Islands are well known for their unique biodiversity and significance in evolutionary and ecological studies. Nevertheless, the extinction of island species accounts for most human-caused extinctions in recent time scales, which have accelerated in recent centuries. Pigeons and doves (Columbidae) are noteworthy for the high number of island endemics, as well as for the risks those species have faced since human arrival.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
October 2023
Humans did not arrive on most of the world's islands until relatively recently, making islands favorable places for disentangling the timing and magnitude of natural and anthropogenic impacts on species diversity and distributions. Here, we focus on parrots in the Caribbean, which have close relationships with humans (e.g.
View Article and Find Full Text PDFWe present 10 nearly complete mitochondrial genomes of the extinct tortoise Chelonoidis alburyorum from the Bahamas. While our samples represent morphologically distinct populations from six islands, their genetic divergences were shallow and resembled those among Galápagos tortoises. Our molecular clock estimates revealed that divergence among Bahamian tortoises began ~ 1.
View Article and Find Full Text PDFThe region from New Guinea through Oceania sustains the world's most diverse set of columbids. We describe osteological characters of the hindlimb (femur, tibiotarsus, tarsometatarsus) that divide the Papuan-Oceanic pigeons and doves into three groups based on functional morphology: "arboreal" (Hemiphaga, Ducula, Ptilinopus, Drepanoptila, Gymnophaps), "intermediate" (Columba, Macropygia, Reinwardtoena), and "terrestrial" (Gallicolumba [includes Alopecoenas], Trugon, Microgoura, Goura, Chalcophaps, Geopelia, Henicophaps, Caloenas, Didunculus, Otidiphaps). The arboreal and terrestrial groups are each distinctive osteologically, especially in the tibiotarsus and tarsometatarsus, which are short relative to the femur in the arboreal group, and long relative to the femur in the terrestrial group.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
October 2020
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).
View Article and Find Full Text PDFQuaternary paleontological and archaeological evidence often is crucial for uncovering the historical mechanisms shaping modern diversity and distributions. We take an interdisciplinary approach using multiple lines of evidence to understand how past human activity has shaped long-term animal diversity in an island system. Islands afford unique opportunities for such studies given their robust fossil and archaeological records.
View Article and Find Full Text PDFSince the late Pleistocene humans have caused the extinction of species across our planet. Placing these extinct species in the tree of life with genetic data is essential to understanding the ecological and evolutionary implications of these losses. While ancient DNA (aDNA) techniques have advanced rapidly in recent decades, aDNA from tropical species, especially birds, has been historically difficult to obtain, leaving a gap in our knowledge of the extinction processes that have influenced current distributions and biodiversity.
View Article and Find Full Text PDFWe describe a late Pleistocene species of extinct rail, Rallus gracilipes n. sp., from Sawmill Sink blue hole on Abaco Island, Little Bahama Bank, The Bahamas.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
November 2017
Proc Natl Acad Sci U S A
September 2017
On low islands or island groups such as the Bahamas, surrounded by shallow oceans, Quaternary glacial-interglacial changes in climate and sea level had major effects on terrestrial plant and animal communities. We examine the paleoecology of two species of songbirds (Passeriformes) recorded as Late Pleistocene fossils on the Bahamian island of Abaco-the Eastern bluebird (s) and Hispaniolan crossbill (). Each species lives today only outside of the Bahamian Archipelago, with occurring in North and Central America and endemic to Hispaniola.
View Article and Find Full Text PDFAccurate accounts of both living and fossil mammal communities are critical for creating biodiversity inventories and understanding patterns of changing species diversity through time. We combined data from from14 new fossil localities with literature accounts and museum records to document the bat biodiversity of Haiti through time. We also report an assemblage of late-Holocene (1600-600 Cal BP) bat fossils from a montane cave (Trouing Jean Paul, ~1825m) in southern Haiti.
View Article and Find Full Text PDFAncient DNA of extinct species from the Pleistocene and Holocene has provided valuable evolutionary insights. However, these are largely restricted to mammals and high latitudes because DNA preservation in warm climates is typically poor. In the tropics and subtropics, non-avian reptiles constitute a significant part of the fauna and little is known about the genetics of the many extinct reptiles from tropical islands.
View Article and Find Full Text PDFWe describe an extinct species of snipe (Gallinago kakuki, new species) from late Quaternary fossils in the Bahamian Archipelago (Abaco, New Providence, Little Exuma, Long, and Middle Caicos islands). The new species is known as well from fossils on Cuba, and Cayman Brac in the Cayman Islands. This rather large species of snipe was volant, although because of its relatively short carpometacarpus, the primary flight feathers probably were short.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
April 2016
Birds are prolific colonists of islands, where they readily evolve distinct forms. Identifying predictable, directional patterns of evolutionary change in island birds, however, has proved challenging. The "island rule" predicts that island species evolve toward intermediate sizes, but its general applicability to birds is questionable.
View Article and Find Full Text PDFSeveral hundred late Holocene fossils from Trouing Jean Paul, a cave in Massif de la Selle, Haiti, represent an extinct species of woodcock (Scolopax brachycarpa, new species). Scolopax brachycarpa is known from most major skeletal elements; although volant, its carpometacarpus was very short relative to its humerus. The only other species of Scolopax from the West Indies is the extinct and presumably closely related S.
View Article and Find Full Text PDFWe document the first specimen of a dipsadid snake from the Anguilla Cays, Cay Sal Bank, The Bahamas. We analyze 3,426 base pairs (bp) of sequence data derived from five mitochondrial loci and one nuclear locus using Maximum Likelihood (ML) and Bayesian Inference (BI) methods. Our molecular data agree with some aspects of morphology (e.
View Article and Find Full Text PDFWe report 95 vertebrate taxa (13 fishes, 11 reptiles, 63 birds, 8 mammals) from late Pleistocene bone deposits in Sawmill Sink, Abaco, The Bahamas. The >5,000 fossils were recovered by scuba divers on ledges at depths of 27-35 m below sea level. Of the 95 species, 39 (41%) no longer occur on Abaco (4 reptiles, 31 birds, 4 mammals).
View Article and Find Full Text PDFWe combined novel radiocarbon dates of bat fossils with time-scaled ecological niche models (ENM) to study bat extinctions in the Caribbean. Radiocarbon-dated fossils show that late Quaternary losses of bat populations took place during the late Holocene (<4 ka) rather than late Pleistocene (>10 ka). All bat radiocarbon dates from Abaco (Bahamas) that represent extirpated populations are younger than 4 ka.
View Article and Find Full Text PDFInsertion/deletion (indel) mutations, which are represented by gaps in multiple sequence alignments, have been used to examine phylogenetic hypotheses for some time. However, most analyses combine gap data with the nucleotide sequences in which they are embedded, probably because most phylogenetic datasets include few gap characters. Here, we report analyses of 12,030 gap characters from an alignment of avian nuclear genes using maximum parsimony (MP) and a simple maximum likelihood (ML) framework.
View Article and Find Full Text PDFAIM: Most studies of avian insular adaptations have focused on oceanic islands, which may not allow characters that are insular adaptations to be teased apart from those that benefit dispersal and colonization. Using birds on continental islands, we investigated characters that evolved in situ in response to insular environments created by late Pleistocene sea level rise. LOCATION: Trinidad and Tobago, nearby Caribbean islands and continental South America.
View Article and Find Full Text PDFLate Preclassic (300 BC-AD 100) turkey remains identified at the archaeological site of El Mirador (Petén, Guatemala) represent the earliest evidence of the Mexican turkey (Meleagris gallopavo) in the ancient Maya world. Archaeological, zooarchaeological, and ancient DNA evidence combine to confirm the identification and context. The natural pre-Hispanic range of the Mexican turkey does not extend south of central Mexico, making the species non-local to the Maya area where another species, the ocellated turkey (Meleagris ocellata), is indigenous.
View Article and Find Full Text PDFBackground: We examined species composition of forest and bird communities in relation to environmental and human disturbance gradients on Lakeba (55.9 km²), Nayau (18.4 km²), and Aiwa Levu (1.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
September 2008
Ratites (ostriches, emus, rheas, cassowaries, and kiwis) are large, flightless birds that have long fascinated biologists. Their current distribution on isolated southern land masses is believed to reflect the breakup of the paleocontinent of Gondwana. The prevailing view is that ratites are monophyletic, with the flighted tinamous as their sister group, suggesting a single loss of flight in the common ancestry of ratites.
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