Ancestral sex-role plasticity facilitates the evolution of same-sex sexual behavior.

Recent attempts to explain the evolutionary prevalence of same-sex sexual behavior (SSB) have focused on the role of indiscriminate mating. However, in many cases, SSB may be more complex than simple mistaken identity, instead involving mutual interactions and successful pairing between partners who can detect each other's sex. Behavioral plasticity is essential for the expression of SSB in such circumstances. To test behavioral plasticity's role in the evolution of SSB, we used termites to study how females and males modify their behavior in same-sex versus heterosexual pairs. Male termites follow females in paired "tandems" before mating, and movement patterns are sexually dimorphic. Previous studies observed that adaptive same-sex tandems also occur in both sexes. Here we found that stable same-sex tandems are achieved by behavioral plasticity when one partner adopts the other sex's movements, resulting in behavioral dimorphism. Simulations based on empirically obtained parameters indicated that this socially cued plasticity contributes to pair maintenance, because dimorphic movements improve reunion success upon accidental separation. A systematic literature survey and phylogenetic comparative analysis suggest that the ancestors of modern termites lack consistent sex roles during pairing, indicating that plasticity is inherited from the ancestor. Socioenvironmental induction of ancestral behavioral potential may be of widespread importance to the expression of SSB. Our findings challenge recent arguments for a prominent role of indiscriminate mating behavior in the evolutionary origin and maintenance of SSB across diverse taxa.

Behavioral thermoregulation in primates: A review of literature and future avenues.

Primates face severe challenges from climate change, with warming expected to increase animals' thermoregulatory demands. Primates have limited long-term options to cope with climate change, but possess a remarkable capacity for behavioral plasticity. This creates an urgency to better understand the behavioral mechanisms primates use to thermoregulate. While considerable information exists on primate behavioral thermoregulation, it is often scattered in the literature in a manner that is difficult to integrate. This review evaluates the status of the available literature on primate behavioral thermoregulation to facilitate future research. We surveyed peer-reviewed publications on primate thermoregulation for N = 17 behaviors across four thermoregulatory categories: activity budgeting, microhabitat use, body positioning, and evaporative cooling. We recorded data on the primate taxa evaluated, support for a thermoregulatory function, thermal variable assessed, and naturalistic/manipulative study conditions. Behavioral thermoregulation was pervasive across primates, with N = 721 cases of thermoregulatory behaviors identified across N = 284 published studies. Most genera were known to utilize multiple behaviors ( x ¯ = 4.5 ± 3.1 behaviors/genera). Activity budgeting behaviors were the most commonly encountered category in the literature (54.5% of cases), while evaporative cooling behaviors were the least represented (6.9% of cases). Behavioral thermoregulation studies were underrepresented for certain taxonomic groups, including lemurs, lorises, galagos, and Central/South American primates, and there were large within-taxa disparities in representation of genera. Support for a thermoregulatory function was consistently high across all behaviors, spanning both hot- and cold-avoidance strategies. This review reveals asymmetries in the current literature and avenues for future research. Increased knowledge of the impact thermoregulatory behaviors have on biologically relevant outcomes is needed to better assess primate responses to warming environments and develop early indicators of thermal stress.

Water velocity shapes fish movement behavior.

Stream and river ecosystems present fluvial fishes with a dynamic energy landscape because moving water generates heterogeneous flow fields that are rarely static in space and time. Fish movement behavior should be consistent with conserving energy in these dynamic flowing environments, but little evidence supporting this hypothesis exists. Here, we tested experimentally whether three general movement behaviors-against the current, with the current, or holding position (i.e., staying in one position and location)-were performed in a way consistent with minimizing the cost of swimming in a heterogeneous flow field. We tested the effects of water velocity on movement behavior across three age classes (0, 1, and 5 years) of two different fluvial specialist fishes, the pallid sturgeon (Scaphirhynchus albus) and shovelnose sturgeon (Scaphirhynchus platorynchus). Individuals from the three age classes were exposed to a continuous and dynamic velocity field ranging from 0.02 to 0.53 m s-1, which represented natural benthic flow regimes occupied by these species in rivers. Both sturgeon species exhibited the same pattern with regard to their tendency to hold position, move upstream, or move downstream. Moving downstream was positively associated with velocity for all age groups. Moving upstream was inversely related to velocity for young fish, but as the fish aged, moving upstream was not related to water velocity. The oldest fish (age 5) moved upstream more frequently compared to the younger age classes. Holding position within a water current was the most frequent behavior and occurred with similar probability across the range of experimental velocity for youngest fish (age 0), but was inversely related to velocity in older fish. Our experiment across age classes suggests that the suite of swimming behaviors exhibited by fluvial specialists might have evolved to mitigate the energetic costs of complex energy landscapes generated by moving water to ultimately maximize net energy gain.

Light Environment Interacts with Visual Displays in a Species-Specific Manner in Multimodal-Signaling Wolf Spiders.

AbstractLight availability is highly variable, yet predictable, over various timescales and is expected to play an important role in the evolution of visual signals. Courtship displays of the wolf spider genus Schizocosa always involve the use of substrate-borne vibrations; however, there is substantial variation in the presence and complexity of visual displays among species. To gain insight into the role the light environment plays in the evolution of courtship displays, we tested the function of visual courtship signaling across distinct light environments in four species of Schizocosa that vary in their degree of ornamentation and dynamic visual signals. We ran mating and courtship trials at three light intensities (bright, dim, and dark) and tested the hypothesis that ornamentation interacts with light environment. We also examined each species' circadian activity patterns. The effects of the light environment on courtship and mating varied between species, as did circadian activity patterns. Our results suggest that femur pigmentation may have evolved for diurnal signaling, whereas tibial brushes may function to increase signal efficacy under dim light. Additionally, we found evidence for light-dependent changes in selection on male traits, illustrating that short-term changes in light intensity have the potential for strong effects on the dynamics of sexual selection.

Dynamic winter weather moderates movement and resource selection of wild turkeys at high-latitude range limits.

For wide-ranging species in temperate environments, populations at high-latitude range limits are subject to more extreme conditions, colder temperatures, and greater snow accumulation compared with their core range. As climate change progresses, these bounding pressures may become more moderate on average, while extreme weather occurs more frequently. Individuals can mitigate temporarily extreme conditions by changing daily activity budgets and exhibiting plasticity in resource selection, both of which facilitate existence at and expansion of high-latitude range boundaries. However, relatively little work has explored how animals moderate movement and vary resource selection with changing weather, and a general framework for such investigations is lacking. We applied hidden Markov models and step selection functions to GPS data from wintering wild turkeys (Meleagris gallopavo) near their northern range limit to identify how weather influenced transition among discrete movement states, as well as state-specific resource selection. We found that turkeys were more likely to spend time in a stationary state as wind chill temperatures decreased and snow depth increased. Both stationary and roosting turkeys selected conifer forests and avoided land covers associated with foraging, such as agriculture and residential areas, while shifting their strength of selection for these features during poor weather. In contrast, mobile turkeys showed relatively weak resource selection, with less response in selection coefficients during poor weather. Our findings illustrate that behavioral plasticity in response to weather was context dependent, but movement behaviors most associated with poor weather were also those in which resource selection was most plastic. Given our results, the potential for wild turkey range expansion will partly be determined by the availability of habitat that allows them to withstand periodic inclement weather. Combining hidden Markov models with step selection functions is broadly applicable for evaluating plasticity in animal behavior and dynamic resource selection in response to changing weather. We studied turkeys at northern range limits, but this approach is applicable for any system expected to experience significant changes in the coming decade, and may be particularly relevant to populations existing at range peripheries.

Mercury Contamination Challenges the Behavioral Response of a Keystone Species to Arctic Climate Change.

Combined effects of multiple, climate change-associated stressors are of mounting concern, especially in Arctic ecosystems. Elevated mercury (Hg) exposure in Arctic animals could affect behavioral responses to changes in foraging landscapes caused by climate change, generating interactive effects on behavior and population resilience. We investigated this hypothesis in little auks (Alle alle), a keystone Arctic seabird. We compiled behavioral data for 44 birds across 5 years using accelerometers while also quantifying blood Hg and environmental conditions. Warm sea surface temperature (SST) and low sea ice coverage reshaped time activity budgets (TABs) and diving patterns, causing decreased resting, increased flight, and longer dives. Mercury contamination was not associated with TABs. However, highly contaminated birds lengthened interdive breaks when making long dives, suggesting Hg-induced physiological limitations. As dive durations increased with warm SST, subtle toxicological effects threaten to increasingly constrain diving and foraging efficiency as climate change progresses, with ecosystem-wide repercussions.

Avoidance behavior and experience-dependent tolerance in response to bitter compounds in Caenorhabditis elegans.

This study investigates the mechanisms governing experience-dependent tolerance of bitter compounds in Caenorhabditis elegans. The nematodes showed an aversion to nicotinamide, MgCl2, isoleucine, and arginine in a Gα-dependent manner. Worms furthermore displayed diminished avoidance of MgCl2 upon MgCl2-preconditioning at the larval stages. AIY interneurons have been suggested to be involved in experience-dependent behavioral plasticity.

Cognitive Training Effect and Imaging Evidence.

Cognitive intervention is a specific form of non-pharmacological intervention used to combat cognitive dysfunction. In this chapter, behavioral and neuroimaging studies about cognitive interventions are introduced. Regarding intervention studies, the form of intervention and the effects of the interventions have been systematically sorted out. In addition, we compared the effects of different intervention approaches, which help people with different cognitive states to choose appropriate intervention programs. With the development of imaging technology, many studies have discussed the neural mechanism of cognitive intervention training and the effects of cognitive intervention from the perspective of neuroplasticity. Behavioral studies and neural mechanism studies are used to improve the understanding of cognitive interventions for the treatment of cognitive impairment.

Worker-like behavioral and physiological phenotype in queens with removed wings in a ponerine ant.

Many highly eusocial insects are characterized by morphological differences between females, which are especially pronounced in ants. How these differences associate with particular behavioral and physiological phenotypes can illuminate early ant evolution. In ants, the morphological queen usually possesses a larger thorax with wings compared with a wingless worker. While queens specialize in reproduction, workers help with non-reproductive tasks and show various levels of reproductive degeneration. Here, we investigated the level of behavioral and physiological plasticity within queens in the ant species Harpegnathos saltator, which shows limited queen-worker dimorphism. We found that the experimental removal of wings led to the expression of worker behaviors and physiology, by examining young queens with wings, known as alate gynes, and those whose wings have been experimentally removed or naturally shed, known as dealate gynes. Compared with alate gynes, dealate gynes displayed higher frequencies of behaviors that are naturally shown by workers during reproductive competition. In addition, dealate gynes exhibited a worker-like range of ovarian activity. Like workers, they lacked the putative sex pheromones on their cuticle characteristic of dispersing gynes. Because gynes activate a worker-like phenotype after wing removal, the essential difference between the queen and worker in this species is a dispersal polyphenism. If the queen plasticity observed in H. saltator reflects the early stages of ant eusociality, a dispersal dimorphism rather than a distinct reproductive dimorphism might represent an early step in ant evolution.

Interacting lethal and nonlethal human activities shape complex risk tolerance behaviors in a mountain herbivore.

Animals perceive human activities as risky and generally respond with fear-induced proactive behaviors to buffer the circadian patterns of lethal and nonlethal disturbances, such as diel migrations (DMs) between risky places during safe nighttime and safer places during risky daytime. However, such responses potentially incur costs through movement or reduced foraging time, so individuals should adjust their tolerance when human activities are harmless, through habituation. Yet this is a challenging cognitive task when lethal and nonlethal risks co-occur, forming complex landscapes of fear. The consequences of this human-induced complexity have, however, rarely been assessed. We studied the individual DM dynamics of chamois (Rupicapra rupicapra rupicapra), 89 GPS-tracked individual-years, from/to trails in the French Alps in areas with co-occurring lethal (hunting) and nonlethal (hiking and skiing) disturbances, with different intensities across seasons. We developed a conceptual framework relying on the risk-disturbance hypothesis and habituation to predict tolerance adjustments of chamois under various disturbance contexts and across contrasted seasonal periods. Based on spatial and statistical analyses combining periodograms and multinomial logistic models, we found that DM in relation to distance to a trail was a consistent response by chamois (~85% of individuals) to avoid human disturbance during daytime, especially during the hiking and hunting periods. Such behavior revealed a low tolerance of most chamois to human activities, although there was considerable interindividual heterogeneity in DM. Interestingly, there was an increased tolerance among the most disturbed diel migrants, potentially through habituation, with chamois performing shorter DMs in areas highly disturbed by hikers. Crucially, chamois that were most human-habituated during the hiking period remained more tolerant in the subsequent harvesting period, which could increase their risk of being harvested. In contrast, individuals less tolerant to hiking performed longer DMs when hunting risk increased, and compared to hiking, hunting exacerbated the threshold distance to trails triggering DMs. No carryover effect of hunting beyond the hunting period was observed. In conclusion, complex human-induced landscapes of fear with co-occurring disturbances by nature-based tourism and hunting may shape unexpected patterns of tolerance to human activities, whereby animal tolerance could become potentially deleterious for individual survival.

Use of Visual Information by Ant Species Occurring in Similar Urban Anthropogenic Environments.

Many insects, including ants, are known to respond visually to conspicuous objects. In this study, we compared orientation in an arena containing only a black target beacon as local information in six species of ants of widely varying degree of phylogenic relatedness, foraging strategy, and eye morphology (Aphaenogaster, Brachyponera, Camponotus, Formica, and two Lasius spp.), often found associated in similar urban anthropogenic habitats. Four species of ants displayed orientation toward the beacon, with two orienting toward it directly, while the other two approached it via convoluted paths. The two remaining species did not show any orientation with respect to the beacon. The results did not correlate with morphological parameters of the visual systems and could not be fully interpreted in terms of the species' ecology, although convoluted paths are linked to higher significance of chemical signals. Beacon aiming was shown to be an innate behavior in visually naive Formica workers, which, however, were less strongly attracted to the beacon than older foragers. Thus, despite sharing the same habitats and supposedly having similar neural circuits, even a very simple stimulus-related behavior in the absence of other information can differ widely in ants but is likely an ancestral trait retained especially in species with smaller eyes. The comparative analysis of nervous systems opens the possibility of determining general features of circuits responsible for innate and possibly learned attraction toward particular stimuli.

Behavioral Causes, Ecological Consequences, and Management Challenges Associated with Wildlife Foraging in Human-Modified Landscapes.

Humans have altered up to half of the world's land surface. Wildlife living within or close to these human-modified landscapes are presented with opportunities and risks associated with feeding on human-derived foods (e.g., agricultural crops and food waste). Understanding whether and how wildlife adapts to these landscapes is a major challenge, with thousands of studies published on the topic over the past 10 years. In the present article, we build on established theoretical frameworks to understand the behavioral causes of crop and urban foraging by wildlife. We then develop and extend this framework to describe the multifaceted ecological consequences of crop and urban foraging for the individuals and populations in which they arise, with emphasis on social species for which interactions with people are, on balance, negative (commonly referred to as raiding species). Finally, we discuss the management challenges faced by urban and rural land managers, businesses, and government organizations in mitigating human-wildlife conflicts and propose ways to improve the lives of both wildlife and humans living in human-modified landscapes and to promote coexistence.

Ants avoid superinfections by performing risk-adjusted sanitary care.

Being cared for when sick is a benefit of sociality that can reduce disease and improve survival of group members. However, individuals providing care risk contracting infectious diseases themselves. If they contract a low pathogen dose, they may develop low-level infections that do not cause disease but still affect host immunity by either decreasing or increasing the host's vulnerability to subsequent infections. Caring for contagious individuals can thus significantly alter the future disease susceptibility of caregivers. Using ants and their fungal pathogens as a model system, we tested if the altered disease susceptibility of experienced caregivers, in turn, affects their expression of sanitary care behavior. We found that low-level infections contracted during sanitary care had protective or neutral effects on secondary exposure to the same (homologous) pathogen but consistently caused high mortality on superinfection with a different (heterologous) pathogen. In response to this risk, the ants selectively adjusted the expression of their sanitary care. Specifically, the ants performed less grooming and more antimicrobial disinfection when caring for nestmates contaminated with heterologous pathogens compared with homologous ones. By modulating the components of sanitary care in this way the ants acquired less infectious particles of the heterologous pathogens, resulting in reduced superinfection. The performance of risk-adjusted sanitary care reveals the remarkable capacity of ants to react to changes in their disease susceptibility, according to their own infection history and to flexibly adjust collective care to individual risk.

Goat as the ideal climate-resilient animal model in tropical environment: revisiting advantages over other livestock species.

In the agriculture sector, livestock are considered extremely resilient to climate change and are tipped to play a significant role in ensuring food security to meet the increased demands of growing human population by 2050. Compared to other domestic species, goats are considered the ideal animal model for climate change due to its high thermal and drought resilience, ability to survive on limited pastures, and high disease resistance. This review is therefore a revisit to the advantages of rearing goats over other livestock species under current and future trends of changes in climate, particularly to cope with recurrent multiple stressors such as heat load, and lack of water and feed. In summary, goats, also called as poor man's cow, are preferred by the small-scale landless farmers due to their low input and assured higher output system, as they require low initial investment, with minimum specialized facilities and labors. Furthermore, they perceive goats as better resilient animal to cope with multiple stressors such as heat load, and water and feed scarcity, and possess better skills to cope with bush, when compared with sheep and cattle. The unique capacity for employing behavioral plasticity and morphological features of goats gives them clear advantage over sheep and cattle, when coping with seasonal biotopes, and experiences of water and feed shortage. When facing with low-quality feed, they also are superior to cattle and sheep to digest dry matter and to recycle nitrogen. Additionally, goats have superior ability to desiccate feces and concentrate urine, when compared with sheep and cattle. These advantages make goat the go-to species for efficiently countering the adversities associated with climate change and to optimize appropriate economic return through sustained production. Therefore, goats are tipped to be the future animals with extreme potential to counter the projected alarming climate change impacts and expected to play a significant role in ensuring food security to meet the demands of the growing human population by the end of this century.

What can a worm learn in a bacteria-rich habitat?

With a nervous system that has only a few hundred neurons, Caenorhabditis elegans was initially not regarded as a model for studies on learning. However, the collective effort of the C. elegans field in the past several decades has shown that the worm displays plasticity in its behavioral response to a wide range of sensory cues in the environment. As a bacteria-feeding worm, C. elegans is highly adaptive to the bacteria enriched in its habitat, especially those that are pathogenic and pose a threat to survival. It uses several common forms of behavioral plasticity that last for different amounts of time, including imprinting and adult-stage associative learning, to modulate its interactions with pathogenic bacteria. Probing the molecular, cellular and circuit mechanisms underlying these forms of experience-dependent plasticity has identified signaling pathways and regulatory insights that are conserved in more complex animals.

Multimodal mechanosensing enables treefrog embryos to escape egg-predators.

Mechanosensory-cued hatching (MCH) is widespread, diverse and important for survival in many animals. From flatworms and insects to frogs and turtles, embryos use mechanosensory cues and signals to inform hatching timing, yet mechanisms mediating mechanosensing in ovo are largely unknown. The arboreal embryos of red-eyed treefrogs, Agalychnis callidryas, hatch prematurely to escape predation, cued by physical disturbance in snake attacks. When otoconial organs in the developing vestibular system become functional, this response strengthens, but its earlier occurrence indicates another sensor must contribute. Post-hatching, tadpoles use lateral line neuromasts to detect water motion. We ablated neuromast function with gentamicin to assess their role in A. callidryas' hatching response to disturbance. Prior to vestibular function, this nearly eliminated the hatching response to a complex simulated attack cue, egg jiggling, revealing that neuromasts mediate early MCH. Vestibular function onset increased hatching, independent of neuromast function, indicating young embryos use multiple mechanosensory systems. MCH increased developmentally. All older embryos hatched in response to egg jiggling, but neuromast function reduced response latency. In contrast, neuromast ablation had no effect on the timing or level of hatching in motion-only vibration playbacks. It appears only a subset of egg-disturbance cues stimulate neuromasts; thus, embryos in attacked clutches may receive unimodal or multimodal stimuli. Agalychnis callidryas embryos have more neuromasts than described for any other species at hatching, suggesting precocious sensory development may facilitate MCH. Our findings provide insight into the behavioral roles of two mechanosensory systems in ovo and open possibilities for exploring sensory perception across taxa in early life stages.

Habitat predicts local prevalence of migratory behaviour in an alpine ungulate.

The resource hierarchy hypothesis predicts that the most important factors limiting a species' distribution act at the coarsest spatial scales. However, resource selection behaviour affords mobile organisms the opportunity to adopt a range of tactics for navigating spatial trade-offs between competing biotic and abiotic constraints. Throughout the animal kingdom, partial migration (where some individuals migrate, and others remain resident year round) offers a pervasive example of such behavioural polymorphism. Identifying the differences between these behaviours is therefore central to understanding the conditions (habitat) needed to sustain migrant and resident populations. Here we test an extension of the resource hierarchy hypothesis. We hypothesized that rather than responding to a single limiting factor, migration and residency represent contrasting scale-specific approaches to managing trade-offs between forage, predation risk and severe winter conditions. Furthermore, we predicted that the distribution of habitat selected by migrants and residents is predictive of the local prevalence of migratory behaviour. To test these hypotheses, we quantified migratory status- (resident/migrant) and season-specific (winter/summer) differences in resource selection by eight populations of federally endangered Sierra Nevada bighorn sheep Ovis canadensis sierrae across three spatial scales: population range, individual range and within individual range. We then integrated these spatial predictions to produce separate spatial predictions of migrant and resident winter habitat. As predicted, model selection provided strong evidence for the importance of status-specific differences in resource selection. Residents showed stronger coarse-scale selection for terrain associated with predator avoidance and stronger fine-scale selection for greenness, while in migrants this pattern was reversed. Availability of migrant habitat predicted the local prevalence of migration (top model pseudo R2 of .87). Our ability to respond to global declines of migratory species depends on improving our understanding of the conditions required to maintain migratory behaviour. Through explicitly contrasting migrant and resident behaviour, our results illustrate seasonal differences in migrant and resident habitat and how these two behaviours represent responses to different limiting conditions. Our analyses provides a novel empirical basis for assessing the local prevalence of migratory behaviour across large landscapes.

Snow-mediated plasticity does not prevent camouflage mismatch.

Global reduction in snow cover duration is one of the most consistent and widespread climate change outcomes. Declining snow duration has severe negative consequences for diverse taxa including seasonally color molting species, which rely on snow for camouflage. However, phenotypic plasticity may facilitate adaptation to reduced snow duration. Plastic responses could occur in the color molt phenology or through behavior that minimizes coat color mismatch or its consequences. We quantified molt phenology of 200 wild snowshoe hares (Lepus americanus), and measured microhabitat choice and local snow cover. Similar to other studies, we found that hares did not show behavioral plasticity to minimize coat color mismatch via background matching; instead they preferred colder, snow free areas regardless of their coat color. Furthermore, hares did not behaviorally mitigate the negative consequences of mismatch by choosing resting sites with denser vegetation cover when mismatched. Importantly, we demonstrated plasticity in the initiation and the rate of the molt and established the direct effect of snow on molt phenology; greater snow cover was associated with whiter hares and this association was not due to whiter hares preferring snowier areas. However, despite the observed snow-mediated plasticity in molt phenology, camouflage mismatch with white hares on brown snowless ground persisted and was more frequent during early snowmelt. Thus, we find no evidence that phenotypic plasticity in snowshoe hares is sufficient to facilitate adaptive rescue to camouflage mismatch under climate change.

Train the brain with music (TBM): brain plasticity and cognitive benefits induced by musical training in elderly people in Germany and Switzerland, a study protocol for an RCT comparing musical instrumental practice to sensitization to music.

BACKGROUND: Recent data suggest that musical practice prevents age-related cognitive decline. But experimental evidence remains sparse and no concise information on the neurophysiological bases exists, although cognitive decline represents a major impediment to healthy aging. A challenge in the field of aging is developing training regimens that stimulate neuroplasticity and delay or reverse symptoms of cognitive and cerebral decline. To be successful, these regimens should be easily integrated in daily life and intrinsically motivating. This study combines for the first-time protocolled music practice in elderly with cutting-edge neuroimaging and behavioral approaches, comparing two types of musical education. METHODS: We conduct a two-site Hannover-Geneva randomized intervention study in altogether 155 retired healthy elderly (64-78) years, (63 in Geneva, 92 in Hannover), offering either piano instruction (experimental group) or musical listening awareness (control group). Over 12 months all participants receive weekly training for 1 hour, and exercise at home for ~ 30 min daily. Both groups study different music styles. Participants are tested at 4 time points (0, 6, and 12 months & post-training (18 months)) on cognitive and perceptual-motor aptitudes as well as via wide-ranging functional and structural neuroimaging and blood sampling. DISCUSSION: We aim to demonstrate positive transfer effects for faculties traditionally described to decline with age, particularly in the piano group: executive functions, working memory, processing speed, abstract thinking and fine motor skills. Benefits in both groups may show for verbal memory, hearing in noise and subjective well-being. In association with these behavioral benefits we anticipate functional and structural brain plasticity in temporal (medial and lateral), prefrontal and parietal areas and the basal ganglia. We intend exhibiting for the first time that musical activities can provoke important societal impacts by diminishing cognitive and perceptual-motor decline supported by functional and structural brain plasticity. TRIAL REGISTRATION: The Ethikkomission of the Leibniz Universität Hannover approved the protocol on 14.08.17 (no. 3604-2017), the neuroimaging part and blood sampling was approved by the Hannover Medical School on 07.03.18. The full protocol was approved by the Commission cantonale d'éthique de la recherche de Genève (no. 2016-02224) on 27.02.18 and registered at clinicaltrials.gov on 17.09.18 ( NCT03674931 , no. 81185).

Howler monkey tolerance to habitat shrinking: Lifetime warranty or death sentence?

Habitat loss and fragmentation are major threats to the conservation of nonhuman primates. Given that species differ in their responses to fragmented landscapes, identifying the factors that enable them to cope with altered environments or that cause their extirpation is critical to design conservation management strategies. Howler monkeys (Alouatta spp.) are good models for studying the strategies of tolerant arboreal taxa and how they cope with spatial restriction, because they live in habitats ranging from vast pristine forests to small disturbed fragments and orchards. While some aspects of their ecology and behavior are conserved, others vary in predictable ways in response to habitat shrinking and decreasing resource availability. We argue that the ability of individual howler monkeys to inhabit low-quality environments does not guarantee the long-term persistence of the small populations that live under these conditions. Their local extirpation explains why few forest fragments below a given area threshold are frequently inhabited in landscapes where recolonization and gene flow are compromised by long isolation distances or less permeable matrices. In sum, howlers' ability to cope with habitat restriction at the individual level in the short-term may mask the inevitable fate of isolated populations, thereby compromising the persistence of the species at a regional scale in the long-term if howlers' need for protection in large forests is undervalued.