76 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. I50 



subelliptical and long oval to long elliptical, in the larger shape some- 

 times somewhat expanded on the larger perimeter, A series of 9 from 

 Isla Chame and 2 from Isla Iguana vary in length from 63.4 to 74.0 

 and in width from 46.0 to 50.0, with the average 70.1 x47.6 mm. 



Back of the sand dunes on the mainland opposite Isla Iguana there 

 is a fresh-water pond, Laguna de la Boca, 250 meters long by 30 to 

 50 meters wide, and fairly deep. In March 1957, all day long a 

 scattered procession of frigatebirds came from the nesting colony on 

 the island to drink and bathe in the sweet water. The great birds 

 arrived in groups of 4 or 5 to 20, circled the pond, and then came 

 down steeply, like airplanes descending to a landing field. Most of 

 them banked above the surface of the water to straighten out and then 

 as they sailed with set wings dipped the bill, swinging the long neck 

 back beneath as they do in seizing a fish. They rose immediately, 

 usually throwing the head up to swallow. Regularly 2 or 3 dropped 

 lower so that the breast feathers broke the surface. Then, when aloft 

 15 or 20 meters or more, they sailed with set wings while they shook 

 the body violently and waggled the tail from side to side — an aerial 

 bath. In early morning drinking and bathing were confined to adult 

 males that came in with the throat sac deflated so that it swung loosely 

 from side to side, accompanied by many white-headed immature birds. 

 It appeared that the females then may have been on nest duty. The 

 young birds appeared to bathe more than the adults and were less 

 expert at it, as their breasts often were more deeply submerged. I saw 

 one hit so hard that most of its body went into the water, and it 

 struggled for 3 or 4 wing strokes before it was able to rise. On an 

 earlier occasion on February 20, 1950, I recorded half a dozen drink- 

 ing at a pool in the Rio Chiman, about 12 kilometers inland from the 

 sea at the mouth of the Rio Curutu. 



The habit of drinking and bathing in fresh water in this species of 

 frigatebird has been noted in literature but seems to have attracted 

 little attention. Bonhote (Ibis, 1903, p. 312) describes small parties 

 that came daily to a fresh-water pond on Little Abaco in the Ba- 

 hamas where the birds "splashed into the water like swallows." 

 Gififord (Proc. California Acad. Sci,, 1913, p. 100) speaks of their 

 visiting the crater lake El Junco at 800 meters elevation on Isla 

 San Cristobal (Chatham Island) in the Galapagos, and the same 

 habit is mentioned by the Conways (The Enchanted Islands, 1948, 

 pp. 164, 165-166) at an upland pond on Isla Santa Maria (or 

 Floreana) in the same group. The bird on Guadeloupe Island in 

 the West Indies that Noble (Bull. Mus. Comp. Zool., vol. 60, 1916, 



