Behavioural Responses of Moulting Barnacle Geese to Experimental Helicopter Noise and a Predator

The response of animals to anthropogenic noise can be aggravated by lack of familiarity with its auditory pattern and also by nervousness characteristic of particular phases of their life cycle. Both conditions apply in the Arctic where human activity is highly localised and field operations, being largely restricted to summer, coincide with the period when animals produce and nurse offspring and, in the case of some birds, are rendered flightless by wing moult. We measured behavioural responses in moulting barnacle geese (Branta leucopsis) in Svalbard to a low flying helicopter and compared these with their responses to the presence of Arctic fox (Vulpes lagopus). The pattern of the responses of the birds was independent of stimulus type but the radius of the effect (response distances) was small (≈50 m) for foxes but large (>3 km) for the helicopter. The geese displayed remarkable auditory discrimination: they responded to the sound of the helicopter at 3.2 km even though engine sound level exceeded background only at ≤2 km from source. We attribute their sensitivity to the fact that fundamental frequencies of calls and absolute auditory sensitivities of Anatidae fall close to the peak noise energy output of small helicopters. The specific instantaneous time and energy costs of the responses observed here were very small. Simple time and energy models indicate that the impact of these natural (fox) and anthropogenic (helicopter) disturbances is likely to depend chiefly on their frequency of occurrence

Analysis of nocturnal actigraphic sleep measures in patients with COPD and their association with daytime physical activity

Background: Sleep disturbances are common in patients with chronic obstructive pulmonary disease (COPD) with a considerable negative impact on their quality of life. However, factors associated with measures of sleep in daily life have not been investigated before nor has the association between sleep and the ability to engage in physical activity on a day-to-day basis been studied. Aims: To provide insight into the relationship between actigraphic sleep measures and disease severity, exertional dyspnoea, gender and parts of the week; and to investigate the association between sleep measures and next day physical activity. Methods: Data were analysed from 932 patients with COPD (66% male, 66.4±8.3 years, FEV1% predicted=50.8±20.5). Participants had sleep and physical activity continuously monitored using a multisensor activity monitor for a median of 6 days. Linear mixed effects models were applied to investigate the factors associated with sleep impairment and the association between nocturnal sleep and patients' subsequent daytime physical activity. Results: Actigraphic estimates of sleep impairment were greater in patients with worse airflow limitation and worse exertional dyspnoea. Patients with better sleep measures (ie, non-fragmented sleep, sleeping bouts ≥225 min, sleep efficiency ≥91% and time spent awake after sleep onset < 57 min) spent significantly more time in light (p < 0.01) and moderate-to-vigorous physical activity (p < 0.01). Conclusions: There is a relationship between measures of sleep in patients with COPD and the amount of activity they undertake during the waking day. Identifying groups with specific sleep characteristics may be useful information when designing physical activity-enhancing interventions

Physical activity patterns and clusters in 1001 patients with COPD

We described physical activity measures and hourly patterns in patients with chronic obstructive pulmonary disease (COPD) after stratification for generic and COPD-specific characteristics and, based on multiple physical activity measures, we identified clusters of patients. In total, 1001 patients with COPD (65% men; age, 67 years; forced expiratory volume in the first second [FEV 1 ], 49% predicted) were studied cross-sectionally. Demographics, anthropometrics, lung function and clinical data were assessed. Daily physical activity measures and hourly patterns were analysed based on data from a multisensor armband. Principal component analysis (PCA) and cluster analysis were applied to physical activity measures to identify clusters. Age, body mass index (BMI), dyspnoea grade and ADO index (including age, dyspnoea and airflow obstruction) were associated with physical activity measures and hourly patterns. Five clusters were identified based on three PCA components, which accounted for 60% of variance of the data. Importantly, couch potatoes (i.e. the most inactive cluster) were characterised by higher BMI, lower FEV 1 , worse dyspnoea and higher ADO index compared to other clusters (p &lt; 0.05 for all). Daily physical activity measures and hourly patterns are heterogeneous in COPD. Clusters of patients were identified solely based on physical activity data. These findings may be useful to develop interventions aiming to promote physical activity in COPD