62,922 research outputs found
Home, dirty home: lesser kestrels prefer to breed in previously used nest sites
No full textPopulations of cavity nesting species are typically limited by the availability of suitable nesting sites. However, the factors driving the choice of a suitable nest sites are poorly investigated. For instance, individuals may prefer breeding in previously unused nest sites, that may host less parasites, or in previously used nest sites, which may provide cues of successful breeding attempt. We performed a simple nestbox choice experiment to assess whether breeding individuals prefer dirty and already used nestboxes vs. newly deployed ones. The study was carried out in Matera, which hosts the larger Italian colony of lesser kestrel. All nestboxes used for this experiment were provided within the framework of LIFE project.
Before lesser kestrel arrival we crated 40 nestbox dyads, pairing 40 used nest box with 40 new ones with nestbox entrances positioned side by side in order to force the choice. To disentangle the effect of nest substrate from the appearance of the nestbox we randomly exchanged entrance panels (old and new) and nest substrate (organic material from previous nesting attempts vs. sand and gravel). We than assessed which nestbox belonging to each dyads was first occupied. At the end of the egg laying period, 38 of 40 dyads had at least one nestbox occupied. Among these, in 36 cases birds selected the nestboxes with the old substrate. The adjoining nestboxes with new substrate was occupied by a second pair just in 4 case. The experiment suggests a strong preference of lesser kestrel for nest sites already used during previous breeding seasons: despite their possible higher parasitic load, used breeding sites may provide cues of previous breeding attempt. Under a management point of view, this result suggests that conservation actions based on installation of nestboxes can benefit from the translocation of substrates from used nestbox to newly deployed ones
Reconstructing the exhumation history of the Lesser Himalaya, Northern, India, from a multi-technique provenance study of the foreland basin Siwalik Group.
No full textThis research presents the first multitechnique provenance study of the Siwalik Group in the Himalayan foreland basin in India, using the Jawalamukhi section, magnetostratigraphically dated at 13–5 Ma. Combined with provenance data from a Dharamsala Formation sedimentary section (21–13 Ma) located close by, it forms the longest temporally continuous record of Himalayan erosion in the Indian foreland basin. Sandstone petrography and heavy mineral analysis, conglomerate clast composition, Ar‐Ar dating of detrital white micas, and Sm‐Nd analyses on siltstones, conglomerate matrix and conglomerate clasts was undertaken to determine (1) shifts in source region through time and (2) changes in detrital lag times related to exhumation rates in the hinterland, together interpreted in the light of thrusting events. We interpret the data to show a slow down in exhumation rate of the Higher Himalaya by 16–17 Ma, after which time the locus of thrusting propagated south of the Main Central Thrust, and erosion of the low grade Haimanta Formation to the south became significant. The nonmetamorphosed Inner Lesser Himalaya breached its Haimanta cover by 9 Ma with the metamorphosed Inner Lesser Himalaya (Lesser Himalayan Crystalline Series) exhuming to surface by 6 Ma. This event caused sufficient disruption to established drainage patterns that all Higher Himalayan material was diverted from this location at this time
Upper crustal structure of an active volcano from refraction/reflection tomography, Montserrat, Lesser Antilles
No full textTo better understand the volcanic phenomena acting on Montserrat, the SEA-CALIPSO seis-mic experiment (Seismic Experiment with Airgun-source – Caribbean Andesitic Lava Island Precision Seismo-geodetic Observatory) was conducted in 2007 December with the aim of imaging the upper crust and the magmatic system feeding the active Soufri ?ere Hills Volcano. The 3-D survey covered an area of about 50
× 40 km and involved the deployment of 247 land stations and ocean-bottom seismometers (OBSs). A subset of the data, recorded by four OBSs and four land stations on a southeast to northwest line, has been analysed, and traveltimes have been inverted to obtain a 2-D seismic velocity model through the island. Inverted phases include crustal and sediment P waves and wide-angle reflections. The resulting velocity model reveals the presence of a high velocity body (3.5–5.5 km s?1 ) beneath the island, with highest velocities beneath the Soufri ?ere and Centre Hills, cor responding primarily to the cores of these volcanic edifices, built of a pile of andesite lava domes and subsequent intrusions. In the off-shore region, velocities in the surficial sediment layer vary from 1.5 to 3.0 km s?1 , consistent with a mainly calcareous and volcaniclastic composition. A wide-angle reflector is observed at a depth of ?1200 m below the seabed, and appears to deepen beneath the island. The upper crust beneath this reflector has velocities of 4.0–6.0 km s?1 and is infer red to cor respond to plutonic and hypabyssal rocks and sedimentary material of the old arc. The high velocity region beneath the island, extends into the crust to a depth of at least 5 km, and is believed to be caused by an intrusive complex, possibly of intermediate composition. A low velocity zone, as would be expected in the presence of an active magma chamber, was not observed perhaps due to the limited resolution beneath ?5 km depth. Our results so far provide the first wide-angle seismic constraints on the upper crustal structure of the island to a depth of 10 km, and will help understanding the processes that drive volcanism at Montserrat and other island arc volcanoes
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Dispelling the Myths Behind First-author Citation Counts
No full textWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
Subspecies and Distribution. D. p. peronii E. Geoffroy Saint-Hilaire, 1810 — E Lesser Sundas (Sumba, Sawu, Roti, Timor, Wetar, Sermata, and Babar Is). D. p. grandis Bergmans, 1978 — W Lesser Sundas (Bali, Nusa Penida, Lombok, Sumbawa, Moyo, Sangeang, Komodo, Rinca, Flores, Lembata, Pantar, and AlorIs). in Pteropodidae
No full textSubspecies and Distribution. D. p. peronii E. Geoffroy Saint-Hilaire, 1810 — E Lesser Sundas (Sumba, Sawu, Roti, Timor, Wetar, Sermata, and Babar Is). D. p. grandis Bergmans, 1978 — W Lesser Sundas (Bali, Nusa Penida, Lombok, Sumbawa, Moyo, Sangeang, Komodo, Rinca, Flores, Lembata, Pantar, and AlorIs).Published as part of Don E. Wilson & Russell A. Mittermeier, 2019, Pteropodidae, pp. 16-162 in Handbook of the Mammals of the World – Volume 9 Bats, Barcelona :Lynx Edicions on page 109, DOI: 10.5281/zenodo.644881
Reproductive decisions in the lesser black-backed gull larus fuscus and their effects on reproductive success
No full textThe effect of several fundamental reproductive 'decisions' upon reproductive success were examined over a three year period at a large, inland gullery in the Pennines. Variations in reproductive parameters in relation to timing of breeding and reproductive success were compared among years. Determinants of the degree of hatching asynchrony were identified. Eggs from two years were taken for yolk lipid analysis, using gas chromatography. Variation in micronutrient content of eggs within clutches and between years was assessed in relation to egg size and yolk size, in order to examine resource allocation decisions of individuals. Timing of breeding of individuals was experimentally manipulated through the exchange of whole clutches of eggs between early and late laying birds, whilst controlling for variation in clutch size and egg-size, in order to assess whether the seasonal decrease in reproductive success was best explained by a decrease in food supply or differences in quality among parents. I experimentally manipulated the within-brood mass hierarchy of gulls, whilst controlling for variation in both chick quality and parental quality, in order to assess the effect of hatching asynchrony per se on chick growth and survival, and whether parents optimized the degree of hatching asynchrony with respect to the prevailing food supply. Brood size was experimentally reduced in order to assess the costs and benefits of the production of supernumary young. This was acheived by comparison of chick growth, feather development and chick survival of unmanipulated three-chick broods with broods where either the a-chick or the c- chick had been removed. I present a general discussion of the results within the context of life-history theory and a model for the evolution of hatching asynchrony in the lesser black-backed gul
Search for the rare decay D+ -> D(0)e(+)nu(e)
No full textKolcu, Onur Buğra (Arel Author)Using a data set with an integrated luminosity of 2.93 fb(-1) collected at root s = 3.773 GeV with the BESIII detector operating at the BEPCII storage rings, we search for the rare decay D+ -> D(0)e(+)nu(e). No signal events are observed. We set the upper limit on the branching fraction for D+ -> D(0)e(+)nu(e) to be 1.0 x 10(-4) at the 90% confidence level
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