* Figures based on identified skins.

x Observed but numbers not recorded.

[Table 9] lists the shore birds seen at Ulithi Atoll, Caroline Islands, on eight field excursions in the period from August 14 to August 22, 1945. Of seven species of shore birds known to visit the atoll, six were taken in this period. As observed at Guam, Pluvialis dominica and Numenius phaeopus were the species most frequently found. Heteroscelus was seen on three occasions; those collected were identified as H. incanus. Most of the shore birds were seen at Pau and Losiep, islands unoccupied by man. Similar tidal flats are present at most of the other small islands in the atoll, but these islands (Asor, Fallalop, Potangeras, Fassarai and Mangejang were visited) were occupied by small detachments of service personnel or by natives, which may have tended to keep many of the shore birds away. At the more populated islands of Asor and Fallalop, no shore birds were seen. Almost as many species were recorded at Ulithi on the eight field trips as were found by the author at Guam in eight months of observations.

Table 10. Populations of Migratory Shore Birds Seen at the Palau Islands in 194

Table 10. Populations of Migratory Shore Birds Seen at the Palau Islands in 194

SpeciesPeleliuAngaur
AugustSeptemberSept.
21
242816*8*9[+]16*20*
Pluvialis dominicaax x x 25 20 x x
Charadrius mongolu x 25 5 x x
C. leschenaultii x 25 5 x x
Numenius phaeopus 3 x 30 20 x x
N. madagascariensis 1 1 15
Limosa lapponica 3 4
Tringa nebularia 6 3
T. glareola[++] 1
Actitis hypoleucos 2
Heteroscelus sp. x x 75 x x x
H. brevipes[++] 3 2 2
Arenaria interpres 20
Capella megala 4
Calidris tenuirostris 15 20
Erolia minuta x 50 50 x x
E. acuminata[++] 3
E. ferruginea[++] 1
Limicola falcinellus[++] 1
Unidentifiedx x x x x x
Total No. of Individualsx 6 x x 271+ 3 129+ x x
Total No. of Species1 1 3 7 10 2 9 7 10

* Observations made on beaches at Akarakoro Point, Peleliu.

x Observed but numbers not recorded.

[+] Observations made at fresh water ponds.

[++] Figures based on identified skins.

* Observations made on beaches at Akarakoro Point, Peleliu.

x Observed but numbers not recorded.

[+] Observations made at fresh water ponds.

[++] Figures based on identified skins.

[Table 10] presents field counts at the Palau Islands in the period from August 24 to September 21, 1945. Of 20 species of shore birds known from the Palaus, 17 species were collected or identified on this trip. It was apparent that the fall migration was at its height at this time. Birds were numerous at inland openings and ponds, air field strips, and on the extensive tidal flats at Akarakoro Point. The latter area is between Peleliu and the adjacent island of Ngesebus to the north. Several observations were made at this area (as indicated by the dates marked with asterisks in the table); on September 8, 271+ shore birds were counted; on September 16, 129+ were counted. Six species were observed to be abundant. The majority of the birds found at these beaches were in small flocks which consisted of several birds of one or more species.

The birds observed at Angaur on September 21 were seen at several fresh and brackish ponds. Four species (Tringa glareola, Erolia acuminata, Limicola falcinellus, Gallinago megala), which were not taken on the tidal flats or elsewhere at Peleliu, were found at these ponds.

The abundance, and more especially the variety, of shore birds at the Palau Islands during this period was in marked contrast to the smaller and less diversified populations of shore birds in rather similar insular environments at Ulithi and Guam. These differences offer support for the supposition that the Asiatic-Palauan Migratory Shore Bird Flyway is distinct from the Japanese-Marianan Migratory Shore Bird Flyway.