1,721,015 research outputs found
Fluke-made bubble rings as toys in bottlenose dolphin calves (Tursiops truncatus)
Full text linkCetaceans display considerable patterns of bubble formation and manipulation for different purposes. While position and acoustic functions of bubbles have been extensively discussed, few details are
known about their use in playing behaviour. The aim of the present work was to conduct a systematic observational study on a novel pattern of flukemade bubble rings (FBR) and associated play behaviour
in two captive calves of Tursiops truncatus. The birth of two, half-siblings bottlenose dolphins less than one month apart in the same aquarium presented a good opportunity to address the issue of individual differences and possible mimicry of such behaviour. Focal animal sampling (Altmann, 1974) sessions lasting 15 min were carried out for each calf according to a decreasing temporal schedule. The following parameters were scored and obtained for each calf: (a) mean frequency of FBR per session, (b) FBR by time of day, and (c) frequency of FBR associated play behaviour per session. FBR formation appeared to be, for both animals, a two-phase action producing a loud percussive sound. A trend in the mean frequency of FBR suggests a possible seasonal negative relationship with human activities. Moreover, the two calves usually were seen together and mimicked each other during FBR formation. Finally, 7 different behavioural categories were observed after FBR formation and their sequence appeared to be well
defined. In conclusion, this paper describes a novel form of play in two bottlenose dolphin calves. Even though data are limited by a small sample size and are only suggestive, they do indicate that FBR
formation and the calves’ ability to manipulate bubble rings could reflect the learning flexibility of the young dolphins and implies a high behavioural versatility
Diabete ed osso: studio osservazionale in una popolazione di pazienti affetti da diapete tipo 2
Full text linkNonostante il DM2 e l'osteoporosi siano tradizionalmente considerati come entità separate, in letteratura si stanno accumulando evidenze che indicano uno stretto legame tra le due patologie. Innanzitutto, dato che le due condizioni hanno un’elevata incidenza tra le persone anziane, che comprendono una proporzione crescente della popolazione generale, diventerà sempre più comune trattare pazienti anziani nei quali diabete ed osteoporosi coesistono. L’osteoporosi, infatti, è una malattia sistemica dello scheletro caratterizzata dalla coesistenza di riduzione e di alterazioni qualitative della massa ossea che si accompagnano ad aumento del rischio di fratture. Numerosi studi hanno dimostrato un'alta incidenza di osteopenia, osteoporosi e fratture nei pazienti con diabete mellito di tipo 2 (DMT2). E' stata evidenziato, inoltre, un aumento della densità minerale ossea (BMD) nei soggetti con DMT2, da ricondurre probabilmente agli elevati livelli di Body Mass Index (BMI), di frequente riscontro in tale patologia. Tuttavia, nonostante i valori elevati di BMD, nel Nurses’ Health Study è stato dimostrato un rischio di fratture 1.7 volte maggiore nelle donne diabetiche rispetto alla popolazione di controllo (85). Il Rotterdam Study ha confermato un aumento del rischio di frattura nei soggetti, sia di sesso maschile che femminile, con diabete di tipo 2, nonostante gli elevati valori di BMD (86). Diversi meccanismi sono stati proposti per spiegare le possibili influenze della malattia diabetica sul tessuto osseo e quindi sul rischio di frattura, tra cui l’ipercalciuria associata a glicosuria, la ridotta funzione renale, la ridotta performance muscolare, la neuropatia, il deficit visivo, l’aumentata concentrazione dei prodotti della glicosilazione nelle fibre di collagene e la microangiopatia a livello osseo (80). Tuttavia, non esistono, ad oggi, dati sull’entità delle fratture ossee nella popolazione diabetica italiana. D'altra parte, la frequenza di diabete e osteoporosi nel mondo occidentale, che va progressivamente invecchiando, pone come problema clinico rilevante, quello di avere strumenti atti a predire con la migliore accuratezza possibile il rischio di frattura nei pazienti con diabete. A tal proposito abbiamo messo a punto uno studio italiano osservazionale prospettico multicentrico volto a stimare la prevalenza di fratture ossee cliniche in una popolazione di pazienti affetti da DM2 ed in una popolazione di controllo, costituita da soggetti non diabetici raccolti contemporaneamente. Obiettivi secondari sono stati la valutazione del rischio di frattura calcolato utilizzando l’algoritmo FRAX come pure lo studio dell’influenza che fattori collegati alla malattia possano avere nel determinare il rischio di frattura
On the sperm whale (Physeter macrocephalus) ecology, sociality and behavior off Ischia Island (Italy): patterns of sound production and acoustically measured growth
Full text linkThe main goal of this research is to contribute to the overall knowledge of the sperm whales’
(Physeter macrocephalus) ecology, sociality, and behavior in the Mediterranean Sea. The
combined use of visual and acoustic methods allows me to:
1) give a detailed outline of the encounters around Ischia Island (Tyrrhenian Sea, Italy)
over 2002-2015 period;
2) provide insights into the acoustic repertoire in encounters with social units (females
with immatures), clusters of presumed/confirmed males and solitary individuals; this information was then used to model habitat suitability and use via analysis of different vocalization types, analyze a type of social sound (i.e. coda), and investigate an unusual tonal sound (i.e. trumpet);
3) present acoustically derived estimates of individual whale growth.
This involved the application of acoustic methods to groups or individual sperm whales located
in the area. Using passive acoustics to study animal behaviour is a developing field. As such,
many of the recent publications describe methods, models and algorithms that can be used to
investigate cetaceans in the wild.
In this thesis I attempt to apply these tools to a larger sample size than previous studies in the
Mediterranean Sea, taking advantage of the long-term data set of audio recordings made around
Ischia Island between 2004 and 2015.
The thesis is organized in 6 chapters.
- Chapters 1 and 2 describe sperm whale general biology and acoustics;
- Goal 1 is addressed in Chapter 3; it provides fundamental background information on the study area, the distribution of sperm whale encounters around Ischia Island, the individual photoidentification and group composition, as well as new insights on the habitat suitability, and diving/resting at surface cycle;
- Goal 2 is addressed in Chapter 4;
- Goal 3 is addressed in Chapter 5;
- The final Chapter (#6) provides conclusions and outlines directions for future research
Behavior of a social unit of sperm whales (Physeter macrocephalus) entangled in a driftnet off Capo Palinuro (Southern Tyrrhenian Sea, Italy)
No full textDriftnet fishing is notorious for being the major source of fatal entanglement of cetaceans and for its devastating impact on some pelagic species of the Mediterranean fauna. Of all the large cetaceans, the sperm whale (Physeter macrocephalus) is most affected by this fishing technique. On 9 August 2004, a group of five sperm whales, two adult females and three juvenile individuals, was found trapped in a driftnet 40 miles southwest off Capo Palinuro (Italy). Their tails were totally immobilised by the net and one animal was completely entangled. All the animals showed numerous lesions on their bodies. The group was freed by the Italian Coast Guard scuba-diving team during a two-day rescue operation. This exceptional case of sperm whale disentanglement was a unique opportunity to study the group’s acoustic and general behaviour during a particularly stressful event. Out of a total video/acoustic recording of 110 minutes, 91 were examined. During the rescue procedures, the whales’ behaviour was described as open mouthed, sideways roll, agitation of fluke and pectoral fins, head rubbing, fluke contact (with head, flippers and back by the liberated animals) and defecation. As expected, the entangled individuals produced different patterns of clicks, identified as ‘usual clicks’, ‘codas’ and ‘creaks’. Each pattern was associated with specific behaviour. Despite international and national regulation banning fishing with driftnets in the Mediterranean Sea, driftnets continue to be used illegally in this sperm whale habitat, posing a constant threat to the species’ survival in the region
Anthropogenic food patches and association patterns of Tursiops truncatus at Lampedusa island, Italy
No full textAnthropogenic food patches in the marine environment, such as aquaculture farms and active trawlers, may impact on the behavior of marine mammals through modification of habitats, changes in predation pressure, or alterations in food distribution, availability, and predictability, affecting related social interactions and population demographics. This study examined patterns of association of a population of common bottlenose dolphins (Tursiops truncatus) around Lampedusa Island (Italy) during 1996–2006 and tested the hypothesis that the trawl fishery and the presence of an aquaculture farm could affect such patterns. Here, we used measures of association between pairs of individuals to assess this impact on social unit composition/cohesion and some analytical techniques to describe the structure of dolphin social networks and temporal stability of associations. Association information for 71 regularly sighted individuals was obtained from photo-identification surveys within groups observed or not at "feeding stations." We found association patterns between dolphins were nonrandom. The Lampedusa population seems to be arranged into 6 clusters and organized in communities composed of animals that were either never seen in association with feeding stations (N individuals) or those that are (Y individuals), although mixed assemblages were also recorded. Both communities showed long-term preferred companions, with different degrees of social cohesion—as resulted by network measures and temporal analysis. Delineating community structure at Lampedusa Island has offered basic information for further investigations in the area, also providing novel evidences on how disparities in association patterns between bottlenose dolphin individuals may have resulted from a combination of ecological and anthropogenic factors
The case study of the marine Canyon of Cuma (Tyrrhenian Sea, Italy): implication for cetacean conservation off Ischia Island
No full textCetaceans value and conservation in the Mediterranean Sea
Full text linkThis review provides an overview of the Mediterranean diversity and conservation status of cetaceans, and the value associated with their conservation and non-consumptive use. Mediterranean Sea is one of the world's diversity hotspots. Its biodiversity is increasingly under threat in the whole region and key species as cetaceans challenge for conservation. All the identified threats are interlinked and cumulatively contribute to the habitat degradation of the entire area as well as reduced health status of the cetaceans that live there. Whales and dolphins, defined as charismatic megafauna, flag species, apex predators and bio indicators of the marine environment health are demanding social substantial changes. Needs are for spatial prioritization within a comprehensive framework for regional conservation planning, the
acquisition of additional information identifying critical habitats in data-poor areas and for data deficient species, and addressing the challenges of establishing transboundary governance and collaboration in socially, culturally and politically complex conditions. This paper examines research gaps, questions and issues (population abundance estimates, as well as the biological, ecological, physiological characteristics) surrounding cetacean species in the context of biodiversity conservation and highlights the need of targeted conservation management actions to reduce sources of disturb of
key threatening processes in the Mediterranean Sea. The ‘precautionary principle’ must be adopted at all levels in attempts to mitigate impacts and thus provides scope for the translation of the principle into operational measures. As natural entities, cetaceans have their objective intrinsic value, not humanly conferred
Role of the conventional ultrasonography and color doppler in predicting malignancy in the neck lymphonodes
No full textOccurrence and spatio-temporal distribution of sperm whale (Physeter macrocephalus) in the submarine canyon of Cuma (Tyrrhenian Sea, Italy)
No full text1. Boat surveys aimed at studying sperm whales in the Tyrrhenian Sea were conducted between 2002 and 2011. During 768 daily surveys, a total effort of 32 602km was achieved within an area of 8800km2 resulting in 92 encounters with 229 sperm whale individuals. 2. Average encounter rates of sperm whales was 0.5 groups per 100km2, with a higher concentration in the vicinity of the submarine canyon of Cuma, confirming the importance for the species of this small hotspot in the Mediterranean Sea. 3. Encounter rates increased with increasing distance from the coast. It is possible that the intense boat traffic and anthropogenic disturbance in the area may be moving animals away from the coast leading to habitat loss. 4. The species–habitat relationship documented in this study has implications for conservation
The development of suckling behaviour in two captive- born calves of bottlenose dolphin (Tursiops truncatus)
No full textFew and contrasting results have been obtained on nursing patterns of newborn and infant dolphin calves, so that the developmental profile of this behavior is still largely unknown. The aim of the present study was to observe, from birth to one year of age, the development of suckling behavior of two calves of Tursiops truncatus that were born three weeks apart in the same aquarium. Duration, frequency, lateralization, and day/night patterns of attempted (AS) and successful (SS) suckling episodes were scored. Observations followed this rationale: a) 1st week: 20 hours/day; b) 2nd-8th week: 20 hours/week; c) 9th-16th week: 20 hours/2 weeks; d) 17th-52nd week: 20 hours/3 weeks. Overall, the ontogenetic profile were rather similar in the two calves, and greater age-related changes were observed during the earlier compared to the later developmental period. AS frequency was high in the first postpartum phase. It readily decreased to very low levels thereafter, when SS frequency sharply increased, so that by the third day of life the correct behavior had almost totally replaced the attempts. SS duration increased over the first few days of life, and showed what appeared as a phase of adjustment around the second month. A circadian pattern was found during the first week of life for successful suckling, whose frequency and duration were higher during the night than during the day time. As for the last months of observation, individual developmental trends of suckling frequency were fairly consistent with the different time-courses of weaning. Finally, no definite evidence for a nipple preference appeared
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