David W Steadman

Florida Museum of Natural History · Collections and Research

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 Amazona parrots in the Caribbean, which have close relationships with humans (e.g., as pets as well...

Variability across frontiers and boundaries challenges the resilience of expanding populations. Here, we contribute to a broader understanding of global patterns of island colonization and expose the diversity of lifeways experienced across the Taíno culture area by exploring Lucayan settlement of the small subtropical islands of the northern Baham...

Worldwide decline in biodiversity during the Holocene has impeded a comprehensive understanding of pre-human biodiversity and biogeography. This is especially true on islands, because many recently extinct island taxa were morphologically unique, complicating assessment of their evolutionary relationships using morphology alone. The Caribbean remai...

We 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 Bah...

Taxonomic revisions using newly available molecular data can have profound consequences for identifying areas of high endemism and, therefore, high conservation priority. A good example of the connection between taxonomy, biodiversity ecology, and conservation issues is genus Phaeiris (Iris subsect. Hexagonae), an endemic taxon of the southeastern...

Modern populations of the Burrowing Owl (Athene cunicularia) occur locally from the western half of North America through Central America and into South America, as well as in Florida and on some Caribbean and Mexican islands. By comparing skeletal measurements, we assessed the morphological differences between late Pleistocene fossils of Burrowing...

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, includi...

In spite of comprising more than 50% of the world's 10,000+ living species of birds, the songbirds (Passeriformes) generally have a poor fossil record. An exception is the Icteridae, with substantial Quaternary fossils at certain sites in North America, South America, and the West Indies. Here we describe 2 new extinct species of icterids from the...

The 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, Gymnophap...

Quaternary 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 opp...

No native species of tortoises ( Chelonoidis spp.) live today in the Bahamian (Lucayan) Archipelago (= The Bahamas + The Turks and Caicos Islands), although a number of species inhabited these islands at the first human contact in the late-Holocene. Until their extinction, tortoises were the largest terrestrial herbivores in the island group. We re...

We report the results of systematic vascular plant and bird surveys in Seasonally Dry Tropical Forest (SDTF) across leeward and windward elevation gradients (31–884 masl) in the Sierra Martín García (SMG), Dominican Republic. We expected to see gradual, systematic changes in plant distributions with elevation owing to the strong effect of topoclima...

Since 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 spe...

Aim: Seasonally dry tropical forest (SDTF) of the Caribbean Islands (primarily West Indies) is floristically distinct from Neotropical SDTF in Central and South America. We evaluate whether tree species composition was associated with climatic gradients or geographical distance. Turnover (dissimilarity) in species composition of different islands o...

We 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. The only other extinct rail known from any Bahamian island is the smaller Rallus cyanocavi, also from late Pleistocene contexts at Sawmill Sink. No fossils of R. gracilipes or R. cyanocavi h...

Avian fossils give us a unique opportunity to assess changes through time in species diversity and distributions. We report a previously unstudied collection of ∼500 bird fossils from Banana Hole, New Providence Island, Commonwealth of The Bahamas. Based on comparisons with fossil sites of known age on Abaco, the species composition of the Banana H...

Aim Seasonally dry tropical forest ( SDTF ) of the Caribbean Islands (primarily West Indies) is floristically distinct from Neotropical SDTF in Central and South America. We evaluate whether tree species composition was associated with climatic gradients or geographical distance. Turnover (dissimilarity) in species composition of different islands...

We report a mid- to late-Holocene, non-cultural vertebrate assemblage from Garden Cave (site EL-229), Eleuthera Island, The Bahamas, with 2450 fossils representing 26 species. The chronology is based on accelerator mass spectrometer (AMS) radiocarbon (¹⁴C) dates determined directly on individual bones of the hutia (Geocapromys ingrahami), an extirp...

The late Pleistocene snake fossils from Sawmill Sink (Abaco, The Bahamas) represent five taxa: blind or thread snake (Scolecophidia indet.: either Leptotyphlopidae or Typhlopidae); Abaco boa (Boidae: Chilabothrus cf. exsul); rat snake (Colubridae: Pantherophis sp.); water snake (Natricidae: Nerodia sp.); and Cuban racer (Dipsadidae: Cubophis cf. vu...

Significance On tropical islands, extensive extirpation of birds and other vertebrates occurred during the Holocene, following human arrival. Much less is known about pre-Holocene extirpation on islands. We focus on two species (Eastern bluebird Sialia sialis and Hispaniolan crossbill Loxia megaplaga ) that were lost in the Bahamas to changes in se...

Accurate 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...

List of specimens examined per species for Trouing Jean Paul, Haiti, from the UF Vertebrate Paleontology collection in Gainesville, FL. (PDF)

Descriptions for all localities where living or fossil bats have been documented in Haiti. Verbatim elevation (in meters) provided for previously published localities if available. Elevation for new localities reported in this study estimated via GoogleEarth. (XLSX)

We report eight new accelerator-mass spectrometer (AMS) radiocarbon (¹⁴C) dates performed directly on individual bones of extirpated species from Crooked Island, The Bahamas. Three dates from the hutia (Geocapromys ingrahami), recovered from a culturally derived bone assemblage in McKay's Bluff Cave (site CR-5), all broadly overlap from AD 1450 to...

Ancient 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 know...

We examined the osteology of Neogene Alligator, with a focus on fossils from the late Miocene (~8–7 million years ago [Ma]) Moss Acres Racetrack locality in Marion County, Florida, USA. These fossils have been referred previously to Alligator cf. A. mefferdi (early late Miocene, ~12–10 Ma, Nebraska), an extinct species that we and others have found...

We 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...

Significance Predictable evolutionary trends illuminate mechanisms that affect the diversity of traits and species on the tree of life. We show that when birds colonize islands, they undergo predictable changes in body shape. Small-island bird populations evolve smaller flight muscles and longer legs. These shifts in investment from wings to legs,...

Fossils from late Miocene localities in north Florida offer new information about the paleoecological relationships between sympatric alligatorine and tomistomine crocodylians. Large, robust tomistomines (traditionally referred to Gavialosuchus americanus) outnumber Alligator fossils at localities representing coastal/estuarine depositional environ...

Significance A flooded sinkhole cave on Abaco (The Bahamas) has yielded the richest (95 species) set of late Pleistocene (ice-age) vertebrates on any Caribbean island. We track changes in species composition on Abaco through time and relate those biotic changes to climate change. The warmer, wetter climate and rising sea levels from 15,000 to 9,000...

Several 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 Scolo...

We 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.g., scale co...

The role of Quaternary glacial-interglacial intervals in shaping the diversity and distribution of Neotropical species has been the focus of considerable research. The Neotropics sustain the highest passerine diversity on Earth, but little is known about this region's historical biogeography based on fossils. To assess how passerine species were af...

AimTo evaluate the roles of Quaternary (< 2.6 Ma) climatic stability and geologic barriers (i.e. the Andes Mountains) in shaping the modern community composition and patterns of endemism in Neotropical dry forest bird communities.LocationMarañón Valley and Tumbes, north-western Peru.Methods We recorded presence and abundance of species in six dry f...

From excavations at the Formative period (3,500 to 900 years old) Chiripa archaeological site on the southern shore of Lake Titicaca on the Bolivian altiplano (elev. 3,820 m), we identified 664 bones that represent 41 extant species of birds. Approximately 80% of the bones are from aquatic species such as coots, grebes, ducks, cormorants, and flami...

How does tree species composition vary in relation to geographical and environmental gradients in a globally rare tropical/subtropical broadleaf dry forest community in the Caribbean? We analyzed data from 153 Forest Inventory and Analysis (FIA) plots from Puerto Rico and the U.S. Virgin Islands (USVI), along with 42 plots that we sampled in the Ba...

The Neotropical lowlands sustain the world's richest bird communities, yet little that we know about their history is based on paleontology. Fossils afford a way to investigate distributional shifts in individual species, and thus improve our understanding of long-term change in Neotropical bird communities. We report a species-rich avian fossil sa...

We 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) t...

Aim To establish a chronology for late Quaternary avian extinction, extirpation and persistence in the Bahamas, thereby testing the relative roles of climate change and human impact as causes of extinction. Location Great Abaco Island (Abaco), Bahamas, West Indies. Methods We analysed the resident bird community as sampled by Pleistocene (> 11.7...

Human activities in the Bahamas and other oceanic islands have damaged terrestrial ecosystems irreparably through the extinction of indigenous species. Tortoise and crocodile bones from Abaco Island in the Bahamas sampled for 14C-dating revealed a small overlap between the last occurrence of these large reptiles and early human settlement in the Ba...

El reconocimiento del papel de los animales en las antiguas dietas, en las economias, politicas y los rituales, es vital para poder entender a las culturas del pasado en su totalidad. Por el otro lado, seguir las claves que se obtienen de restos de animales preteritos puede aproximarnos a entender la antigua relacion que existia entre los humanos y...

We report an intertidal, bone-rich peat deposit on the windward (Atlantic Ocean) coast of Abaco, The Bahamas. The age of the Gilpin Point peat (c. 950-900 cal. yr BP) is based on five overlapping radiocarbon dates (one each from single pieces of wood of buttonwood Conocarpus erectus and sabal palm Sabal palmetto, and single bones of the Cuban croco...

We describe a new species of rail from the Sawmill Sink blue hole on Abaco Island in the northern Bahamas. Known from abundant, beautifully preserved Late Pleistocene fossils, Rallus cyanocavi sp. nov. was a medium-sized, flightless species that probably was endemic to the Little Bahama Bank, which is a carbonate platform surrounded by deeper water...

Recognition of the role of animals in ancient diet, economy, politics, and ritual is vital to understanding ancient cultures. Following the clues available from animal remains in reconstructing environments is vital to understanding the ancient relationship between humans and the world around them. In response to the growing interest in the field...

We report 4800+ late-Holocene, non-passerine avian fossils from Trouing Jean Paul, a high-elevation limestone sinkhole in the Morne La Visite region, Massif de la Selle, Haiti. The fossils represent prey remains of two extant owls, the widespread Tyto alba and the Hispaniolan endemic T. glaucops. Among 23 species of birds, only one is extinct (an u...

Regional patterns of forest composition in West Polynesia were analysed to determine the relative importance of dispersal limitation, speciation, environmental filtering and biotic interactions. West Polynesia (Fiji, Tonga, Samoa). We applied clustering and indicator species analysis to presence/absence data for 397 tree taxa in 338 forest plots to...

Insertion/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 repor...

Aim 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 Plei...

Late 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-Hi...

El Mirador excavation history, provenience descriptions and dating. (DOCX)

Operation 26O baulk and tunnel profile. Redrawn after [14: Fig. 44] . (DOCX)

Operations 35A and 35B wall and baulk profile. Redrawn after [14: Fig. 56]. (DOCX)

Operation 26J baulk profile. Redrawn after [14: Fig. 29] . (DOCX)

Generalized chronology used in the text. (DOCX)

AMS Radiocarbon ages from zooarchaeological remains found in association with the archaeological turkey bones. (DOCX)

Results of PCR amplification and sequence analysis. (DOCX)

Multiple alignment of M. gallopavo and M. ocellata control-region reference sequences, with the retrieved ancient sequence. (DOCX)

Multiple alignments of obtained sequences demonstrating DNA damage induced transitions. (DOCX)

Meleagris primers for PCR amplification. (DOCX)

Songbirds (Passeriformes) have a very limited fossil record in spite of making up more than one-half of the world's 10,000 living species of birds. From the late Pleistocene fossil site of Térapa in east-central Sonora, Mexico, the identifiable fossils of songbirds consist exclusively of species of Icteridae. The seven extant species (Red-winged Bl...

Basal area by species (square m/ha) and environmental and stand variables for 23 forest plots in Lau, each 500 m2 in area. (DOC)

Species accumulation curve. Estimated rate of accumulation of new species for 23 vegetation plots on Lakeba, Nayau and Aiwa Levu islands, Lau Group, Fiji. Note that the number of species accumulates rapidly from 1 to ∼10 plots and then begins to level off (the rate of accumulation slows). The estimated number of species in the sampled forests is 11...

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 (1.2 km²), islands in the Lau Group of Fiji, West Polynesia. The unique avifauna of West Polynesia (Fiji, Tonga, Samoa) has been subjected to prehistoric human-caused extin...

We identify 70 bird bones from the Peva dune site, Rurutu, Austral Islands. These bones represent 10 species, dominated by the extant White-tailed Tropicbird, Phaethon lepturus; the nonnative chicken, Gallus gallus; and an undescribed species of extinct rail, Gallirallus sp. Two other species are extinct (the ground-doves Gallicolumba undescribed s...

Fósiles recientemente colectados en una localidad del Pleistoceno Tardío (edad de mamífero terrestre de Rancholabrea) en Térapa, Sonora, México, corresponden a 31 especies de aves no paserinas. Veintitrés de las especies (74%) son acuáticas (zambullidores, pelícano, cormorán, garzas, ibis, cigüeña, gansos, patos, rascones), reflejando el medio ambi...

Aim By establishing a prehistoric fossil record for the vertebrate fauna of Guam, we can document the composition of the island’s fauna prior to Western contact. It will also complement the extensive prehistoric fossil data already known from the nearby islands of Rota, Tinian and Aguiguan, and improve our understanding of natural distributional pa...

We surveyed indigenous landbirds at two upland, mostly forested sites in southwestern Santo, Vanuatu. One site (Wunarohaehare, 600–1,250 m elevation) lies on the western, rain-shadowed slope of Mt. Tabwemasana. The other (Tsaraepae, 500–700 m elevation) is 16 km to the south, on the southeastern, very wet slope of Peak Santo. These are the richest...

A new extinct species of parrot, Eclectus infectus Steadman, is described from 21 bones from archaeological (late Holocene) and paleontological (late Pleistocene) sites on three islands in the Kingdom of Tonga, with limited referred material (ulna, tibiotarsus) from a late Holocene archaeological site on Malakula, Vanuatu. Probably, therefore, the...

We identified the faunal vertebrate assemblages from two pre-Columbian village sites on the Río Tanamá in northwestern Puerto Rico. The sites (AR-38, AR-39) are only 100 meters apart but come from different time periods—the late Saladoid/early Ostionoid (AD 400–800) for AR-39, and the late Ostionoid (AD 1100–1500) for AR-38. This diachronic study e...

St. John, U.S. Virgin Islands, is one of the most forested islands in the West Indies and provides an opportunity to conserve both resident birds and wintering neotropical migrants. We conducted double-observer point counts of landbirds in December 2005 and 2006 in Forest Inventory and Analysis (FIA) plots and National Park Service (NPS) trails in...

The depauperate modern terrestrial biota of Easter Island contrasts with that of most other southeastern Polynesian high islands, which characteristically support a number of endemic species of insects, land snails, birds, and plants. We investigated cultural and noncultural late Holocene deposits at Anakena, Easter Island, establishing the former...

Recobramos fósiles Pleistocenos de un depósito de un río represado por lava a lo largo del Río de Moctezuma en el noreste de Sonora, a 29°41′N, 109°39′W, y a 605 m de altura. Hoy la región es semiárida con matorral desértica. El encierro que produjo la represa de lava resultó en un área pantanosa de poca duración con una sabana adyacente. La fauna...