Despite their inherent importance and utility as ecological examples, island
species are among the most endangered and least studied groups. Guam
Micronesian Kingfishers (Halcyon cinnamomina cinnamomina) exemplify the
plight of insular biota as a critically endangered and understudied island bird that
went extinct in the wild before they could be studied in their native habitat. Guam
kingfishers currently exist only as a captive population in U.S. zoos. Using radio
telemetry and visual observations of a wild subspecies of Micronesian Kingfisher
(H. c. reichenbachii) from the island of Pohnpei, this study examined factors
critical for the persistence of both the Guam and Pohnpei kingfishers.
Behavioral observations indicated that the birds employ a cooperative social
system, which included non-parent individuals that assisted in reproductive
attempts of others. Because resource limitations have been cited as a potentially
important factor in the evolution of cooperative behaviors and in conservation, this
investigation assessed the characteristics and availability of a potentially limited
nesting resource, arboreal termite nests. First, the characteristics of termite nests,
or termitaria, selected by Micronesian Kingfishers for use as nest sites were
modeled. Results suggested that Micronesian Kingfishers selected termitaria that
were higher from the ground and larger in volume than unused termitaria. Further,
there was little evidence that birds selected from among termitaria based on
proximity to forest edges and foraging areas, placement on a tree, vegetation
characteristics, or microclimate. Second, the number of termitaria with
characteristics indicative of nest sites was assessed to determine if reproductive
opportunities might be limited by the abundance of suitable termitaria. Results
from this analysis suggested that although fewer termitaria existed with
characteristics similar to those used for nesting, reproductive opportunities did not
appear to be limited by their abundance. Therefore, while conservation strategies
should be directed towards providing ample and appropriate nesting substrates, I
found no evidence suggesting that termitaria abundance played a role in the
evolution of cooperative breeding in Pohnpei Micronesian Kingfishers. Findings
presented here will hopefully enhance our understanding of cooperative behaviors,
as well as improve conservation efforts for Micronesian Kingfishers and other
insular avifauna. / Graduation date: 2002
| Identifer | oai:union.ndltd.org:ORGSU/oai:ir.library.oregonstate.edu:1957/32284 |
| Date | 12 March 2002 |
| Creators | Kesler, Dylan C. |
| Contributors | Haig, Susan M. |
| Source Sets | Oregon State University |
| Language | en_US |
| Detected Language | English |
| Type | Thesis/Dissertation |
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