1,720,966 research outputs found
Where to go and what to eat... When you are just born. Feeding behaviour of four bottlenose dolphin newborns in Rimini Delfinario
No full textBlowhole hormonal analysis: a new approach to the study of tursiops truncatus pregnancy?
No full textINTRODUCTION Hormones and behaviour are reciprocally influenced. Monitoring hormones levels can therefore provide insights into the mechanistic aspects of behaviour. Hormones are usually extracted from blood samples or saliva, urine and faeces. In cetaceans, an alternative source may be found in blowhole samples, which can be collected non-invasively. Given the current scientific knowledge on pregnancy endocrinology in dolphins, specific aims of this trail were a) to set up and validate progesterone (P4) and cortisol determination procedures from blowhole samples and b) to determine the concentration and profile of progesterone and cortisol during Tursiops truncatus pregnancy.
MATERIAL AND METHODS The study was conducted in the Rimini Delfinario (Italy) on a female monitored from July to September 2003 during the last three months of gestation. The observations were made once a week until the final week before delivery when samples were taken on three alternative days. The bottlenose dolphin was trained to blow into polypropylene sterile bottles with a screw closure. The samples were stored at –20°C until assayed. Concentrations of steroid hormones were determined by validated radioimmunoassays (Seren et al., 1974; Tamanini et al., 1983).
RESULTS AND DISCUSSION Progesterone concentrations during the last 12 weeks of gestation always remained high and didn’t change throughout the observed period. However, during the final week progesterone values gradually decreased as the birth date approached and continued to fall until reaching the minimum 40 days after the event. As for cortisol, its concentrations were low until 10 days before the delivery when, as expected, they started to dramatically rise until reaching the maximum the day before the birth. In conclusion, since these results are analogous to those obtained from blood serum and milk in the same species and in other mammals under similar physiological conditions, blowhole samples could represent a suitable biological material in order to detect and quantify by RIA progesterone and cortisol levels during pregnancy. At the same time, the sampling method is easy to be applied and absolutely non-invasive for the animals
Cetaceans 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
Behavioural sequences displayed by a bottlenose dolphin (Tursiops truncatus) community during swim programmes dedicated to autistic children
No full textAggressivity and social balance in a captive tursiops truncatus community
No full textSocial systems in which animals are arranged according to ranks, such as the bottlenose dolphin ones, usually find in aggressive interactions a means for determining social balance and hierarchies. The aim of this study was to quantitatively investigate, according to the age and sex of the animals, intra-communal agonistic behaviours, in particular pointing out: a) quality and distribution of the displays, b) features of the agonistic sessions and c) dominance relationships among individuals. Five subjects (adults: 1,1; young: 2,1) were focally observed at the Rimini Delfinario (Italy) from April to October 2005, through a total of 780 systematic observations lasting 15 minutes each (total 195 hours, i.e. 39 hours/animal). A specific behavioural catalogue and Observer (Noldus) were applied to measure the frequency and duration of seven conflictual behaviours, a priori chosen for the study. As for active assaults, beside a general low intensity level of aggressiveness and a frequency range included within 2.01 and 13.98 events/hour (respectively registered in adults and young), the results showed that male aggressions were usually twice as frequent as female ones, while the young surpass adults up to seven times. In all classes, "chasing" (always > 30%) was the preferred action, but similar values were reached by females also in "tail hitting". Moreover, aggressive behaviours seemed to occur in distinctive agonistic sessions, lasting between 57.0 (in adults) and 149.8 (in young) seconds and including up to 4 displays each. Again, from the observation of winner/looser diadic interactions, a predominance of the pair composed by the adult female and her still unweaned calf emerged over all the rest of the group. In the end, even in the typically cooperative bottlenose dolphin societies, intra-communal aggressiveness reveals to a certain level to be absolutely functional for group relationships and coordination, as well as, from an evolutionistic point of view, crucial for species conservation
Quantification of cortisol, progesterone and testosterone in saliva-samples collected from walruses (Odobenus rosmarus divergens).
No full textBlow-samples as substratum to extract and quantify reproductive and adrenal hormones of beluga whales (Delphinapterus leucas)
No full textBlow progesterone profile during estrous cycle, pregnancy and Lactation in female bottlenose dolphins
No full textBLOW PROGESTERONE PROFILE DURING ESTROUS CYCLE, PREGNANCY AND LACTATION IN FEMALE BOTTLENOSE DOLPHINS
Tizzi, Raffaella*(1) , Accorsi, Pier Attilio(2), Zordan, Silvia(2) and Severi, Carlotta(1)
(1) Delfinario Rimini, Lungomare Tintori 2 – 47900 Rimini, Italy
(2) Dipartimento di Morfofisiologia Veterinaria e Produzioni Animali, Università degli Studi di Bologna, Via Tolara di Sopra, 40064 Ozzano Emilia (BO), Italy
Previous studies underlined a significant correlation between progesterone concentrations measured in blood and in biological material released with the blow. The aim of present work was to take advantages of the complete non invasivity and results' reliability of the new technique based on blow sampling, for systematically monitoring progesterone profiles during estrous cycle (A), pregnancy (B) and lactation (C). Three Tursiops truncatus females were sampled every week: the subject "Alfa" (approx. 27 years old) was monitored from March 2006 for a period of 23 months during all the phases A, B and C; the captive born dolphins "Blue" and "Luna" (8 and 10 years old, respectively) were monitored from May 2005 for a period of 24 months (phases A and B) the former, and from March 2006 for a period of 14 months (phase A) the latter. While Blue was housed at Oltremare (Riccione, Italy), both other females were living in Rimini Delfinario (Italy). Progesterone concentrations were determined by a validated RIA. The results confirmed the bottlenose dolphin nature of seasonal poliestral species, with ovulation occurring at least 2-3 times per year in a period lasting between early spring and late autumn. A dramatic increase of blow progesterone concentrations emerged as soon as pregnancy started. In particular, both Alfa and Blue showed mean values of hormone significantly different (p<0.01) shifting from a non pregnant to a pregnant status (Alfa: 104.72 ± 11.19 vs. 206.22 ± 13.71 pg/ml; Luna: 75.60 ± 9.12 vs. 571.63 ± 44.46 pg/ml). The development of diagnostic procedures and stress avoiding approaches such as the blow sampling not only supports captive animals’ management with respect to their wellness, but also provides an opportunity for using the enhanced knowledge in programmes of conservation aimed at improving species' reproductive potential in the wild. This work was supported by a RFO (Bologna University) grant
Correlation between progesterone concentration in blow and behaviour in a young female bottlenose dolphin
No full textDetermination of cortisol in blow of bottlenose dolphin and correlation with behavioural displays during pregnancy.
No full textCortisol is useful to monitor physiological and pathological conditions in dolphins.
This hormone is usually extracted through consolidate procedures from blood,
saliva, urine and faeces. However, an innovative source may be found in blow,
which can be collected non-invasively. Specific aims of this study were a) to set up
and validate cortisol determination procedures from blowhole samplings and b) to
assess the correlation between cortisol levels and behavioural displays expressed
during pregnancy. As for a) three Tursiops truncatus (1,2) in Rimini Delfinario
(Italy) were sampled from November 2002 to June 2007. The dolphins were trained
to blow into polypropylene bottles and the samples were stored at -20°C. Hormone
concentrations were determined by a validated radioimmunoassay. The Pearson's
Correlation Test applied to cortisol levels, simultaneously measured in blow and
blood, revealed the reliability of the concentrations in blow (r=0,89; d.f.=13;
p<0,0001). Regarding b) a pregnant female was monitored from July 2006 during
all the 52 weeks of her gestation. The behavioural observations were carried out
twice a week with focal sessions lasting 1hr each (total 416hrs). A specific
behavioural catalogue and Observer (Noldus) were applied to quantify frequency
and duration of 64 behaviours a priori chosen for this study. The comparison
between the behavioural trends and cortisol values, daily measured throughout the
pregnancy, showed several cases of significant correlation. In particular, a positive
relationship with stationary positions such as lie or rest at surface, the bending of
the body or the emission of bubbles emerged. In conclusion, blow is safe, ready
available and easy to store and transport. Blow sampling does not involve pain or
infection and it is unaffected by the stress of animal handling. Moreover, the results
underline the connection between cortisol and animal activities, providing an
opportunity for further studies in both physiology and behaviour
- …
