Using UAV‐mounted thermal cameras to detect the presence of nesting nightjar in upland clear‐fell: A case study in South Wales, UK

1. Confirming the presence and location of European Nightjar Caprimulgus europaeus nests is a significant fieldwork challenge in ecological monitoring. Nest sites can be located through direct observation or capture and radio tracking of breeding individuals; however, such work is time consuming, disturbing and costly.2. Unmanned aerial vehicles (UAV) equipped with thermal sensors may enable rapid survey over large areas by detecting nest locations based on the contrast of relatively warm nests and the surrounding cooler ground. The application of this concept using UAV‐mounted thermal sensors was trialled in two upland clear‐fell forestry sites in South Wales, UK.3. Detection trials were undertaken at five known nightjar nest sites to assess optimal timing and flight height for surveys. Nest heat signatures were clear during dusk and dawn, but not during the daytime. Nests were identifiable at flight heights up to 25 m, but flight heights of 12–20 m were optimal for the numbers of pixels per nest.4. This approach was tested in a field trial of a 17‐ha forestry site where the presence and position of nesting nightjars were unknown. An automated transect at dusk and dawn at 15 m flight elevation identified two active nightjar nests and four male nightjar roost sites. Without image analysis automation, the process of manual inspection of 2607 images for ‘hotspots’ of the approximate size and shape of nightjar nests was laborious.5. The UAV approach took around 18 h including survey time, processing and ground verification, whilst a nightjar nest finding survey would take 35 h for the same area. The small size of nightjars and the low resolution of the thermal sensors requires low altitude flight in order to maximize detectability and pixel coverage. Low flight elevation requires more consideration of the risk of collision with trees or posts. Consequently, the approach would not be suitable for covering areas of highly variable terrain

Teaching data analysis to life scientists using “R” statistical software: Challenges, opportunities, and effective methods

Data analysis is one of the most important and empowering transferable skills that a scientist can possess; yet many life scientists find statistics a daunting subject that they perceive as difficult to master. In this paper, we reflect on our experiences of teaching statistics in a wide variety of contexts in the life sciences. We address the challenge of teaching statistics in general, and of teaching statistics using R in particular, examining several complementary approaches that we have found to be engaging and effective with a diverse range of learners; (1) set-piece taught and practical “lecture-workshop” sessions on specific topics, (2) annotation by learners of template analysis scripts, (3) a user-friendly guidebook with generic script coding that maps onto our other teaching materials, (4) informal, student-led “data analysis clinics”, (5) friendly online support, (6) a dedicated Q&A forum (Facebook “R-Space”) that facilitates peer-to-peer teaching as well as expert input, and (7) video podcast tutorials, enabling independent learning. We consider R to present an important opportunity for enabling “deep learning” (pedagogic meaning) about data analysis, by encouraging users to engage fully with the rationale and detail of statistical methods, designing and implementing appropriate analyses, interpreting them correctly, and reporting them accurately and transparently

Contrasting sensitivity of nestling and fledgling Barn Swallow Hirundo rustica body mass to local weather conditions

Local weather can influence the growth and development of young birds either indirectly, by modifying prey availability, or directly, by affecting energetic trade-offs. Such effects can have lasting implications for life history traits, but the nature of these effets may vary with the developmental stage of the birds, and over timescales from days to weeks. We examined the interactive effects of temperature, rainfall and wind speed on the mass of nestling and fledgling Barn Swallows Hirundo rustica both on the day of capture and averaging weather across the time since hatching. At the daily timescale, nestling mass was negatively correlated with temperature, but the strength of this association depended on the level of rainfall and wind speed; nestlings were typically heavier on dry or windy days, and the negative effect of temperature was strongest under calm or wet conditions. At the early lifetime timescale (i.e. from hatching to pre-fledging), nestling mass was negatively correlated with temperature at low wind speed. Fledgling body mass was less sensitive to weather; the only weather effect evident was a negative correlation with temperature at the daily scale under high rainfall that became slightly positive under low rainfall. These changes are consistent with weather effects on theavailability and distribution of insects within the landscape (e.g. causing high concentrations of flying insects) and with the effects of weather variation on nest microclimate. These results together demonstrate the impacts of weather on chick growth, over immediate (daily) and longer term (nestling/fledgling lifetime) timescales. This shows that sensitivity to local weather conditions varies across the early lifetime of young birds (nestling–fledgling stages) and illustrates the mechanisms by which larger scale (climate) variations influence the body condition of individuals