Intra-Annual Variability in Responses of a Canopy Forming Kelp to Cumulative Low Tide Heat Stress: Implications for Populations at the Trailing Range Edge.

Anthropogenic climate change is driving the redistribution of species at a global scale. For marine species, populations at trailing edges often live very close to their upper thermal limits and, as such, poleward range contractions are one of the most pervasive effects of ongoing and predicted warming. However, the mechanics of processes driving such contractions are poorly understood. Here, we examined the response of the habitat forming kelp, Laminaria digitata, to realistic terrestrial heatwave simulations akin to those experienced by intertidal populations persisting at the trailing range edge in the northeast Atlantic (SW England). We conducted experiments in both spring and autumn to determine temporal variability in the effects of heatwaves. In spring, heatwave scenarios caused minimal stress to L. digitata but in autumn all scenarios tested resulted in tissue being nonviable by the end of each assay. The effects of heatwave scenarios were only apparent after consecutive exposures, indicating erosion of resilience over time. Monthly field surveys corroborated experimental evidence as the prevalence of bleaching (an indication of physiological stress and tissue damage) in natural populations was greatest in autumn and early winter. Overall, our data showed that L. digitata populations in SW England persist close to their upper physiological limits for emersion stress in autumn. As the intensity of extreme warming events is likely to increase with anthropogenic climate change, thermal conditions experienced during periods of emersion will soon exceed physiological thresholds and will likely induce widespread mortality and consequent changes at the population level.

Raspberry Pi nest cameras: An affordable tool for remote behavioral and conservation monitoring of bird nests.

Bespoke (custom-built) Raspberry Pi cameras are increasingly popular research tools in the fields of behavioral ecology and conservation, because of their comparative flexibility in programmable settings, ability to be paired with other sensors, and because they are typically cheaper than commercially built models.Here, we describe a novel, Raspberry Pi-based camera system that is fully portable and yet weatherproof-especially to humidity and salt spray. The camera was paired with a passive infrared sensor, to create a movement-triggered camera capable of recording videos over a 24-hr period. We describe an example deployment involving "retro-fitting" these cameras into artificial nest boxes on Praia Islet, Azores archipelago, Portugal, to monitor the behaviors and interspecific interactions of two sympatric species of storm-petrel (Monteiro's storm-petrel Hydrobates monteiroi and Madeiran storm-petrel Hydrobates castro) during their respective breeding seasons.Of the 138 deployments, 70% of all deployments were deemed to be "Successful" (Successful was defined as continuous footage being recorded for more than one hour without an interruption), which equated to 87% of the individual 30-s videos. The bespoke cameras proved to be easily portable between 54 different nests and reasonably weatherproof (~14% of deployments classed as "Partial" or "Failure" deployments were specifically due to the weather/humidity), and we make further trouble-shooting suggestions to mitigate additional weather-related failures.Here, we have shown that this system is fully portable and capable of coping with salt spray and humidity, and consequently, the camera-build methods and scripts could be applied easily to many different species that also utilize cavities, burrows, and artificial nests, and can potentially be adapted for other wildlife monitoring situations to provide novel insights into species-specific daily cycles of behaviors and interspecies interactions.