Cavity use and breeding biology of endangered Bahama Swallows (Tachycineta cyaneoviridis): implications for conservation

Bird populations, especially on islands, have declined or gone extinct due to overhunting, habitat loss and fragmentation, and adverse effects of the introduction of non-native species. Bahama Swallows (Tachycineta cyaneoviridis), endangered secondary cavity nesters that breed on only three islands in the northern Bahamas, are an island species with a declining population, but the causes of this decline are unknown. During four breeding seasons on Great Abaco Island (2014–2017), we identified cavity-nesting resources used by breeding swallows in native pine forest and other habitats, and estimated phenology and breeding parameters from a subset of nests. Bahama Swallows nest in cavities in a variety of structures, but rely most on woodpecker-excavated cavities in pine snags and utility poles. Swallows nesting in cavities in pine snags had higher fledging success (92%) than those nesting in cavities in utility poles (50–62%), which were concentrated in non-pine habitat that may expose swallows to predation and increased competition for nest cavities from other species. The high reproductive success of Bahama Swallows nesting in the pine forest indicates that the decline in population cannot be attributed to poor productivity on southern Great Abaco. However, our results suggest that the dependence of Bahama Swallows on cavities excavated by Hairy Woodpeckers (Dryobates villosus) for nesting sites may be a factor in their decline, and highlight the potential importance of the protection and management of pine forests in future efforts to ensure the survival of Bahama Swallows.     

Première indication de la présence de phorusracidés,famille d'oiseaux géants d'amérique du sud,dans le tertiaire Européen: Ameghinornis nov. gen. (Aves,ralliformes) des phosphorites du quercy,France

Some bird remains, from the «Phosphorites du Quercy deposits are closely related to the corresponding bones of Phorusrhacidae, an extinct family of birds which underwent an extensive diversification in South America from Oligocene to Pleistocene times. It included many giant flightless species. The form of the Quercy is a rather primitive one, of medium size and of probably somewhat reduced flying ability.The simultaneous occurrence of Phorusrhacidae inFrance and South America is of great biogeographical significance. The Phorusrhacidae seem most probably to be the descendants of a rather primitive group of Ralliformes, already diversified in Gondwanaland prior to its separation into different continental masses.     

A refined model of body mass and population density in flightless birds reconciles extreme bimodal population estimates for extinct moa

Flightless birds were once the largest and heaviest terrestrial fauna on many archipelagos around the world. Robust approaches for estimating their population parameters are essential for understanding prehistoric insular ecosystems and extinction processes. Body mass and population density are negatively related for extant flightless bird species, providing a method for quantifying densities and population sizes of extinct flightless species. Here we assemble an updated global data set of body mass and population densities for extant flightless birds and estimate the relationship between these variables. We use generalised least squares models that account for phylogenetic relatedness and incorporate the effects of limiting factors (e.g. habitat suitability) on population density. We demonstrate the applicability of this allometric relationship to extinct species by estimating densities for each of the nine species of moa (Dinornithiformes) and generating a combined spatially explicit map of total moa density across New Zealand. To compare our density estimates with those previously published, we summed individual species' abundances to generate a mean national density of 2.02–9.66 birds km⁻² for low- and high-density scenarios, respectively. Our results reconcile the extreme bimodality of previous estimates (< 2 birds km⁻² and > 10 birds km⁻²) and are comparable to contemporary densities of large herbivorous wild mammals introduced into New Zealand about 150 yr ago. The revised moa density has little effect on the harvest rates required to bring about extinction within 150–200 yr, indicating that rapid extinction was an inevitable response to human hunting, irrespective of the initial population of moa.     

Late neogene biostratigraphy and stable isotope stratigraphy of a drilled core from the Gulf of Mexico

Late Neogene stable isotope stratigraphy and planktonic foraminiferal biostratigraphy have been examined in a high sedimentation rate core (E67-135, Shell Oil Co.) drilled at 725 m water depth in the De Soto Canyon, Gulf of Mexico. The 305 m core contains sections that are Late Miocene, Early Pliocene, Late Pliocene, and Quaternary in age, and is rich in well-preserved assemblages of planktonic foraminifera.A biostratigraphy has been established based on the ranges of 34 selected species of foraminifera. The core 3orrelates with sections from the Gulf of Mexico, the Caribbean Sea, and the subtropical North and South Atlantic Oceans using, as datums, the evolutionary appearances of Globorotalia miocenica Palmer and Globorotalia margaritae evoluta Cita, the extinction of Globorotalia miocenica and the first appearance of Globorotalia truncatulinoides (d'Orbigny).Oxygen and carbon isotope stratigraphy is based on analysis of the benthonic foraminifer, Uvigerina d'Orbigny. Isotopic trends are similar to those observed in the Pacific and Atlantic Oceans. From Early Pliocene to Late Pleistocene time, average δ¹⁸O values increase (2.42‰ to 3.36‰) and exhibit a wider range of values (0.71‰ in Early Pliocene compared to 1.65‰ in Late Pleistocene sediments), probably reflecting Late Neogene climatic deterioration. The ratio ${}^{13}\text{C}{}^{12}\text{C}$ decreases significantly by ?0.21‰ from the Late Miocene to the Early Pliocene. A decrease in δ¹³C is observed in other cores and is probably related to changing oceanic circulation patterns in Late Miocene time.     

Cryptic diversity and conservation units in the Bahama parrot

Wide application of genetic approaches has enhanced the detection of cryptic diversity, even in historically well-studied organisms. In addition to improving our knowledge of biodiversity, detection of cryptic diversity can have important management implications within imperiled groups, such as the Cuban parrot complex (Amazona leucocephala). Bahama parrots (A. l. bahamensis) were once widespread throughout the archipelago, but are now restricted to the two largest islands (Abaco and Inagua). Mitochondrial DNA-based population genetic and phylogenetic analyses revealed the distinctiveness of the Abaco, Inagua and now extirpated Acklins populations, detecting diagnostic character support and reciprocal monophyly indicative of three phylogenetic species. Congruent results were obtained for the Abaco and Inagua populations based on Bayesian clustering analyses of microsatellite genotypic data. Genetic signatures of demographic contraction were identified on Abaco, but not Inagua. These findings were consistent with lower genetics-based estimates of effective population size on Abaco, as well as the disproportionate human impacts reported on the island relative to Inagua. Overall, our results suggest that the taxonomy of the Cuban parrot complex requires revision and that the conservation status of the Abaco phylogenetic species should be immediately elevated to reflect its historical isolation, recent population decline and continued threats to its persistence.     

Late Pleistocene and Holocene chitons (Mollusca, Polyplacophora) from Uruguay: Palaeobiogeography and palaeoenvironmental reconstruction in mid latitudes of the southwestern Atlantic

Here we present a revision of the fossil record of chitons (Mollusca, Polyplacophora) of Late Pleistocene and Holocene marine deposits of Uruguay and discuss their potential for palaeoenvironmental reconstruction. Chitons were recorded as isolated valves in bivalve- and gastropod-rich assemblages. They are represented by the species Chaetopleura angulata (Spengler), C. isabellei (d’Orbigny), C. asperrima (Gould) and Ischnochiton striolatus (Gray). The last two species are recorded for the first time as fossils not only in Uruguay but also in South America. Exclusively recorded for the Late Pleistocene is the warm water species I. striolatus, whose current southern range limit is located in Santa Catarina, Brazil. Higher temperatures than at present are inferred for the Uruguayan coast during the Late Pleistocene, probably driven by the southward influence of the warm Brazilian Current along the eastern margin of South America. Chitons from Holocene deposits show a wider geographic distribution along the Uruguayan coast in comparison to current distributions. They are recorded where an estuarine and eurihaline fauna lives today, which suggests the former existence of marine conditions. This is explained by the westward displacement of the marine front in the Uruguayan coast during the Holocene transgressive events. Chitons have proven to be useful palaeoenvironmental proxies for the reconstruction of salinity and temperature trends in the Uruguayan coast during the climatic oscillations of the Late Pleistocene and Holocene epochs. As such, their patterns of distribution are related to the recent physical evolution of the Southwestern Atlantic Ocean.     

Thermal history of reef-associated environments during a record cold-air outbreak event

Summary Several polar continental air masses intruding into the south Florida/northern Bahama Bank region during January 1981 caused record low air temperatures and rapid chilling of extensive shallow-water carbonate systems. Numerous coral kills along the Florida reef tract and massive fish mortalities in Florida Bay were attributable to unusually cold waters generated at this time. Thermal evolution of Florida Bay/Florida reef tract and northern Bahama Bank waters from 8 to 21 January was assessed from thermal infrared data acquired by the NOAA-6 environmental satellite, in situ water temperatures, local meteorological data, and a computerized heat flux model. Field observations and laboratory experiments identify 16°C as a thermal stress threshold for most reef corals (Mayor 1915; Davis 1981). Temperaturecorrected digital satellite data indicated that water temperatures below 16°C were generated in Florida Bay and on Little and Great Bahama Banks during a 10-day period in January. Lowest temperatures on the Florida reef tract resulted from offshelf transport of Florida Bay water through major tidal channels. Offshelf movement of bay water is driven primarily by strong northerly winds, density gradients, and tidal pumping. Absence of reef development opposite major tidal passes along the Florida reef tract (Ginsburg and Shinn 1964) and aperiodic coral kills along bank margins can be attributed to this process, which has probably had a limiting influence on Holocene reef development in these areas.     

The timing of diversification within the most divergent parrot clade

The Strigopidae are an ancient parrot (Psittaciformes) family consisting of three extant species placed in two genera (Nestor, Strigops) and restricted to New Zealand. Their evolutionary history is clouded because the timing of divergence events within this family has variously been attributed to Pleistocene climate change or much earlier earth‐historic events. Here we examine new psittaciform DNA sequence data, and combine them with previously published sequences, to shed light on the poorly understood timing of diversification within the Strigopidae. Using calibrations indirectly derived from both psittaciform and non‐psittaciform fossils, our data indicate a Late Pliocene or Early Pleistocene (ca 1.2–3.6 mya) differentiation between the two Nestor species (kea and kaka), possibly in response to shifts in habitat distribution associated with sea level fluctuations. The unique, monotypic, nocturnal and flightless genus Strigops (kakapo) is shown to have diverged from the Nestor lineage probably ca 28–29 mya, coinciding with the potential Oligocene submergence of Zealandia when much of its landmass may have been fragmented into smaller islands, providing a setting for allopatric diversification.     

The Xujiayao 14 Mandibular Ramus and Pleistocene Homo Mandibular Variation

The earlier Late Pleistocene mandibular ramus from Xujiayao (northern China) preserves traits that vary distributionally among western Old World Pleistocene Homo samples and between Early/Middle Pleistocene archaic humans and Late Pleistocene modern humans in eastern Eurasia. Xujiayao 14 presents a lateral mandibular notch crest, an open mandibular foramen, a wide ramus, an asymmetrical mandibular notch, an enlarged superior medial pterygoid tubercle, (probably) a retromolar space, and gonial eversion, as well as an unusual depression in the planum triangulare. The first two traits appear ancestral for Later Pleistocene and recent Homo and are dominant among modern humans. The second two traits largely separate Xujiayao 14 and archaic Homo from modern humans. The next two traits are found in the highest frequency among the Neandertals, although gonial eversion contrasts with Late Pleistocene Neandertals. Xujiayao 14, in the context of Pleistocene and recent Homo samples and the other Xujiayao human remains, therefore provides a morphological mosaic, highlighting regional variation through the Pleistocene.     

Unexpected visitors: flightless beetles in window traps

Ancient woodlands are highly important for biodiversity. Flightless beetles and window traps may first appear to be incompatible as a study group and a study method. Little is known about the actual capability of window traps in monitoring of entire forest arthropod communities. We try to determine the possibility of using window traps (designed as tree traps) as an additional method to trap flightless beetles of the genera Carabus (Carabidae), Acalles and Trachodes (Curculionidae), as vulnerable representatives of wildlife forest fauna with high conservation value. From the environmental point of view, the occurrence of the studied flightless beetles was significantly more influenced by altitude than tree species as the studied environmental variables. Several beetles also showed positive significant species to species relationships during their observed phenological activity. Our results showed that the studied flightless beetles may reappear in secondary forests if these reach their optimal structure. On the other hand, they may be sensitive to large scale disturbances and not only to those caused by commercial forestry. The results also showed that window traps designed as tree traps could be used to successfully trap assemblages of forest fauna including flightless species.     

Ancient forests and grasslands in the desert: Diet and habitat of Late Pleistocene mammals from Northcentral Sonora, Mexico

Despite high taxonomic diversity elsewhere in North America during the Pleistocene, vertebrate faunas are exceedingly rare in the region of northern Mexico. Térapa, a unique fossil site located in the present-day desert of Northcentral Sonora, Mexico (29°41′N, 109°39′W, 605 m elevation), contributes to our understanding of the paleoecology and paleoclimate of the region during the Late Pleistocene, ca. 43,000-40,000 cal. yr BP. At least 60 vertebrate taxa, including amphibians, turtles, a crocodilian, snakes, birds and many mammals, have been recovered from an 11-m thick sequence of fossiliferous sediments. The diversity and tropical affinity of these taxa suggest a more-forested environment than the thornscrub desert habitat present in this region today.Isotopic analyses of tooth enamel carbonate from ancient mammalian herbivores suggest that the Sonoran desert has undergone considerable climate change since the Late Pleistocene. Bulk carbon (δ¹³C) and oxygen (δ¹⁸O) isotopes from nine mammalian fossils indicate a habitat mosaic with variations in diet that include browsers, mixed feeders and C4 hyper-grazers (δ¹³C range of − 10‰ to 2‰). Unique to this site are δ¹³C tooth enamel values of − 6.1 and − 5.6 ‰ for the deer Odocoileus, which suggest a more variable diet than strict browsing, including possibly feeding on CAM and/or C4 plants. Serial sampling of carbon (δ¹³C) and oxygen (δ¹⁸O) isotopes for ancient mammal teeth with hypsodont dentitions (fossil Equus and Bison,) as well as δ¹⁸O meteroric water estimates from well-supported climatic models suggest a cooler and more equable environment at Térapa during the Late Pleistocene. These results also support previous habitat reconstructions inferred from the macrobotanical and packrat midden records of northern Sonora (Mexico). High-resolution stable isotope geochemistry indicates that: 1) ancient Térapa was covered with forest and grassland habitats that extended northward into Mexico by about 350 km relative to their present-day northern limits during the Late Pleistocene; and 2) an Amount Effect (AE) is demonstrated in the fossil record at Térapa even though the climate was less seasonal compared to the modern desert habitat.     

Leeward bank margin Halimeda meadows and draperies and their sedimentary importance on the western Great Bahama Bank slope

Bryopsidalean algal meadows in water depths of 20–40 m on the leeward side of western Great Bahama Bank (WGBB) lie between non-skeletal-dominated sand flats on the bank top to the east and a cemented steep escarpment to the west. The meadows contain dense populations of rhipsalian Halimeda species, as well as Udotea and Rhipocephalus. Extensive populations of other Halimeda species (opuntioids) occur at greater depths on the cemented rocky escarpment, growing as drapes or vines rather than as upright thalli. These meadows and draperies are important sources of coarse-grained carbonate sediments. This is shown by (1) deeper bank-edge sediments (30–60 m) containing considerably more Halimeda fragments than do the bank top, non-skeletal sands, and (2) the coarser fraction of slope sediments (down to 200 m) dominated by Halimeda plates, partly or extensively altered and internally cemented by magnesian calcite and aragonite. A transect across the bank margin from bank top (<10 m) to lower slope (300 m) provides a useful comparison for the locus of sediment production and accumulation. The production of Halimeda in these bank-edge habitats approximates that in the Great Barrier Reef or off Indonesia and Nicaragua in similar water depths. The apparent lack of thick sediment accumulation in WGBB compared to that seen elsewhere may reflect the high rates of downslope transport off Great Bahama Bank.     

Une vue d’ensemble sur Melka Kunture,grand complexe de sites pléistocènes dans la vallée supérieure de l’Awash (Éthiopie)

Melka Kunture is a cluster of Pleistocene sites, extending over ?100 km² between 2000 and 2200 m asl, in the upper Awash Valley of Ethiopia. Starting around 2 million-years ago, the archaeological sequence includes sites with lithic productions of the Oldowan, Early Acheulean, middle Acheulean, final Acheulean, Early Middle Stone Age, Middle Stone Age and Late Stone Age. All over the Pleistocene, the climate was rainy and cooler than at the lower elevations of the Rift Valley, allowing the development of Afromontane vegetation. Hippopotamuses are ubiquitous and dominant in terms of biomass, but Alcelaphini are well represented, notably with genus Connochaetes and genus Damaliscus. Hominin fossils have been discovered in association with the Oldowan, the Early Acheulean, the middle Acheulean and the Early Middle Stone Age. Animal tracks and hominin footprints have also been documented, the latter ones in layers dated between 1.2 and 0.7 million-years.     

How old is the cheetah skull shape? The case of Acinonyx pardinensis (Mammalia,Felidae)

It is generally believed that the skull CCEC-161821 of Acinonyx pardinensis from Saint-Vallier, an Early Pleistocene French locality, is similar to that of the modern cheetah, in contrast to several other Late Pliocene and Early Pleistocene Old World felids with cheetah-like teeth, assigned either to Acinonyx Brookes, 1828, or to Sivapanthera Kretzoi, 1929. Morphological comparisons and morphometric analysis of the fossil and recent material show that the Acinonyx pardinensis from Saint-Vallier, although dentally similar to the modern cheetah, is not cheetah-like in its skull shape. All those Late Pliocene and Early Pleistocene forms can also be included in Acinonyx, implying that the characteristic skull shape of the modern form is probably a recent acquisition.     

Development and characterization of microsatellite loci in the Centricnemus leucogrammus weevil

Centricnemus leucogrammus is a weevil characteristic of European xerothermic habitats and steppes. The species was probably more widespread during the Pleistocene glaciations, while its current distribution is limited to “warm-stage refugia.” It may be regarded as a typical representative of flightless xerothermophilous beetles. Previous studies concentrated on its genetic variation using mitochondrial genes. Here, we identified, tested and characterized 24 polymorphic microsatellite loci with the use of 454 sequencing of microsatellite enriched genomic libraries. The new set of loci will be used in studies on the population structure of this weevil and may provide valuable information for its conservation.     

A new early Frasnian (Late Devonian) foraminifer from eastern Taurides (Turkey): Evolutionary and paleobiogeographic implications

A complete Devonian sequence is well exposed in the eastern Taurides, forming more than 1000 m-thick succession of carbonate and siliciclastic sediments. The carbonate succession, stratigraphically ranging from Middle Devonian to early Late Devonian and mostly comprising limestones, dolomitic limestones and reefal limestones, contains abundant and diverse assemblages of foraminifers, corals, stromatoporoids, calcareous algae, bivalves, brachiopods, ostracods, and conodonts. The limestone samples collected from a more closely sampled stratigraphic section have been investigated for their foraminiferal content. The micropalaeontological analyses carried out on these samples have revealed the presence of an early Frasnian foraminiferal assemblage including predominantly unilocular parathuramminid species and multilocular forms of the genera Nanicella, Paratikhinella and Semitextularia? and further indicated the presence of a new genus and a new species Halevikia deveciae n. gen. n. sp. which appears as an important phylogenetic and stratigraphic transitional taxon between the families Baituganellidae n. fam. and Tournayellinidae, the phylogenetic potentiality of which during the Late Devonian is currently probably underestimated.     

Revision of Late Pleistocene and Holocene Galliformes Fauna from the Crimean Mountains

The Late Pleistocene and Holocene Galliformes faunas from the Crimean Mountains included seven species of birds belonging to the families Phasianidae and Tetraonidae: Phasianus colchicus, Alectoris chukar, Perdix perdix, Coturnix coturnix, Lyrurus tetrix, Lagopus mutus, and Lagopus lagopus. The habitation of Gallus representatives in the Crimea in the Late Pleistocene has not been confirmed. Representatives of the family Phasianidae were present in the Crimean fauna at least for most of the Late Pleistocene. All of them survived until the Late Holocene. Pheasants became extinct around the eighteenth century, and the rock partridge seems to have disappeared only in the first half of the twentieth century. The species were restored in the Crimea in the second half of the twentieth century. Gray partridges were common resident birds of the Crimean Mountains throughout the Late Pleistocene and Holocene. Quail was not a numerous breeding species of the Crimean Mountains at the same time, but mass migration of this species through the Crimea appeared only at the end of the Late Pleistocene and evolved over the Holocene warming. Species of Tetraonidae appeared in the fauna of the Crimea long before the beginning of the cold-phase maximum of the last glaciations but no later than 28000 years ago and became extinct in the Early Holocene warming but no later than 9000 years ago.     

Speciational history of North American Haemorhous finches (Aves: Fringillidae) inferred from multilocus data

We investigated species relationships and timing of speciation in North American Haemorhous finches by using a mitochondrial phylogeographic approach combined with a multilocus species tree reconstruction. Haemorhous purpureus and H. cassinii were strongly supported as sister taxa, and H. mexicanus was sister to H. purpureus + H. cassinii. Our divergence times indicated that diversification within Haemorhous occurred progressively from the Late Miocene into the Pleistocene. Our inferred pattern of speciation demonstrates the complexity of the origins of North American birds, and provides additional evidence that a single cause for speciation in closely related North American birds, such as Late Pleistocene glacial–interglacial cycles, is unlikely.     

NEW ENDOLITHIC CYANOPHYTES FROM THE NORTH ATLANTIC OCEAN. II. HYELLA GIGAS LUKAS & GOLUBIC SP. NOV. FROM THE FLORIDA CONTINENTAL MARGIN1

A new species of endolithic cyanophyte, Hyella gigas Lukas and Golubic (Order: Pleurocapsales), differs from other species of Hyella by its larger cell and filament dimensions and its laminated, often pigmented sheath. It bores into mollusk shells and other marine carbonate substrates on the east coast of North America, the Bahama Islands and the Northern Mediterranean Sea, where it is found from near mean low water down to 25 m depth. This comparatively shallow maximum depth is probably due to the limited capacity of Hyella gigas to adapt to changing light quality and intensity. We reject the suppression of the genus Hyella as proposed by Drouet and Daily.