Extinction Risk and Conservation Options for Maui Parrotbill, an Endangered Hawaiian Honeycreeper

Abstract

Extinction rates for island birds around the world have been historically high. For forest passerines, the Hawaiian archipelago has suffered some of the highest extinction rates and reintroduction is a conservation tool that can be used to prevent the extinction of some of the remaining endangered species. Population viability analyses can be used to assess risks to vulnerable populations and evaluate the relative benefits of conservation strategies. Here we present a population viability analysis to assess the long-term viability for Maui parrotbill (Kiwikiu) Pseudonestor xanthophrys, a federally endangered passerine on the Hawaiian island of Maui. Contrary to indications from population monitoring, our results indicate Maui parrotbills may be unlikely to persist beyond 25 y. Our modeling suggests female mortality as a primary factor driving this decline. To evaluate and compare management options involving captive-rearing and translocation strategies we made a female-only stage-structured, meta-population simulation model. Maui parrotbills have low reproductive potential in captivity; therefore, the number of individuals (~20% of the global population) needed to source a reintroduction solely from captive reared birds is unrealistic. A reintroduction strategy that incorporates a minimal contribution from captivity and instead translocates mostly wild individuals was found to be the most feasible management option. Habitat is being restored on leeward east Maui, which may provide more favorable climate and habitat conditions and promote increased reproductive output. Our model provides managers with benchmarks for fecundity and survival needed to ensure reintroduction success, and highlights the importance of establishing a new population in potentially favorable habitat to ensure long-term persistence.

Population estimates and trends of three Maui Island‐endemic Hawaiian Honeycreepers

“…Climate‐based models project a loss of > 75% of the current estimated range of ʻĀkohekohe and Kiwikiu by 2100 (Fortini et al 2015). However, population trajectories suggest Kiwikiu is unlikely to persist beyond 25 years and will likely become functionally extinct in as few as 10 years (Mounce et al 2018). The species is dependent on high adult survivorship and limited by low fecundity so may have difficulty rebounding from the loss of breeding adults (Mounce et al 2018).…”

“…However, population trajectories suggest Kiwikiu is unlikely to persist beyond 25 years and will likely become functionally extinct in as few as 10 years (Mounce et al 2018). The species is dependent on high adult survivorship and limited by low fecundity so may have difficulty rebounding from the loss of breeding adults (Mounce et al 2018). The scarcity and decline of Maui endemics bear similarities to the current catastrophic decline of honeycreeper populations elsewhere in Hawaiʻi.…”

“…Landscape control of malaria and predation will be expensive and outcomes are uncertain, but a growing body of evidence suggests they are the only two actions with the potential to halt or reverse the long‐term decline of communities of native Hawaiian birds (Paxton et al 2018). Adding to the urgency of this situation is the finding that efforts to establish new populations or propagate Kiwikiu in captivity have had limited and inconsistent success (Mounce et al 2018). Other investigators have concluded that now is the time to act, even with imperfect knowledge (Samuel et al 2011, Fortini et al 2015).…”

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

“…Abundance estimates for Maui 'alauahio and kiwikiu are 99,060 ± 9510 and 157 ± 67 individuals, respectively (Judge et al, 2019). Most detections of these species occurred in elevations above 1500 m, where mosquitos and disease prevalence are reduced (Fortini et al, 2020; Mounce et al, 2018). The occurrences and nests for all species on east Maui were concentrated in the Nature Conservancy's Waikamoi Preserve and the Hanawi NARs.…”

Towards redressing inaccurate, offensive and inappropriate common bird names

“…Subsequently, local conservation efforts began using the name Kiwikiu to refer to the species, largely aligning the species with other Hawaiian honeycreepers that retain Indigenous common names. Publications in EcoHealth (Atkinson et al 2013), Conservation Genetics (Mounce et al 2015), Journal of Ornithology (Warren et al 2015) and Journal of Fish and Wildlife Management (Mounce et al 2018) have used the name Kiwikiu. However, when the NACC was petitioned to use Kiwikiu as the official common name for the bird, the proposal was met with extreme aversion (NACC 2011a).…”