Temperature-induced Multi-species Cohort Effects in Sympatric Snakes

In reptiles, reproductive maturity is often determined by size rather than age. Consequently, growth early in life may influence population dynamics through effects on generation time and survival to reproduction. Because reproductive phenology and pre- and post-natal growth are temperature-dependent, environmental conditions may induce multi-species cohort effects on body size in sympatric reptiles. I present evidence of this using ten years of neonatal size data for three sympatric viviparous snakes, Dekay’s Brownsnakes (Storeria dekayi), Red-bellied Snakes (S. occipitomaculata) and Common Gartersnakes (Thamnophis sirtalis). End-of-season neonatal size varied in parallel across species such that snout-vent length was 36-61% greater and mass was 65-223% greater in years when gestating females could achieve higher April-May (vs. June-July or August-September) operative temperatures. Thus, temperature had a larger impact during follicular enlargement and ovulation than during gestation or post-natal growth. Multi-species cohort effects like these may affect population dynamics and increase with climate change.

Warming in the land of the midnight sun: breeding birds may suffer greater heat stress at high- vs low-Arctic sites

Rising global temperatures are expected to increase reproductive costs for wildlife as greater thermoregulatory demands interfere with essential breeding activities such as parental care. However, predicting the temperature threshold where reproductive performance is negatively impacted remains a significant hurdle. Using a novel thermoregulatory polygon approach, we predicted the threshold temperature at which an Arctic songbird-the snow bunting (Plectrophenax nivalis)-would need to reduce activity and perform below the 4-times basal metabolic rate (BMR) required to sustain nestling provisioning to avoid overheating. We then compared this threshold to operative temperatures recorded at high (82°N) and low (64°N) Arctic sites to estimate how heat constraints translate into site-specific impacts on sustained activity level. We predict buntings would become behaviourally constrained at operative temperatures above 11.7°C, whereupon they must reduce provisioning rates to maintain thermal balance. Low Arctic sites had larger fluctuations in solar radiation, producing consistent daily periods when operative temperatures exceeded 11.7°C. However, high-latitude birds faced entire, consecutive days where parents would not be able to sustain required provisioning rates. These data indicate that Arctic warming is likely already disrupting the breeding performance of cold-specialist birds, but also suggests counterintuitive and severe negative impacts of warming at high-latitude breeding locations.

Simulating and Comparing Different Vertical Greenery Systems Grouped into Categories Using EnergyPlus

The use of vegetation for the energy efficiency of buildings is an increasingly widespread practice; therefore, the possibility of representing these systems correctly with the use of simulation software is essential. VGS performances have been widely studied, but currently, the lack of a unique simulation method to assess the efficiency of different types of VGS and the absence of studies evaluating the performances of all the systems available, proposing simulation models for each of them, leads to an incomplete energy representation. The aim of this study is to achieve a consistent and complete simulation method, comparing the different systems’ performances. The research is made up of five main steps. Firstly, a classification to group these systems into specific categories was proposed; secondly an in-depth analysis of existing literature was worked out to establish the methods used for different types of VGS. The study of plant physiology allowed the definition of an energy balance, which is valid for all vegetated surfaces; then, each category was associated to a mathematical formula and finally integrated into the EnergyPlus software. The results achieved for each model were compared evaluating two important parameters for the termohygrometric conditions control: outside walls face temperatures and operative temperatures.

Dehydration risk, not ambient incubation, limits nest attendance at high temperatures

High air temperatures have measurable negative impacts on reproduction in wild animal populations, including during incubation in birds. Understanding the mechanisms driving these impacts requires comprehensive knowledge of animal physiology and behaviour under natural conditions. We used a novel combination of a non-invasive doubly-labelled water technique and behaviour observations in the field to examine effects of temperature, rainfall, and group size on physiology and behaviour during incubation in southern pied babblers Turdoides bicolor, a cooperatively-breeding passerine endemic to a semi-arid region in southern Africa. The proportion of time that clutches of eggs were incubated declined as air temperatures increased, traditionally interpreted as a benefit of ambient incubation. However, we show that a) clutches were less likely to hatch when exposed to high air temperatures; b) pied babbler groups incubated their nests almost constantly (97% of daylight hours) except on hot days; c) operative temperatures in unattended nests were substantially higher than air temperatures and frequently exceeded 40.5°C, above which bird embryos are at risk of death; d) pied babblers incubating for long periods of time failed to maintain water balance on hot days but not cool days; and e) pied babblers from incubating groups did not maintain body mass on hot days. These results suggest that, rather than taking advantage of opportunities for ambient incubation, pied babblers leave the nests during hot periods to avoid dehydration as a consequence of incubating at high operative temperatures. As mean air temperatures increase and extreme heat events become more frequent under climate change, birds will likely incur greater water costs during incubation, leading to compromised nest attendance and increased likelihood of eggs overheating, with implications for nest success and, ultimately, population persistence.

Thermal ecology of the Atlas day gecko Quedenfeldtia moerens in an arid area of Morocco, and a comparison with its congener Q. trachyblepharus

The Atlas day gecko, Quedenfeldtia moerens, a Moroccan endemic lizard, is strictly diurnal and widely distributed across the dry Atlas Mountains. We quantified thermoregulation in adult males and adult females during their active season in the L’kest Mountain at 1300 m a.s.l., Anti-Atlas region of Morocco. The operative temperatures and air temperatures were sampled using data-loggers in the field from 2016 to 2018. Body temperatures of active lizards and substrate temperatures in the field were simultaneously measured. Finally, we measured preferred body temperatures (Tset) in a laboratory thermal gradient for 24 adult geckos. Mean Tset was 33.3 ± 0.3°C, with the mean 25% and 75% quartiles being 32.3 ± 0.3°C and 34.6 ± 0.3°C, respectively. Active lizards rarely reached their Tset range from March to June, but spent most of the day within Tset in July and August. Our study suggests that Q. moerens have higher Tset than its congeneric Q. trachyblepharus living at high altitude. Likewise, thermoregulatory effectiveness of Q. moerens showed an increase from spring to summer while it was the opposite for Q. trachyblepharus.

Multi-Site and Multi-Year Remote Records of Operative Temperatures with Biomimetic Loggers Reveal Spatio-Temporal Variability in Mountain Lizard Activity and Persistence Proxy Estimates

Commonly, when studies deal with the effects of climate change on biodiversity, mean value is used more than other parameters. However, climate change also leads to greater temperature variability, and many papers have demonstrated its importance in the implementation of biodiversity response strategies. We studied the spatio-temporal variability of activity time and persistence index, calculated from operative temperatures measured at three sites over three years, for a mountain endemic species. Temperatures were recorded with biomimetic loggers, an original remote sensing technology, which has the same advantages as these tools but is suitable for recording biological organisms data. Among the 42 tests conducted, 71% were significant for spatial variability and 28% for temporal variability. The differences in daily activity times and in persistence indices demonstrated the effects of the micro-habitat, habitat, slope, altitude, hydrography, and year. These observations have highlighted the great variability existence in the environmental temperatures experienced by lizard populations. Thus, our study underlines the importance to implement multi-year and multi-site studies to quantify the variability and produce more representative results. These studies can be facilitated by the use of biomimetic loggers, for which a user guide is provided in the last part of this paper.

The Influence of the Process Parameters on the Densification and Microstructure Development of Laser Powder Bed Fused Inconel 939

This work aims to investigate the effect of the process parameters on the densification and microstructure of Inconel 939 (IN939) alloy processed by laser powder bed fusion (LPBF). IN939 is a Ni-based superalloy with high creep and corrosion resistance that can be used up to around 850 °C under load, resulting in higher operative temperatures than the ones commonly allowed for Inconel 718 and Inconel 625 alloys (around 650 °C). However, this alloy can suffer from poor weldability involving possible crack formation. In order to minimize the residual porosity and the cracking density, specific process parameters were investigated. The parameters to generate IN939 samples almost pores-free (porosity ≤0.22%) with a cracking density ≤1.36 mm/mm2 as well as samples almost crack-free (≤0.10 mm/mm2) with limited residual porosity (≤0.89%) were determined. The microstructure revealed fine dendritic/cellular structures with the formation of sub-micrometric phases. A high concentration of these phases was also found along the intergranular cracks, suggesting that their presence, coupled to the high thermal stresses, can be the primary reason for crack formation during the LPBF process.

Broad seasonal changes in thermoregulation of Podarcis lilfordi (Squamata, Lacertidae) at Binicodrell islet (Menorca, Spain)

Most lizards maintain quite constant body temperatures by behavioural means. Seasonal variations of environmental factors, such as temperature, sunlight exposure and wind intensity, influence lizard thermoregulatory abilities. Understanding how seasonal environmental shifts influence lizards’ thermoregulation helps us to know how they deal behaviourally with environmental changes, in general. We examined seasonal shifts (spring vs. summer) in behavioural thermoregulation in Podarcislilfordi from Binicodrell islet (Menorca, Spain). Operative temperatures varied between microhabitats and seasons, being lower in spring than in summer, regardless of sunlight exposure. Lizard body temperatures were also lower in spring than in summer. Lizards used sunny microhabitats more frequently in spring and shaded areas in summer. Habitat thermal quality was similar during both seasons, but lizards thermoregulated less accurately in spring than in summer. Thermoregulatory effectiveness was low in spring (0.28) and moderate in summer (0.76). In comparison with previously published results, our findings showed the marked seasonal variation in the effectiveness of thermoregulation amongst island populations, which should be considered in future comparative studies.

Assessment of Indoor Environmental Quality for Retrofitting Classrooms with An Egg-Crate Shading Device in A Hot Climate

In the Mediterranean climate, a large number of educational buildings suffer from discomfort due mostly to energy-deficient thermal envelopes and a lack of cooling systems. Impending climate change is expected to worsen overheating in classrooms, especially during heatwave periods. Therefore, the protection of window openings to reduce incident solar radiation while maintaining adequate indoor environmental quality must be considered a necessary key focus. The main objective of this research is to assess the influence of an egg-crate shading device on the indoor environmental quality of a classroom in Southern Spain. To do so, two classrooms—with and without this shading device—were simultaneously monitored over a whole year. The implementation of an egg-crate shading device allowed for a significant reduction of the incident solar radiation, both in summer and mid-season (around 45–50%), which objectively slightly conditioned indoor operative temperatures. Given the noticeable influence of the user patterns observed, indoor illuminance was also improved, as the rolling shutters tended to be opened at higher aperture levels.