(P. Tharus) is a closely allied species found from Brazil and Amazonia throughout South America to the Straits of Magellan, being especially abundant in Argentina, where its habits have been extensively observed by Mr. Hudson, whom we have so frequently quoted. This species, while a carrion eater to some extent, appears to indulge in this diet only when it is unable to secure fresh meat, of which it is ” amazingly fond.” Like its relative it also feeds on a variety of things, such as frogs, lizards, and insects, but it is apparently more given to capturing birds and small mammals. It is frequently mobbed by the Lapwings, of which it usually takes little notice, but occasionally it apparently loses patience, and singling out a particular individual it gives chase, and no matter how the Lapwing turns or dodges the Hawk is close behind and in a few moments it is seized and borne screaming away. They are very quick to detect injured or ailing birds or mammals and several will often combine in an attack on such an one, but not infrequently they may single out an uninjured bird and “fly” it down. Mr. Hudson graphically describes such an attack on a White Egret by four Caranchos. These birds had alighted near a stream in which were numerous Gulls and Glossy Ibises and a solitary White Egret. ” Presently one of them sprung into the air and made a dash at the birds in the water, and instantly all the birds in the place rose into the air screaming loudly, two young brown Caranchos only remaining on the ground. For a few moments I was in ignorance of the meaning of all this turmoil, when suddenly out of the confused black and white cloud of birds the Egret appeared, mounting vertically upward with vigorous measured strokes. A moment later and first one and then the other Carancho also emerged from the cloud, evidently pursuing the Egret, and only then the two brown birds sprung into the air and joined in the chase. For some minutes I watched the four birds toiling upward with a wild zigzag flight, while the Egret, still rising vertically, seemed to leave them hopelessly far behind. But before long they reached and passed it, and each bird as he did so would turn and rush downward, striking at the Egret with his claws, and while one descended the others were rising, bird following bird with the greatest regularity. In this way they continued toiling upward until the Egret appeared a mere white speck in the sky, about which the four hateful black spots were still revolving. I had noticed them from the first with the greatest excitement, and now began to fear that they would pass from sight and leave me in ignorance of the result; but at length they began to descend, and then it looked as if the Egret had lost all hope, for it was dropping very rapidly, while the four birds were all close to it, striking at it every three or four seconds. The descent for the last half of the distance was exceedingly rapid, and the birds would have come down almost at the very spot they started from, which was about forty yards from where I stood, but the Egret was driven aside, and sloping rapidly down struck the earth at a distance of two hundred and fifty yards from the starting-point. Scarcely had it struck the ground before the hungry quartette were tearing it with their beaks.”
Of the two other known species of this genus, one is found in the Tres Marias Islands and the other on Guadalupe Island, Lower California.