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1.
BMC Health Serv Res ; 24(1): 419, 2024 Apr 03.
Article in English | MEDLINE | ID: mdl-38570788

ABSTRACT

BACKGROUND: Keeping best practice guidelines up-to-date with rapidly emerging research evidence is challenging. 'Living guidelines' approaches enable continual incorporation of new research, assisting healthcare professionals to apply the latest evidence to their clinical practice. However, information about how living guidelines are developed, maintained and applied is limited. The Stroke Foundation in Australia was one of the first organisations to apply living guideline development methods for their Living Stroke Guidelines (LSGs), presenting a unique opportunity to evaluate the process and impact of this novel approach. METHODS: A mixed-methods study was conducted to understand the experience of LSGs developers and end-users. We used thematic analysis of one-on-one semi-structured interview and online survey data to determine the feasibility, acceptability, and facilitators and barriers of the LSGs. Website analytics data were also reviewed to understand usage. RESULTS: Overall, the living guidelines approach was both feasible and acceptable to developers and users. Facilitators to use included collaboration with multidisciplinary clinicians and stroke survivors or carers. Increased workload for developers, workload unpredictability, and limited information sharing, and interoperability of technological platforms were identified as barriers. Users indicated increased trust in the LSGs (69%), likelihood of following the LSGs (66%), and frequency of access (58%), compared with previous static versions. Web analytics data showed individual access by 16,517 users in 2016 rising to 53,154 users in 2020, a threefold increase. There was also a fourfold increase in unique LSG pageviews from 2016 to 2020. CONCLUSIONS: This study, the first evaluation of living guidelines, demonstrates that this approach to stroke guideline development is feasible and acceptable, that these approaches may add value to developers and users, and may increase guideline use. Future evaluations should be embedded along with guideline implementation to capture data prospectively.


Subject(s)
Health Personnel , Stroke , Humans , Australia , Stroke/therapy
2.
BMC Med ; 22(1): 131, 2024 Mar 22.
Article in English | MEDLINE | ID: mdl-38519952

ABSTRACT

BACKGROUND: Pandemics and climate change each challenge health systems through increasing numbers and new types of patients. To adapt to these challenges, leading health systems have embraced a Learning Health System (LHS) approach, aiming to increase the efficiency with which data is translated into actionable knowledge. This rapid review sought to determine how these health systems have used LHS frameworks to both address the challenges posed by the COVID-19 pandemic and climate change, and to prepare for future disturbances, and thus transition towards the LHS2.0. METHODS: Three databases (Embase, Scopus, and PubMed) were searched for peer-reviewed literature published in English in the five years to March 2023. Publications were included if they described a real-world LHS's response to one or more of the following: the COVID-19 pandemic, future pandemics, current climate events, future climate change events. Data were extracted and thematically analyzed using the five dimensions of the Institute of Medicine/Zurynski-Braithwaite's LHS framework: Science and Informatics, Patient-Clinician Partnerships, Continuous Learning Culture, Incentives, and Structure and Governance. RESULTS: The search yielded 182 unique publications, four of which reported on LHSs and climate change. Backward citation tracking yielded 13 additional pandemic-related publications. None of the climate change-related papers met the inclusion criteria. Thirty-two publications were included after full-text review. Most were case studies (n = 12, 38%), narrative descriptions (n = 9, 28%) or empirical studies (n = 9, 28%). Science and Informatics (n = 31, 97%), Continuous Learning Culture (n = 26, 81%), Structure and Governance (n = 23, 72%) were the most frequently discussed LHS dimensions. Incentives (n = 21, 66%) and Patient-Clinician Partnerships (n = 18, 56%) received less attention. Twenty-nine papers (91%) discussed benefits or opportunities created by pandemics to furthering the development of an LHS, compared to 22 papers (69%) that discussed challenges. CONCLUSIONS: An LHS 2.0 approach appears well-suited to responding to the rapidly changing and uncertain conditions of a pandemic, and, by extension, to preparing health systems for the effects of climate change. LHSs that embrace a continuous learning culture can inform patient care, public policy, and public messaging, and those that wisely use IT systems for decision-making can more readily enact surveillance systems for future pandemics and climate change-related events. TRIAL REGISTRATION: PROSPERO pre-registration: CRD42023408896.


Subject(s)
COVID-19 , Learning Health System , United States , Humans , Pandemics , Climate Change , COVID-19/epidemiology , Patient Care
3.
Int J Health Plann Manage ; 39(3): 781-805, 2024 May.
Article in English | MEDLINE | ID: mdl-38308433

ABSTRACT

BACKGROUND: As global CO2 emissions continue to rise and the 'era of global boiling' takes hold, the health workforce must cope with the challenge of providing care to increasing numbers of patients affected by climate change-related events (e.g., hurricanes, wildfires, floods). In this review, we describe the impacts of these events on the health workforce, and strategies responding to these challenges. METHODS: This rapid systematic review was guided by the Preferred Reporting Items for Systematic reviews and Meta-Analyses and a registered protocol (PROSPERO CRD42023433610). Eight databases were searched in May 2022 and again in June 2023. Empirical studies discussing climate change and workforce policy, planning, preparedness, and capacity were included. Inductive thematic analysis of extracted data was conducted. RESULTS: From the 60 included studies, two categories emerged: the impacts of climate events on the health workforce (n = 39), and workforce responses to and preparations for climate events (n = 58). Thirty-seven studies reported on both categories. Four impact themes were identified: absenteeism, psychological impacts, system breakdown, and unsafe working conditions; and six responses and preparations themes: training/skill development, workforce capacity planning, interdisciplinary collaboration, role flexibility, role incentivisation, and psychological support. CONCLUSION: This review provides an overview of some of the deleterious impacts of climate events on the health workforce, as well as potential strategies for the health workforce to prepare or respond to climate events. Future studies should assess the implementation and effectiveness of these strategies to ensure a continuously improving healthcare system, and a well-supported health workforce.


Subject(s)
Capacity Building , Climate Change , Humans , Health Workforce , Delivery of Health Care/organization & administration , Health Planning
4.
Implement Sci ; 18(1): 62, 2023 Nov 13.
Article in English | MEDLINE | ID: mdl-37957669

ABSTRACT

OBJECTIVE: To identify barriers and facilitators associated with the sustainability of implemented and evaluated improvement programs in healthcare delivery systems. DATA SOURCES AND STUDY SETTING: Six academic databases were searched to identify relevant peer-reviewed journal articles published in English between July 2011 and June 2022. Studies were included if they reported on healthcare program sustainability and explicitly identified barriers to, and facilitators of, sustainability. STUDY DESIGN: A systematic integrative review guided by the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) statement. Study quality was appraised using Hawker's Quality Assessment Tool. DATA COLLECTION/EXTRACTION METHODS: A team of reviewers screened eligible studies against the inclusion criteria and extracted the data independently using a purpose-designed Excel spreadsheet. Barriers and facilitators were extracted and mapped to the Integrated Sustainability Framework (ISF). Frequency counts of reported barriers/facilitators were performed across the included studies. RESULTS: Of the 124 studies included in this review, almost half utilised qualitative designs (n = 52; 41.9%) and roughly one third were conducted in the USA (n = 43; 34.7%). Few studies (n = 29; 23.4%) reported on program sustainability beyond 5 years of program implementation and only 16 of them (55.2%) defined sustainability. Factors related to the ISF categories of inner setting (n = 99; 79.8%), process (n = 99; 79.8%) and intervention characteristics (n = 72; 58.1%) were most frequently reported. Leadership/support (n = 61; 49.2%), training/support/supervision (n = 54; 43.5%) and staffing/turnover (n = 50; 40.3%) were commonly identified barriers or facilitators of sustainability across included studies. Forty-six (37.1%) studies reported on the outer setting category: funding (n = 26; 56.5%), external leadership by stakeholders (n = 16; 34.8%), and socio-political context (n = 14; 30.4%). Eight studies (6.5%) reported on discontinued programs, with factors including funding and resourcing, poor fit, limited planning, and intervention complexity contributing to discontinuation. CONCLUSIONS: This review highlights the importance of taking into consideration the inner setting, processes, intervention characteristics and outer setting factors when sustaining healthcare programs, and the need for long-term program evaluations. There is a need to apply consistent definitions and implementation frameworks across studies to strengthen evidence in this area. TRIAL REGISTRATION: https://bmjopen.bmj.com/content/7/11/e018568 .


Subject(s)
Delivery of Health Care , Health Facilities , Humans , Program Evaluation , Leadership
5.
Health Expect ; 26(3): 1107-1117, 2023 06.
Article in English | MEDLINE | ID: mdl-36810854

ABSTRACT

BACKGROUND: Preventative healthcare is crucial for improving individual patient outcomes and is integral to sustainable health systems. The effectiveness of prevention programs is enhanced by activated populations who are capable of managing their own health and are proactive to keep themselves well. However, little is known about the level of activation among people drawn from general populations. We used the Patient Activation Measure (PAM) to address this knowledge gap. METHODS: A representative, population-based survey of Australian adults was conducted in October 2021 during the Delta strain outbreak of the COVID-19 pandemic. Comprehensive demographic information was collected, and the participants completed the Kessler-6 psychological distress scale (K6) and PAM. Multinomial and binomial logistic regression analyses were performed to determine the effect of demographic factors on PAM scores, which are categorised into four levels: 1-participants disengaged with their health; 2-becoming aware of how to manage their health; 3-acting on their health; and 4-engaging with preventative healthcare and advocating for themselves. RESULTS: Of 5100 participants, 7.8% scored at PAM level 1; 13.7% level 2, 45.3% level 3, and 33.2% level 4. The mean score was 66.1, corresponding to PAM level 3. More than half of the participants (59.2%) reported having one or more chronic conditions. Respondents aged 18 to 24 years old were twice as likely to score PAM level 1 compared with people aged 25-44 (p < .001) or people aged over 65 years (p < .05). Speaking a language other than English at home was significantly associated with having low PAM (p < .05). Greater psychological distress scores (K6) were significantly predictive of low PAM scores (p < .001). CONCLUSION: Overall, Australian adults showed high levels of patient activation in 2021. People with lower incomes, of younger age, and those experiencing psychological distress were more likely to have low activation. Understanding the level of activation enables targeting sociodemographic groups for extra support to increase the capacity to engage in prevention activities. Conducted during the COVID-19 pandemic, our study provides a baseline for comparison as we move out of the pandemic and associated restrictions and lockdowns. PATIENT OR PUBLIC CONTRIBUTION: The study and survey questions were co-designed with consumer researchers from the Consumers Health Forum of Australia (CHF) as equal partners. Researchers from CHF were involved in the analysis of data and production of all publications using data from the consumer sentiment survey.


Subject(s)
COVID-19 , Adolescent , Adult , Humans , Young Adult , Australia/epidemiology , Communicable Disease Control , COVID-19/epidemiology , Pandemics , Patient Participation/psychology
6.
Front Psychiatry ; 13: 1028384, 2022.
Article in English | MEDLINE | ID: mdl-36339853

ABSTRACT

Background: Previous research suggests that the COVID-19 pandemic caused significant disruption to the lives and mental health of Australians. In response, health services adapted rapidly to digital modes of treatment, prevention and care. Although a large amount of research emerged in the first year of the pandemic, the longer-term mental health impacts, contributing factors, and population-level utilization of digital health services are unknown. Methods: A population-based online survey of 5,100 Australians adults was conducted in October 2021. Psychological distress was assessed with the Kessler 6-item Psychological Distress Scale. Additional survey questions included use and satisfaction with digital health services. Where available, data were compared with our previous survey conducted in 2018, permitting an examination of pre- and post-pandemic digital health service utilization. Results: In 2021, almost a quarter (n = 1203, 23.6%) of respondents reported serious levels of psychological distress; participants with pre-existing health related conditions, of younger age, lower educational attainment, those who lost their job or were paid fewer hours, or living in states with lockdown policies in place were at highest risk of serious psychological distress. Almost half of all respondents (n = 2177, 42.7%) reported using digital health technologies in 2021, in contrast to just 10.0% in 2018. In 2021, respondents with serious psychological distress were significantly more likely to consult with a healthcare professional via telephone/videoconferencing (P < 0.001), access healthcare via a telephone advice line (P < 0.001), or via an email or webchat advice service (P < 0.001) than those with no serious psychological distress. Those with and without psychological distress were highly satisfied with the care they received via digital health technologies in 2021. Conclusion: Rates of serious psychological distress during the second year of the pandemic remained high, providing further evidence for the serious impact of COVID-19 on the mental health of the general population. Those with psychological distress accessed digital mental health services and were satisfied with the care they received. The results highlight the continued need for mental health support and digital health services, particularly for people living with chronic conditions, younger adults and people most impacted by the COVID-19 pandemic, both in the short term and beyond.

8.
J Am Med Inform Assoc ; 29(12): 2168-2173, 2022 11 14.
Article in English | MEDLINE | ID: mdl-35822400

ABSTRACT

Climate change, human health, and healthcare systems are inextricably linked. As the climate warms due to greenhouse gas (GHG) emissions, extreme weather events, such as floods, fires, and heatwaves, will drive up demand for healthcare. Delivering healthcare also contributes to climate change, accounting for ∼5% of the global carbon emissions. To rein in healthcare's carbon footprint, clinicians and health policy makers must be able to measure the GHG contributions of healthcare systems and clinical practices. Herein, we scope potential informatics solutions to monitor the carbon footprint of healthcare systems and to support climate-change decision-making for clinicians, and healthcare policy makers. We discuss the importance of methods and tools that can link environmental, economic, and healthcare data, and outline challenges to the sustainability of monitoring efforts. A greater understanding of these connections will only be possible through further development and usage of models and tools that integrate diverse data sources.


Subject(s)
Carbon Footprint , Carbon , Humans , Delivery of Health Care , Informatics
9.
JMIR Med Inform ; 10(2): e34907, 2022 Feb 23.
Article in English | MEDLINE | ID: mdl-35195529

ABSTRACT

BACKGROUND: The development and adoption of a learning health system (LHS) has been proposed as a means to address key challenges facing current and future health care systems. The first review of the LHS literature was conducted 5 years ago, identifying only a small number of published papers that had empirically examined the implementation or testing of an LHS. It is timely to look more closely at the published empirical research and to ask the question, Where are we now? 5 years on from that early LHS review. OBJECTIVE: This study performed a scoping review of empirical research within the LHS domain. Taking an "implementation science" lens, the review aims to map out the empirical research that has been conducted to date, identify limitations, and identify future directions for the field. METHODS: Two academic databases (PubMed and Scopus) were searched using the terms "learning health* system*" for papers published between January 1, 2016, to January 31, 2021, that had an explicit empirical focus on LHSs. Study information was extracted relevant to the review objective, including each study's publication details; primary concern or focus; context; design; data type; implementation framework, model, or theory used; and implementation determinants or outcomes examined. RESULTS: A total of 76 studies were included in this review. Over two-thirds of the studies were concerned with implementing a particular program, system, or platform (53/76, 69.7%) designed to contribute to achieving an LHS. Most of these studies focused on a particular clinical context or patient population (37/53, 69.8%), with far fewer studies focusing on whole hospital systems (4/53, 7.5%) or on other broad health care systems encompassing multiple facilities (12/53, 22.6%). Over two-thirds of the program-specific studies utilized quantitative methods (37/53, 69.8%), with a smaller number utilizing qualitative methods (10/53, 18.9%) or mixed-methods designs (6/53, 11.3%). The remaining 23 studies were classified into 1 of 3 key areas: ethics, policies, and governance (10/76, 13.2%); stakeholder perspectives of LHSs (5/76, 6.6%); or LHS-specific research strategies and tools (8/76, 10.5%). Overall, relatively few studies were identified that incorporated an implementation science framework. CONCLUSIONS: Although there has been considerable growth in empirical applications of LHSs within the past 5 years, paralleling the recent emergence of LHS-specific research strategies and tools, there are few high-quality studies. Comprehensive reporting of implementation and evaluation efforts is an important step to moving the LHS field forward. In particular, the routine use of implementation determinant and outcome frameworks will improve the assessment and reporting of barriers, enablers, and implementation outcomes in this field and will enable comparison and identification of trends across studies.

10.
Learn Health Syst ; 6(1): e10265, 2022 Jan.
Article in English | MEDLINE | ID: mdl-35036549

ABSTRACT

INTRODUCTION: The emergent field of learning health systems (LHSs) has been rapidly evolving as the concept continues to be embraced by researchers, managers, and clinicians. This paper reports on a scoping review and bibliometric analysis of the LHS literature to identify key topic areas and examine the influence and spread of recent research. METHODS: We conducted a scoping review of LHS literature published between January 2016 and May 2020. The authors extracted publication data (eg, journal, country, authors, citation count, keywords) and reviewed full-texts to identify: type of study (empirical, non-empirical, or review), degree of focus (general or specific), and the reference used when defining LHSs. RESULTS: A total of 272 publications were included in this review. Almost two thirds (65.1%) of the included articles were non-empirical and over two-thirds (68.4%) were from authors in the United States. More than half of the publications focused on specific areas, for example: oncology, cardiovascular care, and genomic medicine. Other key topic areas included: ethics, research, quality improvement, and electronic health records. We identified that definitions of the LHS concept are converging; however, many papers focused on data platforms and analytical processes rather than organisational and behavioural factors to support change and learning activities. CONCLUSIONS: The literature on LHSs remains largely theoretical with definitions of LHSs focusing on technical processes to reuse data collected during the clinical process and embedding analysed data back into the system. A shift in the literature to empirical LHS studies with consideration of organisational and human factors is warranted.

12.
Intern Med J ; 51(7): 1060-1067, 2021 07.
Article in English | MEDLINE | ID: mdl-33350562

ABSTRACT

BACKGROUND: With 50% of Australians having chronic disease, health consumer views are an important barometer of the 'health' of the healthcare system for system improvement and sustainability. AIMS: To describe the views of Australian health consumers with and without chronic conditions when accessing healthcare. METHODS: A survey of a representative sample of 1024 Australians aged over 18 years, distributed electronically and incorporating standardised questions and questions co-designed with consumers. RESULTS: Respondents were aged 18-88 years (432 males, 592 females) representing all states and territories, and rural and urban locations. General practices (84.6%), pharmacies (62.1%) and public hospitals (32.9%) were the most frequently accessed services. Most care was received through face-to-face consultations; only 16.5% of respondents accessed care via telehealth. The 605 (59.0%) respondents with chronic conditions were less likely to have private health insurance (50.3% vs 57.9%), more likely to skip doses of prescribed medicines (53.6% vs 28.6%), and miss appointments with doctors (15.3% vs 10.1%) or dentists (52.8% vs 40.4%) because of cost. Among 480 respondents without private health insurance, unaffordability (73.5%) or poor value for money (35.3%) were the most common reasons. Most respondents (87.7%) were confident that they would receive high quality and safe care. However, only 57% of people with chronic conditions were confident that they could afford needed healthcare compared with 71.3% without. CONCLUSIONS: Health consumers, especially those with chronic conditions, identified significant cost barriers to access of healthcare. Equitable access to healthcare must be at the centre of health reform.


Subject(s)
Health Care Reform , Health Services Accessibility , Adult , Australia/epidemiology , Chronic Disease , Costs and Cost Analysis , Female , Humans , Male , Middle Aged
13.
Animals (Basel) ; 7(3)2017 Mar 09.
Article in English | MEDLINE | ID: mdl-28282909

ABSTRACT

In this exploratory study, we tracked free-range laying hens on two commercial flocks with Radio Frequency Identification (RFID) technology with the aim to examine individual hen variation in range use. Three distinct outdoor zones were identified at increasing distances from the shed; the veranda [0-2.4 m], close range [2.4-11.4 m], and far range [>11.4 m]. Hens' movements between these areas were tracked using radio frequency identification technology. Most of the hens in both flocks (68.6% in Flock A, and 82.2% in Flock B) accessed the range every day during the study. Of the hens that accessed the range, most hens accessed all three zones (73.7% in Flock A, and 84.5% in Flock B). Hens spent half of their time outdoors in the veranda area. Within-individual consistency of range use (daily duration and frequency) varied considerably, and hens which were more consistent in their daily range use spent more time on the range overall (p < 0.001). Understanding variation within and between individuals in ranging behaviour may help elucidate the implications of ranging for laying hens.

14.
Behav Processes ; 125: 101-5, 2016 Apr.
Article in English | MEDLINE | ID: mdl-26915426

ABSTRACT

Correctly directing social behaviour towards a specific individual requires an ability to discriminate between conspecifics. The mechanisms of individual recognition include phenotype matching and familiarity-based recognition. Communication-based recognition is a subset of familiarity-based recognition wherein the classification is based on behavioural or distinctive signalling properties. Male fowl (Gallus gallus) produce a visual display (tidbitting) upon finding food in the presence of a female. Females typically approach displaying males. However, males may tidbit without food. We used the distinctiveness of the visual display and the unreliability of some males to test for communication-based recognition in female fowl. We manipulated the prior experience of the hens with the males to create two classes of males: S(+) wherein the tidbitting signal was paired with a food reward to the female, and S (-) wherein the tidbitting signal occurred without food reward. We then conducted a sequential discrimination test with hens using a live video feed of a familiar male. The results of the discrimination tests revealed that hens discriminated between categories of males based on their signalling behaviour. These results suggest that fowl possess a communication-based recognition system. This is the first demonstration of live-to-video transfer of recognition in any species of bird.


Subject(s)
Animal Communication , Chickens , Recognition, Psychology , Animals , Female , Male , Social Behavior
15.
Ecol Evol ; 4(2): 113-20, 2014 Jan.
Article in English | MEDLINE | ID: mdl-24558567

ABSTRACT

Aposematism involves predators learning conspicuous signals of defended prey. However, prey species utilize a wide range of chemical (or physical) defenses, which are not likely to be equally aversive to all predators. Aposematism may therefore only be effective against a physiologically sensitive subset of potential predators, and this can only be identified through behavioral testing. We studied the emerging model organism Tectocoris diophthalmus (Heteroptera: Scutelleridae), an aposematically colored but weakly defended shieldback stinkbug, to test the efficacy of its defenses against a suite of predator types. We predicted the bugs' defenses would be ineffectual against both experienced and naïve birds but aversive to predaceous insects. Surprisingly, the opposite pattern was found. Both habituated wild passerines and naïve chickens avoided the bugs, the chickens after only one or two encounters. To avian predators, T. diophthalmus is aposematic. However, praying mantids showed no repellency, aversion, or toxicity associated with adult or juvenile bugs after multiple trials. Comparison with prior studies on mantids using bugs with chemically similar but more concentrated defenses underscores the importance of dose in addition to chemical identity in the efficacy of chemical defenses. Our results also emphasize the importance of behavioral testing with multiple ecologically relevant predators to understand selective pressures shaping aposematic signals and chemical defenses.

16.
Anim Cogn ; 16(5): 691-700, 2013 Sep.
Article in English | MEDLINE | ID: mdl-23420511

ABSTRACT

Face recognition in humans is a complex cognitive skill that requires sensitivity to unique configurations of eyes, mouth, and other facial features. The Thatcher illusion has been used to demonstrate the importance of orientation when processing configural information within faces. Transforming an upright face so that the eyes and mouth are inverted renders the face grotesque; however, when this "Thatcherized" face is inverted, the effect disappears. Due to the use of primate models in social cognition research, it is important to determine the extent to which specialized cognitive functions like face processing occur across species. To date, the Thatcher illusion has been explored in only a few species with mixed results. Here, we used computerized tasks to examine whether nonhuman primates perceive the Thatcher illusion. Chimpanzees and rhesus monkeys were required to discriminate between Thatcherized and unaltered faces presented upright and inverted. Our results confirm that chimpanzees perceived the Thatcher illusion, but rhesus monkeys did not, suggesting species differences in the importance of configural information in face processing. Three further experiments were conducted to understand why our results differed from previously published accounts of the Thatcher illusion in rhesus monkeys.


Subject(s)
Illusions/psychology , Primates/psychology , Recognition, Psychology , Animals , Biological Evolution , Discrimination, Psychological , Face , Female , Macaca mulatta/psychology , Male , Pan troglodytes/psychology , Photic Stimulation
17.
J Exp Biol ; 212(Pt 6): 835-42, 2009 Mar.
Article in English | MEDLINE | ID: mdl-19252000

ABSTRACT

With the notable exception of bee dances, there are no established examples of multimodal referential signals. The food calls of male fowl, Gallus gallus, are functionally referential and the acoustic component of a multimodal display. However, the specificity of the receiver's response to the visual component (tidbitting) has never been tested. Here we provide the first detailed analysis of tidbitting, and test the hypothesis that these characteristic movements are functionally referential. We conducted a playback experiment with five high-definition video stimuli: Silent tidbit, Matched-frequency motion in the opposite direction, Silent crows, Inactive male and Empty cage. Females searched for food more during Silent tidbitting than under any other condition, suggesting that this visual display specifically predicts the presence of food and hence has similar functional properties to food calls. Silent tidbitting was also singularly effective at evoking approach and close inspection, which may enhance signal memorability. These social responses suggest that the visual component of the display has the unique function of triggering assessment of signaler identity and quality as a potential mate. The acoustic and visual components are hence redundant as a food signal, but synergistic when additional functions are considered. These findings emphasize the perceptual complexity of multimodal displays and provide the first demonstration of multimodal referential signaling in a vertebrate.


Subject(s)
Animal Communication , Chickens/physiology , Feeding Behavior/physiology , Animals , Female , Male , Social Behavior
18.
J Exp Biol ; 211(Pt 13): 2052-7, 2008 Jul.
Article in English | MEDLINE | ID: mdl-18552293

ABSTRACT

Many social birds produce food-associated calls. In galliforms, these vocalizations are typically accompanied by a distinctive visual display, creating a multimodal signal known as tidbitting. This system is ideal for experimental analysis of the way in which signal components interact to determine overall efficacy. We used high-definition video playback to explore perception of male tidbitting by female fowl, Gallus gallus. Hens experienced four treatments consisting of multimodal tidbitting, visual tidbitting without sound, audible tidbitting without a male present, and a silent empty cage control. Hens took longer to begin food search when the display was silent, but the overall rate of this response did not differ among the multimodal, visual only or audio only playback treatments. These results suggest that the visual and vocal components of tidbitting are redundant, but they also highlight the importance of a temporal dimension for any categorization scheme. Visual displays also evoked inspection behavior, characterized by close binocular fixation on the head of the playback male, which is known to facilitate individual recognition. This may also allow hens to assess male quality. Such social responses reveal that tidbitting probably has multiple functions and provide a new insight into the selective factors responsible for the evolution of this complex multimodal signal.


Subject(s)
Animal Communication , Chickens/physiology , Acoustic Stimulation , Animals , Feeding Behavior/physiology , Female , Male , Photic Stimulation , Signal Transduction/physiology , Social Behavior , Video Recording
19.
Article in English | MEDLINE | ID: mdl-16273409

ABSTRACT

Changes in reproductive state or the environment may affect the sensitivity of the hypothalamic-pituitary-andrenal (HPA) axis. However, little is known about the dynamics of the resulting corticosteroid stress response, in particular in tropical mammals. In this study, we address the modulation of corticosterone release in response to different reproductive conditions and seasonality in 326 free-living common fruit-eating bats (Artibeus jamaicensis) on Barro Colorado Island in Panama during dry and wet seasons. We present strong evidence that stress sensitivity is primarily modulated by reproductive condition. In reproductively active females, corticosterone increases were more rapid and reached higher levels, but also decreased significantly faster than in inactive females. The corticosterone response was weaker in reproducing males than in females and delayed compared to non-reproductive males. Testes volume in reproductively active males was negatively correlated with corticosterone concentrations. Our findings suggest differentiated dynamics in the corticosterone stress response between sexes, potentially reflecting conflicting ecological demands. In females, a strong acute corticosterone response may represent high stress- and risk-sensitivity that facilitates escape and thus helps to protect reproduction. In males, suppression during reproductive activity could reflect lowered stress sensitivity to avoid chronically elevated corticosterone levels in times of frequent aggressive and therefore costly inter-male encounters.


Subject(s)
Chiroptera/physiology , Corticosterone/blood , Reproduction , Animals , Chiroptera/blood , Environment , Female , Glucocorticoids/blood , Hypothalamo-Hypophyseal System/physiology , Male , Panama , Pituitary-Adrenal System/physiology , Radioimmunoassay , Seasons , Sex Characteristics , Stress, Physiological , Testis/anatomy & histology
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