Fred Ruhe
Well-known member
David W. Steadman & Janet Franklin, 2020.
Bird populations and species lost to Late Quaternary environmental change and human impact in the Bahamas.
Proceedings of the National Academy of Sciences of the United States of America. in press. doi:10.1073/pnas.2013368117
Significance
Among the 90 resident species of landbirds known from Bahamian fossils, 62 species (69%) have different distributions today from in the recent past, ranging from single-island extirpations to global extinction. Placing the modern bird communities in a deeper time perspective shows how dynamic geographic ranges are through time, including providing explanations for illogical modern distributions and apparent endemism in the Caribbean. The fragmented existing Bahamian bird communities have withstood 1,000 y of human impact, and thus represent species with some resiliency. They nevertheless face an uncertain future because the factors that have fueled extirpations and extinctions through time are still at play.
Abstract and free pdf: https://www.pnas.org/content/early/2020/09/29/2013368117
Comparing distributional information derived from fossils with the modern distribution of species, we summarize the changing bird communities of the Bahamian Archipelago across deep ecological time. While our entire dataset consists of 7,600+ identified fossils from 32 sites on 15 islands (recording 137 species of resident and migratory birds), we focus on the landbirds from four islands with the best fossil records, three from the Late Pleistocene (∼25 to 10 ka [1,000 y ago]) and one from the Holocene (∼10 to 0 ka). The Late Pleistocene sites feature 51 resident species that have lost one or more Bahamian populations; 29 of these species do not occur in any of the younger Holocene sites (or in the Bahamas today). Of these 29 species, 17 have their closest affinities to species now or formerly living in Cuba and/or North America. A set of 27 species of landbirds, most of them extant somewhere today, was more widespread in the Bahamas in the prehistoric Holocene (∼10 to 0.5 ka) than they are today; 16 of these 27 species were recorded as Pleistocene fossils as well. No single site adequately captures the entire landbird fauna of the combined focal islands. Information from all sites is required to assess changes in Bahamian biodiversity (including endemism) since the Late Pleistocene. The Bahamian islands are smaller, flatter, lower, and more biotically depauperate than the Greater Antilles, resulting in more vulnerable bird communities.
Enjoy,
Fred
Bird populations and species lost to Late Quaternary environmental change and human impact in the Bahamas.
Proceedings of the National Academy of Sciences of the United States of America. in press. doi:10.1073/pnas.2013368117
Significance
Among the 90 resident species of landbirds known from Bahamian fossils, 62 species (69%) have different distributions today from in the recent past, ranging from single-island extirpations to global extinction. Placing the modern bird communities in a deeper time perspective shows how dynamic geographic ranges are through time, including providing explanations for illogical modern distributions and apparent endemism in the Caribbean. The fragmented existing Bahamian bird communities have withstood 1,000 y of human impact, and thus represent species with some resiliency. They nevertheless face an uncertain future because the factors that have fueled extirpations and extinctions through time are still at play.
Abstract and free pdf: https://www.pnas.org/content/early/2020/09/29/2013368117
Comparing distributional information derived from fossils with the modern distribution of species, we summarize the changing bird communities of the Bahamian Archipelago across deep ecological time. While our entire dataset consists of 7,600+ identified fossils from 32 sites on 15 islands (recording 137 species of resident and migratory birds), we focus on the landbirds from four islands with the best fossil records, three from the Late Pleistocene (∼25 to 10 ka [1,000 y ago]) and one from the Holocene (∼10 to 0 ka). The Late Pleistocene sites feature 51 resident species that have lost one or more Bahamian populations; 29 of these species do not occur in any of the younger Holocene sites (or in the Bahamas today). Of these 29 species, 17 have their closest affinities to species now or formerly living in Cuba and/or North America. A set of 27 species of landbirds, most of them extant somewhere today, was more widespread in the Bahamas in the prehistoric Holocene (∼10 to 0.5 ka) than they are today; 16 of these 27 species were recorded as Pleistocene fossils as well. No single site adequately captures the entire landbird fauna of the combined focal islands. Information from all sites is required to assess changes in Bahamian biodiversity (including endemism) since the Late Pleistocene. The Bahamian islands are smaller, flatter, lower, and more biotically depauperate than the Greater Antilles, resulting in more vulnerable bird communities.
Enjoy,
Fred
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