BIRD ROOKERIES OF TORTTJGAS BARTSCH. 475 



for themselves and their young. In this respect they differ from the Sterna 

 stolida, which, when overtaken at sea by darkness, even when land is only a 

 few miles distant, alight on the water, and frequently on the yards of vessels, 

 where if undisturbed they sleep until the return of day. It is from this cir- 

 cumstance that they have obtained the name of Noddy, to which in fact they 

 are much better entitled than the present species, which has also been so 

 named, but of which I never observed any to alight on a vessel in which I was 

 for thirty-five days in the Gulf of Mexico, at a time when that bird was as 

 abundant during the day as the other species, of which many were caught at 

 my desire by the sailors. 



The present species rarely alights on the water, where it seems incommoded 

 by its long tail; but the other, the Sterna stolida, which, in the shape of its 

 tail, and iii some of its habits, shows an affinity to the Petrels, not only fre- 

 quently alights on the sea, but swims about on floating patches of the Gulf 

 Weed, seizing on the small fry and little crabs that are found among the 

 branches of that plant, or immediately beneath them. 



I have often thought, since I became acquainted with the habits of the bird 

 which here occupies our attention, that it differs materially from all the other 

 species of the same genus that occur on our coasts. The Sterna fuliginosa 

 never dives headlong and perpendicularly as the small species are wont to do, 

 such as St. Mrundo, St. arctica, St. minuta, St. Dougallii, or St. nigra, but 

 passes over its prey in a curved line, and picks it up. Its action I cannot better 

 compare to that of any other bird than the Night Hawk, while plunging over 

 its female. I have often observed this Tern follow and hover in the wake of 

 a porpoise, while the latter was pursuing its prey, and at the instant when by 

 a sudden dash it frightens and drives toward the surface the fry around it, the 

 Tern as suddenly passes over the spot, and picks up a small fish or two. 



Nor is the flight of this Tern characterized by the buoyancy and undecided- 

 ness, if I may so speak, of the other species mentioned above, it being as firm 

 and steady as that of the Cayenne Tern, excepting during the movements per- 

 formed in procuring its food. Like some of the smaller gulls, this bird not un- 

 frequently hovers close to the water to pick up floating objects, such as small 

 bits of fat pork and greasy substances thrown overboard purposely for making 

 the experiment. It is not improbable that the habits peculiar to this species, 

 the Noddy, and one or two others, of which I shall have occasion to speak else- 

 where, may tend to induce systematic writers to place them in a new "sub- 

 genus." 



There is a circumstance connected with the habits of the two species of 

 which I now more particularly speak, which, although perhaps somewhat out 

 of place, I can not refrain from introducing here. It is that the Sterna stolida 

 alumys forms a nest on trees or bushes, on which that bird alights with as 

 much ease as a Crow or Thrush ; whereas the Sterna fuliffinosa never forms a 

 nest of any sort, but deposits its eggs in a slight cavity which it scoops in the 

 sand under the trees. But, reader, let us return to the Bird Key. 



Early the next morning I was put on shore, and remained there until I had 

 completed my observations on the Terns. I paid no attention to their lament- 

 able cries, which were the less piercing that on this occasion I did not molest 

 them in the least. Having seated myself on the shelly sand, which here 

 formed the only soil, I remained almost motionless for several hours, in con- 

 sequence of which the birds alighted about me, at the distance of only a few 

 yards, so that I could plainly see with what efforts and pains the younger 

 females deposited their eggs. Their bill was open, and their pantings indicated 

 their distress, but after the egg had been expelled, they immediately walked 

 off in an awkward manner, until they reached a place where they could arise 



