Do captive waterfowl alter their behaviour patterns during their flightless period of moult?

Many different behavioural changes have been observed in wild waterfowl during the flightless stage of wing moult with birds frequently becoming inactive and reducing time spent foraging. Increased predation risk, elevated energetic demands of feather re-growth and restriction of foraging opportunities are thought to underlie these changes. By studying captive populations of both a dabbling and a diving duck species at the same site, we determined whether captive birds would reflect the behavioural responses of wild waterfowl to moult. The time-budgets of 42 Common Eiders, Somateria mollissima, (a diving duck) and 18 Garganeys, Anas querquedula, (a dabbling duck) were recorded during wing moult (July–August) and non-moult (January) with behaviour recorded under six categories. Despite captivity providing a low predation risk and constant access to food, birds altered their behaviour during the flightless period of wing moult. Time allocated to foraging and locomotion decreased significantly during moult compared to non-moult periods, while resting time increased significantly. Moulting Eiders underwent a greater reduction in time spent foraging and in locomotion compared with Garganeys, which is likely to be in response to a higher energetic cost of foraging in Eiders. It is possible that increased resting in both diving and dabbling ducks reduces their likelihood of detection by predators, while allowing them to remain vigilant. We demonstrate that there is much potential for using captive animals in studies that can augment our knowledge of behaviours of free-living conspecifics, the former being a hitherto under-exploited resource.     

Immobilized β-glucanases and their applications

Summary A number of -glucanase active enzyme preparations were successfully immobilized either by adsorption on Duolite S-761 phenol-formaldehyde resin or covalently on silanized Spherosil XOB-075 porous silica beads to obtain remarkably stable active biocatalysts. A Duolite immobilized -glucanase could be employed for continuous treatment of barley wort in a packed-bed column reactor to decrease viscosity and to improve filtrability. A Duolite immobilized cellulase that exhibited no detectable Avicel hydrolyzing activity could be applied for batch treatment of wheat starch process water. The same enzyme when covalently bound on Spherosil was, however, capable of hydrolyzing microcrystalline cellulose in a recirculating fluidized-bed reactor.     

Do plants adjust their sex allocation and secondary sexual morphology in response to their neighbours?

Background and aims

Changes in the sex allocation (i.e. in pollen versus seed production) of hermaphroditic plants often occur in response to the environment. In some homosporous ferns, gametophytes choose their gender in response to chemical cues sent by neighbours, such that spores develop as male gametophytes if they perceive a female or hermaphrodite nearby. Here it is considered whether a similar process might occur in the androdioecious angiosperm species Mercurialis annua, in which males co-occur with hermaphrodites; previous work on a Spanish population of M. annua found that individuals were more likely to develop as males at high density.

Methods

Using a novel approach to treat plants with leachate from pots containing males or hermaphrodites of M. annua, the hypothesis that individuals assess their mating opportunities, and adjust their sex expression accordingly, was tested through an exchange of chemical cues through the soil.

Key Results

For the population under study, from Morocco, no evidence was found for soil-signal-dependent sex expression: neither sex ratios nor sex allocation differed among experimental treatments.

Conclusions

The results imply either that the Moroccan population under study behaves differently from that previously studied in Spain (pointing to potential geographical variation in plasticity for sex expression), or that our method failed to capture the signals used by M. annua for adjustment of sex expression.     

Do consensus conferences influence their participants?

OBJECTIVE: To determine whether participation in a consensus conference on the assessment of dementia would influence conference participants with respect to their recommendations to primary care physicians for the assessment of dementia. DESIGN: Questionnaire before and after the conference. SETTING: Canadian Consensus Conference on the Assessment of Dementia, held in Montreal, Oct. 5 and 6, 1989. PARTICIPANTS: All 38 experts representing relevant health disciplines who participated in the consensus conference; 36 completed both questionnaires. OUTCOME MEASURES: Participants'' opinion before and after the conference as to how frequently each of 28 manoeuvres (12 blood tests, 4 neurologic imaging procedures, 4 types of consultation and 8 "other" tests) should be ordered by primary care physicians as part of an assessment of a patient with dementia suspected in clinical grounds. RESULTS: For 18 (64%) of the 28 manoeuvres (10 of the 12 blood tests, 3 of the 4 neurologic imaging procedures and 5 of the 8 "other" tests), there was a shift in opinion after the conference toward recommending that primary care physicians order them less often; for 10 of these 18 (5 blood tests and 5 "other" tests) the shift was statistically significant. For the remaining 10 manoeuvres (36%) the shift in opinion was toward a recommendation that primary care physicians order them more often; the shift was not statistically significant for any of these 10 manoeuvres. CONCLUSION: Expert members of a consensus conference are influenced by the process of having participated in such a conference and are capable and willing to chance their initial recommendations when confronted with relevant data.     

Do Great Tit Parus major parents gear their brood defence to the quality of their young?

Parental investment theory suggests that animals should increase their reproductive success by investing more heavily in higher-quality offspring than in lower-quality offspring. Great Tit Parus major nestlings of higher body weight have been shown to enjoy a higher survival rate after fledging. We examine for the first time whether Great Tit parents invest more heavily in heavier nestlings as measured by defence (six variables) against a Pygmy Owl Glaucidium perlatum, similar to G. passerinum, which is a predator of both adult and nestling birds including hole-nesters like the Great Tit. Thirty-two parent Great Tit pairs in a wood- and parkland study area in Essen-Stadtwald did not vary their antipredator behaviour in relation to nestling weight; between-brood variation of weight was similar to that found in different populations and in different years. However, parental defence behaviour varied, as expected, with parent's sex and nestling number, though overall responsivity of parents to many other independent variables appeared lower than found previously.     

Do dolphins know their own minds?

Knowledge of one's own states of mind is one of the varieties of self-knowledge. Do any nonhuman animals have the capacity for this variety of self-knowledge? The question is open to empirical inquiry, which is most often conducted with primate subjects. Research with a bottlenose dolphin gives some evidence for the capacity in a nonprimate taxon. I describe the research and evaluate the metacognitive interpretation of the dolphin's behaviour. The research exhibits some of the difficulties attached to the task of eliciting behaviour that both attracts a higher-order interpretation while also resisting deflationary, lower-order interpretations. Lloyd Morgan's Canon, which prohibits inflationary interpretations of animal behaviour, has influenced many animal psychologists. There is one defensible version of the Canon, the version that warns specifically against unnecessary intentional ascent. The Canon on this interpretation seems at first to tell against a metacognitive interpretation of the data collected in the dolphin study. However, the model of metacognition that is in play in the dolphin studies is a functional model, one that does not implicate intentional ascent. I explore some interpretations of the dolphin's behaviour as metacognitive, in this sense. While this species of metacognitive interpretation breaks the connection with the more familiar theory of mind research using animal subjects, the interpretation also points in an interesting way towards issues concerning consciousness in dolphins.     

Culture collections — their services to biotechnology

The need to recruit qualified and experienced employees is a major concern of many organizations engaged in biotechnology. Universities and industry are scoured to find the right people, but where are we to find promising new candidates for the most numerous, and arguably most talented section of the biotechnological workforce — microorganisms and other types of cells? The international network of culture collections offers the best answer, and a proper understanding of their roles and capabilities can save biotechnologists an immense amount of time and money.Among the millions of microbial, plant and animal cells stored in the world's culture collections it is often possible to find one that exactly suits a biotechnologist's particular requirements or one that can be developed to perform a specific task. This article outlines the services offered by culture collections, generally using the UK collections as examples of the main activities throughout the world.     

How do animals choose their mates?

How animals search for and evaluate prospective mates has, until recently, been a neglected aspect of sexual selection. Theory and field data suggest that discrimination varies with the costs and benefits of choice, but a consensus has yet to be reached on the tactics by which prospective mates are evaluated. This intriguing issue may be clarified by new studies that deal explicitly with the process of information acquisition.     

APC activators caught by their tails?

The complexity of the Anaphase-Promoting Complex (APC), the major ubiquitin ligase in mitotic control, has been puzzling investigators ever since its discovery. Recent biochemical and genetic studies have now provided insights not only into the architecture of the complex, but also into how activators are recruited to the APC. In this article, we discuss the implications of these findings on our current understanding of APC activation.     

Is the oostegite structure of amphipods determined by their phylogeny or is it an adaptation to their environment?

The oostegites of amphipods attached to peraeopods 2–5 are of two main types — broad with relatively short marginal setae and narrow with long marginal setae. Broad oostegites are found in other peracarids and are considered the primitive type. Amphipods with broad oostegites tend to have smaller eggs than those with narrow oostegites. It is concluded that following the evolution of the major amphipod groups, the oostegites were modified as egg sizes have changed as part of the reproductive strategies of the species within these groups.     

Can birds count eggs in their nests?

Sensory mechanisms controlling avian clutch size have diversified into distinct types, according to the nature of the input that is used to disrupt the growth of ovarian follicles and hence halt egg‐laying. In an article on brood parasitism, Lyon (2003) claimed that female American Coots Fulica americana can reduce their clutch size on the basis of visual cues in response to eggs laid in their nests by other females; in this species, therefore, egg counting would be used to control clutch size. After a close examination of the physiological determination of clutch size in American Coots, I show that seven of 17 parasitized clutches were smaller than the range controlled through the mechanism using an input to disrupt follicular growth (7–10 eggs per clutch). My reanalysis suggests that American Coots are incapable of adjusting clutch size via counting and re‐asserts that a species that can count eggs has yet to be found among birds that rely upon their own body heat for incubation.     

May mothers given warfarin breast-feed their infants?

Warfarin was measured with a sensitive and specific method in the plasma and breast milk of 13 mothers. Less than 0-08 micronmol warfarin per litre (25 ng/ml) of breast milk was found in each instance. Seven of the mothers were breast-feeding their infants, in none of whom was warfarin detected in the plasma; furthermore, in three the British corrected ratio of the plasma was appreciably less than that of the mother and was within the expected range. We conclude that nursing mothers given warfarin may safely breast-feed their infants.     

Does dog-human attachment affect their inter-specific cooperation?

Leading a blind or blindfolded person is a complex cooperative task influenced by many factors. The aim of this study was to determine if quality of attachment affects the performance of dog and owner dyads showed on an Obstacle Course. Modified Ainsworth's Strange Situation Test was used for assessing attachment quality. Only one dimension of the attachment, the 'anxiety' factor was found to correlate with behavioural measures of the Obstacle Course (e.g. number of mistakes, initialisation index that reflects which participant initiates more actions in a dyad). We found significant differences of performance between the three groups of dog-owner pairs (pet dog, guide dog and police dog dyads), but we could not show significant differences in the 'attachment' factor among these groups. We concluded that it is not the attachment type that causes the main differences in the leading behaviour of our three study groups. Dogs have an innate ability for cooperation with humans that was enhanced by selective breeding during domestication and this basic ability can be modified by training but seem to be less affected by the relationship with the owner.     

Should bad workmen always blame their tools?

In this issue of Neuron, differentiated brain regions in humans that are selectively responsive to viewing motion: (1) of humans, (2) of tools/utensils, and (3) in general. Active regions were the superior temporal sulcus, middle temporal gyrus, and MT/V5, respectively. This study provides impetus for future work in motion perception and its relationship to apraxia.