Page:Condor21(6).djvu/18

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232
Vol. XXI
THE CONDOR

by representatives from the California Museum of Vertebrate Zoology, from September 18 until November 7. Messrs. Halsted G. White, Joseph Dixon and J. Grinnell constituted the party, and one or more of these collectors worked in the immediate vicinity of Morro during the entire time. For a portion of this period the Elegant Tern proved to be a fairly common water bird on Morro Bay, or else on the outside ocean beach. The first one was positively identified on September 22, the last on October 4. Field notes follow.

September 22: One shot from company with six Royal Terns flying over the breakers of sea-beach, about two miles north of Morro (H. G. W). On Morro Bay close to Morro, many terns seen, but not closely, of three sizes, the middle-sized one believed to be the Elegant (J. G.).

September 23: Around sandbar in Morro Bay, one Elegant Tern seen in a bunch of about twenty Royal Terns. The bill of the latter looked to. be darker orange at base. Elegant appeared midway in size between Forster and Royal. No "rosy flush" could be seen in the plumage of the Elegant, even within forty yards, in strong sunlight, and with the aid of binoculars (J. D.).

September 27: One shot from company of about thirteen Royal Terns flying along sea-beach north of Morro. The bird was recognized by its smaller size', and at a distance of about twenty yards the pink coloring beneath was noticed. In flight it looked like a Royal Tern but seemed "more airy", or more graceful. It more often "cut figures in the sky", in other words it was slightly less heavy on the wing, this perhaps due merely to its smaller size (H. G. W.).

September 28: Along the sea-beach two miles north of Morro, thirty-two terns were encountered. Four of these were Forster, about twenty were Royal, and about eight were Elegant. The collector used a dead Willet as a decoy, aad by throwing this into the air and letting it splash in the water, three of the. Elegant Terns were brought into shot-gun range and secured.. In this case it seemed that of the three species of tern, the Elegant showed the most curiosity (H. G.W.). Also one seen flying "just out of range, over the spit" opposite Morro (J. D.).

September 29: Two seen along sea-beach within two miles north of Morro (H. G. W.). Flock of about twenty-five seen on the Bay close to Morro. One shot. Pink bloom "not visible even when the birds were within easy shot-gun range" (J. D.).

October 1: Elegant Terns, in company with Arctic, kept flying about sandbar in Morro Bay during visit there (J. D.).

October 2: One Elegant secured at sandbar in Bay out of a mixed company of Royal, Elegant and Arctic, about one hundred in all (J. D.).

October 4: On sandbar in Morro Bay: terns wild; of these the Royal, Elegant and Arctic took flight in about the order named (J. D.).

As regards marks for field identification, there seems to be no outstanding positive feature by which the Elegant Tern may be distinguished at any ordinary distance from its congeners, unless conditions be such that relative size is determinable. From the notes of the field collectors just quoted, it is to be inferred that the pink blush of the lower surface can be seen clearly only under very exceptional circumstances. The relative slenderness of the bill of the Elegant might be used, if the proportions of this member in the Royal be vividly in mind or if birds of the two species be seen contemporaneously within short range.

Relative size is quite positively diagnostic of the-Elegant, if other sea-coast frequenting species of terns be in sight at the same time. Roughly, elegans is a large tern, yet decidedly smaller than its usual associate, the Royal. Some exact figures will here be instructive. Weight is, of course; a much more accurate index of the volume or "bulk" of a bird, generally speaking, than is any measurement Such as total length or length of closed wing. The seven