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476 SHORT COMMUNICATIONS THE MISSISSIPPI KITE IN ARIZONA old, from the intense heat in the nest located about 40 ft up in a pole-sized cottonwood (Populus fre- montii). SEYMOUR H. LEVY Judging from the amount of riparian habitat avail- Route 9, Box 960 Tucson, Arizona 85705 able along this stretch of the San Pedro River, the number of individuals sighted, and their distribution, it is our calculated guess that as many as 10 pairs The Mississippi Kite (Ictitia misisippiensis) is gen- of Mississippi Kites inhabit this particular area. erally considered a bird of south-central and south- Amadeo M. Rea found nine individuals in the Mam- eastern United States, breeding from Kansas and moth area along the San Pedro River about 20 miles South Carolina south to Texas and Florida (AOU, above Winkelman on 19 August 1970. At least seven Check-list of North American birds. Fifth ed. AOU, of these were in adult plumage ( pers. corr. ) . Baltimore. 1957, p. 101) . In recent years it has been This species has not heretofore been recorded in found breeding in southeastern New Mexico (J. P. Arizona. Phillips et al. (The birds of Arizona, Univ. Hubbard, Check-list of the birds of New Mexico, of Ariz. Press, Tucson, 19864) do not mention the spe- New Mexico Ornithol. Society Publ. No. 3, 1970). cies in their definitive work. It was, therefore, quite a surprise when my brother It is interesting to speculate on whether this colony John and I found four individuals of this species on represents newly occupied territory, or whether it 7 June 1970 about 5 mi. S of Winkehnan in Final merely has been overlooked in the past. With the County, Arizona, along the lower San Pedro River. many ornithologists, past and present, investigating The sight of these kites feeding on the wing among southern Arizona, it seems unlikely that so conspicuous the giant cactus (Carnegiea gigunteu) and other a bird could be overlooked. Phillips commented on desert vegetation was unusual indeed. the absence of the Mississippi Kite in Arizona in light We returned to this area on 9 June 1970 and found of its recent range expansion into New Mexico (The one pair in flight, feeding over the desert. Another instabilitv of the distribution of land birds in the pair was sighted in flight directly over the town of Southwest. Papers Arch. Sot. New Mexico 1:153, Hayden, Gila County, Arizona, about 2 mi. NW of 1968). Winkelman. One thing is sure! Be this species an ancient or re- On 15 June 1970, we returned to this area and cent arrival in Arizona, its elimination appears vir- counted at least eight Mississippi Kites along the tually certain. The riparian habitat it requires along San Pedro River downstream from the mouth of the San Pedro River south of Winkelman is sched- Aravaipa Creek to the Gila River. One of them was uled for phreatophyte eradication and river channel- bar-tailed, indicating that it had been raised in 1969. ization by the U. S. Army Corps of Engineers, for An adult female was collected and is deposited in the water salvage and flood control purposes (R. R. National Museum of Natural History, Washington, Manes and B. Bristow, The Fatal Future, Wildlife D. C. She had sliehtlv enlarged ovaries and what au- Views, Ariz. Game and Fish Dept., June 1970) and peared to be the beginning of a brood patch. _ there will end the life of the Mississippi Kite in On our next visit to the area, 24 July 1970, my Arizona! brother and I located a kite nest. An adult was shading a downy chick, approximately three weeks Accepted for publication 23 November 1970. CENSUS OF THE BIRDS OF is no doubt that there are more than 50,000 in- CLIPPERTON ISLAND, 1968 dividuals.” Nobody else seems to have taken a census of the hirds on this island. the emerged surface of which is JEAN P. EHRHARDT not over 1.8 km.’ As I had alkady committed myself Division de Biologie GQn&ale et Ecologic du (with a group of 16 men) to count the very abundant Centre de Recherches du Service de Sat& des Arm&s landcrabs (Gecarcinus plunatus Stimpson, Ehrhardt Museum d’Histoire Naturelle 57, Rue Cuvier 1968a), I undertook to determine the bird populations Paris. France (Ehrhardt 196813). The grouu of 16 was divided into Y _ eight teams, each in charge of a particular area. This procedure enabled us to determine not only total No one reading the literature on Clipperton Island numbers but also the distribution on the island of (Sachet 1960) can fail to be struck by the statements each species. concerning the number of the birds living on this island. When the American captain, Benjamin CENSUS TIME AND AREAS Morell, went ashore at Clipperton on 17 August 1825, The time to start the counting was an important fac- he found “myriads of sea-birds.” Later, in 1839, tor. Indeed, such an operation made in broad day- Sir Edward Belcher, drawing the first map published light would have given misleading results because by the British Navy from Clipperton, stated that “the most birds would have been fishing. We also had whole island was covered with birds.” In 1858. when the lieutenant commander Le Coat de Kerveguen to take account of the different times of return of all took possession of Clipperton on behalf of the French species. For example, the terns (Anous stolidus ridg- government, he affirmed, “the number of the birds wayi and A. tenuirostris diamesus) return between on this island is innumerable.” More recently the 16:90 and 17:00 (sierra time), while the boobies French geologist, A. G. Obermuller ( 1959), asserted, (Sula leucogaster nesiotes and S. dactylatra granti) “the island is inhabited by a multitude of birds, the are still fishing, and the frigatebirds are flying off number of which is difficult to appreciate, but there and soaring. At 17:30 the first boobies are returning, SHORT COMMUNICATIONS 477 COCOANUTTREE FIGURE 1. Map of Clipperton Island, with the census areas. and by 18:00 most are back. At 18:30 all birds are gin of error of 10 per cent is added, our total (25,662) at rest, and the census time therefore began at 18:50 is less by 30,OOlObirds. on 23 July 1968. Our census shows a predominance of boobies (77.29 In order to synchronize the operation,’ the teams of per cent of the total population) and, more partic- men were taken by car to their respective areas be- ularly, the predominance of the White-bellied Booby fore the fixed time, permitting the birds to become (Sula leucogaster nesiotes or S. leucogaster brew- accustomed to the men who had to count them when steri); in 1958 the population of these Sulidae did the car went way. In order to count all the birds in not exceed 560 individuals (Stager 1964). A factor each of the eight designated areas, one member of which limited the expansion of boobies nesting on the team counted the birds present on one side of the land was the presence on the island of about 50 the road running over the island while the other pigs that ate the eggs and even the young boobies. checked those on the opposite side. Each one also The extermination of these pigs in 1958 (Sachet enumerated the flying birds (those returning from 1960; Stager 1964) allowed this apparent population their fishing, or those flying off). explosion. For the same reason the population of The eight areas, their limits, and the landmarks are Blue-faced Boobies has now reached more than 4000 shown on the map in figure 1. The stretch of land individuals, while in 1958 Stager indicated a “small between Areas II and III, 1500 m long and 56-100 number.” m wide, was free of birds. That long sand area was Concerning the Red-footed Boobies, Stager (1964) occasionally covered by the waves during storms and found only one specimen, which he designated as also by high tides (Sachet 1960). Similarly, there belonging to the subspecies Sula sula websteri. He were no birds between the Areas III and IV. states that this “solitary Red-footed Booby was ob- served sitting atop a coca palm at the east side of Except for Area VII, where the low density of birds Clipperton” and “was again observed in the same allowed a relatively precise counting (an error of grove of coca palms” four days later. The next day less than 2 per cent), the results admit a margin of two others were seen on the fronds of a coca palm error of about 10 per cent. in the main grove on the west side of the island. We have seen, as did Niaussat et al. (1968) before us, RESULTS AND DISCUSSION Red-footed Boobies nesting on the coca palms in the Table 1 summarizes the total 1968 population by main grove in which our camp was situated. This family and species. The estimate by Obermuller fact is striking because, among the Sulidae of the is- ( 1959), which is twice as large as the population land, they are the only ones to build their nest in a found in our census, seems excessive. Even if a mar- tree rather than on the ground or in the cavities of 478 SHORT COMMUNICATIONS TABLE 1. Overall numbers of birds found on Clip- ulation. There are three families: Sulidae, Fregatidae, perton Island, 1968. and Phaethontidae. The first is unquestionably the most important with 77 per cent of the total popula- % of tion.

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