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Dietary controls on extinction versus survival among avian megafauna in the late Pleistocene

Kena Fox-Dobbs, Thomas A. Stidham, Gabriel J. Bowen, Steven D. Emslie and Paul L. Koch
Dietary controls on extinction versus survival among avian megafauna in the late Pleistocene
Geology (Boulder) (August 2006) 34 (8): 685-688


The late Pleistocene extinction decimated terrestrial megafaunal communities in North America, but did not affect marine mammal populations. In coastal regions, marine megafauna may have provided a buffer that allowed some large predators or scavengers, such as California condors (Gymnogyps californianus), to survive into the Holocene. To track the influence of marine resources on avifaunas we analyzed the carbon, nitrogen, and hydrogen isotope composition of collagen from late Pleistocene vultures and raptors, including species that survived the extinction (condor, bald eagle, golden eagle) and extinct species (teratorn, black vulture). At the Rancho La Brea and McKittrick tar pits of southern California, isotope values for extinct teratorns (Teratornis merriami, n = 10) and black vultures (Coragyps occidentalis, n = 8) show that they fed entirely in a terrestrial C (sub 3) ecosystem. In contrast, La Brea condors cluster into two groups, one with a terrestrial diet (n = 4), and the other with a strong marine influence (n = 5). At localities in the American southwest, Texas, and Florida, where condors became extinct, they have isotope values indicating entirely terrestrial diets (n = 10). Our results suggest that dependence upon terrestrial megafaunal carrion as a food source led to the extinction of inland California condor populations and coastal populations of teratorns and black vultures at the Pleistocene-Holocene boundary, whereas use of marine foods allowed coastal condor populations to survive.

ISSN: 0091-7613
EISSN: 1943-2682
Serial Title: Geology (Boulder)
Serial Volume: 34
Serial Issue: 8
Title: Dietary controls on extinction versus survival among avian megafauna in the late Pleistocene
Affiliation: University of California at Santa Cruz, Earth Sciences Department, Santa Cruz, CA, United States
Pages: 685-688
Published: 200608
Text Language: English
Publisher: Geological Society of America (GSA), Boulder, CO, United States
References: 27
Accession Number: 2006-062592
Categories: Vertebrate paleontology
Document Type: Serial
Bibliographic Level: Analytic
Annotation: With GSA Data Repository Item 2006138
Illustration Description: illus. incl. 1 table, sketch map
N34°03'47" - N34°03'47", W118°21'17" - W118°21'17"
Secondary Affiliation: Texas A&M University, USA, United StatesPurdue University, USA, United StatesUniversity of North Carolina at Wilmington, USA, United States
Country of Publication: United States
Secondary Affiliation: GeoRef, Copyright 2017, American Geosciences Institute. Reference includes data supplied by the Geological Society of America, Boulder, CO, United States
Update Code: 200635
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