 gm. Wing-formula and tail structure: 3rd primary longest, 4th 1 mm shorter, 2nd 2.5 mm. shorter, 5th 4 mm. shorter, 6th 13 mm. shorter, 7th 18 mm. shorter, 8th 21 mm. shorter, 1st 11 mm. shorter than longest primary covert; 3rd, 4th and 5th emarginated; 12 tail-feathers, all slightly abraded but still showing pointed tips; no obvious damage to shafts of wing or tail feathers.
On being released, the bird immediately flew to cover among brambles at the foot of a wall.
It was caught again on 15th and 20th September, when its weight had increased from 24.6 gm. to 26.6 gm. and 36.7 gm. respectively, and it was last seen on 25th September.
It had, on the first day, been provisionally identified as a Summer Tanager (Piranga rubra) and on 20th September it was compared in the hand with a male specimen of this species which, in the meantime, had kindly been lent by R. Wagstaffe of the City of Liverpool Public Museums; it was found that the scattered red feathers in various parts of its plumage very closely resembled those on the specimen.
In the field it was noted as smaller than a Song Thrush (Turdus philomelos) and all observers were struck by the resemblance, already remarked, to a very large male Greenfinch without the yellow flashes. The upper-parts appeared olive-green with darker primaries and secondaries, the under-parts deep yellow. The bill looked pale, blunt and heavy, and with the steep forehead gave a distinctive shape to the head. The legs appeared darkish and very short for the size of the bird. The tail, blunt but slightly forked, extended well beyond the wing-tips. The shapes of bill and tail, and the proportions of the latter in relation to the wings, are well illustrated in the photographs reproduced on plate 12, as are the uniformity of the body-feathers and the darker wings with their pale-edged inner secondaries.
During its stay of 15 days the bird spent most of its time in an area which included much bramble and gorse, and some small willows and plum trees, in addition to the laboratory buildings. Normally, when undisturbed, it perched openly in a rather upright, shrike-like manner, but as soon as it was alarmed it generally flew to some adjacent cover; occasionally it crouched in an almost horizontal position.
Its flight was rapid, low and undulating, variously likened to that of a woodpecker or heavy finch, and it arrived at a perch with an upward sweeping curve. It was seen to make flycatcher-like sallies on two occasions, and occasionally to flick its wings like a flycatcher; it also cocked its tail and raised its crown-feathers from time to time. On 12th September it uttered a double note "chic-chic" as it took flight on being disturbed, and then a similar but single chic when it reached cover.
Blackberries were apparently its main food. These it often merely chewed, seeming to take only the juice, but it passed seeds in the laboratory on 20th September. On the 13th it was seen to pick a blackberry, place it on a fence post and then peck at it. W. M. Condry once watched it take a small fly in the air.
Observers who saw the bird, apart from those listed at the beginning as being present on the first day, included W. M. Condry, D. Condry, B. Griffiths, B. Little, R. C. Pratt, M. P. M. Richards, A. Soper and W. B. Workman.'
[The breeding range of the Summer Tanager extends from the east-central United States south to Florida and Mexico, and the species winters from Mexico south to Peru.
As briefly mentioned above, the verification of this record has largely been concerned with the elimination of the possibility of confusion with an immature of the Scarlet Tanager (P. olivacea), another North American summer visitor, whose breeding range extends into the eastern province of Canada, and the Rarities Committee would like here to acknowledge the great help it has received in this connection from Dr. Charles Vaurie and Dr. Eugene Eisenmann, both of the American Museum of Natural History, as well as from J. D. Macdonald of the British Museum (Natural History) and R. Wagstaffe of the City of Liverpool Public Museums.
Dr. Vaurie wrote: 'I believe your bird is a Summer Tanager. These documents and photos have been pored over by a number of good field men and, of course, some of these and myself have looked at skins.
Everyone decided that, on the basis of the photos, it was impossible to be certain of whether the bird had been a Summer or Scarlet Tanager. The coloration, including the wings, varies individually, and if the bird had been immature the identification was even more uncertain. However, one measurement in your documents offered a chance to be diagnostic, namely the length of the bill measured from the nostril, which you said was 14 mm.
Mr. Paul Buckley was kind enough to measure 40 mixed specimens (male, female and imm.) of each and found that in rubra the bill measured 12-15 and in only one was the bill as short as 12, against 10-12 in olivacea with only 4 birds measuring as much as 12. As your bird measured 14, the chances are therefore greatly in favour of rubra.
Mr. Eisenmann later wrote, however: "Banders can separate the immatures of the two species by the larger bill of the Summer and the richer, more orange (or sometimes buffy) tone of the yellowish under-parts. The Scarlet is a more greenish yellow below. These are fine points, but are discernible by those familiar with these species and are obvious in skins. In addition, young male Scarlets have black lesser (and sometimes also middle) wing-coverts; adult and moulting males have the wings wholly or largely black".
Thus, while the scattering of red feathers on the head, mantle and rump of the Bardsey bird showed it to be a male, the fact that the lesser coverts were mainly olive (and even had one reddish feather on the right wing) showed that it was not a male Scarlet Tanager.
The identification established, it was necessary to examine the possibility of its being an escaped cage-bird. In view of the restrictions on the export of birds from North America, it seemed unlikely that any immature Summer Tanagers would be found in captivity in Europe as early as the beginning of September.
In fact, we were informed by the avicultural authorities we consulted - notably Derek Goodwin, R. A. Richardson and R. C. J. Sawyer - that they did not believe this species to be kept in captivity at all in this country (though the Scarlet Tanager is). Moreover, the increase in this bird's weight, from 24.6 gm. on 11th September to 26.6 gm. on the 15th and 36.7 gm. on the 20th, strongly suggests an arduous passage before arrival at Bardsey.
In this connection, Mrs. M. M. Nice and Dr. Robert Storer kindly provided us with data on the weights of Summer Tanagers in America: apart from one very light individual, all the figures were well above the initial weight of the Bardsey bird and the normal range for this species appears to be 30-36 gm. - Eds.]
Admitted nationally as the first for Britain (BOURC (1963) Ibis 105: 290).
