bluuebunny/crossref_metadata_2025 huggingface dataset:
Holistic symptom management: modelling the interaction phase
Authors: Haworth Sandra K. , Dluhy Nancy M.
Published: March 2003

Holistic symptom management: modelling the interaction phase

Aim. This article details an interaction model that links the way a nurse participates in a client’s effort to describe the symptom experience and the eventual symptom management outcome.

Rationale. Symptoms represent more than clues to an underlying disease process. Within a nursing perspective, managing symptoms requires an understanding of the person’s experience and the meaning associated with each symptom. All nurses engage in symptom work with clients, but the extent of their accountability varies within their scope of practice. In the United States of America (USA) model of advanced practice nursing, the scope expands to include all aspects of symptom management such as eliciting an accurate understanding, using a symptom cluster to determine underlying causes, and involving the client in management decisions. A holistic nursing approach to symptom management is particularly well suited to the increasing numbers of people with chronic illness.

Method. The discussion herein details the interaction phase of the evolving model of Negotiated Symptom Management in chronic illness. Analysis of the participants, process, and context governing this encounter reveal the complexities of the interaction.

Findings. It is argued that variables within the interaction have the potential to compromise desired nurse and client outcomes. Although symptom acknowledgement and relief is a primary goal, the emphasis for the nurse clinician remains on the person, not the symptom. Effective symptom management is dependent on hearing and attending to the lifeworld of the client.

Conclusion. Attending to key areas of influence in the interaction process facilitates the achievement of desired outcomes in symptom management – accurate diagnosis, symptom relief, and agreement on a course of action. The dominance of chronic illness in health care, and the centrality of the symptom experience underscores the value of sensitizing nurses to these issues.
A stage planning programme model for health education/health promotion practice
Authors: Whitehead Dean
Published: March 2003

A stage planning programme model for health education/health promotion practice

Aim. To investigate the validity of a stage planning programme model for health education/health promotion practice in nursing settings and to develop a specific model for this purpose.

Background/rationale. The last decade or so has seen a marked increase in the amount of health educational/health promotional activities that nurses are expected to undertake. This has followed concerted calls to make health promotion a familiar and recognized part of nursing practice. Despite this, however, current health‐related practices are still unstructured, haphazard and under‐evaluated. This state of affairs is further compounded by the lack of any generic and systematic nursing planning process model by which health education/health promotion programmes are applied in practice. This paper puts forward the case for such a model, develops it, and demonstrates its possible application in clinical settings.

Method. A systematic literature review was conducted in order to develop a new theoretical perspective for health promotion/health education nursing practice. The proposed model has evolved from this new perspective. The process of developing this model has drawn on existing contemporary planning models – using them as a means to develop a conceptual framework. Consequently, the proposed model seeks to critique, adapt and adopt some of their components within a nursing context.

Conclusion. If the current situation continues, in which planning process models are not adopted as a routine part of practice, then nursing may well remain a ‘bystander’ in health promotion/health education.
Learning preferences of paediatric intensive care nurses
Authors: Hewitt‐Taylor Jaquelina , Gould Dinah
Published: March 2003

Learning preferences of paediatric intensive care nurses

Aim. This paper reports the views of students on the teaching and learning strategies used in paediatric intensive care nursing courses.

Study methods. Qualitative methods of data collection and analysis were used. A case study of one paediatric intensive care nursing course was carried out, followed by group interviews with students from a further seven courses. Local ethics committee protocols were followed. Data were analysed using constant comparative analysis.

Study findings. Qualified nurses undertaking paediatric intensive care nursing courses seek a specific knowledge base, relevant to their clinical practice. Their preferred way of learning in this situation is teaching by knowledgeable experts who are also prepared to discuss issues that arise. Although in some instances student centred or self‐directed approaches were considered acceptable, Students still require clear guidance and structure in their learning. Students did not summarily oppose student centred approaches to teaching and learning, however, time considerations and whether this would reduce the amount of study time provided by their employers were important factors. There was evidence that students do not necessarily have one specific learning preference.

Limitations. This study explored only paediatric intensive care nurse education, and was not intended to be generalizable beyond this field.

Conclusion. The findings from this study indicate that no single educational approach is universally seen as the most attractive for PICU nurses. The major considerations in designing and implementing PICU nursing courses should be that content is clearly rated to the clinical speciality, theory is clearly linked to practice, and that the time constraints for students who are additionally in full time employment are taken into account.
Factors influencing nursing leadership effectiveness in Hong Kong
Authors: Chan Sally
Published: March 2003

Background.  Nursing education in Hong Kong has undergone major reform in recent years, similar to that in Australia and the United Kingdom (UK), involving the introduction of degree level preparation. Although there were some changes in the nursing education system, the reform was considered slow. While a combination of complex factors contributed to the reform, the effects of nurse leaders was instrumental in influencing policy development.

Aim.  This study investigated the factors that influenced the effectiveness of nursing leadership in the reform of nursing education in Hong Kong.

Design.
 A case study approach was used. Methods of data collection included document search and semi‐structured interviews (n = 27). The time frame of the study extended from the first proposal of nursing degree programme in the year 1985 to 2000 by which 200 nursing degree places were secured.

Results.
 Situational variables that impacted on leadership effectiveness were categorized as barriers and facilitators. Barriers were related to nursing professional socialization in a health care system that was dominated by the medical profession. Facilitators were related to socio‐politic‐economical changes in the wider environment.

Conclusion.  This study suggests the importance of education, positive socialization and unity in promoting nursing leadership development.
Vertical equity in service provision: a model for the Irish public health nursing service
Authors: Hanafin Sinéad , Houston Anna M. , Cowley Sarah
Published: March 2003

Aims.  This paper analyses the policy and conceptual basis of public health nursing service provision in the Republic of Ireland and situates it within an international context. It draws on the principles of horizontal and vertical equity in proposing a new model of public health nursing service provision. It gives the reader an understanding of a model of service delivery underpinned by the principle of vertical equity.

Background issues.  The Public Health Nurse in the Republic of Ireland has a wide remit encompassing primary, secondary and tertiary care at the level of the individual, family and community. The changing sociological and demographic nature of society in Ireland has impacted on a service that has largely remained unchanged since 1966. Since 1997 four review bodies have provided recommendations that are incompatible with each other. There remains a need to find a solution to the overwhelming demands placed on the public health nursing service in the Republic of Ireland.

Key issues.  The public health nursing service goes beyond the provision of a purely clinical nursing service. Communities differ in demography, epidemiology, environment, history, composition, support and most importantly needs. Using three exemplars a new model for the public health nursing service is explicated. This model has as its main focus the needs of the community it serves.

Conclusions.  A service underpinned by the principle of vertical equity can be used to deliver locally based, needs driven public health nursing services. The application of such a model would make the public health nursing service more flexible and responsive to local need. Public health nursing composition and provision must be determined using the principal of vertical equity determined by the needs of the community it serves.
Unmet nursing care needs of home‐based disabled patients
Authors: Hung Li‐Chen , Liu Chien‐Chi , Kuo Hsien‐Wen
Published: March 2003

Background.  In Taiwan, family members care for 80–90% of disabled people, but most have no professional training or knowledge of care for the disabled. Therefore, the adequacy of care received by the disabled needs to be assessed.

Aims.  To evaluate the unmet nursing care needs of physically disabled patients and determine the relevant factors.

Methods.  All 322 subjects were over 18 years of age, had a Barthel Index of less than 80 and became disabled 2 years prior to the commencement of this study. All subjects were outpatients of hospitals in central Taiwan and were contacted by phone to schedule an interview. Based on activity of daily living (ADL) scores, patients were divided into three groups: complete dependency, severe dependency and moderate dependency. After training, nurses evaluated the patients' ADL and completed the 20‐item Assessment of Nursing Activity (ANA) questionnaire. Based on the ANA, subjects' unmet needs and caregivers' knowledge requirements were assessed.

Findings.  The results showed the mean number of unmet needs was approximately five. Percentage of unmet needs was 44·8%. For complete dependency patients, the unmet needs score of patients and the needs score of caregiver's knowledge was highest, followed by the severe dependency group, and the moderate dependency group. Based on multiple linear regression, the factors that affected unmet need were as follows: age of patient, ADL score, education level of the caregivers, average daily duration of care and need of caregiving knowledge. Our findings indicate that the provision of counseling and educational support for family caregivers is required to promote quality of care for the disabled.
Empowering: the experiences of exercise among heart transplantation patients in Taiwan
Authors: Jeng Chii , Chu Fu‐Ling , Tsao Lee‐Ing
Published: March 2003

Aim.  To explore the experiences of exercise among Taiwanese heart transplant patients on the basis of a grounded theory.

Background.  Although studies conducted around the world have proven how important exercise is to heart transplant patients, little information was found about heart transplant patients' exercise experience. In addition, because of different cultural backgrounds, people in Taiwan do not care about ‘regular exercise’ as much as Americans and Europeans do. Therefore, it is very important to find ways so that they can value ‘regular exercise.’

Methods.  In‐depth interviews were undertaken with a purposive sample of eight heart transplant patients. Data was analysed by repeated verification.

Results.  Eight valid cases were separately and thoroughly interviewed while they were exercising at a sports medical centre. The results revealed that ‘empowering the new heart’ is the core reason for their exercise. During the exercise training process, every participant felt that his or her new heart was filled with power or energy. The ‘hardness and endurance’ in terms of feeling discomfort in the body was identified at the beginning of post‐surgical exercise training. Throughout the process of empowerment, patients experienced the following five interactive behaviour categories: ‘self‐protection’, ‘sharing’, ‘being watched and cared for’, ‘being aware of the benefits’, and ‘strengthening the new heart’.

Conclusions.  Exercise can empower the new heart. After the exercise training, all patients felt that their new hearts were empowered with energy and vigour, and thus were willing to continue exercising. They even expanded their regimen to include folk therapies such as Tai Chi and breathing exercises.
Larger clutch size increases fledging success and offspring quality in a precocial species
Authors: Lepage Denis , Gauthier Gilles , Desrochers André
Published: March 2003

1.  We tested the hypothesis that the ability of parents to raise viable offspring limits clutch size in the greater snow goose (Anser caerulescens atlanticus L.), a precocial bird.

2.  We manipulated clutch size by exchanging complete clutches between pairs of nests to increase or decrease the clutch size by zero (control), one, two or three eggs in 314 nests over 2 years.

3.  Pre‐fledging survival of goslings increased in enlarged broods and decreased in reduced broods compared to control. Consequently, enlarged broods fledged more offspring and the reverse was true for reduced broods.

4.  Size and mass of goslings near fledging was also higher in enlarged broods than in control, which suggests that offspring quality was also enhanced by the manipulation. This is contrary to the common trade‐off between offspring numbers and quality.

5.  Large families were dominant over smaller ones in feeding sites, which could explain the increased survival and growth of enlarged broods.

6.  Our results suggest that the ability to raise young does not limit clutch size in this species and that parents could be more successful (i.e. increase both the number and quality of their offspring) by laying more eggs. However, the time required to lay additional eggs reduces the viability of all offspring and may explain why females do not lay more eggs.
Effects of habitat size and quality on equilibrium density and extinction time of Sorex araneus populations
Authors: Klok Chris , De Roos André M.
Published: March 2003

1.  The effects of changes in habitat size and quality on the expected population density and the expected time to extinction of Sorex araneus are studied by means of mathematical models that incorporate demographic stochasticity.

2.  Habitat size is characterized by the number of territories, while habitat quality is represented by the expected number of offspring produced during the lifetime of an individual.

3.  The expected population density of S. araneus is shown to be mainly influenced by the habitat size. The expected time to extinction of S. araneus populations due to demographic stochasticity, on the other hand, is much more affected by the habitat quality.

4.  In a more general setting we demonstrate that, irrespective of the actual species under consideration, the likelihood of extinction as a consequence of demographic stochasticity is more effectively countered by increasing the reproductive success and survival of individuals then by increasing total population size.
Diet overlap and relative abundance of sympatric dasyurid carnivores: a hypothesis of competition
Authors: JONES MENNA E. , BARMUTA LEON A.
Published: March 2003

1.  Diet overlap among age and sex classes of sympatric dasyurid carnivores (Marsupialia: Dasyuridae) at Cradle Mountain National Park in Tasmania, Australia, was determined to assess the likelihood of current interspecific competition, which could influence and explain the disparate population densities of the three species.

2.  The carnivore guild divided into two groups based on body size and prey size, within which diet overlapped: Tasmanian devils (Sarcophilus laniarius) and male spotted‐tailed quolls (Dasyurus maculatus), which consumed larger prey species, and female spotted‐tailed quolls and eastern quolls (D. viverrinus), which consumed smaller prey species. Male spotted‐tailed quolls overlapped in diet with adult devils in winter, but not in summer. However, in summer the small number of male spotted‐tailed quolls overlapped in both body weight and diet with a large cohort of young devils. Too few data were obtained to repeat these analyses with female and young spotted‐tailed quolls and eastern quolls, but results indicated that a similar pattern of overlap may occur.

3.  Spotted‐tailed quolls would experience the highest degree of dietary overlap with another species of carnivore, with all age and sex classes experiencing overlap for much of the year. Adult devils and young eastern quolls would both be free of overlap for more than half the year.

4.  No indications of seasonal food limitation, when competition is most likely to occur, were found during this study, but this may occur over a longer time scale.

5  If the high degree of diet overlap experienced by spotted‐tailed quolls means higher competitive pressure, this may explain the low density of this species at Cradle Mountain.

6.  These results, high levels of interference experienced by spotted‐tailed quolls, and the behavioural and numerical dominance of devils, the largest species in the guild, support Brown & Maurer’s (1986) and Cotgreave’s (1993) ideas that competitive dominance may be more important than energetic equivalence in determining relationships between body size and abundance in local assemblages of animals.
What changed the demography of an introduced population of an herbivorous lady beetle?
Authors: Ohgushi Takayuki , Sawada Hiroichi
Published: March 2003

1. The population dynamics of an introduced population of Epilachna niponica (Lewis) (Coleoptera: Coccinellidae) was investigated for a 7‐year period following its introduction to a site outside of its natural range. A population from Asiu Experimental Forest was introduced to Kyoto University Botanical Garden, 10 km south of its natural distribution.

2. Arthropod predation was much lower in the introduced than in the source population. As a result of the lower predation in the Botanical Garden, larvae reached densities five times higher than in the Asiu Forest and host plants were frequently defoliated. Food shortage caused larval deaths from starvation and increased dispersal.

3. The density of the introduced population was much more variable than that of the source population. The variation in population density in both the introduced and source populations is limited by density‐dependent reduction in fecundity and female survival. However, variation in the introduced population's density was increased due to host plant defoliation that resulted in overcompensating density‐dependent mortality. In years with high larval density plants were defoliated and this increased adult mortality during the prehibernation period. Besides, the density‐dependent regulatory mechanisms that produce population stability were weaker in the introduced population than in the source population.
Geographic expansion of an increasing brown bear population: evidence for presaturation dispersal
Authors: Swenson Jon E. , Sandegren Finn , SO‐Derberg Arne
Published: March 2003

1. The distribution of brown bears (Ursus arctosL.) expanding into suitable habitat in Sweden following near extermination was estimated using harvest data from the period 1981–93. Core areas were defined as female concentration areas, where 90% of the hunter‐killed females were taken.

2.Three predictions were tested, based on results of earlier bear dispersal studies, which show that females are extremely philopatric. Prediction 1: the relative density of females declines more rapidly from the centre of a core area towards the edge than for males. Prediction 2: males dominate in the peripheral areas, especially males in the age of most active dispersal (2–4 years of age). Prediction 3: females in the periphery are found closer to the edge of the core area than males.

3.The results of the present study supported Predictions 1 and 2, but not Prediction 3. This indicates that males were more prone to disperse from the core areas than females. However, females that did disperse did not differ from males in distance from the core areas, and females were found up to 80–90 km from them. Such long‐distance female dispersal has apparently not been previously documented in other bear populations that are stable or declining. The results strongly suggest that presaturation dispersal, i.e. dispersal occurring before the carrying capacity of the habitat has been reached, is occurring in this increasing population. This phenomenon might be more common in increasing populations of large mammals than was previously thought. Regarding conservation of bears, this result is positive for gene flow and metapopulation dynamics and negative for livestock losses in formerly bear‐free areas.

4.Core and peripheral areas can be identified based on the age and sex of shot bears. This allowed us to classify Norway as a peripheral area. Bear density appears difficult to estimate near an expansion front because of large differences in densities over short distances.
Genetic variation in patch time allocation in a parasitic wasp
Authors: Wajnberg Eric , Rosi Marzia Cristiana , Colazza Stefano
Published: March 2003

1.The intra‐patch experience acquired by foraging parasitoid females has often been considered to have a strong influence on their tendency to leave a patch, and thus on their total patch residence time. Most studies that have been performed on this subject suggest that the patch‐leaving rules observed are adaptive because they enable the females to adjust their patch residence time to local environmental conditions.

2.Considering a behavioural rule as being adaptive supposes that it has been progressively settled by natural selection, and thus that there is, in the population, genetic variation on which the natural selection could act.

3.Therefore, this study aimed to discover whether there was indeed genetic variability in the patch‐leaving decision rules in a population of the egg parasitoid speciesTelenomus busseolae, which attacks patches of its hosts, the eggs ofSesamia nonagrioides. Different wasp families were compared using the isofemale lines method, and the behavioural records were analysed by means of a modified version of the Cox's proportional hazards model proposed byHaccouet al. (1991) andHemerik, Driessen & Haccou (1993).

4.The results obtained show thatT. busseolaefemales increase their tendency to leave the patch after each successful oviposition. Each host rejection also led to an increase in the tendency to leave the patch, but this effect was smaller when host rejections were observed between two ovipositions occurring in rapid succession. Subsequent visits to the patch also increased the patch‐leaving tendency.

5.Genetic variability was found in both the global patch‐leaving tendency and in the effect that successful ovipositions and host rejections have on this tendency.

6.The adaptive and evolutionary consequences of these results are discussed.
Habitat selection as a major resource partitioning mechanism between the two sympatric sibling bat speciesMyotis myotisandMyotis blythii
Authors: Arlettaz Raphael
Published: March 2003

1.Ecomorphological studies have described local bat communities as densely‐packed species assemblages arising from non‐deterministic processes. Together with the observation that insectivorous bats readily exploit patchy, often unlimited trophic resources, this has even led to the claim that partitioning of niche space may be absent. However, the paucity of data on resource exploitationper seamong bat guilds rarely allows these assertions to be verified. In particular, the mechanisms allowing the co‐existence of similar species have proved difficult to determine.

2.As a subset of an insectivorous guild, the vespertilionid batsMyotis myotisandM. blythiioffer an opportunity to examine this question. Genetically closely‐related, they are morphologically almost identical. Yet, as established by faecal analysis, they exploit distinct trophic niches, preying upon ground‐ and grass‐dwelling prey taxa, respectively. The distinct habitat requirements of their basic prey suggest that ecological segregation may stem primarily from a differential allocation of foraging space.

3.The present study tests the hypothesis that sympatricM. myotisandM. blythiisegregate spatially to an extent which prevents competitive interference. I performed radio‐tracking on Swiss sympatric populations. Using multivariate analyses and randomized contingency table procedures, I looked for (i) habitat overlap and overall inter‐specific differences in habitat choice, and (ii) the habitat preferences exhibited by individuals when foraging within their own feeding areas.

4.Primary foraging habitats were largely species‐specific. Not only were they spatially segregated, but they also differed structurally. All habitats selected byM. myotisoffered a high accessibility to ground‐dwelling prey (freshly‐cut meadows, mown grass in intensively cultivated orchards, forests without undergrowth), whereas grassland predominated in all habitats ofM. blythii(steppe, unmown meadows, pastures). This corroborates the predictions drawn from dietary niches.

5.This study shows that refined mechanisms of resource partitioning, not predictable by the study of morphological characters or echolocation alone, may still account for the organization of parts of insectivorous bat guilds. It also supports the view that habitat selection may prove to be a major mode of resource allocation amongst similar insectivorous bats, particularly for species exploiting limited food supplies.
Abundance, diversity and body size: patterns from a grassland arthropod community
Authors: Siemann EvaN. , Tilman David , Haarstad JohN.
Published: March 2003

1.The empirical relationships among body size, species richness and number of individuals may give insight into the factors controlling species diversity and the relative abundances of species. To determine these relationships, we sampled the arthropods of grasslands and savannahs at Cedar Creek, MN using sweep nets (90 525 individuals of 1225 species) and pitfall traps (12 721 individuals of 92 species). Specimens were identified, enumerated and measured to determine body size.

2.Both overall and within abundant taxonomic orders, species richness and numbers of individuals peaked at body sizes intermediate for each group. Evolution could create unimodal diversity patterns by random diversification around an ancestral body size or from size‐dependent fitness differences. Local processes such as competition or predation could also create unimodal diversity distributions.

3.The average body size of a species depended significantly on its taxonomic order, but on contemporary trophic role only within the context of taxonomic order.

4.Species richness (Si) within size classes was related to the number of individuals (Ii) asSi = Ii0·5. This relationship held across a 100 000‐fold range of body sizes. Within size classes, abundance distributions of size classes were all similar power functions. A general rule of resource division, together with similar minimum population sizes, is sufficient to generate the relationship between species richness and number of individuals.

5.Smaller bodied species had slightly shallower abundance distributions and may, in general, persist at lower densities than larger species.

6.Our results suggest there may be fewer undescribed small arthropod species than previously thought and that most undescribed species will be smaller than arthropods.
Annual variation in fat storage by a migrant warbler overwintering in the Indian tropics
Authors: Katti Madhusudan , Price Trevor
Published: March 2003

1. We studied fat storage in a population of greenish leaf warblers (Phylloscopus trochiloides) in southern India over four winters (1993–97). This species breeds in temperate regions and overwinters in India from October to April.

2. Diurnal variation in fat scores was comparable to that seen among temperate wintering passerines. Seasonal variation was slight, except for premigratory fattening. There was significant annual variation: in drier winters, which were also winters of low food supplies, fat scores were higher.

3. Energy metabolized overnight is unlikely to vary across winters, and annual variation in fat scores is considered a response to uncertainty of food intake on a given day. Fat scores varied inversely with short‐term rainfall, which drives the abundance of arthropod prey.

4. Annual variation in fat scores was not accompanied by changes in total body mass. This suggests that protein reserves were being compromised by increased fat deposition in dry years and offers an explanation for the observed delay in moult during drier winters. These results suggest that strategies for maximizing short‐term probability of survival translate into future fitness costs, and may shape long‐term life‐history strategies through simple physiological processes.
Viruses of the Serengeti: patterns of infection and mortality in African lions
Authors: Packer C. , Altizer S. , Appel M. , Brown E. , Martenson J. , O'Brien S. J. , Roelke‐Parker M. , Hofmann‐Lehmann R. , Lutz H.
Published: March 2003

1. We present data on the temporal dynamics of six viruses that infect lions (Panthera leo) in the Serengeti National Park and Ngorongoro Crater, Tanzania. These populations have been studied continuously for the past 30 years, and previous research has documented their seroprevalence for feline herpesvirus, feline immunodeficiency virus (FIV), feline calicivirus, feline parvovirus, feline coronavirus and canine distemper virus (CDV). A seventh virus, feline leukaemia virus (FeLV), was absent from these animals.

2. Comprehensive analysis reveals that feline herpesvirus and FIV were consistently prevalent at high levels, indicating that they were endemic in the host populations. Feline calici‐, parvo‐ and coronavirus, and CDV repeatedly showed a pattern of seroprevalence that was indicative of discrete disease epidemics: a brief period of high exposure for each virus was followed by declining seroprevalence.

3. The timing of viral invasion suggests that different epidemic viruses are associated with different minimum threshold densities of susceptible hosts. Furthermore, the proportion of susceptibles that became infected during disease outbreaks was positively correlated with the number of susceptible hosts at the beginning of each outbreak.

4. Examination of the relationship between disease outbreaks and host fitness suggest that these viruses do not affect birth and death rates in lions, with the exception of the 1994 outbreak of canine distemper virus. Although the endemic viruses (FHV and FIV) were too prevalent to measure precise health effects, there was no evidence that FIV infection reduced host longevity.
Evaluating the severity of the population bottleneck in the Mauritius kestrel Falco punctatus from ringing records using MCMC estimation
Authors: Groombridge Jim J. , Bruford Michael W. , Jones Carl G. , Nichols Richard A.
Published: March 2003

The Mauritius kestrel Falco punctatus (Temminck 1823) has recovered from very low numbers. In order to evaluate the severity of the population bottleneck that it experienced, we have developed a method for estimating the productivity of the nests that escaped detection. This method uses ringing records for MCMC estimation of parameters describing the recruitment of adults to the breeding population and the growth in productivity of undiscovered nests.

 Comparison of the estimates for the two restored populations (eastern and western) showed a far lower proportion of undiscovered nests in the former, as predicted because of widespread use of nestboxes. This served to verify the method of estimation. The estimates show a steady increase in population size, in contrast with field estimates indicating a recent reduction in growth.

 The results suggest that the alarmingly low estimates of population size in 1974 (two breeding pairs) were accurate, and that few undiscovered nests existed during the bottleneck.

 The recovery of the population seems to have been initiated by the intensive conservation effort. The most rapid period of population growth coincides with the reintroduction programme. The results imply that the eastern population is much more reliant on intensive management for its future growth.
Resource partitioning among British and Irish mustelids
Authors: McDonald Robbie A.
Published: March 2003

summary

 Seven species of mustelid carnivore live in the British Isles: weasel, stoat, mink, polecat, pine marten, badger and otter. Recent studies have hypothesized that coexistence of these species is facilitated by partitioning of resources according to prey size, particularly that of mammalian prey. This hypothesis has been supported by evidence of character displacement derived from even size ratios in skull length and canine diameter.

 To test whether this hypothesis is supported by empirical data, 98 studies of the diet of mustelids living in Great Britain and Ireland were analysed. Two main predictions were tested; that larger males ate larger prey than females and that larger species ate larger prey than smaller species.

 Male mustelids ate larger prey than females but there was no relationship between predator size and prey size, either for all species or when largely vermivorous badgers and piscivorous otters were excluded. There was no difference in dietary niche breadth between the sexes. Dietary niche breadth increased with body size in the assemblage excluding otters and badgers. The dietary niches of mustelids were partitioned along several axes, none of which was clearly related to prey size.

 The dietary niches of the five species living in Ireland (stoat, mink, pine marten, otter and badger) were more similar to one another in Ireland than in Great Britain and there was no difference in niche breadth between Irish and British mustelids. There was no evidence of competitive release in the diets of Irish mustelids.

 Resource partitioning according to prey size is apparent between the sexes within species, and this is probably correlated to sexual selection for size dimorphism. Empirical data do not, however, support a hypothesis of resource partitioning according to prey size between species. Interspecific aggression provides an alternative hypothesis explaining character displacement among mustelids.
Stress during feather development predicts fitness potential
Authors: Bortolotti Gary R. , Dawson Russell D. , Murza Gillian L.
Published: March 2003

Measures of the quality of an individual are important in the study of proximate and ultimate factors in biology. Records of developmental history are particularly desirable, as many phenotypical traits are influenced by conditions during growth. Conspicuous irregularities in feathers, known as fault bars, result from a variety of stresses that occur during feather growth. The frequency of fault bars was evaluated on primary and tail feathers (grown 1 year previously) of 1919 adult American kestrels from a breeding population in Canada (1990–97).

Most (91·5%) birds exhibited some fault‐barring, although females had significantly more feathers with fault bars than males (17% vs. 14%, respectively). Body size, intensity of haematozoan infections and leucocyte differentials were all unrelated to fault bars; however, birds with many fault bars were in poor body condition during prelaying (males) and incubation (males and females).

Individual kestrels tended to be consistent in the number of feathers with fault bars from year to year.

The percentage of feathers with fault bars was not associated with the timing of arrival in spring or prey abundance per territory; however, birds of both sexes with many bars were less likely to breed. Birds paired non‐randomly, as mates tended to have a similar frequency of fault bars. Males and females with many bars had significantly later clutch initiation dates, but there were no negative consequences regarding clutch size or egg size.

Female kestrels with many fault bars had lower survival probabilities. Both sexes were also less likely to be recaptured in years following initial banding if they had many bars, suggesting that they were more likely to emigrate from the study area temporarily.

Fault bars on feathers appear to be indicative of an individual’s susceptibility to stress, and are useful in predicting components of fitness. The use of fault bars is a promising tool as they are easy to evaluate and can be assessed on live or dead birds, on moulted feathers and on individuals repeatedly over time.
Reindeer summer activity pattern in relation to weather and insect harassment
Authors: Hagemoen Rolf Iver M. , Reimers Eigil
Published: March 2003

During the brief growing season in Arctic and high mountain ecosystems, undisturbed grazing is crucial in order to maximize growth and fattening. During summer 1997 we investigated the influence of weather and insect harassment on the behaviour and group dynamics of reindeer (Rangifer tarandus tarandusL.).

Climatic data, activity of parasitic flies, and female reindeer behaviour were recorded from two wild reindeer populations in Southern Norway. Temperature and solar irradiation were good predictors of oestrid fly activity. Throughout the warm summer, reindeer were exposed to vigorous oestrid fly harassment, which caused dramatic decrease in feeding and lying, and increase in walking, running and standing. This behavioural change may compromise the physical condition of individuals entering winter.

Mosquitoes had little influence on reindeer activity patterns. In the absence of oestrid flies, weather parameters had no influence on reindeer activity pattern. Even during the warmest days, no signs of heat stress were recorded. Accordingly, snow patches, marshes and windy mountaintops were used primarily to avoid oestrid fly harassment. Thus, most disruptions of feeding that are often reported on warm days are responses to oestrids, not thermal stress.
Peak morphological diversity in an ecotone unveiled in the chukar partridge by a novel Estimator in a Dependent Sample (EDS)
Authors: Kark Salit , Mukerji Tapan , Safriel Uriel N. , Noy‐Meir Imanuel , Nissani Rachel , Darvasi Ariel
Published: March 2003

Areas of environmental transition (i.e. ecotones) have recently been shown to play an important role in the maintenance of genetic diversity, divergence and in speciation processes. We test the hypothesis that ecotone populations maintain high phenotypic diversity compared to other populations across the distribution range.

Focusing on the chukar partridge (Alectoris chukar Gray), we study trends in morphological diversity across a steep ecotone within the species native range in Israel and Sinai. Using 35 traits and 23 ratios between traits, we apply a novel weighted average statistic that we term ‘Estimator in a Dependent Sample’ (EDS). This estimator enables us to compare levels of diversity across populations using multiple‐correlated traits and is especially useful when sample sizes are small.

We provide a program for calculating the EDS and a bootstrapping procedure to describe its confidence interval and standard deviation. This estimator can be applied widely in a range of studies using multiple‐correlated traits in evolutionary biology, ecology, morphology, behaviour, palaeontology, developmental biology and genetics.

Our results indicate that within‐population diversity peaks in chukar populations located in the Mediterranean‐desert ecotone in Israel. However, had we not included the ecotone region in our study, we would have drawn different conclusions regarding patterns of morphological diversity across the range. We suggest that ecotones should be given higher priority in future research and conservation planning, potentially serving as within‐species diversity hotspots.
Modelling hantavirus in fluctuating populations of bank voles: the role of indirect transmission on virus persistence
Authors: Sauvage Frank , Langlais Michel , Yoccoz Nigel G. , Pontier Dominique
Published: March 2003

Using field data published in the literature, we investigated pathogen dynamics and conditions of persistence in a mathematical model of the bank vole (Clethrionomys glareolus)–Puumala hantavirus system. The host population is assumed to have a 3‐year periodic cycle. The duration of very low host density is critical for virus transmission and survival.

Field epidemiological data strongly suggested a transmission of the hantavirus by the contaminated environment. We thus studied whether this ‘indirect’ transmission affected the virus persistence in the host population.

The model assumptions were derived from the following conditions found in the literature: (1) there is no additional mortality nor fecundity loss due to the virus in infected hosts, thus the cyclic demographical pattern is not due to the virus; (2) no remission has been observed, thus we did not consider the existence of recovered individuals; (3) adult females are territorial and juveniles disperse to find a new territory and reach sexual maturity. A fragmented landscape was assumed to occur: individuals can live in favourable or unfavourable patches.

The model was a compartmental model; the population was structured into susceptible or infectious individuals. We considered two age classes, juveniles and adults, and two sites (populations) connected by juvenile dispersal.

Model dynamics accurately predicted the cyclic trend in disease prevalence as observed in epidemiological studies. They also showed that indirect transmission significantly increased the probability for the virus to persist during the low‐density period of the host population. More precisely, even a low survival rate of the virus outside the host was sufficient to decrease extinction risk of the infection by stochastic events.

Elasticity analysis showed a high robustness of the model to changes in the parameters of indirect transmission but a high sensitivity to changes in adult density.
Mammal species richness and habitat use in rainforest and abandoned agricultural fields in Chiapas, Mexico
Authors: MedellÍN Rodrigo A. , Equihua Miguel
Published: March 2003

1.  We evaluated the potential of small, isolated cornfields embedded in a large forest matrix as an appropriate compromise between conservation and sustainable development.

2.  We examined the relationship between habitat structure and diversity with overall mammal species richness and abundance of six common small mammals in four 6‐year‐old abandoned cornfields (oldfields) and four continuous rainforest sites in the most speciose region in Mexico, the Selva Lacandona, Chiapas.

3.  Species richness did not differ between forests and oldfields, indicating that forest‐dependent mammals penetrate oldfields of size 0·9–2·9 ha, presumably because forest cover and resources are nearby. Even species which strongly selected forest habitat, such as H. desmarestianus and D. marsupialis, were present in oldfields, and only the latter showed a significant decline in the number of captures as a function of distance from forest edge.

4.  The Lacandon Indian use of the land for agriculture in the form of small (> 3 ha) agricultural plots embedded in a large forest matrix increases spatial heterogeneity and promotes mammal diversity.

5.  Those small plots (in agricultural production terms) are intermediate in size when the whole continuum of the local natural and anthropogenic disturbance sizes are considered; more common are the extensive clearings for agriculture or cattle ranching, whereas the most common forest disturbance is treefall gaps, at least 20 times smaller than oldfields.

6.  This form of land use should be considered as an important, appropriate productive element when decisions are made about managing reserves and pursuing sustainable development.
Effects of habitat fragmentation and road density on the distribution pattern of the moor frog Rana arvalis
Authors: Vos C.C. , Chardon J.P.
Published: March 2003

1.  The effects of habitat fragmentation on the distribution pattern of the moor frog Rana arvalis were investigated. Also, the possible isolation effects of the road network were taken into account.

2.  Indications were found that habitat fragmentation partly explains the distribution pattern of the moor frog. The statistical models showed a positive effect of pond size (or marsh area) and a negative effect of road density on the probability of occupation of a moorland pond.

3.  Because of the strong correlation between habitat quality variables and isolation variables, no unambiguous effects of isolation, described as the amount of suitable terrestrial habitat (moorland) in the surroundings of a moorland pond in a radius of 100–2000 m, could be demonstrated.

4.  Spatial differences in road density can play a role in the selection of optimal locations for nature protection areas. The regression model used in this study predicts a reduced occupation probability in 55% of the study area. In the part of the study area adjacent to a motorway, occupation probability is lowered to less than 30%.

5.  European studies of habitat fragmentation on amphibian species revealed a mean distance between occupied ponds of <1 km in all studies. This could be a general rule of thumb for persistent amphibian populations. Effects of pond size on the probability of occupation were more variable.

6.  When discussing the effects of habitat fragmentation on amphibians and other ground dwelling species, the negative effects of roads are often underestimated.
An estimate of the sustainable rate of shell extraction from the Dutch Wadden Sea
Authors: Beukema J. J. , Cadée G. C.
Published: March 2003

1. Shell production by cockles Cerastoderma edule was studied to examine whether or not the present licensed rate of shell extraction in the Dutch Wadden Sea exceeds the current rate of shell addition to the exploitable stocks.

2. Long‐term data on numbers of cockles and weights of their shells were used to estimate their annual production on Balgzand, a 50‐km2 tidal flat area in the western‐most part of the Wadden Sea. During the 1969–97 period, it amounted to an average of 125 g m–2, including 107 g m–2 of shells large enough to be exploitable for shell‐lime fishery.

3. The very irregular annual recruitment of cockles was the main cause of the wide 95% confidence limits (74 and 140 g m–2 year–1) of this 28‐year estimate. Moreover, high mortality rates in severe winters substantially reduced production per recruit in some year classes.

4. About one‐third of the estimated production does not reach exploitable stocks, because it is fragmented by birds (particularly eider ducks), permanently buried in the sediment, or removed by the fishery for live cockles.

5. During the last few decades, the estimated mean amount added annually to the exploitable stocks was 88 million kg or 132 000 m3 of large cockle shells. This amount compares favourably with the current annual level of removal of 134 000 m3 of shells, three‐quarters of which are cockles.

6. Even at temporarily lower production rates, the exploitation of shell stocks at its present rate is not expected to lead to a rapid exhaustion of the existing stocks in the tidal inlets of the Dutch Wadden Sea, as these stocks will be in the order of a few million m3.