Millions of birds in the United States die annually due to vehicle collisions on roads. Collisions may be of particular interest for species of conservation concern, such as the endangered Hawaiian goose (Nēnē), which is endemic to Hawai'i. Using a nearly 40-year dataset of Nēnē road mortality in and around Hawai'i Volcanoes National Park, we sought to answer the following research questions: 1) has Nēnē mortality changed over time? 2) are there times of the year in which mortality is greatest and does it relate to specific events in the species' lifecycle? 3) does age at mortality differ over time, space, or sex? 4) given that existing mortalities appear to occur only in certain locations, do the number of mortality events differ across these locations; 5) does mortality rate show any density dependence? and, 6) are mortality rates related to numbers of visitors or vehicles? Between 1977 and 2014, a total of 92 Nēnē died from vehicle collisions; while absolute mortality increased over this time, the mortality rate remained the same.
View Article and Find Full Text PDFHuman exploitation of marine ecosystems is more recent in oceanic than near shore regions, yet our understanding of human impacts on oceanic food webs is comparatively poor. Few records of species that live beyond the continental shelves date back more than 60 y, and the sheer size of oceanic regions makes their food webs difficult to study, even in modern times. Here, we use stable carbon and nitrogen isotopes to study the foraging history of a generalist, oceanic predator, the Hawaiian petrel (Pterodroma sandwichensis), which ranges broadly in the Pacific from the equator to near the Aleutian Islands.
View Article and Find Full Text PDFAlthough West Nile Virus (WNV) has not been reported in Hawai'i, eventual introduction appears unavoidable with potential adverse effects on avian species. Nēnē (Branta sandvicensis) are endemic endangered Hawaiian geese that are susceptible to WNV. We demonstrate that a vaccine developed against WNV for humans (WN-80E) is also highly immunogenic in Nēnē and does not produce adverse biologic effects.
View Article and Find Full Text PDFForaging segregation may play an important role in the maintenance of animal diversity, and is a proposed mechanism for promoting genetic divergence within seabird species. However, little information exists regarding its presence among seabird populations. We investigated genetic and foraging divergence between two colonies of endangered Hawaiian petrels (Pterodroma sandwichensis) nesting on the islands of Hawaii and Kauai using the mitochondrial Cytochrome b gene and carbon, nitrogen and hydrogen isotope values (δ(13)C, δ(15)N and δD, respectively) of feathers.
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