| unexpected hydrogen isotope variation in oceanic pelagic seabirds. | hydrogen isotopes have significantly enhanced our understanding of the biogeography of migratory animals. the basis for this methodology lies in predictable, continental patterns of precipitation δd values that are often reflected in an organism's tissues. δd variation is not expected for oceanic pelagic organisms whose dietary hydrogen (water and organic hydrogen in prey) is transferred up the food web from an isotopically homogeneous water source. we report a 142‰ range in the δd values of fli ... | 2014 | 24989118 |
| broad-scale trophic shift in the pelagic north pacific revealed by an oceanic seabird. | human-induced ecological change in the open oceans appears to be accelerating. fisheries, climate change and elevated nutrient inputs are variously blamed, at least in part, for altering oceanic ecosystems. yet it is challenging to assess the extent of anthropogenic change in the open oceans, where historical records of ecological conditions are sparse, and the geographical scale is immense. we developed millennial-scale amino acid nitrogen isotope records preserved in ancient animal remains to ... | 2017 | 28356448 |
| millennial-scale isotope records from a wide-ranging predator show evidence of recent human impact to oceanic food webs. | human 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 ... | 2013 | 23671094 |
| ancient dna reveals genetic stability despite demographic decline: 3,000 years of population history in the endemic hawaiian petrel. | in the hawaiian islands, human colonization, which began approximately 1,200 to 800 years ago, marks the beginning of a period in which nearly 75% of the endemic avifauna became extinct and the population size and range of many additional species declined. it remains unclear why some species persisted whereas others did not. the endemic hawaiian petrel (pterodroma sandwichensis) has escaped extinction, but colonies on two islands have been extirpated and populations on remaining islands have con ... | 2012 | 22844071 |
| population divergence and gene flow in an endangered and highly mobile seabird. | seabirds are highly vagile and can disperse up to thousands of kilometers, making it difficult to identify the factors that promote isolation between populations. the endemic hawaiian petrel (pterodroma sandwichensis) is one such species. today it is endangered, and known to breed only on the islands of hawaii, maui, lanai and kauai. historical records indicate that a large population formerly bred on molokai as well, but this population has recently been extirpated. given the great dispersal po ... | 2012 | 22434012 |
| foraging segregation and genetic divergence between geographically proximate colonies of a highly mobile seabird. | foraging 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 hydro ... | 2012 | 21837410 |
| trophic declines and decadal-scale foraging segregation in three pelagic seabirds. | we investigated how foraging habits vary among three ecologically distinct wide-ranging seabirds. using amino acid δ15n proxies for nutrient regime (δ15nphe) and trophic position (δδ15nglu-phe), we compared newell's shearwater (puffinus newelli) and laysan albatross (phoebastria immutabilis) foraging habits over the past 50-100 years, respectively, to published records for the hawaiian petrel (pterodroma sandwichensis). standard ellipses constructed from the isotope proxies show that inter-popul ... | 2019 | 30618004 |