The guam kingfisher (sihek) currently only exists in captivity and is at risk of extinction unless its total population size can be increased

The goal of this project is to reduce species extinction risk by increasing total population size, through establishment of a wild population on palmyra atoll. This wild population will act as an extension to the captive population and substantially increase total carrying capacity, thereby stimulating population growth. The objectives of the project are to construct (1) a quarantined rearing facility at an AZA facility and (2) release aviaries on palmyra atoll. The quarantined rearing facility will provide additional space to rear sihek eggs and chicks for release to the wild. The facility will also allow birds intended for release to be reared in pathogen and vector free conditions, to ensure translocations of sihek do not introduce novel pathogens to release sites. The release aviaries are required to hold birds for a short period after transportation to palmyra atoll as part of a 'soft' release which is aimed to take place in 2022. This project therefore supports the priority recovery action to increase sihek population size, and aids in the ultimate goal of reintroduction of sihek to guam. This project will construct a new quarantined rearing facility for sihek, which will provide increased capacity at AZA facilities for rearing sihek. This will enable the production of birds for release to the wild without taking space needed in AZA facilities to maintain the captive population. Further, translocation of sihek from mainland US breeding facilities to palmyra atoll, as well as other future wild release sites, needs to be done carefully to prevent accidental CO-introduction of pathogens. In particular, introduction of west nile virus is a serious concern as this has been detected in sihek in collections in the US mainland, but not on palmyra toll or other proposed release sites. The proposed quarantined rearing facility will allow sihek eggs and chicks to be reared under pathogen and vector free conditions, and allow birds intended for release to be placed remotely from other animal collections at breeding facilities. This will ensure that translocations of sihek do not introduce novel pathogens to the release site. The quarantine facility is also designed so that IT can be moved between AZA institutions, or be held in a central location to receive eggs from breeding pairs spread across the US, to ensure released birds are unrelated to each other and maximize genetic diversity within the release cohort. This project will also construct three release aviaries on palmyra atoll, to hold up to 9 birds at a given time. Release aviaries are required to hold birds for a short period after transportation (approximately one month), so that birds can receive supportive management while they become acclimatized to the novel wild environment (i.e., a 'soft' release). This project will reduce the extinction risk to guam kingfishers by increasing the total population size through increasing capacity to rear sihek in captivity, and by supporting establishment of a wild population that will substantially expand total carrying capacity of the sihek population. Once the actions in this proposal are fully implemented and releases to palmyra atoll take place, the carrying capacity for this species will increase by up to 20 breeding pairs, which would represent a 42% increase in the total number of breeding pairs of sihek, and mean that the target population size of 200 birds can be achieved (johnson ET AL. 2015, newland ET AL. 2020).