31 research outputs found

    Release of constraints on nest-site selection in burrow-nesting petrels following invasive rat eradication

    Get PDF
    Introduced mammals have been eradicated from many offshore islands around the world, removing predation pressure from burrow-nesting seabirds and other affected wildlife. Nest-site selection in procellariiform seabirds is mediated by nesting habitat characteristics and social information, although it is unclear if, or how, nest-site selection will affect post-eradication colony growth. Using a Bayesian hierarchical modeling approach we assessed how nest-site selection differs among burrow-nesting seabird colonies at different stages of recovery after Pacific rat (Rattus exulans) eradication. We compared nest-site selection in a community of seven procellariiform species among six offshore islands in northeastern New Zealand: four designated rat-free over a continuum within the last 26 years, an island which never had rats, and an island with rats present. We hypothesized that, immediately after eradication, birds would be constrained to nesting habitat where they were less vulnerable to predation, and as time since eradication increased birds would eventually spread to new habitat. We found a positive relationship between mean burrow density and time since rat eradication. Soil depth was the most important predictor of burrow presence, abundance, and occupancy in plots among islands, with more burrows found in deeper soil. We found that the relationships between habitat covariates and nest-site selection decreased with increasing time since eradication. The probability of a covariate having a significant effect on nest-site selection decreased with increasing time since eradication and decreasing variability in the covariate across an island. Our results suggest that the eradication of rodents reduced constraints on petrel nesting distribution and that nest-site selection in burrow-nesting petrels may be influenced by burrow density, where selection of particular nesting habitat characteristics may be relatively more important in small recovering populations. We conclude that colony expansion immediately after predator removal is complex, influenced by numerous interacting factors, but may be partly limited by the availability of suitable nesting habitat.Peer Reviewe

    Anthropogenic noise events perturb acoustic communication networks

    Get PDF
    Anthropogenic noise sources impact ecological processes by altering wildlife behavior and interactions with cascading impacts on community structure. The distribution and magnitude of such noise has grown exponentially over the past century, and now inundates even remote areas. Here we investigate biological responses to prolific, anthropogenic noise sources associated with the physical presence of the source (vehicle noise and human voices) and disconnected from it (aircraft overflight). Bioacoustic responses to these noise sources were documented at 103 sites in 40 U. S. National Park units. The presence of bird sounds was noted in 10-s audio samples every 2 min, for 8 days at each site and related to the presence of human voices, vehicle noise, and aircraft noise in the same and preceding samples. Generalized additive models were used to fit smoothing splines to weight the influence of noise in past samples on the probability of detecting bird sounds in the present sample. We found that the probability of hearing birds increased immediately following noise events, and decreased about 2 h after the event. The negative effects were persistent more than 3 h after a noise event. The persistence of these responses – especially for noise from jets that were many kilometers distant – raises questions about the functional significance and ecological consequences of this altered activity, particularly in light of the widespread and diverse habitats in this study and ubiquity of the noise sources evaluated

    The \u27Healthy Parks-Healthy People\u27 Movement in Canada: Progress, Challenges, and an Emerging Knowledge and Action Agenda

    Get PDF
    In this article, we outline progress and challenges in establishing effective health promotion tied to visitor experiences provided by protected and conserved areas in Canada. Despite an expanding global evidence base, case studies focused on aspects of health and well-being within Canada’s protected and conserved areas remain limited. Data pertaining to motivations, barriers and experiences of visitors are often not collected by governing agencies and, if collected, are not made generally available or reported on. There is an obvious, large gap in research and action focused on the needs and rights of groups facing systemic barriers related to a variety of issues including, but not limited to, access, nature experiences, and needs with respect to health and well-being outcomes. Activation of programmes at the site level continue to grow, and Park Prescription programmes, as well as changes to the Accessible Canada Act, represent significant, positive examples of recent cross-sector policy integration. Evaluations of outcomes associated with HPHP programmes have not yet occurred but will be important to adapting interventions and informing cross-sector capacity building. We conclude by providing an overview of gaps in evidence and practice that, if addressed, can lead to more effective human health promotion vis-à-vis nature contact in protected and conserved areas in Canada

    Why conservation biology can benefit from sensory ecology

    Get PDF
    Global expansion of human activities is associated with the introduction of novel stimuli, such as anthropogenic noise, artificial lights and chemical agents. Progress in documenting the ecological effects of sensory pollutants is weakened by sparse knowledge of the mechanisms underlying these effects. This severely limits our capacity to devise mitigation measures. Here, we integrate knowledge of animal sensory ecology, physiology and life history to articulate three perceptual mechanisms—masking, distracting and misleading—that clearly explain how and why anthropogenic sensory pollutants impact organisms. We then link these three mechanisms to ecological consequences and discuss their implications for conservation. We argue that this framework can reveal the presence of ‘sensory danger zones’, hotspots of conservation concern where sensory pollutants overlap in space and time with an organism’s activity, and foster development of strategic interventions to mitigate the impact of sensory pollutants. Future research that applies this framework will provide critical insight to preserve the natural sensory world

    New loci associated with birth weight identify genetic links between intrauterine growth and adult height and metabolism.

    Get PDF
    Birth weight within the normal range is associated with a variety of adult-onset diseases, but the mechanisms behind these associations are poorly understood. Previous genome-wide association studies of birth weight identified a variant in the ADCY5 gene associated both with birth weight and type 2 diabetes and a second variant, near CCNL1, with no obvious link to adult traits. In an expanded genome-wide association meta-analysis and follow-up study of birth weight (of up to 69,308 individuals of European descent from 43 studies), we have now extended the number of loci associated at genome-wide significance to 7, accounting for a similar proportion of variance as maternal smoking. Five of the loci are known to be associated with other phenotypes: ADCY5 and CDKAL1 with type 2 diabetes, ADRB1 with adult blood pressure and HMGA2 and LCORL with adult height. Our findings highlight genetic links between fetal growth and postnatal growth and metabolism

    Effect of angiotensin-converting enzyme inhibitor and angiotensin receptor blocker initiation on organ support-free days in patients hospitalized with COVID-19

    Get PDF
    IMPORTANCE Overactivation of the renin-angiotensin system (RAS) may contribute to poor clinical outcomes in patients with COVID-19. Objective To determine whether angiotensin-converting enzyme (ACE) inhibitor or angiotensin receptor blocker (ARB) initiation improves outcomes in patients hospitalized for COVID-19. DESIGN, SETTING, AND PARTICIPANTS In an ongoing, adaptive platform randomized clinical trial, 721 critically ill and 58 non–critically ill hospitalized adults were randomized to receive an RAS inhibitor or control between March 16, 2021, and February 25, 2022, at 69 sites in 7 countries (final follow-up on June 1, 2022). INTERVENTIONS Patients were randomized to receive open-label initiation of an ACE inhibitor (n = 257), ARB (n = 248), ARB in combination with DMX-200 (a chemokine receptor-2 inhibitor; n = 10), or no RAS inhibitor (control; n = 264) for up to 10 days. MAIN OUTCOMES AND MEASURES The primary outcome was organ support–free days, a composite of hospital survival and days alive without cardiovascular or respiratory organ support through 21 days. The primary analysis was a bayesian cumulative logistic model. Odds ratios (ORs) greater than 1 represent improved outcomes. RESULTS On February 25, 2022, enrollment was discontinued due to safety concerns. Among 679 critically ill patients with available primary outcome data, the median age was 56 years and 239 participants (35.2%) were women. Median (IQR) organ support–free days among critically ill patients was 10 (–1 to 16) in the ACE inhibitor group (n = 231), 8 (–1 to 17) in the ARB group (n = 217), and 12 (0 to 17) in the control group (n = 231) (median adjusted odds ratios of 0.77 [95% bayesian credible interval, 0.58-1.06] for improvement for ACE inhibitor and 0.76 [95% credible interval, 0.56-1.05] for ARB compared with control). The posterior probabilities that ACE inhibitors and ARBs worsened organ support–free days compared with control were 94.9% and 95.4%, respectively. Hospital survival occurred in 166 of 231 critically ill participants (71.9%) in the ACE inhibitor group, 152 of 217 (70.0%) in the ARB group, and 182 of 231 (78.8%) in the control group (posterior probabilities that ACE inhibitor and ARB worsened hospital survival compared with control were 95.3% and 98.1%, respectively). CONCLUSIONS AND RELEVANCE In this trial, among critically ill adults with COVID-19, initiation of an ACE inhibitor or ARB did not improve, and likely worsened, clinical outcomes. TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT0273570

    Monitoring and managing recovery of nocturnal burrow-nesting seabird populations on recently predator-eradicated Aleutian Islands

    Get PDF
    Few quantitative data exist measuring nocturnal burrow-nesting seabirds that were heavily affected by predator introductions in the Aleutian Islands, due to challenges associated with monitoring. I evaluated the feasibility of using automated recording and recognition of call activity as a way to examine restoration. I assessed recording quality and call recognition rate in the windy Aleutian environment, characteristic of remote seabird breeding islands. With only 3% of nights unusable due to wind noise, devices were extremely robust. I used this method to inventory call activity across the western Aleutian Islands and relate patterns to recovery rate. I found that nocturnal seabird activity is positively related to time since eradication, however a number of other factors render recovery rate complicated. In order to encourage re-colonization I performed a series of social attraction experiments. Continued acoustic monitoring and artificial attraction are required to promote population recovery throughout the Aleutian chain

    Monitoring vocal activity and temporal patterns in attendance of White-chinned Petrels using bioacoustics

    No full text
    Monitoring of population sizes and trends using conventional surveys is challenging for nocturnal, burrow-nesting seabirds. The White-chinned Petrel is the most commonly killed species in Southern Ocean fisheries and its breeding success at many sites is reduced because of predation by invasive cats and rodents. As adaptive management of such threats requires cost-effective and reproducible protocols for monitoring populations, we examined the potential of automated bioacoustic techniques for measuring colony attendance patterns (relative number of birds visiting at a given time) using data from acoustic recorders deployed over a breeding season at Bird Island, South Georgia. Generic recognition software was of limited utility, but a suite of acoustic indices in a random forest model reliably predicted the occurrence of vocalisations. Vocal activity showed clear temporal patterns, despite high day-to-day variability, and was lowest during the pre-laying period, in the early evening, and on moonlit nights. To facilitate estimation of population density using acoustic recorders, we determined the mean vocalisation rate of individuals (2.3 min−1), mean call length (~15.3 sec), and detection distance (~15 m based on signal to noise ratios of playbacks). Our results indicate that acoustic indices are a useful measure of colony attendance. If these indices can be linked to density, acoustic monitoring would provide a powerful and cost-effective census method for White-chinned Petrels and other nocturnal species

    Pairing camera traps and acoustic recorders to monitor the ecological impact of human disturbance

    No full text
    Over the past two decades, the use of camera traps and acoustic monitoring in the investigation of animal ecology have grown rapidly, with each technique enhancing broad-scale wildlife surveying. Camera traps are a cost-effective, noninvasive means of sampling communities of mid-to large-terrestrial species, and acoustic recording devices capture human sounds and sound-producing animals, including species of mammals, birds, anurans, and insects. Rarely are these techniques combined, despite the advantages of merging their respective strengths. Namely, camera traps paired with acoustic recorders can evaluate the abundance, distribution, and behavior of multiple guilds and trophic levels across landscapes while concurrently monitoring multiple human stressors in real time. Moreover, integrating these approaches enhances detection accuracy and strengthens statistical inference at multiple survey scales. We conducted a literature review, and found only 13 studies that combine camera traps and acoustic recorders, 8 of which either compared the ability of each technique to detect species of interest or discussed the advantages of each technique. We outline potential questions that can be addressed by pairing acoustic recorders and camera traps, including enabling the simultaneous assessment of noise pollution and its impacts on mammal and avian communities. Furthermore, we discuss how the analysis of data from each technique face similar challenges; thus, simultaneous innovation offers the ability to apply solutions to both techniques and amplify their respective strengths. Digital technologies and big data are changing nature conservation in increasingly profound ways and integration of camera traps and acoustic recorders will facilitate new, transformative discoveries to meet modern conservation challenges. Keywords: Acoustic monitoring, Anthropogenic disturbance, Biodiversity, Cameras, Community structure, Inventory and monitoring, Multiple stressor
    corecore