62 THE CONDOR Vol. XIII first place where the terns had made a demonstration. All the time we were within seventy-five or eighty yards of the nest the birds circled about over us, sometimes poising almost motionless with rapidly beating wings, and continually uttering the characteristic shrill Black Tern cry. We did not see the birds alight a single time, so when we saw one fly up from among the rushes, not more than thirty feet from us, we went to the spot, and there was the nest. It was built on a dense carpet of dead cat-tails, blown over by the wind, forming a smooth, level and perfectly dry mat, upon which the nest and eggs, though small, showed conspicuously, even from a distance of fifteen or twenty feet. The nest proper was very similar to the nests of the Forster Tern though smaller; made entirely of short pieces of dead cat-tail blades, rather slightly cupped but compactly built. It was located about ten feet from the low boggy shore, in a sparse- ly covered spot amongst dense cat-tail growth and over not more .than six inches of water." On May 30, 1908, we were more fortunate, finding two nests within a short distance of each other after a very brief search. The first nest was of the usual construction, and was built, on a large circular wooden top of a duck blind, which was i floating just at the edge of the cat-tails, in a small rush-bound pond. it contained two eggs and was ren- dered very .conspicuous by its peculiar location. The water at this spot was almost waist deep. Not far away the second nest was found "built on a mass of dead floating cat-tails" and made en- tirely of dead brown cat-tail blades, fairly well cupped and I,..,? .'?" ....,.,..- ,. ?-,?. ? ,? ,
containing three eggs. In both
- ' " ?' -=--?'? .,fl.,J1 cases the birds were very noisy and demonstrative, and we quick- Fig. 28. NESTING SITE OF BLACK TERN; EGGS MAY BE ly located their nests by their SEEN IN LOWER CENTER OF PICTURE actions. Other work prevented us from observing these nests during the period of in- cubation and from studying the young, but the appearance and habits of the young birds would in all probability vary but little from those of the young Forster Terns with which we were somewhat familiar. The most baffling question with which we were confronted was whether or not only a very small part of the summer residents nested. It hardly seems possible that only a few birds of the hundreds seen by us on nearly every trip were breed- ing, yet or/the other hand, it is hard to believe that our careful search over all the -most suitable ground, would fail to discover the nests if they were nesting in large numbers.
