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ABSTRACT.-
We provide the first descriptions of Micronesian Honeyeater (Myzomela rubratra saffordi) nests (n = 7) and nestlings (n = 6) from Saipan in the Mariana Islands. Measured nests (n = 3) averaged 46.7 mm in inner cup diameter, 65.7 mm in outer diameter, 41.3 mm in cup height, and 55.3 mm in external nest height. We found all nests in two species of native trees, 1.47-5.1 m above the ground. Nesting materials were primarily vine tendrils and Casuarina equisetifolia needles. We also report observations of parental behavior. Nests, nest placements, and behaviors appeared broadly similar to those reported for this species prior to its extirpation on Guam, and on other islands in Micronesia.
Received 2 May 2005, accepted 26 January 2006.
The Meliphagidae family (honeyeaters) is restricted to the Australo-Papuan region (Mayr 1945). Micronesian Honeyeaters (Myzomela rubratra) occur throughout the high islands (i.e., those of volcanic origin rising more than a few meters above sea level) of Micronesia, with subspecies endemic to Palau (M. r. kobayashii), Yap (M. r. kurodai), Chuuk (M. r. major), Pohnpei (M. r. dichromata), Kosrae (M. r. rubratra), and the Mariana Islands (M. r. saffordi; Pratt et al. 1987). Within the Mariana Islands, Baker (1951) found that birds from Guam, Rota, Tinian, and Saipan are similar with respect to morphometric measurements, and he does not separate them taxonomically. Micronesian Honeyeaters, along with most other native forest birds, were extirpated from Guam in the mid-1980s with the arrival and range expansion of the brown treesnake (Boiga irregularis; Savidge 1987, Wiles et al. 2003). Surveys on Rota, Tinian, and Saipan (the inhabited islands of the Commonwealth of the Northern Mariana Islands [CNMI]) have indicated that Micronesian Honeyeaters are less numerous on Saipan than on Rota or Tinian (Pratt et al. 1979, Ralph and Sakai 1979, Jenkins and Aguon 1981, Jenkins 1983, Craig 1996), although Engbring et al. (1986) found that densities were greater on Saipan than on Tinian. On Saipan, Engbring et al. (1986) counted 549 honeyeaters (mean of 2.25 birds per station ± 0.14 SE), and estimated the total Micronesian Honeyeater population at 22,573. In a repeat survey, the U.S. Fish and Wildlife Service (1997) counted 316 honeyeaters (mean of 1.30 birds per station ± 0.09 SE; no population estimate...