Minimizing extinction risk in the face of uncertainty: Developing conservation strategies for 2 rapidly declining forest bird species on Kaua‘i Island

Abstract

Many species around the world are declining precipitously as a result of multiple threats and changing climate. Managers tasked with protecting species often face difficult decisions in regard to identifying which threats should be addressed, given limited resources and uncertainty in the success of any identified management action. On Kaua'i Island, Hawai'i, USA, forest bird species have experienced accelerated declines over the last 20 years, and 2 species, the 'akikiki (Oreomystis bairdi) and 'akeke'e (Loxops caeruleirostris), are now at the brink of extinction. Both species face multiple threats, and managers face difficult decisions on whether to mitigate threats in the wild, establish a captive population as insurance against extinction, translocate birds to novel locations, or some combination of these actions.Each set of actions (alternatives) would require substantial resources with considerable uncertainty in success. In 2014, we brought together 14 experts representing biologists and managers familiar with the species and island to develop a conservation strategy under a structured decision making (SDM) framework, an approach for making complex decisions under uncertainty. The group's challenge was to identify a set of alternatives that reduces the risk of extinction, set the foundation for one or more genetically viable, reproducing, stable to

High resolution lidar data shed light on inter‐island translocation of endangered bird species in the Hawaiian Islands

“…The only comparable areas between the islands under current climate conditions are 'akeke'e general‐use ranges with 58.06 km 2 on east Maui and 57.57 km 2 on Kaua'i. However, translocation is a complicated and expensive process that can take several years (Dade et al, 2014; Paxton et al, 2022). This is also true of potential mitigation efforts to eliminate avian malaria from Hawaiian Islands, such as the Wolbachia incompatible insect technique (Paxton et al, 2022).…”

“…However, translocation is a complicated and expensive process that can take several years (Dade et al, 2014; Paxton et al, 2022). This is also true of potential mitigation efforts to eliminate avian malaria from Hawaiian Islands, such as the Wolbachia incompatible insect technique (Paxton et al, 2022). Therefore, translocation necessitates areas that will remain suitable under future climate conditions to allow for the time it will take to make native ranges mosquito free for potential reintroduction.…”

“…It is also important to note that Fortini et al (2017) found a 100% loss of climatically suitable habitat on Kaua'i by 2080 for both 'akikiki and 'akeke'e under future climate conditions, so it may be inappropriate to compare current Kaua'i ranges with future Maui ranges. Given the recent emergency status of 'akikiki on Kaua'i, translocation to Maui may be a viable option to provide future nesting habitat for this nearly extinct species of honeycreeper (Paxton et al, 2022). The results of lidar‐ and climate‐based models can lead to the determination of candidate release locations for translocation by identifying areas of high suitability and low uncertainty (Figure 5).…”

“…Another essential aspect of translocation planning is risk assessment, including consideration of previous extinctions of target species congeners and potential novel competitive interactions in destination areas (IUCN, 2013; Paxton et al, 2022; Plein et al, 2015). A close relative to 'akeke'e, the Maui 'akepa ( Loxops ochraceus ), last seen in 1988, was declared extinct in east Maui in 2021 (Fish and Wildlife Service, 2021).…”

Designing a mate choice program: Tactics trialed and lessons learned with the critically endangered honeycreeper, 'akikiki (Oreomystis bairdi)

“…Fish and Wildlife Service, 2010), the 'akikiki had an estimated population of 468 individuals by 2012 (Paxton et al, 2018), and has continued to decline precipitously. The most recent estimate is for extinction to occur between 2022 and 2025 (Paxton et al, 2022). Unfortunately many Hawaiian forest birds will only survive through ex situ CBPs, after suffering rapid declines due to habitat loss, disease, and introduced plant and animal species (Paxton et al, 2018; Reed et al, 2012).…”