Journal of Thermal Biology

O_LIThe frequency and intensity of heat events is increasing across marine and terrestrial ecosystems. Within the same ecological community, the relative exposure and sensitivity to heat stress may vary considerably among interacting species, like predators and prey. This can be especially true for species that interact at the aquatic-terrestrial interface, as well as for interactions between primarily nocturnal and diurnal species, making it difficult to predict how such communities will respond to habitat warming. C_LIO_LIThermal limit metrics such as CTmax are often assumed to equate with ecological death because such temperatures impair behavioral activity and/or physiological functioning. Prey that are diurnally active can be more frequently exposed to temperatures that approach CTmax compared to their nocturnal predators, which may use thermal refuges during the day. Yet the impacts of daytime heat exposure on nighttime predation risk remain unknown. C_LIO_LIHere, we compared the thermal environment, performance, and heat tolerance between the predatory blue crab, Callinectus sapidus and one of its prey species, the mangrove periwinkle Littoraria anguilifera in a tropical mangrove ecosystem. We examined how exposing prey to heat stress at and below their CTmax affected their capacity to avoid predation in the field at night when predation risk is highest. C_LIO_LIWe found that acute exposure to temperatures near CTmax during the day increased the prey species susceptibility to predation during recovery at night. Although both interacting predator and prey have high thermal tolerance, prey are exposed to conditions that already reach CTmax, suggesting that current extremes in temperatures may already be influencing vulnerability to predation in this ecosystem. C_LIO_LIOur results suggest that differential exposure to sublethal heat stress in diurnal prey relative to their predator, along with the subsequent impact of these exposures on predation risk, will play a role in shaping these interacting as climate warms. C_LI

Linking animal movements to environmental drivers is essential for understanding ecological processes and anticipating species responses to climate change. We investigated habitat-specific movements in a globally significant aggregation of loggerhead turtles (Caretta caretta) nesting in Cabo Verde. Satellite tags on 15 adults (12 females, 3 males) provided multi-year tracks spanning breeding, migration, and foraging habitats. Movements and phenology differed by habitat. During the breeding season, females used either coastal areas, remaining within [~]20 m depth, or undertook long looping forays up to 360 km. Males showed two strategies: two remained resident in Cabo Verde waters, including Fra, the largest male tracked (Curved carapace length of 105 cm compared with a male mean of 90.7 {+/-} 10.3 cm), while the third migrated annually to distant foraging grounds and returned ahead of the subsequent breeding season. In foraging habitats, turtles adopted neritic or oceanic strategies: neritic turtles remained localised in warm, productive waters, whereas oceanic turtles ranged widely in deeper, less productive areas. Time- and space-shift analyses showed that oceanic foragers used intermediate sea surface temperature and chlorophyll-a conditions relative to nearby or temporally shifted alternatives, consistent with movement within a thermal-trophic trade-off. Together, these results show how sex, body size, and energy balance drive habitat-specific movement dynamics in a changing ocean.

Many marine invertebrates are characterized by broad and highly plastic thermal limits, though the dynamic molecular mechanisms that enable extended thermal acclimation remain poorly understood. A classic example is the green crab (Carcinus maenas), which is a prolific and damaging non-indigenous species. Using a 22-day thermal exposure to cold (5{degrees}C), ambient (13{degrees}C), or warm (30{degrees}C) temperatures, we characterized plastic shifts in C. maenas performance using respirometry and time-to-right. We then used untargeted metabolomics and lipidomics analysis of heart tissues from days 4 and 22 to identify the molecular mechanisms underpinning plastic responses over time. Crabs at 30{degrees}C exhibited higher oxygen consumption rates than counterparts at 5{degrees}C. Interestingly, oxygen consumption rate increased over time at both temperatures, indicating thermal plasticity of aerobic respiration. Temperature-dependent metabolic reprogramming was employed by crabs to sustain aerobic respiration across temperature. Catabolism of branched-chain amino acids was important for energy production at elevated temperatures, while catabolism of arginine may have sustained the minimal energy needs of crabs exhibiting metabolic depression at cold temperatures. Righting response was positively correlated with temperature, and did not exhibit any changes over time. Lipidome remodeling consistent with homeoviscous adaptation could have enabled motor activity across temperature. Higher abundances of saturated and monounsaturated lipids likely provided structural integrity to cell membranes at 30{degrees}C, while lower abundances of these compounds may have enabled membrane fluidity at 5{degrees}C. Our work demonstrates the importance of ongoing molecular reprogramming in long-term acclimation, even when whole-animal physiology remains relatively stable. Summary StatementThis study demonstrates how the highly invasive green crab regulates metabolite and lipid pathways over time to maintain physiological performance across different temperatures.

Global marine heatwaves have devastated tropical coral reefs, and further mortality is projected under ongoing climate change. Identifying thermally tolerant coral colonies is therefore a priority for conservation, restoration, and research. Portable acute heat stress assays (e.g., CBASS) enable rapid, standardized estimates of coral thermal tolerance under field conditions. However, it remains unresolved whether such experimentally derived metrics (ED5, ED50, DW) predict bleaching and mortality in situ. Here, we quantified acute thermal tolerance metrics for 2,068 coral colonies across 12 common Indo-Pacific species, six months prior to an unprecedented heat stress event in northeastern Peninsular Malaysia and compared experimentally derived ED and DW values to subsequent bleaching severity and mortality in the field. Experimental thermal tolerance metrics explained only a limited proportion of variation in bleaching outcomes and survival. Predictive power varied among species and was higher in slow-growing species. Our findings suggest that while acute heat stress assays capture substantial variation in coral thermal tolerance, their ability to predict in situ outcomes is context-dependent and diminishes under severe thermal stress. Ultimately, in situ coral bleaching under severe heat stress may reduce the discriminatory capacity of acute assay-derived tolerance metrics.

Heat tolerance determines the vitality of tree species under climate change independently of drought tolerance, but has been much less studied than tree water relations. We studied species-specific differences and the capacity for seasonal heat acclimation in Central Europes naturally most important tree species, Fagus sylvatica, in comparison with two exotic tree species (Fagus orientalis, Pseudotsuga menziesii) that are considered for silvicultural climate change adaptation in managed forests. Foliage of mature trees was incubated at temperatures from 35-50 {degrees}C for up to 4 h to simulate daily heat maxima during heat waves. The maximum quantum yield (Fv/Fm) of photosystem II (PS II) of dark-adapted leaves was measured, because the PS II is particularly sensitive to heat and its functionality can decide on plant survival under heat. Fagus sylvatica was much more tolerant to heat than Pseudotsuga menziesii, but weakly (albeit significantly) less tolerant than Fagus orientalis. Within its limits, Pseudotsuga menziesii showed high seasonal heat acclimation with constantly increasing tolerance during the growing season. Fagus orientalis, but practically not Fagus sylvatica, also acclimated to heat. This makes Fagus orientalis slightly superior over Fagus sylvatica in terms of heat tolerance, whereas the suitability of Pseudotsuga menziesii for silvicultural climate change adaptation is questionable. Strong heat acclimation, but also overall low heat tolerance, in Pseudotsuga menziesii might be the result of evergreenness, which requires the generation of both cold and heat tolerance during the year.

BackgroundEnvironmental conditions shape the evolutionary trajectories of RNA viruses, yet little is known about how complex physical stressors such as microgravity influence host-virus interactions and viral evolution. Here, we investigated the short-term evolutionary consequences of simulated microgravity on the Caenorhabditis elegans - Orsay virus (OrV) system. MethodsOrV was subjected to six serial passages in hosts acclimated to low-shear modeled microgravity, with parallel evolution under standard-gravity. Evolutionary outcomes were evaluated using virulence, transmission, and replication traits, all measured under standard-gravity conditions. ResultsViral load fluctuated across passages in both environments, with lower mean accumulation in microgravity-evolved lineages. After evolution, we detected no significant changes in virulence. Transmission increased in standard-gravity lineages but not in microgravity-evolved ones, while viral replication decreased in all lineages, with a stronger decline in those evolved under microgravity. However, the magnitude of phenotypic changes was generally modest. DiscussionThese results indicate that evolution under microgravity can alter viral phenotypic trajectories over short timescales. However, because all traits were assayed under standard-gravity conditions, we cannot directly assess local adaptation to microgravity, and the observed differences may reflect environment-specific trade-offs rather than reduced fitness per se. Furthermore, the limited number of passages and the modest magnitude of phenotypic change suggest that evolutionary responses may still be in an early stage. ConclusionOverall, our findings provide initial evidence that simulated microgravity can influence the evolutionary dynamics of an RNA virus, while highlighting the need for reciprocal fitness assays and longer-term experiments to fully characterize adaptation to altered gravitational environments.

The presence of multiple discrete color patterns within a species has captivated evolutionary biologists for more than a century, especially when such polymorphism is confined to one sex. The brown anole Anolis sagrei exhibits a female-limited polymorphism in dorsal patterning, which is controlled by allelic variation at the autosomal gene CCDC170. Here, we present and test a threshold model that can explain why the polymorphism is female-limited. We hypothesize that allelic variation at the CCDC170 locus affects only female color pattern because this gene is co-expressed with its neighboring gene ESR1, highly expressed in female, but not male, embryos. By manipulating embryonic estradiol levels, we show that genetic males can be induced to express the polymorphism according to allelic variation at the CCDC170 locus, which is naturally masked by low expression levels of this gene. Inversely, treating genetic females with fadrozole, which depletes estradiol, leads to monomorphic patterns irrespective of genotype, as for natural males. Using RT-qPCR, we demonstrate that these effects are accompanied by a direct influence of estradiol and fadrozole on gene expression levels of CCDC170 and ESR1, thereby validating the threshold model. Our results suggest that the CCDC170-ESR1-locus is part of a mechanistic link between the morph-determining and the sex differentiation systems and provide a causal explanation for the developmental origin of a sex-limited color polymorphism.

BackgroundThe Andean bear (Tremarctos ornatus), South Americas only ursid, is one of the worlds most elusive large mammals, making movement data collection exceptionally rare. Addressing this gap, we present the largest telemetry dataset ever assembled, spanning 19 individuals tracked across three Ecuadorian National Parks over two decades, paired with a novel analytical approach. MethodsWe integrated Continuous-Time Movement Models (CTMM), Auto-correlated Kernel Density Estimators (AKDEs), Hidden Markov Models (HMM) and a diel niche theoretical framework to mitigate biases previously unaccounted for the species in telemetry studies. Fine-scale AKDEs and non-linear movement metrics were calculated to understand seasonal space use and movement behaviors. Speed and diffusion from CTMM and behavioral states from HMM were modelled with environmental covariates to investigate which conditions shape diel and seasonal activity. ResultsPopulation mean home range was 138.2 km2 (95% Confidence Intervals 78.7-225.5), with males (239.8 km2; 182.8-307.5), significantly exceeding females (58.5 km2; 35.5-90.3). Notably, three females exhibited ranges comparable to some males. Weekly and monthly AKDEs uncovered cyclic home range dynamics potentially driven by resource availability, with contractions around corn harvests, mortino and achupalla fruiting, and expansions during paramo transitions. Decoupling speed from diffusion rates showed region-specific behaviors: intensive patch exploitation in Llanganates, broad exploratory ranging in Cayambe-Coca, and suppressed female locomotion in Cotacachi-Cayapas. Statistical analyses identified temperature as a key diel modulator and precipitation as the seasonal driver. Foraging probability increased between 2:00-6:00, large displacements between 7:00-14:00, and nocturnal movement rose significantly under colder conditions. Across diel hypothesis frameworks, bears were classified as cathemeral rather than strictly diurnal, corroborated by camera-trap records from Colombia, Ecuador, and Peru. ConclusionsWe propose a cathemeral diel phenotype that responds to thermal fluctuations and situates Andean bears within a broader ursid context of thermoregulatory niche plasticity. This dataset reveals unprecedented resolution of regional and sex specific behaviors that will facilitate and accelerate comparative studies in rapidly changing Andean landscapes. By releasing this long-term dataset as an open resource, we provide a foundation for climate-resilient conservation strategies. More broadly, we advocate for data democratization and invite collaboration.

In many tropical areas, seasonal rainfall leads to distinct dry and wet seasons. Many butterflies developing under wet season conditions develop into adults with large ventral eyespots on the wing margins, whereas those developing under dry season conditions have smaller or no eyespots. In greener, wet season habitats, larger eyespots can divert predator attacks toward the wing margins, while reduced eyespot size improves camouflage in the dry leaf litter-dominated habitat during the dry season. However, the dry season is also characterised by higher desiccation stress than the wet season. We hypothesised that larvae developing under dry season conditions develop into adults with higher desiccation tolerance than those reared under wet season conditions. We tested this by rearing larvae of the butterfly Mycalesis mineus under simulated dry and wet season conditions and assaying the desiccation tolerance of the resulting adults. Butterflies reared in dry conditions survived longer under desiccation stress, lost lesser water during pupal-adult metamorphosis, and were heavier than those reared in wet conditions. We also tested the correlation between eyespot size and desiccation tolerance. A negative correlation between the traits would be expected if similar developmental pathways regulate them. Consistent with this expectation, individuals with smaller eyespots had higher desiccation tolerance. Our results demonstrate plasticity in desiccation tolerance, and suggest that predator avoidance and desiccation tolerance traits may share similar developmental pathways.

Changing climates are reshaping animal populations, but our understanding of how demographic trends are shaped by individual responses to local environmental conditions is often limited to long-term studies with restricted spatial scales. Increasing evidence suggests that climatic extremes exert differential selection pressures across environments, often leading to nonstationary biological responses among populations. Participatory science (i.e. citizen science) observations can detect this variation at large geographic scales, but analyses of these data often lack insight into the individual-level responses that are required to explain the origins of such variation. Here we present a new research framework that uses long-term data to validate, then inform analyses of participatory science data to measure reproductive responses to environmental variation across large geographic scales. We use this approach to investigate how reproduction in a montane-adapted songbird, the mountain chickadee (Poecile gambeli), varies across elevations and latitudes in response to extreme scarcity and extreme accumulation of snow throughout the Sierra Nevada Mountains in North America. Chickadee reproduction in lower and higher elevation populations was often differentially impacted by drought and deluge snowfall extremes, but these relationships varied across latitudes. Reproductive performance in the northern Sierra Nevada was negatively affected by snow deluge conditions at high elevations, whereas snow drought conditions reduced reproductive output at low elevations. These relationships changed in the central Sierras where drought conditions negatively impacted both elevations, but deluge conditions improved reproductive performance at both low and high elevations. Reproduction in the southern Sierra Nevada was less affected by spring snow levels, likely due to the lower snow accumulation and earlier snowmelt in this region. These results emphasize the power of long-term studies to inform and interpret participatory science data in order to better understand how animal responses to environmental extremes vary across large geographic scales.

Avian collision rates are certain to rise as renewable energy industries roll out wind and solar farms to reduce fossil fuel impacts in biologically diverse areas of the world. Technological solutions are often sought to decrease mortality rates, but for developing nations automated shut downs are expensive, and alternatives required. A promising route is to increase blade visibility to birds using high contrast colours. Despite the success of the solid black-blade experiment in Norway only one other black-blade field-study in the Netherlands has explored this possibility, with no significant results. We tested the use of colour-patterned blades at a species-rich, 37-turbine, wind facility in Hopefield, South Africa. Two broad "signal red" stripes were applied to a single blade at four high-fatality turbines, in 2023 by Umoya Energy. Avian fatality rates were compared before and after painting using the Before-After-Control-Impact (BACI) approach. Seventy-five fatalities of 23 species of raptors, passerines and wetland species over 24 months were compared for the same 20 turbines after patterning with two sets of controls: (i) their four nearest neighbours (NN) and (ii) all 16 controls (AC). Over 32 months 25 fatalities were recorded, 23 occurred at the controls and only two at the patterned turbines. Testing with Bayesian Generalized Linear Models (BGLMs) revealed a median 83% reduction in fatalities at the patterned blades for both the NN turbines (credible intervals 14% - 98%) and the AC comparisons (30% - 97%). Bayes Factors (BF) revealed strong statistical support for NN (BF = 49.9) and AC comparisons (BF = 159). There was little evidence that birds avoiding patterned turbines increased fatalities at the neighbouring turbines as there was a small median 15% increase in fatality rates when NN controls were compared with other controls, and weak statistical support (BF = 0.15). Among 14 raptor species recorded on site, 10 species have suffered fatalities. Of seven individuals killed prior to treatment at the four patterned blades, only one was killed post-treatment suggesting blade patterning is equally effective at reducing raptor fatalities. Our results show that patterned blades had a high probability (83%) of reducing fatalities with strong statistical support despite the small samples. This supports the Norway experiment in a high diversity African setting, but with red patterns not a solid black design. The strong effect of red stripes may arise from both the high contrast it provides and the possible warning effect that red may elicit. We call for additional experiments to differentiate the effect of patterns and colours for the optimal design to reduce avian-turbine collisions.

Birdsong mediates territory acquisition and mate choice. In agonistic interactions, local songs generally elicit stronger responses than songs from more distant populations. However, the molecular mechanisms associated with differential responses to local vs. foreign songs are poorly understood. We addressed this knowledge gap by combining behavioral assays in the field with blood transcriptomic analysis, using a within-subjects design to ask whether male song sparrows (Melospiza melodia) show differential gene expression when exposed to playback of local and foreign songs. Transcriptomic profiles reflected the difference in behavioral response to local vs. foreign songs, with individuals exposed to local songs showing greater expression of genes associated with song perception and production, anti-inflammatory responses and energy metabolism. Our study suggests that changes in expression of key molecular pathways correlate with behavioral responses to geographic song variation, providing insight into the potential mechanisms regulating signal recognition and response to social challenges. HighlightsO_LIGene expression in sparrow blood was measured after simulated territorial intrusion. C_LIO_LIStronger response to local songs was associated with differential gene expression. C_LIO_LISong-associated genes (FOXP2, NRXN1) had higher expression when birds heard local songs. C_LIO_LIGene expression in the blood contains potential biomarkers of song recognition. C_LI

Freediving in rats has emerged as a relevant model to study physiology and neural adaptation underlying submersion mechanisms. However, despite well-established strain-dependent differences in behaviour and physiological responses, most studies about freediving rely on Sprague Dawley rats. As the choice of strain could significantly shape experimental results depending on the field of research, we conducted a behavioural comparative study between Long Evans (LE) rats, genetically closer to the Wild Norway rat, with the commonly used Sprague Dawley (SD) strain. We developed an 11-week progressive voluntary freediving protocol involving four distances (from 5 to 11 meters), and assessed the rats natural willingness to dive and swim, and identified several parameters for evaluation of their confidence (waiting time before diving, speed), performance capacity (freediving time) and population variability. We found that Long Evans rats were naturally more willing to dive and more confident, compared to Sprague Dawley rats: they showed better performance with longer time underwater and slower diving speed. We also uncover differences in their variability, at trial-to-trial intra-individual and population inter-individual levels, which can guide the choice of one strain over the other, depending on the aim of the scientific inquiry. HighlightsO_LILong Evans rats were naturally more willing and confident at the beginning of the freediving training. C_LIO_LILong Evans freedivers showed greater ease in the water during the course of training compared to Sprague Dawleyfreedivers. C_LIO_LILong Evans freedivers demonstrated greater inter- and intra-individual variability. C_LI

Ocean warming is altering abiotic environments and biotic interactions experienced by marine organisms, where sensitive early developmental windows occur in biologically complex seawater communities. The impact of these interactions on developmental processes and fitness in hosts is not well understood, but likely contingent on the establishment of a host-associated microbiome. Here, we hypothesize that temperature and microbial exposure during embryogenesis influence larval microbiome assembly and host morphology. Strongylocentrotus purpuratus embryos were raised in low microbial richness (LMR) or high microbial richness (HMR) seawater at ambient (14 {degrees}C) or elevated (18 {degrees}C) temperature, then collected at 2, 4, and 6 days post-fertilization (dpf) following multiple feedings. Higher microbial diversity was observed in larvae that developed in HMR seawater when compared to LMR. Differences in relative abundances of dominant microbial families between seawater and larvae suggest some degree of host selectivity in microbiome assembly. Temperature did not strongly alter microbiome composition, but both temperature and microbial condition led to differences in larval morphology by 6 dpf, potentially due to enrichment of microbes with chemoheterotrophic functions. By linking how temperature and microbial communities interact with host development, we contribute novel insights into how early-life environmental conditions impact holobiont formation and morphology. One sentence summaryEarly developmental temperature and microbial conditions shape larval microbiome establishment and morphology.

The ongoing decline in biodiversity highlights the need for understanding the causes of population changes. This study uses 25-year, large-scale monitoring dataset to investigate the influence of climate and landscape structure on the annual population growth rates of 84 bird species across Poland. Our methodological framework involves the spatiotemporal decomposition of these environmental drivers to decouple demographic effects of long-term carrying capacities from the short-term effects of environmental perturbations. Using species-specific demographic models followed by a community-wide meta-analysis, we evaluated how individual species responses scale up to shape community-level dynamics. The results reveal significant variation in species-specific responses to individual drivers. At the community level, our findings suggest that bird populations are mainly regulated by the long-term spatial constraints rather than short-term disturbances. Persistent environmental heterogeneity had the strongest positive demographic effect on birds, followed by temperature, forest dominance over croplands, and precipitation. In contrast, rapid temporal shifts in environmental heterogeneity and precipitation anomalies negatively affected population growth, whereas urbanisation consistently exerted a negative effect across both spatiotemporal dimensions. Our results highlight the significance of protecting existing heterogeneous and ecotonal habitats, as well as the need to incorporate features that enhance habitat heterogeneity into urban development. Article impact statementPreserving heterogeneous habitats is essential for the conservation of bird populations.

Background: Literature on the role of thermal discomfort (heat- and cold-stress) on in-vitro fertilization (IVF) outcomes are scarce and inconclusive. This multi-center research examines association between heat stress and IVF treatment outcomes in Andhra Pradesh, which is prone to year around chronic heat stress. Methods: IVF data were abstracted from clinical chart review of all patients from three IVF from centers 2019 to 2023, which included time-stamped data on each IVF procedure, demographics and pre-existing comorbidities. Weather data were acquired from the National Climatic Data Center (NCDC). IVF outcomes were modelled with respect to time-lagged exposure to ambient temperature stratified by hyper- and hypo-thermic conditions using Poisson and logistic regressions depending on the scale of IVF outcomes adjusting for confounders. Results: Heat stress peaked in June, which corresponded with elevated number of spontaneous abortions/miscarriage (SAM). Under hypo- and hyper-thermic conditions a unit increase ambient temperature was associated with an 11% higher and an 8% lower number of oocytes retrieved, respectively. Adjusting for confounders, a 10 degree F increase in two-day lag heat stress was associated with a 30% higher odds of SAM (odds ratio ~ 1.03; 95% CI = 1.001 to 1.068; p-value < 0.043), and odds of PTB were 3 times higher when three day-lagged heat index (HI) was greater than 35 degree C (odds ratio 1.13 to 7.99; p < 0.05). Conclusion. Our findings warrant strategies to engage IVF patients in mitigating their exposure to thermal discomfort before and during the treatment.

Giant pangolin (Smutsia gigantea) is one of the least studied pangolin species worldwide, with no published hematological and biochemical data available. We report the first blood parameters from a rehabilitated adult male from Campo Maan National Park (southern Cameroon). Hematological and biochemical findings are described and discussed in relation to available data from other pangolin species. These preliminary results provide the first reference framework for this species and highlight their relevance for clinical assessment, health monitoring, and conservation management.

Multimodal communication plays a central role in animal behavior, particularly when individuals must integrate information from different sensory channels to make rapid decisions. In aquatic environments, chemical and visual cues differ markedly in their spatial and temporal properties, such that chemical signals may be constrained by limited spatial resolution and temporal instability, potentially requiring visual information to reliably guide social decisions. In decapod crustaceans, both cue types are known to mediate reproduction, yet their relative contribution to mate-location behavior remains unclear. Here, we tested how visual and chemical cues from males influence mate-location behavior in females of the prawn Macrobrachium rosenbergii. Females were placed in a central arena and exposed to four stimulus configurations combining visual cues (a life-size photograph of a male or a control background) and chemical cues (water from an aquarium with or without a male). Attraction was quantified as the time spent in each half of the arena. Females showed no directional preference when exposed to chemical cues alone or when visual and chemical cues were spatially incongruent. In contrast, females spent significantly more time near male-associated stimuli only when visual and chemical cues were spatially congruent. These results indicate that mate-location behavior in this species depends on multimodal integration with a strong contextual dependence on visual information, which appears to gate the effectiveness of chemical cues. Spatially congruent multimodal signals are therefore necessary to guide orientation during mate search, suggesting that disruption of visual or chemical information in aquaculture systems may impair mating efficiency.

Rhesus macaques (Macaca mulatta) are widely used as non-human primate models for biomedical research. When housed in captivity, it is essential to provide an environment that supports their natural behaviours; otherwise, they risk developing mood disorders, stereotypies, and other behavioural issues that may lead to physical harm. The objective of this preliminary study was to monitor the behaviour of three aged rhesus macaques ([&ge;] 20 y.o.), relocated from a laboratory to a Rescue Centre for Exotic Animals (Italy), and to assess the impact of novel food enrichments. Behavioural data were collected over 18 weeks, beginning at their arrival, using continuous focal sampling from video recordings. Simultaneously, faecal samples were gathered for cortisol analysis. The study was divided into three phases: a control phase without enrichments, a feeding enrichment phase (divided into two periods), and a final control phase without enrichments. Each phase comprised 900 minutes of observations for each subject. Data were analysed using generalized linear mixed models. Results showed an increase in locomotion during the enrichment and final phase compared to the initial phase. Additionally, a reduction in scratching and body-shaking behaviours was observed in the final phase compared to the initial phase. These findings suggest that implementing an enrichment program can enhance the welfare of aged non-human primates and can be considered a valuable tool in the rehabilitation of non-human primates previously housed in laboratories. GRAPHICAL ABSTRACT O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=113 SRC="FIGDIR/small/719840v1_ufig1.gif" ALT="Figure 1"> View larger version (50K): org.highwire.dtl.DTLVardef@152a3a1org.highwire.dtl.DTLVardef@74b53forg.highwire.dtl.DTLVardef@275b21org.highwire.dtl.DTLVardef@1d004d8_HPS_FORMAT_FIGEXP M_FIG C_FIG RESEARCH HIGHLIGHTSO_LIEnvironmental enrichment positively affected activity and stress indicators in aged ex-laboratory rhesus macaques. C_LIO_LILocomotion rates increased while scratching, body-shaking, and cortisol levels decreased. C_LIO_LIEnrichment enhance welfare during rehabilitation, even in older individuals. C_LI

Sky islands are high-elevation ecosystems surrounded by lowland habitats that create isolated environments with distinct climatic conditions. These factors have driven the evolution of many endemic species, separated from their larger, contiguous populations. An Individual-Based Model (IBM) was used to simulate population dynamics by modeling the behaviors and interactions of Tamiasciurus hudsonicus grahamensis (Mount Graham Red Squirrel) a subspecies of the American red squirrel (Tamiasciurus hudsonicus) that is endemic to the Pinaleno Mountains in southeastern Arizona. This approach can help predict future population trends based on historical species data leading to better conservation decisions. Using species-specific ecological preferences--including temperature, precipitation, and vegetation indices (NDVI)--an IBM was developed to simulate population dynamics and spatial distribution projections through 2100. Climate change projections, based on the best- and worst-case scenarios outlined in the 2014 National Climate Assessment, were incorporated to assess potential future population trends under changing environmental conditions. The population faces a 45-62% probability of extinction by 2100, with a significant risk of extinction within the next 50 years. A translocation experiment was conducted to evaluate the viability of relocating individuals to the Chiricahua Mountains, another sky island with a larger habitable area. However, the risk of extinction remains even higher (87-89%) due to environmental disturbances affecting both the Chiricahua and Pinaleno regions. This highlights the challenges of conservation efforts in the face of climate change and emphasizes the need for targeted management strategies to preserve this critically endangered subspecies.