The Guam Micronesian Kingfisher As of June 2003, 60 sihek survive in captivity in 11 institutions within the continental United States, and 3 were recently transferred to a new facility on Guam. The sihek has a recovery priority number of 3 on a scale of 1 (highest) to 18 (lowest), reflecting a high degree of threat, strong prospects for recovery, and its taxonomic status as a subspecies. Habitat Requirements and Limiting Factors Prior to its extirpation from the wild, the sihek was found only on the island of Guam. This kingfisher utilized a wide variety of habitats on the island including limestone forest, strand forest, ravine forest, agricultural forest, edge habitats, and forest openings. However, mature forests with appropriate nest sites may be an important component of kingfisher reproductive activities. The cavity-nesting sihek apparently requires large, standing dead trees averaging 43 centimeters (17 inches) in diameter in which to excavate their nests (Marshall 1989). Diverse vegetative structure providing a variety of both invertebrate and vertebrate prey, as well as exposed perches and areas of open ground for foraging, are also important. Habitat degradation and loss, human persecution, contaminants, and introduced species such as disease organisms, cats (Felis cattus), rats (Rattus spp.), black drongos (Dicrurus macrocercus), monitor lizards (Varanus indicus), and brown treesnakes (Boiga irregularis) have all been suggested as factors in the populations decline of this species. However, predation by the brown treesnake is believed to have been the overriding factor in the extirpation of sihek. Factors that continue to prevent the recovery of the sihek include poor reproductive success and high mortality in the captive population and the continued high density of brown treesnakes on Guam. Therefore, the majority of the recovery actions in this recovery plan address the brown treesnake on Guam. Therefore, the majority of the recovery actions in this recovery plan address the brown treesnake threat and captive propagation issues. Habitat loss and degradation is currently not a major threat due to the availability of suitable forest on Guam. However, this threat may increase as the island of Guam becomes further developed and additional forested areas are cleared or modified and feral ungulate populations remain high. Recovery Strategy : Recovery actions in this plan are designed to address the threats to the sihek in order to achieve the recovery objectives for this species. Recovery actions focus on increasing the size of the captive population, controlling brown treesnakes, protecting and enhancing habitat for reintroduction, and reintroducing kingfishers into the wild on Guam. Establishing a captive breeding program on Guam may alleviate some of the problems that have been encountered with increasing the captive population are also needed to increase the captive population. Controlling ungulates, weeds, and fires; and replanting native plants in degraded areas, as needed. Reintroducing kingfishers to Guam is essential to the recovery of the species, and will involve developing appropriate techniques, selecting and managing suitable release sites, and releasing kingfishers to the wild. Recovery will require the establishment of at least two subpopulations of kingfishers on Guam to reduce the subspecies' vulnerability to environmental fluctuations and natural or unnatural catastrophes. One subpopulation should occur in northern Guam and one in southern Guam. Recovery Goals and Objectives : The primary goals of this recovery plan are to first downlist the sihek to threatened status, and ultimately to recover the sihek to the point that it may be removed from the Federal list of threatened and endangered species. These goals will be attained by increasing the captive population to a level sufficient to allow reintroductions on Guam, reestablishing a wild population of kingfishers on Guam, and increasing the wild population to attain at least two viable, self-sustaining subpopulations through initial population augmentation and the control of identified threats.