30 research outputs found
Behavioral Pattern of Rissoâs Dolphin (Grampus griseus) in the Gulf of Taranto (Northern Ionian Sea, Central-Eastern Mediterranean Sea)
Relatively scant information is available on the Rissoâs dolphin in comparison to the other
species regularly present in the Mediterranean Sea. Recently, its conservation status has been updated to
Endangered by the International Union for Conservation of Nature (IUCN) in this Sea. Therefore, the
need to increase information on its biology and ecology is even more urgent. This study reports the first
preliminary information on the behavioral traits of the species occurring in the Gulf of Taranto (Northern
Ionian Sea). Data on predominant behavioral activity states and on a set of group composition variables
(group formation, cruising speed, dive duration and interaction between individuals) were collected
from April 2019 to September 2021, applying the focal-group protocol with instantaneous scan sampling.
Group size, depth and group composition variables were compared between activity states. Results
highlight that both the group size and the several variables considered varied significantly depending
on activity state. The group size was significantly smaller during feeding than resting and traveling and
a characterization in terms of group formation, cruise speed, dive duration and interaction between
animals is provided for the different activity states. Moreover, a list of behavioral events which occurred,
as well as their relative frequency of distribution among activity states, is reported. Finally, details on the
sympatric occurrences between Rissoâs and striped dolphins, as well as the repetitive interaction
observed between adult individuals and plastic bags floating on the sea surface, are reported and
discussed
A study of CP violation in B-+/- -> DK +/- and B-+/- -> D pi(+/-) decays with D -> (KSK +/-)-K-0 pi(-/+) final states
A first study of CP violation in the decay modes and , where labels a or meson and labels a or meson, is performed. The analysis uses the LHCb data set collected in collisions, corresponding to an integrated luminosity of 3 fb. The analysis is sensitive to the CP-violating CKM phase through seven observables: one charge asymmetry in each of the four modes and three ratios of the charge-integrated yields. The results are consistent with measurements of using other decay modes
Measurement of Upsilon production in collisions at root s=2.76 TeV
The production of , and mesons decaying into the dimuon final state is studied with the LHCb detector using a data sample corresponding to an integrated luminosity of 3.3 collected in proton-proton collisions at a centre-of-mass energy of TeV. The differential production cross-sections times dimuon branching fractions are measured as functions of the transverse momentum and rapidity, over the ranges $p_{\rm T} Upsilon(1S) X) x B(Upsilon(1S) -> mu+mu-) = 1.111 +/- 0.043 +/- 0.044 nb, sigma(pp -> Upsilon(2S) X) x B(Upsilon(2S) -> mu+mu-) = 0.264 +/- 0.023 +/- 0.011 nb, sigma(pp -> Upsilon(3S) X) x B(Upsilon(3S) -> mu+mu-) = 0.159 +/- 0.020 +/- 0.007 nb, where the first uncertainty is statistical and the second systematic
Study of forward Z + jet production in pp collisions at âs=7 TeV
A measurement of the +jet production cross-section in collisions at a centre-of-mass energy TeV is presented. The analysis is based on an integrated luminosity of recorded by the LHCb experiment. Results are shown with two jet transverse momentum thresholds, 10 and 20 GeV, for both the overall cross-section within the fiducial volume, and for six differential cross-section measurements. The fiducial volume requires that both the jet and the muons from the Z boson decay are produced in the forward direction (). The results show good agreement with theoretical predictions at the second-order expansion in the coupling of the strong interaction.A measurement of the +jet production cross-section in collisions at a centre-of-mass energy TeV is presented. The analysis is based on an integrated luminosity of recorded by the LHCb experiment. Results are shown with two jet transverse momentum thresholds, 10 and 20 GeV, for both the overall cross-section within the fiducial volume, and for six differential cross-section measurements. The fiducial volume requires that both the jet and the muons from the Z boson decay are produced in the forward direction (). The results show good agreement with theoretical predictions at the second-order expansion in the coupling of the strong interaction
Social Structure and Temporal Distribution of Tursiops truncatus in the Gulf of Taranto (Central Mediterranean Sea)
This study aims to provide information on the site fidelity, residency patterns and the social structures of bottlenose dolphins occurring in the Gulf of Taranto in order to supply effective indications supporting the future management and conservation measures of the species. Out of 141 photo-identified individuals about 76% were re-sighted from 2 up to 31 times. The site fidelity analysis of photo-identified individuals highlighted the occurrence of 20 seasonal residents, 62 visitors and 59 transient individuals that were included in a local population in which emigration and reimmigration events occurred, as suggested by the residency-pattern analysis. The association pattern, performed using SOCPROG 2.9, highlighted a relatively low mean value of the overall half-weight association index (0.11 ± 0.04). However, the test for the null hypothesis of ârandom associationâ was rejected and the temporal analysis made with SLAR suggested the presence of both extremely fluid and stable associations between individuals, describing a fission fusion social structure with a certain degree of social organization. Moreover, the cluster and social network analysis showed two geographically and socially segregated units. Thus, more investigations are needed and the development of a specific conservation plan for bottlenose dolphins in the whole area is required
Residency patterns and site fidelity of Grampus griseus (Cuvier, 1812) in the Gulf of Taranto (Northern Ionian Sea, Central-Eastern Mediterranean Sea)
The residency pattern and site fidelity of Rissoâs dolphin Grampus griseus were studied using sightings data collected during
standardized vessel-based surveys carried out from 2013 to 2018 in the Gulf of Taranto (Northern Ionian Sea, Central-Eastern
Mediterranean Sea). The photo-identification of 91 individuals of G. griseus and the occurrence of re-sighted dolphins up to 8
times provide the evidence that this mid-sized odontocetes persistently occurred in the study area. The presence of transient
individuals, visitors, and seasonal residents in the Gulf of Taranto, along with the 29 multi-year resident Rissoâs dolphins
observed from 2 to 4 times on different years, indicated some degree of inter-annual variability in its temporal use of the area.
Moreover, the occurrence of newborns and calves through the study period suggests the possibility to consider the Gulf of
Taranto as both nursery and feeding area for females caring for their offspring. The importance of the Gulf of Taranto as critical
habitat for the Rissoâs dolphin as well as the common bottlenose dolphin and the striped dolphin candidates this area as potential
Important Marine Mammal Area, in which enforce specific conservation measures are aimed to mitigate the anthropogenic
pressure on different cetacean species according to ACCOBAMS and the MMPATF indication
Emission rate of acoustic signals for the common bottlenose and striped dolphins in the gulf of taranto (Northern Ionian Sea, Central-Eastern Mediterranean Sea)
Dolphins emit a large variety of acoustic signals on which they rely for navigation, communication and searching for food. Nevertheless, each species uses quantitative and qualitative species-specific characteristics for tonal and pulsed signals, and the different behavioral contexts may affect the use of these signals. The main aim of this work is to evaluate if the emission rate of acoustic signals can be used as a cue to recognize species, and as an intra-specific feature for recognizing behavioral contexts. We collected acoustic and behavioral data during 27 sightings of bottlenose and striped dolphins in the Gulf of Taranto, (Northern Ionian Sea, Central-Eastern Mediterranean Sea). 396.31minutes of recordings were considered for analysis. The emission rate, calculated as the number of vocalizations/minutes of recording per animals within the group, was compared among species and behaviors. A higher emission rate was recorded for bottlenose dolphins clicks during traveling compared to striped dolphins involved in the same behavior, and for striped dolphins whistles during socializing compared to other behaviors of the same species. However, we must consider that smaller groups were analyzed for bottlenose dolphins. Results suggest that dolphins share click echoes in larger groups and increase communication signals during social activities. Our preliminary results can help inform management and conservation actions, in the framework of EU regulations, in this high impacted area
Exploring data from an individual stranding of a Cuvier's beaked whale in the Gulf of Taranto (Northern Ionian Sea, Central-eastern Mediterranean Sea)
Cetacean stranding events are an important source of information and biological samples, providing data on species occurrence, distribution and population dynamics as well as on mortality rate induced by human activities or natural causes. This is even truer for species such as Z. cavirostris, whose elusive behavior has made its field observation difficult in many Mediterranean areas. Although the occurrence of single or serial strandings of this species and the rise in survey effort have increased the knowledge on its presence, there are still gaps in some Mediterranean areas, especially in the Gulf of Taranto (North-western Ionian Sea, Italy), where a critical habitat suitable for different cetacean species has been identified. Despite no sightings of Z. cavirostris having been recorded so far, ACCOBAMS designates the Gulf of Taranto as an Area of Special Concern for Beaked Whales (ASC-BW) on the basis of atypical mass strandings of 12 individuals which occurred in the Ionian Sea in 2011. Moreover, the conservation status of the Z. cavirostris has recently passed from Data Deficient to Vulnerable, according the IUCN criteria adopted for the Mediterranean Sea, thus showing the urgent need for basic information on its bio-ecological features, suitable habitat and threats at local or wider scale. This study is the first attempt at application in the Mediterranean Sea of a Lagrangian prediction model simulating the carcass drift trajectories to investigate the at-site sea origin of an individual of Z. cavirostris stranded in the Gulf of Taranto. Moreover, a necropsy was carried out to detect the possible cause of death and the results of bacteriological, biomolecular and toxicological analysis are provided. Finally, a collection of osteological data as well as the process of turning and displaying the skeleton in a museum are detailed, highlighting the importance of these exhibits from a scientific and educational point of view