Several theoretical and empirical studies have suggested that immunocompetence may act as a constraint on learning, due to a trade-off in investment in the two processes. Here we tested whether experimentally depressing immune responsiveness of male BKW mice using antithymocyte serum (ATS) would lead to reduced learning performance in a radial maze task. Correct choices in the maze were indicated by the presence of familiar odours, incorrect choices by unfamiliar odours. We showed that temporarily depressing cellular immunity led to a reduction in performance in terms of a reduced proportion of correct choices. We also found a positive relationship between the proportion of correct entries over the period of testing and haemagglutination titre, indicating that mice showing greater immune responsiveness performed better in the maze. We conclude that depressing the immune system reduces learning performance in a combined odour/spatial learning task, and that some individuals are better able to compensate for the experimental immunodepression. In contrast to previous studies, there was no evidence that the effect of ATS was mediated by associated changes in corticosterone or testosterone secretion. There were no significant effects of the presence of female odour on learning performance, and therefore no evidence that the down regulation of learning in relation to immune depression was influenced by apparent reproductive opportunity.

This study examined the effects of social housing manipulations on bodyweight, corticosterone levels, and performance of T-maze alternation in male CD-1 mice. Males that adopted a dominant social rank were heavier than those that adopted a subordinate social rank. Dominant males also had lower corticosterone concentrations than the subordinates. However, there was little to suggest that these physiological indicators of social rank were moderated by housing condition. Indeed, statistical analysis confirmed that the difference in bodyweights was evident before males were socially housed. The mice showed high levels of spatial alternation on the T-maze from the start of testing so performance accuracy was high. Neither social rank nor housing condition had any clear categorical effect on T-maze performance. However, performance did fluctuate over successive blocks of testing and there was a negative association between accuracy on the T-maze and corticosterone levels (consistent with performance impairment because of elevated corticosterone). Therefore, under present conditions, individual differences in corticosterone were a better predictor of T-maze performance than social rank or housing condition. The results of the present study lend further support to the proposition that corticosterone levels measured non-invasively in urine may be used to predict diverse welfare outcomes for laboratory mice, from bodyweight to cognitive performance. Moreover, intrinsic physiological parameters rather than external influences, such as social housing, may have more influence on mouse behaviour.

SUMMARY Helminth infections were studied in bank voles ( Myodes glareolus ) from 3 woodland sites in N.E. Poland in the late summers of 1999 and 2002, to assess the temporal stability of derived statistics describing the regional helminth fauna and component community structure, and spatial influence on the latter. Regional helminth fauna changed dramatically between the two years, primarily due to a fall in the abundance of Syphacia petrusewiczi but was partially compensated for by an increase in Mesocestoides lineatus and Cladotaenia globifera . It was dominated by nematodes overall, but more so in 1999 than in 2002 when larval cestodes were more frequent. Most derived parameters for component community structure varied considerably between sites and the two surveys, the hierarchical order for sites not being maintained between surveys. They were susceptible to the disproportionate influence of three relatively rare, unpredictable species with the greatest overall aggregated distribution among hosts. Jaccard's similarity index was less influenced by the rare species, showing greater stability between sites and across years. In conclusion, temporal variation confounded any site-specific characteristics of the summary measures quantified in this study and their usefulness is therefore restricted to the years in which the surveys were conducted.

The relative importance of temporal and spatial effects was assessed in helminth communities of bank voles (Myodes glareolus) in 3 woodland sites in N.E. Poland in the late summers of 1999 and 2002. Among common species the rank order of sites in relation to prevalence and abundance of infection was maintained between surveys. Site effects accounted for most of the deviance (in statistical models), bind time was less important, so the exact location from which voles were sampled was of critical importance. The only exception was Syphacia petrusewiczi. In contrast, for derived measures Such as species richness and diversity, most deviance was accounted for by host age, and the interaction between site and year was significant, implying that rank order of sites changed between years. Temporal effects on derived measures were generated primarily by a combination of relatively small changes in prevalence and abundance of the common, rather than the rare, species between the years of the study. In the medium-term, therefore, helminth communities of bank voles in N.E. Poland had a stable core, suggesting substantial strong element of predictability.

Veterinary RecordVolume 160, Issue 8 p. 275-276 Letter Guidance on animal behaviour Stephen M. Wickens, Stephen M. Wickens ASAB Accreditation Committee, c/o Universities Federation for Animal Welfare, The Old School, Brewhouse Hill, Wheathampstead, Hertfordshire, AL4 8ANSearch for more papers by this authorChristopher Barnard, Christopher Barnard ASAB Accreditation Committee, c/o Universities Federation for Animal Welfare, The Old School, Brewhouse Hill, Wheathampstead, Hertfordshire, AL4 8ANSearch for more papers by this authorDaniel S. Mills, Daniel S. Mills ASAB Accreditation Committee, c/o Universities Federation for Animal Welfare, The Old School, Brewhouse Hill, Wheathampstead, Hertfordshire, AL4 8ANSearch for more papers by this authorKendal Shepherd, Kendal Shepherd ASAB Accreditation Committee, c/o Universities Federation for Animal Welfare, The Old School, Brewhouse Hill, Wheathampstead, Hertfordshire, AL4 8ANSearch for more papers by this authorSarah Heath, Sarah Heath ASAB Accreditation Committee, c/o Universities Federation for Animal Welfare, The Old School, Brewhouse Hill, Wheathampstead, Hertfordshire, AL4 8ANSearch for more papers by this author Stephen M. Wickens, Stephen M. Wickens ASAB Accreditation Committee, c/o Universities Federation for Animal Welfare, The Old School, Brewhouse Hill, Wheathampstead, Hertfordshire, AL4 8ANSearch for more papers by this authorChristopher Barnard, Christopher Barnard ASAB Accreditation Committee, c/o Universities Federation for Animal Welfare, The Old School, Brewhouse Hill, Wheathampstead, Hertfordshire, AL4 8ANSearch for more papers by this authorDaniel S. Mills, Daniel S. Mills ASAB Accreditation Committee, c/o Universities Federation for Animal Welfare, The Old School, Brewhouse Hill, Wheathampstead, Hertfordshire, AL4 8ANSearch for more papers by this authorKendal Shepherd, Kendal Shepherd ASAB Accreditation Committee, c/o Universities Federation for Animal Welfare, The Old School, Brewhouse Hill, Wheathampstead, Hertfordshire, AL4 8ANSearch for more papers by this authorSarah Heath, Sarah Heath ASAB Accreditation Committee, c/o Universities Federation for Animal Welfare, The Old School, Brewhouse Hill, Wheathampstead, Hertfordshire, AL4 8ANSearch for more papers by this author First published: 24 February 2007 https://doi.org/10.1136/vr.160.8.275-aRead the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume160, Issue8February 2007Pages 275-276 RelatedInformation

1. Doing Science: Where do questions come from? 1.1 Science as asking questions 1.2 Basic considerations 1.3 The skill of asking questions 1.4 Where do questions come from? 1.5 What this book is about 2. Asking Questions: The art of framing hypotheses and predictions 2.1 Observation 2.2 Exploratory analysis 2.3 Forming hypotheses 2.4 Summary 3. Answering Questions: What do the results say? 3.1 Confirmatory analysis 3.2 What is statistical significance 3.3 Significance tests 3.4 Testing hypotheses 3.5 Testing predictions 3.6 Refining hypotheses 3.7 Summary 4. Presenting Information: How to communicate outcomes and conclusions 4.1 Presenting figures and tables 4.2 Presenting results in the text 4.3 Writing reports 4.4 Summary Test finder and help guide Some self-test questions Appendix I: Table of confidence limits to the median Appendix II: How to calculate some simple significance tests Appendix III: Significance tables Answers to self-test questions Index Quick test finders

1. Honeybees foraging on lavender have been shown to choose inflorescences that are larger and have more flowers. If they are selecting optimally then these inflorescences should yield higher net rates of energy gain. The number and distribution of flowers within inflorescences is a complex function of age, however, which might itself influence nectar quality and availability. 2. Sampling of the overnight nectar secretion of visited and unvisited inflorescences showed that younger inflorescences with more flowers produced more sugar per flower and had fewer unproductive flowers than other inflorescences, but the size of the inflorescence had no effects. 3. Overall display size attracted bees to inspect inflorescences, as inflorescences that were inspected but rejected were larger and/or had larger or more bracts than those that were ignored. Bees, however, accepted more productive inflorescences based on different cues: inflorescence age and number of flowers. 4. Inflorescence choice thus appeared to reflect a two-stage decision process based on different morphological criteria at each stage.

While, historically, studies of classical conditioning have been concerned mainly with the rules and mechanisms of stimulus association, more recent work is providing evidence of its adaptive value to the animal. Much of this has focused on reproductive advantages, such as learning to predict the availability of a potential mate or competitor. We looked at classically conditioned stimulus association in the novel context of sperm competition. Using field crickets, Gryllus bimaculatus, we looked at the ability of adult males to associate topographical features of the environment (configurations of toy bricks) or olfactory cues (artificial odours) with the presence or absence of an apparent competitor (another male on the other side of a clear partition). Males were able to learn associations between apparent competition and one of two spatial configurations or odours, in that they transferred larger spermatophores to a female in the conditions associated with another male, both during training (when another male was present) and during testing (when it was not). Males thus appeared to modulate sperm transfer in relation to learned environmental predictors of sperm competition. However, while males began stridulating sooner after the introduction of a female, stridulated more often and were quicker to transfer a spermatophore in some conditions associated with the presence of another male, these differences were apparent only during training, and not during testing. (c) 2006 The Association for the Study of Animal Behaviour. Published by Elsevier Ltd. All rights reserved.

There is accumulating evidence that learning is metabolically costly. One way in which this may manifest itself is in trade-offs between learning effort and immune function, with learning increasing susceptibility to infection. We tested this idea in the context of odour learning using outbred (BKW) male laboratory mice. Mice were exposed to three experimental treatments in which they were required to learn different numbers of urinary odours. While treatment affected the extent to which mice habituated to test odours during training, differences were not a simple function of the number of odours. The fact that there was also no significant effect of treatment on the degree of preference for novel over familiar odours in subsequent tests suggests mice retained learned odour profiles equally well regardless of the number of odours. That subsequent infection with Babesia microti increased with the number of odours mice had to learn is then consistent with an increased cost to learning effort when more odours were presented. Analysis within treatments, and relationships with the change in corticosterone concentration over the period of the experiment, suggested that it was a failure to learn, rather than maintaining learning performance, in more difficult learning tasks that led to greater infection. As in a previous study of maze learning in the strain, there was no direct relationship between infection and measures of peripheral antibody (total IgG) titre. The results are discussed in relation to studies in other learning contexts and reported relationships between glucocorticoid hormones and learning outcomes.

Haemoparasite infections and infestations with potential arthropod vectors were assessed in spiny mice Acomys dimidiatus from four wadis in the arid montane region of the southern Sinai in Egypt in late summer 2000. Five taxa of haemoparasites (Haemobartonella spp. 80%, Hepatozoon sp. 20.6%, Trypanosoma acomys 17.5%, Bartonella spp. 2.5% and Babesia sp. 1.9%) were recorded. Additionally, infections with two intestinal protozoa, Cryptosporidium cf. parvum and Giardia sp., were quantified, both with similar prevalence (17.0 and 17.6%, respectively). 17.9% of mice carried fleas (Parapulex chephrensis and Xenopsylla dipodilli) and 32.1% had lice (Polyplax oxyrrhyncha and Polyplax brachyrrhycha combined). Marked differences in the prevalence and abundance of infections were detected between the four wadis, particularly with respect to T. acomys, Hepatozoon sp. and fleas, which were largely aggregated in just two of the four sites (Wadis Gharaba and Tlah). In contrast, the intestinal protozoa were more common, and abundance was higher, in Wadi El Arbaein. Intrinsic factors also contributed to a variation in prevalence, with strong age-dependent increases in the prevalence and abundance of Hepatozoon sp., higher mean species richness, prevalence of Cr. cf. parvum, and abundance of Giardia sp. and Hepatozoon sp. in female mice. Haemobartonella spp. showed an age-dependent reduction in abundance and higher abundance among male mice. A weak association was found between the prevalence of T. acomys and its putative flea vector. The single extrinsic factor in the study, site of capture, was more important than the intrinsic factors in explaining variation in the prevalence and abundance of haemoparasites, intestinal protozoa and arthropod vectors. In the high mountains of southern Sinai, the parasite fauna of spiny mice is distinct in each wadi, and hence we expect the parasites to exert spatially different co-evolutionary pressures on their hosts, with a resultant variation in host life histories.

We used urinary assays as a non-invasive method to examine corticosterone levels in two outbred strains of male laboratory mice (BKW and CD-1). Measures were taken before and after 2 weeks of pair housing, to examine the effects of social stress. We found that CD-1 mice had significantly higher corticosterone levels compared to BKW mice both before and after pairing. Behavioural measures provided evidence that, when paired, both strains of mice polarised into dominants and subordinates, with a higher overall incidence of aggressive acts in the BKW mice. Some pairings had to be separated to prevent injuries so the pairing procedure introduced a selection for non-aggressive socially tolerant mice. Social status was nevertheless found to be associated with pre-existing differences in urinary corticosterone in the CD-1 strain: mice that later became dominant had overall lower levels of urinary corticosterone compared to subordinates. In conclusion, urinary corticosterone levels indicated clear differences in physiology, likely to be related to the adrenal stress response, dependent on both strain and social status. Thus, this non-invasive measure could help to predict the welfare outcomes of social housing and how these may depend on dominance status, rather than overall levels of aggression, in different strains of mice.

In the wild, house mice live in social groups, whereas in the laboratory male mice are often singly housed. Environmental enrichment such as that provided by social housing has been argued to improve the cognitive performance of laboratory animals in experimental tests. The aim of the present study was to test the cost of aggressive social interactions on learning in male CD-1 mice. We found that subordinate mice from more aggressive dyads showed spatial learning impairment, measured as alternation on a T-maze. Learning impairments in subordinates have hitherto been presumed attributable to the animals' exposure to, and relative standing within, the social group. By contrast, the impairment we observed could not have been the result of recent social defeat because it persisted weeks later when the mice were housed alone. Elevated urinary corticosterone predicted later subordination, though paradoxically these abnormally high levels were reduced by pair housing.

It has long been recognized that learning can be impaired when animals are infected or immunodepressed. Several things could account for this, including deficits in exploratory activity or attention due to stress, metabolic burden or parasitic manipulation. With the exception of parasitic manipulation, such effects may reflect an adaptive trade-off in investment between learning and either maintaining steady-state immune responsiveness or mounting a response to infection. One prediction of the adaptive trade-off hypothesis is that increased learning effort, which might be reflected as an increased level of performance or maintaining a given level of performance in more difficult learning tasks, will lead to reduced immunocompetence and thus resistance to infection. We tested this prediction in outbred BKW mice using a simple maze learning task. Mice required to learn more variable food locations in a radial maze showed a reduced proportion of correct responses and a positive relationship between learning performance and the severity of a subsequent infection with the blood protozoan Babesia microti. While a general increase in total IgG concentration (a measure of peripheral immune responsiveness) over the experiment was damped in high variability treatments, this did not relate directly to learning performance. While neither learning performance nor infection correlated with intercurrent changes in steroid hormones (corticosterone and testosterone), infection was positively associated with pre-experimental corticosterone concentration, and learning performance weakly so. The results thus suggest some predisposition towards spatial learning and infection among mice with higher starting concentrations of corticosterone, but no modulation of corticosterone in relation to the learning experience itself.

1. Nectar-foraging honeybees (Apis mellifera) on lavender (Lavandula stoechas) appear to forage so as to maximise net energy return from foraging bouts; however, evidence from other studies suggests that foraging has a detrimental effect on survival, due at least in part to physiological deterioration of the flight mechanism. But foragers also acquire wing damage during foraging, which may increase foraging effort and reduce foraging lifespan.2. The accumulation of damage over time and its effects on foraging flight and flower choice were studied in the field using a system in which the criteria for flower preference by foragers was known from previous work. Wing damage accumulated exponentially over time and resulted in foragers becoming less choosy about the flowers they visited.3. Damage added experimentally contributed independently to the effect on choosiness. Effects of wing damage (natural and added experimentally) were also independent of those of a relative measure of age, which related in an inconsistent way to changes in foraging preferences.

We compared helminth communities in spiny mice ( Acomys dimidiatus ) from 4 wadis in the arid montane region of the southern Sinai in Egypt, in a 4-week period in late summer. Total helminth species richness was 14 (8 nematodes, 5 cestodes and 1 acanthocephalan) with 94% of mice carrying at least 1 species and an overall mean species richness of 1·85. The most prevalent parasites were Protospirura muricola (47·8%) and Dentostomella kuntzi (46·3%). One larval cestode, Joyeuxiella rossicum , represents a new host record. The helminth community was dominated by intestinal nematodes (88·7%) of which 58·2% were arthropod-transmitted heteroxenic species. At the component community level, 70% of the worms were recovered from mice in just two wadis (Gharaba and Tlah) and 48·6% of intestinal nematodes were from Wadi Gharaba. Although only 7 species of helminths were recorded from Wadi Gharaba, this site gave the highest Berger-Parker dominance index because of P. muricola. P. muricola was also dominant in Wadi El Arbaein whilst Syphacia minuta was the dominant species in Wadis Gebal and Tlah. At the infracommunity level, mean species richness and Brillouin's index of diversity were highest in Wadi Tlah and lowest in Wadi Gebal, and the former was age dependent. Whilst mice from different wadis differed in the nematodes that were most common, those from Wadi Gharaba carried the highest mean number of worms/mouse. The abundance of P. muricola in particular varied markedly between sites: Wadi Gharaba was distinct as the site showing the highest mean worm burden whereas mice from Wadi Gebal were uninfected. None of the directly transmitted oxyuroid nematodes showed significant variation in abundance between wadis, or host sex or age classes. Overall, the single extrinsic factor in the study, site of capture, was more important than the intrinsic factors in explaining variation in helminth communities in the region. We conclude that in the high mountains of southern Sinai, each wadi is distinct in terms of its rodent parasites, and hence we expect spatially different coevolutionary pressures on their hosts, with resultant variation in life-histories.

While associations between sexual selection, developmental stress and fluctuating asymmetry (FA) remain controversial, this does not necessarily undermine the more general hypothesis that FA reflects developmental instability and functional competence. This applies as much to reproductive processes as to any other. If this is the case, however, we should expect FA and measures of performance to covary under conditions of developmental stress. Using an established association between morphometric FA and reproductive performance in the gryllid crickets Gryllus bimaculatus and Gryllodes sigillatus, we looked at the effect of food stress on covariation between FA and measures of performance (vigour of locomotion and interaction, mating speed, sperm transfer, egg production and offspring weight). The results showed a clear effect of food treatment in males and females of both species, with composite measures reflecting greater FA and reduced performance being greatest when crickets were reared on impoverished food. Inspection of independent means suggested FA may have been most influenced by a relaxation of food stress under high quality feeding conditions, while reproductive performance was more susceptible to the reduction in food quality under low quality conditions.

The spirurid nematode, Protospirura muricola, is of intrinsic interest as a rodent model of gastric nematode infections. Since worm burdens can be very heavy in nature, density dependent processes may constrain parasite growth. Laboratory mice (BKW) were exposed to varying doses of infective larvae of P. muricola in the range 5 to 40 third-stage larvae (L3), in four separate experiments in which progressively higher doses were utilized. All mice were culled 60 days after infection and a total of 518 worms (226 male and 292 female worms) was recovered, measured and weighed. Overall survival was 58.9%, but survival declined significantly with increasing dose by approximately 21% (from 66% at 5 L3 per mouse to 52% at 40 L3 per mouse). The length and weight of worms correlated positively in both sexes. Total worm biomass increased linearly with increasing numbers of worms. However, whilst the length and weight of male worms declined with increasing worm burden (8.4 and 24.6% respectively), female worms were less affected, only length showing a significant reduction with increasing parasite burden (16.0%). Therefore, increasing worm burdens impeded growth of P. muricola, but reduction in length and weight were relatively small in relation to the overall size of this nematode. Increasing worm burdens were associated with loss of host weight and reduction in stomach weight and worm burdens in excess of 20 exerted a measurable cost to the host, which in the field, may be associated with loss of overall host fitness.