Long-term monitoring of leatherback turtle diving behaviour during oceanic movements

The diving behaviour of four leatherback turtles (Dermochelys coriacea) was recorded for periods of 0.5-8.1 months during their postnesting movements in the Indian and Atlantic Oceans, when they covered 1569-18,994 km. Dive data were obtained using satellite-linked transmitters which also provided information on the dive depths and profiles of the turtles. Turtles mainly dove to depths < 200 m, with maximum dive durations under 30-40 min and exhibited diel variations in their diving activity for most part of the routes, with dives being usually longer at night. Diurnal dives were in general quite short, but cases of very deep (> 900 m) and prolonged (> 70 min) dives were however recorded only during daytime. The three turtles that were tracked for the longest time showed a marked change in behaviour during the tracking, decreasing their dive durations and ceasing to dive deeply. Moreover, diel variations disappeared, with nocturnal dives becoming short and numerous. This change in turtle diving activity appeared to be related to water temperature, suggesting an influence of seasonal prey availability on their diving behaviour. The turtle diving activity was independent on the shape of their routes, with no changes between linear movements in the core of main currents or looping segments in presence of oceanic eddies.     

Predicting the swimming and diving behaviour of penguins from muscle biochemistry

Energy metabolism in the pectoralis and supracoracoideus muscles of seven species of penguins was investigated by determining muscle fibre diameter, myoglobin content, pH buffering capacity and the distribution and properties of lactate dehydrogenase isoenzymes.The penguins can be arranged as follows in order of increasing anaerobic capabilities of the muscles: little < rockhopper and royal < gentoo < Adelie, emperor and king.As a good correlation exists between muscle biochemistry and known diving behaviour of emperor, king, gentoo and little penguins, predictions can be made about the behaviour of species for which only the biochemical data are available.     

Diving behaviour, dive cycles and aerobic dive limit in the platypus Ornithorhynchus anatinus

We investigated the diving behaviour, the time allocation of the dive cycle and the behavioural aerobic dive limit (ADL) of platypuses (Ornithorhynchus anatinus) living at a sub-alpine Tasmanian lake. Individual platypuses were equipped with combined data logger-transmitter packages measuring dive depth. Mean dive duration was 31.3 s with 72% of all dives lasting between 18 and 40 s. Mean surface duration was 10.1 s. Mean dive depth was 1.28 m with a maximum of 8.77 m. Platypuses performed up to 1600 dives per foraging trip with a mean of 75 dives per hour. ADL was estimated by consideration of post-dive surface intervals vs. dive durations. Only 15% of all dives were found to exceed the estimated ADL of 40 s, indicating mainly aerobic diving in the species. Foraging platypuses followed a model of optimised recovery time, the optimal breathing theory. Total bottom duration or total foraging duration per day is proposed as a useful indicator of foraging efficiency and hence habitat quality in the species.     

Finding your mate in a seabird colony: contrasting strategies of the Guillemot Uria aalge and King Penguin Aptenodytes patagonicus

Capsule King Penguins recognize their mates by voice, but Guillemots do not need acoustic cues even though their calls show individual variation.

Aims To determine whether the structure of Guillemot calls could allow individual recognition, as with King Penguin, and whether acoustic cues are used to locate mates among a dense mass of conspecifics at a colony.

Methods Observations were made on breeding Guillemots and King Penguins. Calls made by birds returning to their mates were recorded, the signals digitized and the calls analysed. Calls were later played back to the mates of the birds concerned and the effects noted on both them and their neighbours.

Results Both Guillemots and King Penguins emitted calls on return to the breeding site which contained individual signatures and were therefore potentially usable for mate recognition. In King Penguins, auditory recognition was essential for finding a mate, whereas in Guillemots most of the arriving birds located their mate in a dense crowd of conspecifics without the help of acoustic signals. Guillemots could differentiate neighbours from strangers without auditory cues.

Conclusion Calls are essential for the successful identification of mates by King Penguins but not by Guillemots.     

The influence of body size on the diving behaviour and physiology of the bimodally respiring turtle, Elseya albagula

In aquatic vertebrates that acquire oxygen aerially dive duration scales positively with body mass, i.e. larger animals can dive for longer periods, however in bimodally respiring animals the relationship between dive duration and body mass is unclear. In this study we investigated the relationships between body size, aquatic respiration, and dive duration in the bimodally respiring turtle, Elseya albagula. Under normoxic conditions, dive duration was found to be independent of body mass. The dive durations of smaller turtles were equivalent to that of larger individuals despite their relatively smaller oxygen stores and higher mass specific metabolic rates. Smaller turtles were able to increase their dive duration through the use of aquatic respiration. Smaller turtles had a relatively higher cloacal bursae surface area than larger turtles, which allowed them to extract a relatively larger amount of oxygen from the water. By removing the ability to respire aquatically (hypoxic conditions), the dive duration of the smaller turtles significantly decreased restoring the normal positive relationship between body size and dive duration that is seen in other air-breathing vertebrates.     

Molecular surveillance for avian influenza A virus in king penguins (<Emphasis Type="Italic">Aptenodytes patagonicus</Emphasis>)

An investigation of the presence of influenza A virus has been conducted in king penguins (Aptenodytes patagonicus) at the Possession Island in the Crozet Archipelago, Antarctica, using a rapid molecular diagnostic method based on real-time polymerase chain reaction. No evidence of outbreak or positive viral infection of influenza A virus was found in this study. We however recommend the implementation of long-term surveillance in seabird populations of polar ecosystems to detect the potential introduction of exotic strains and potential existence of a local epidemiological cycle for avian influenza viruses.     

Movement and behaviour patterns of the critically endangered common skate Dipturus batis revealed by electronic tagging

Understanding animal distributions and habitat utilisation is vital for the management of populations, especially those of endangered species. However, this information is not available for the majority of marine species and is difficult to obtain for those with low population densities. The common skate, Dipturus batis, was once abundant and widespread in the North-East Atlantic but is now thought to be locally extinct in the Irish Sea and in the central and southern North Sea, and is listed as Critically Endangered on the IUCN Red List. The constraints of skate body morphology on locomotory mode assume low levels of activity with long periods spent resting on the seabed, therefore predicting a high degree of site fidelity. To investigate this hypothesis we tagged 8 common skate (two male and six female, mass range: 10.9–63.5 kg) with depth and temperature-logging data storage tags off the west coast of Scotland in May 2008. All 6 tags attached to females were recovered after 1–9 months at liberty. All 6 individuals exhibited pronounced site fidelity to highly localised areas. Within these local areas however, time-depth profiles were dominated by periods of high activity, with vertical movements of > 100 m being conducted on a regular, sometimes daily, basis. Intra-individual plasticity was observed in vertical activity patterns with individuals switching between low and high activity patterns. Smaller skate were generally less active and occupied deeper depths. Limited short-term horizontal movements in preferred habitats supporting apparently high foraging activity highlights the need for spatial management of ‘refugial’ populations of this once widespread fish, that appears now largely extirpated from European waters.     

Land cover change and management implications for the conservation of a seabird in an urban coastal zone under climate change

Little Penguin (Eudyptula minor) is one of the most ecologically important seabirds in New Zealand and depends strongly on terrestrial ecosystems for nesting, moulting and breeding. Wellington, New Zealand, is one of the world's most important biodiversity hot spots for this species, mostly in confluence with human urban settlements. This species is currently suffering from the local impacts of climate change associated with urbanisation. Two suburbs of Wellington, New Zealand, that are used seasonally by Little Penguin as terrestrial habitat were selected as the study area to address two issues: (i) how local impacts of climate change may affect the population and habitat structure of species in urban coastal zones where land cover change occurs; and (ii) how landscape management practices may help to mitigate the impacts imposed by climate change on the species in such a context. Remote Sensing and Geographical Information Systems techniques were applied to quantify and measure the extent of the prehuman forests and current land cover classes in the study area to reveal the degree to which land cover has changed from predevelopment to the present time. The research shows that land cover change in the study area has been widespread and partly irreversible, particularly in areas covered by the class Built‐up Area. Results reveal that there are still spatial opportunities to safeguard this vulnerable species against the ill effects of climate change through landscape management practices.     

A simple method for classifying genes and a bootstrap test for classifications

A new simple method for classifying genes is proposed based on Klastorin's method. This method classifies genes into monophyletic groups which are made distinct from each other by evolutionary changes. The method is applicable as long as the phylogenetic tree of genes is obtained. There is a fast algorithm for obtaining the classification. A bootstrap test of a classification is also presented. As an example, we classified opsin genes. The classification obtained by this method is the same as the previous classification based on the function of opsins.     

A method for combining molecular markers and phenotypic attributes for classifying plant genotypes

Classifying genotypes into clusters based on DNA fingerprinting, and/or agronomic attributes, for studying genetic and phenotypic diversity is a common practice. Researchers are interested in knowing the minimum number of fragments (and markers) needed for finding the underlying structural patterns of diversity in a population of interest, and using this information in conjunction with the phenotypic attributes to obtain more precise clusters of genotypes. The objectives of this study are to present: (1) a retrospective method of analysis for selecting a minimum number of fragments (and markers) from a study needed to produce the same classification of genotypes as that obtained using all the fragments (and markers), and (2) a classification strategy for genotypes that allows the combination of the minimum set of fragments with available phenotypic attributes. Results obtained on seven experimental data sets made up of different plant species, number of individuals per species’ and number of markers, showed that the retrospective analysis did indeed find few relevant fragments (and markers) that best discriminated the genotypes. In two data sets, the classification strategy of combining the information on the relevant minimum fragments with the available morpho-agronomic attributes produced compact and well-differentiated groups of genotypes.     

Ross seal (<Emphasis Type="Italic">Ommatophoca rossii</Emphasis>) annual distribution,diving behaviour,breeding and moulting,off Queen Maud Land,Antarctica

Six out of ten adult Ross seals that were tagged with Argos satellite-linked dive recorders off Queen Maud Land, just after the moult in February, provided data on location and diving activity throughout a year. Shortly after tagging, the animals headed 2,000 km north and stayed pelagic in the area south of the Antarctic Polar Front, until October when they went south into the pack-ice. Throughout the year they made about 100 dives a day, most to a depth of 100–300 m, the deepest dive on record being 792 m, while some dives were very shallow during their stay in the pack-ice. Most dives, outside the breeding and moulting period, lasted for 5–15 min throughout the year. This diving behaviour is consistent with feeding on mid-water fish, like Pleurogramma antarcticum, squid, and to some extent krill (Euphausia superba), when in the pack-ice, and myctophid fish and several species of squid, when in the open ocean. The nursing period was 13 days in mid-November, and moulting occurs in late January–early February, which is the period when sightings surveys for this species should be done.     

A method for surveying and classifying Leuconostoc spp. glucansucrases according to strain-dependent acceptor product patterns

A number of Leuconostoc spp. strains were screened for their ability to produce glucansucrases and carry out acceptor reactions with maltose. Acceptor products were analyzed by thin-layer chromatography (TLC) and it was discovered that they could be grouped into four distinct categories based on oligosaccharide product patterns. These patterns corresponded with structural features of the dextrans each strain is reported to produce. Strains that produced a typical dextran—characterized by a predominantly linear (16)-linked d-glucan chain with a low to moderate degree of branching—produced a homologous series of isomaltooligosaccharides via acceptor reactions. Strains that produced dextrans with moderate to high levels of (12) branch points, exemplified by NRRL B-1299, synthesized the same isomaltodextrins as well as another series of oligosaccharides migrating slightly faster in our TLC system. Strains that produced dextrans with higher levels of (13)-branches, such as NRRL B-742, synthesized isomaltodextrins plus a series of oligosaccharides that migrated slightly more slowly on TLC. And finally, strains known to produce alternansucrase produced isomaltodextrins plus oligoalternans. Within a given type, variability exists in the relative proportions of each product. The data presented here may be useful in selecting strains for the production of specific types of oligosaccharides, for example as prebiotics.     

A simple method for differentiation of Propionibacterium acnes and Propionibacterium propionicum

Abstract TLC glycolipid profiles of several culture collection and clinical strains of Propionibacterium acnes and Propionibacterium propionicum were examined. The former were characterized by weak orcinol-positive minor glycolipids of type g, while the others had mainly strong orcinol-positive major glycolipids of type G. The simple and rapid small scale procedure seemed to be useful for differentiation of these phenotypically similar and genotypically closely related species irrespective of their serotypes.     

A new laboratory method for monitoring deep-water coral polyp behaviour

Deep-water corals are found along the oceanic margins world-wide and in the north east Atlantic the most abundant species is Lophelia pertusa (L.). There is now growing evidence that deep-water reefs formed by such species are coming under increasing pressures from resource exploitation, principally deep-sea trawling and hydrocarbon exploration. Here a novel and unobtrusive method of recording deep-water coral behaviour in the laboratory is described using time-lapse video to record silhouettes of the polyps under infrared illumination. The polyps of L. pertusa behaved asynchronously and did not show any clear diurnal patterns over a three-day observation period. Conceptually, sessile benthic suspension feeders appear to be vulnerable to smothering by sediments disturbed by bottom trawls or sub-seabed drilling. This method allows deep-water coral polyp behaviour to be continuously monitored in the laboratory and, therefore, the responses of coral polyps to environmental perturbations such as sedimentation can be recorded. Further work is necessary to resolve the sensitivity of deep-water corals to short-term environmental change and the combined approach of in situ monitoring and subsequent laboratory experimentation has great potential to address these issues.     

A stochastic method for the reconstruction of protein structures from one-dimensional structural profiles

We discuss a computational approach for reconstructing the native structures of proteins from the knowledge of a structural profile - the first eigenvector of the contact map of the native structure itself. The procedure consists in carrying out Monte Carlo simulations of a tube model of the protein structure with an energy bias towards the target structural profile. We present the reconstruction of two small proteins and address problems arising in the reconstruction of larger proteins. Our results indicate that an accurate physico-chemical energy function should be used in conjunction with the structural profile bias in order to achieve accurate reconstructions.     

A method for studying social and reproductive behaviour of subterranean rodents in captivity

A methodology for studying the social and reproductive behaviour of solitary subterranean rodents under laboratory conditions is proposed. A first account ofCtenomys talarum (Thomas, 1898) behaviour is also provided with the aim of evaluating the proposed methodology and to advance presently unknown information on its social behaviour and mating system. The device is a seminatural enclosure, departing from traditional test cages with respect to increased: (1) size, (2) structural complexity, (3) social complexity, and (4) resemblance to natural conditions. It consists of artificial burrows each comprising 3.5 m of tunnel, a resource cage and a nest box, resembling the structural complexity described forC. talarum burrows. Burrows are connected to a common space, which allows social interaction among various individuals. Animals were observed in the seminatural enclosure — 3 females and 2 males, in accordance with sex ratios found in natural populations — for a period of 6 months. We obtained data related to reproductive and social behaviour: marking, aggression, vocalization, courtship and copulation, pregnancy, pup development, and parental care. The proposed system enables the collection of behavioural data as yet unavailable due to the secretive habits and aggressiveness that characterize this group of rodents, coupled with the difficulties associated with simulating subterranean conditions.