Frigate Birds and the Laysan Rail
Frigate Birds and the Laysan Rail.-Baldwins ’ (Condor, 49, 1947:14-21) account of the Laysan Rail (Porzanula palmer+) is interesting to me as I had the pleasure of participating in the Bishop Museum “Tanager” Expedition to Midway and Laysan islands in 1923. It is my impression that a, Frigate Bird (op. cit.:16) cannot catch any animal that would try to escape by dodging. I believe that the rails could have escaped an attack by dodging. As for Dill’s statement that a Frigate Bird picked up full grown rabbits, I would like to hear that this observation has been repeated. Mr. Lewis W. Walker of the Srqn Diego Society of Natural History has experimented with the weight-lifting ability of the large birds of prey and found that their lifting power is very small. The Frigate Bird, according to my memory, does not weigh more than a full grown rabbit-of the size that I saw and killed on Laysan-and I doubt very much that a Frigate Bird could lift a half grown individual or that a rabbit in good health could be caught by a Frigate Bird. One tale, that a Frigate Bird cannot rise from the water, I disproved by taking a Frigate Bird into the water where I held it submerged all but the head. Upon releasing the bird, it rose clear with one down stroke of the wings.
We did not find any fresh water on Wake Island where rails were numerous, which would make it appear that the Wake Island rail can subsist without water (op. cit.: 19). On the other band there was permanent water on Laysan and Midway, where some faucets were always left dripping for the canaries, finches and rails. We brought a few rails back to Laysan and liberaled them, but they apparently did not find the fresh-water “spring,” as we found them all dead along the shore of the lagoon. I believe the Laysan Rail needed fresh water and that its introduction to a waterless island was a foredoomed failure.-CHAPMAN GRANT, San Diego,.California, February 10, 1947.
