Proactive behavior, but not inhibitory control, predicts repeated innovation by spotted hyenas tested with a multi-access box

Wild raccoons demonstrate flexibility and individuality in innovative problem-solving

Cognitive skills, such as innovative problem-solving, are hypothesized to aid animals in urban environments. However, the significance of innovation in wild populations, and its expression across individuals and socio-ecological conditions, is poorly understood. To identify how and when innovation arises in urban-dwelling species, we used advanced technologies and new testing and analytical methods to evaluate innovative problem-solving abilities of wild raccoons (Procyon lotor). We deployed multi-compartment puzzle boxes with either one or multiple solution types and identified raccoons using radio frequency identification. Raccoons solved these novel extractive foraging tasks, and their success was influenced by age and exploratory diversity. Successful raccoons always discovered multiple different solution types, highlighting flexible problem-solving. Using a unique, comparative sequence analysis approach, we found that variation in raccoon solving techniques was greater between individuals than within individuals, and this self-similarity intensified during times of competition. Finally, the inclusion of an easier solution in the multi-solution trials enabled previously unsuccessful raccoons to bootstrap their learning and successfully open multiple difficult solutions. Our study suggests that innovative problem-solving is probably influenced by many factors and has provided novel field and analytical methods, as well as new insights on the socio-ecological dynamics of urban populations.

Exposure to humans and task difficulty levels affect wild raccoons (Procyon lotor) learning

Cognition helps wildlife exploit novel resources and environments. Raccoons (Procyon lotor) have successfully adapted to human presence, in part due to their cognitive abilities. However, interactions between humans and wildlife can create conflict. A better understanding of the raccoon's behavioral flexibility and learning ability could mitigate some conflicts. Our objective was to evaluate wild raccoons learning in contexts varying in terms of exposure to humans (recreational and preservation zoning within protected areas) and task difficulty. Learning can be evaluated over multiple exposures to a cognitive task. Across three years of experiment, we employed 2 food extraction tasks to gauge the change in problem-solving performance over trials. This assessment considered the success probability (the number of successful trials divided by the total number of trials) and the time taken to solve the puzzles. We also looked at the effects of 2 behavioral traits, exploratory diversity and persistence. We found strong evidence for learning over consecutive trials in terms of improved success probability. Improvement in terms of success probability and solving time was more pronounced with the initially easier task. We detected an increase in success probability over trials only in the recreation zones, and there was no evidence of an effect of behavioral traits. The improved performance attributed to learning was also maintained over consecutive years. We provide additional evidence that raccoons can learn how to solve a problem, resulting in a more effective solution in consecutive trials. Finally, we consider the management implications of dealing with raccoons accessing anthropogenic resources.

Innovative problem-solving in a small, wild canid

Innovation - the ability to solve problems in a novel way - is not only associated with cognitive abilities and relative brain size, but also by noncognitive traits, such as personality and motivation. We used a novel foraging task with three access options to determine how neophobia, exploration, and persistence influence innovation in 12 habituated bat-eared foxes (Otocyon megalotis) in the Kalahari Desert. Bat-eared foxes offer a unique system to understand cognition as they have the smallest relative brain size of measured canids and a specialized, termite-based diet, yet have displayed foraging innovations. Interestingly, most of our individuals solved the task at least once and six individuals solved the task in every trial. Neophobia did not influence success on the first trial, but both exploration and persistence influenced success across all trials. Those individuals that solved the puzzle over multiple trials became faster over time, suggesting that they learned how to open the box more efficiently. We found some variation in the method to open the puzzle box with six individuals solving the puzzle using two methods and one individual using all three methods. This is the first study to show innovation in a novel foraging task in wild bat-eared foxes.

"Monkeying around" together facilitates problem solving

Sehner et al. (PNAS Nexus, 2022, 1-14) report that groups of common marmosets solve problems more frequently and faster than individuals working alone. This result is partially explained by greater persistence at the task in the group context and may have important implications for the evolution of cognition and culture.

The current state of carnivore cognition

The field of animal cognition has advanced rapidly in the last 25 years. Through careful and creative studies of animals in captivity and in the wild, we have gained critical insights into the evolution of intelligence, the cognitive capacities of a diverse array of taxa, and the importance of ecological and social environments, as well as individual variation, in the expression of cognitive abilities. The field of animal cognition, however, is still being influenced by some historical tendencies. For example, primates and birds are still the majority of study species in the field of animal cognition. Studies of diverse taxa improve the generalizability of our results, are critical for testing evolutionary hypotheses, and open new paths for understanding cognition in species with vastly different morphologies. In this paper, we review the current state of knowledge of cognition in mammalian carnivores. We discuss the advantages of studying cognition in Carnivorans and the immense progress that has been made across many cognitive domains in both lab and field studies of carnivores. We also discuss the current constraints that are associated with studying carnivores. Finally, we explore new directions for future research in studies of carnivore cognition.

Congratulations to Animal Cognition on its 50th birthday! Some thoughts on the last 50 years of animal cognition research

In this article, the author reflects on some of the key issues that have arisen in comparative cognition and the role and impact of the journal Animal Cognition through its first 25 years by pretending to look back at this period from the year 2047. Successes within comparative cognition are described and the role that Animal Cognition has played in the growth of comparative cognition are discussed. Concerns are presented about issues that affect the opportunities that researchers have to work with nonhuman species and to produce good comparative cognitive science. Prescriptions for what the author hopes will happen next also are offered all in the lens of a prospectively imagined retrospective on this field.

Scaredy-cats don't succeed: behavioral traits predict problem-solving success in captive felidae

Behavioral traits can be determined from the consistency in an animal's behaviors across time and situations. These behavioral traits may have been differentially selected in closely related species. Studying the structure of these traits across species within an order can inform a better understanding of the selection pressures under which behavior evolves. These adaptive traits are still expected to vary within individuals and might predict general cognitive capacities that facilitate survival, such as behavioral flexibility. We derived five facets (Flexible/Friendly, Fearful/Aggressive, Uninterested, Social/Playful, and Cautious) from behavioral trait assessments based on zookeeper surveys in 52 Felidae individuals representing thirteen species. We analyzed whether age, sex, species, and these facets predicted success in a multi access puzzle box-a measure of innovation. We found that Fearful/Aggressive and Cautious facets were negatively associated with success. This research provides the first test of the association between behavioral trait facets and innovation in a diverse group of captive felidae. Understanding the connection between behavioral traits and problem-solving can assist in ensuring the protection of diverse species in their natural habitats and ethical treatment in captivity.

Scavenging vs hunting affects behavioral traits of an opportunistic carnivore

Background

Human-induced changes to ecosystems transform the availability of resources to predators, including altering prey populations and increasing access to anthropogenic foods. Opportunistic predators are likely to respond to altered food resources by changing the proportion of food they hunt versus scavenge. These shifts in foraging behavior will affect species interactions through multiple pathways, including by changing other aspects of predator behavior such as boldness, innovation, and social structure.

Methods

To understand how foraging behavior impacts predator behavior, we conducted a controlled experiment to simulate hunting by introducing a prey model to captive coyotes (Canis latrans) and compared their behavior to coyotes that continued to scavenge over one year. We used focal observations to construct behavioral budgets, and conducted novel object, puzzle box, and conspecific tests to evaluate boldness, innovation, and response to conspecifics.

Results

We documented increased time spent resting by hunting coyotes paired with decreased time spent active. Hunting coyotes increased boldness and persistence but there were no changes in innovation. Our results illustrate how foraging behavior can impact other aspects of behavior, with potential ecological consequences to predator ecology, predator-prey dynamics, and human-wildlife conflict; however, the captive nature of our study limits specific conclusions related to wild predators. We conclude that human-induced behavioral changes could have cascading ecological implications that are not fully understood.

Exploring innovative problem-solving in African lions (Panthera leo) and snow leopards (Panthera uncia)

Cognitive ability is likely linked to adaptive ability; animals use cognition to innovate and problem-solve in their physical and social environments. We investigated innovative problem-solving in two species of high conservation importance: African lions (Panthera leo; n = 6) and snow leopards (Panthera uncia; n = 9). We designed a custom multi-access puzzle box (MAB) to present a simple and effective behavioral test for the cats to explore. We measured Repeated Innovation, Persistence, Success, Contact Latency, and the Exploration Diversity of individuals interacting with the MAB. Of the six African lions, three (50%) solved one door to the box, one solved two doors (16.67%), and one solved three doors (16.67%). Of the nine snow leopards, one solved one door (11.11%), three solved two doors (33.33%), and none solved all three doors (0%). Persistence was a significant predictor of Success in African lions and snow leopards; more Persistent individuals were more likely to open a door. We also observed significant individual variation in Persistence for both species, but only snow leopards also exhibited differences in Contact Latency and Exploration Diversity. These results suggest individuals vary in their problem-solving approaches. Our findings support both species as successful, repeated innovators. Carnivores face ecological and social challenges and, presumably, benefit from cognitive abilities facilitating the successful navigation of these challenges in captivity and the wild.

Persistence is key: investigating innovative problem solving by Asian elephants using a novel multi-access box

Innovative problem solving is considered a hallmark measure of behavioral flexibility as it describes behavior by which an animal manipulates its environment in a novel way to reach a goal. Elephants are a highly social taxa that have demonstrated a remarkable capacity for adapting to changing environments. To understand how individual differences in behavior impact expressions of innovation, we used a novel extractive foraging device comprised of three compartments to evaluate innovation in 14 captive Asian elephants. In the first phase of testing, elephants had an opportunity to learn one solution, while the second phase gave them an opportunity to innovate to open two other compartments with different solutions. We measured the behavioral traits of neophilia, persistence, motivation, and exploratory diversity, and hypothesized that higher levels of each would be associated with more success in the second phase. Eight elephants innovated to solve three compartments, three solved two, and two solved only one. Consistent with studies in other species, we found that higher success was associated with greater persistence, but not with any other behavioral traits when analyzed per test session. Greater persistence and, unexpectedly, lower exploratory diversity, were associated with success when analyzed at the level of each individual door. Further work is needed to understand how innovation varies both within and between species, with particular attention to the potential impact of anthropogenic changes in wild environments.

Nesting innovations allow population growth in an invasive population of rose-ringed parakeets

Certain traits of recipient environments, such as the availability of limiting resources, strongly determine the establishment success and spread of non-native species. These limitations may be overcome through behavioral plasticity, allowing them to exploit alternative resources. Here, we show how a secondary cavity nester bird, the rose-ringed parakeet Psittacula krameri, innovates its nesting behavior as a response to the shortage of tree cavities for nesting in its invasive range in Tenerife (Canary Islands). We observed that some breeding pairs excavated their own nest cavities in palms, thus becoming primary cavity nester, whereas others occupied nests built with wood sticks by another invasive species, the monk parakeet Myiopsitta monachus. The use of these novel nesting strategies increased the number of breeding pairs by up to 52% over 6 years, contributing to a 128.8% increase of the whole population. Innovative nests were located at greater heights above ground and were more aggregated around conspecifics but did not result in greater breeding success than natural cavities. Occupation of monk parakeet colonies by rose-ringed parakeets also benefited the former species through a protective-nesting association against nest predators. Our results show how an invasive species innovate nesting behaviors and increase nest-site availability in the recipient environment, thus facilitating its population growth and invasion process. Potential behavioral innovations in other invasive rose-ringed parakeet populations may be overlooked, and should be considered for effective management plans.

Personality and Cognitive Profiles of Animal-Assisted Intervention Dogs and Pet Dogs in an Unsolvable Task

Dogs are biologically predisposed to communicate with humans in cooperative contexts. They show individual differences in dog-human communication and inhibition, potentially enhanced by life experience, e.g., Animal-Assisted Interventions. This study aimed to investigate whether dogs' personality, defined by biologically meaningful neural circuits described in the Reinforcement Sensitivity Theory of Personality (RST), predicted dogs' communication, task orientation, emotional state, and approach of an unsolvable task. We also investigated the differences between dogs experienced in Animal-Assisted Interventions (AAI) and inexperienced dogs. The results indicated that a high sensitivity to the RST personality trait related to managing uncertainty (Behavioural Inhibition System, BIS) predicted fewer task orientations but increased referential and non-referential looking, which we interpreted as a way to obtain directions from the owner. Conversely, a high sensitivity to the traits reflecting tendencies to approach rewards (Behavioural Approach System, BAS) and avoid punishment (Fight-Flight-Freeze System, FFFS) predicted lower looking. High sensitivity to the FFFS also predicted more frequent task orientations, which we interpreted as frustration. Finally, the dogs in the AAI program looked more at their owner and were less oriented towards the task. These results provide empirical evidence of individual differences tied to the psychobiological personality traits in canine cognitive skills. Understanding such cognitive profiles may have an enormous impact on activities that rely upon dog-human collaborative interaction.

Simple but Complex—A Laying Hen Study as Proof of Concept of a Novel Method for Cognitive Enrichment and Research

Enrichment can reduce stress and stereotypic behavior and therefore enhance captive animal welfare. In cognitive enrichment, cognitive tasks engage and challenge the animals' natural behavioral repertoire and provide mental stimulation. Enrichment with similarities to “puzzle boxes” in cognitive research is widespread in zoos but rarely applied in commercial farming, as it requires costly time and effort. Here, we introduce a flexible method for cognitive enrichment and research. The test battery apparatus (TBA) is a configurable cubic box with frames for interchangeable test panels, each holding a problem-solving task that must be solved for a food reward. As a proof of concept, we report observations and first results from two groups of laying hens (Gallus gallus forma domestica; 52 birds in total) to show the TBA's feasibility in commercial farming and to investigate the animals' spontaneous interaction with four test panels. While we could not reliably identify individuals, we found the majority of the hens highly motivated to engage with the device. At least five individuals in each group were successful and there was a significant gradient of success rates across the four panels. As the implementation and maintenance required little time and effort, the TBA is promising as a cognitive enrichment device in farm settings. Its potentially limitless configurations allow diverse opportunities for cognitive and behavioral engagement in the long term. While further studies will be crucial to validate welfare effects and problem-solving tasks, the TBA is simple in its application but complex in its possibilities.

The effect of urbanization on innovation in spotted hyenas

Urbanization represents a dramatic form of evolutionary novelty in the landscapes inhabited by many extant animals. The Cognitive Buffer Hypothesis suggests that innovation, the process by which animals solve novel problems or use novel behaviors, may be key for many animals when adapting to novel environments. If innovation is especially beneficial in urban environments, then we would expect urban animals to be more innovative than their non-urban counterparts. However, studies comparing innovative problem-solving between urban and rural habitats have produced mixed results. Here, we hypothesized that these findings result from comparing only two levels of urbanization when related research suggests that the stage of invasion of urban habitats likely has a strong effect on demand for innovation, with demand being highest during early establishment in a novel environment. To test this hypothesis, we assessed innovation in three locations where spotted hyenas experienced varying degrees of urbanization. Spotted hyenas are relatively innovative compared to other carnivores and, although many large carnivores in Africa are endangered, spotted hyenas remain abundant both inside and outside protected areas. We measured innovation with a multi-access puzzle box with four different doors through which hyenas could obtain a food reward. We predicted that hyenas in a transitional, rapidly urbanizing habitat would be more innovative, measured by the number of unique doors opened, than those in rural or fully urban habitats. Contrary to our predictions, hyenas in the rural habitat were the most innovative. These results challenge the idea that the evolutionary novelty associated with urbanization favors greater innovativeness.

Linking Human Perceptions and Spotted Hyena Behavior in Urban Areas of Ethiopia

Humans have shaped carnivore behavior since at least the Middle Paleolithic period, about 42,000 years ago. In more recent times, spotted hyenas (Crocuta crocuta) in Ethiopia have adapted to living in urban areas, while humans have adapted to living with hyenas. Yet, relationships between coexisting humans and carnivores are rarely addressed beyond mitigating conflicts. We provided a case study for how to broadly think about coexistence and how to study it when measuring if humans and carnivores affect one another. We collected data in four Ethiopian cities: Mekelle, Harar, Addis Ababa, and Arba Minch. We held focus groups and key informant interviews that incorporated feedback from 163 people, representing a wide array of religious, economic, and educational backgrounds. We also determined how many hyenas resided in these cities, hyena behavioral responses to humans using a flight initiation test, and problem-solving abilities via puzzle box trials. We found that in three of the cities, hyenas and humans coexist at high densities and frequently encounter each other. While all participants recognized the importance of hyenas as scavengers to maintain a clean environment, there was pronounced variation in cultural perspectives across cities. For example, while the people of Harar revere hyenas in spiritual terms, in Arba Minch hyenas were regarded as nuisance animals. Hyenas were universally respected as a formidable predator across cities but reports of attacks on livestock and humans were few. Flight initiation tests revealed hyenas fled at significantly closer distances in Harar and Addis Ababa than in Mekelle. Hyenas succeeded at solving a puzzle box in Harar but not in Mekelle. These variable behavior in hyenas correlated to different human perceptions. Our case study results suggest that the hyena-human dynamic is highly variable across these locations. We conclude by exploring the implications of these findings for how humans and hyenas can shape one another's behavior. Developing studies to link human perceptions and animal behavior could advance wildlife conservation, especially in urban areas.

Leveraging Motivations, Personality, and Sensory Cues for Vertebrate Pest Management

Managing vertebrate pests is a global conservation challenge given their undesirable socio-ecological impacts. Pest management often focuses on the 'average' individual, neglecting individual-level behavioural variation ('personalities') and differences in life histories. These differences affect pest impacts and modify attraction to, or avoidance of, sensory cues. Strategies targeting the average individual may fail to mitigate damage by 'rogues' (individuals causing disproportionate impact) or to target 'recalcitrants' (individuals avoiding standard control measures). Effective management leverages animal behaviours that relate primarily to four core motivations: feeding, fleeing, fighting, and fornication. Management success could be greatly increased by identifying and exploiting individual variation in motivations. We provide explicit suggestions for cue-based tools to manipulate these four motivators, thereby improving pest management outcomes.

Innovative problem-solving in wild hyenas is reliable across time and contexts

Individual differences in behavior are the raw material upon which natural selection acts, but despite increasing recognition of the value of considering individual differences in the behavior of wild animals to test evolutionary hypotheses, this approach has only recently become popular for testing cognitive abilities. In order for the intraspecific approach with wild animals to be useful for testing evolutionary hypotheses about cognition, researchers must provide evidence that measures of cognitive ability obtained from wild subjects reflect stable, general traits. Here, we used a multi-access box paradigm to investigate the intra-individual reliability of innovative problem-solving ability across time and contexts in wild spotted hyenas (Crocuta crocuta). We also asked whether estimates of reliability were affected by factors such as age-sex class, the length of the interval between tests, or the number of times subjects were tested. We found significant contextual and temporal reliability for problem-solving. However, problem-solving was not reliable for adult subjects, when trials were separated by more than 17 days, or when fewer than seven trials were conducted per subject. In general, the estimates of reliability for problem-solving were comparable to estimates from the literature for other animal behaviors, which suggests that problem-solving is a stable, general trait in wild spotted hyenas.

How does cognition shape social relationships?

The requirements of living in social groups, and forming and maintaining social relationships are hypothesized to be one of the major drivers behind the evolution of cognitive abilities. Most empirical studies investigating the relationships between sociality and cognition compare cognitive performance between species living in systems that differ in social complexity. In this review, we ask whether and how individuals benefit from cognitive skills in their social interactions. Cognitive abilities, such as perception, attention, learning, memory, and inhibitory control, aid in forming and maintaining social relationships. We investigate whether there is evidence that individual variation in these abilities influences individual variation in social relationships. We then consider the evolutionary consequences of the interaction between sociality and cognitive ability to address whether bi-directional relationships exist between the two, such that cognition can both shape and be shaped by social interactions and the social environment. In doing so, we suggest that social network analysis is emerging as a powerful tool that can be used to test for directional causal relationships between sociality and cognition. Overall, our review highlights the importance of investigating individual variation in cognition to understand how it shapes the patterns of social relationships.This article is part of the theme issue 'Causes and consequences of individual differences in cognitive abilities'.

The role of life experience in affecting persistence: A comparative study between free-ranging dogs, pet dogs and captive pack dogs

Persistence in object manipulation has been consistently associated with problem-solving success and it is known to be affected, at the individual level, by life experience. Differences in life experiences are particularly poorly studied in the problem-solving context and mainly refer to the comparison between wild and captive animals. Dogs represent interesting study subjects, since dog populations differ widely in their life experiences. In this comparative study we investigated subjects' persistence when presenting a novel object containing food that could not be accessed (impossible task) to three dog populations with very diverse life experiences: free-ranging village dogs (in Morocco), pet dogs (in Vienna) and captive pack living dogs (Wolf Science Center-WSC). We found that pet dogs and captive dogs (WSC) were more manipulative and persistent than free-ranging dogs. The low persistence of free ranging-dogs is unlikely the effect of a lack of exposure to objects, since they are confronted with many human’ artefacts in their environment daily. Instead, we suggest that the higher persistence of captive dogs and pet dogs in comparison to free-ranging dogs might be due to their increased experience of human-mediated object interaction. This provides subjects with a socially guided experience in manipulating and interacting with objects increasing their motivation to engage in such tasks.

Behavioral flexibility of a generalist carnivore

Innovative problem solving, repeated innovation, learning, and inhibitory control are cognitive abilities commonly regarded as important components of behaviorally flexible species. Animals exhibiting these cognitive abilities may be more likely to adapt to the unique demands of living in novel and rapidly changing environments, such as urbanized landscapes. Raccoons (Procyon lotor) are an abundant, generalist species frequently found in urban habitats, and are capable of innovative problem solving, which makes them an ideal species to assess their behavioral flexibility. We gave 20 captive raccoons a multi-access puzzle box to investigate which behavioral and cognitive mechanisms enable the generation of innovative and flexible behaviors in this species. Over two-thirds of raccoons tested were not only capable of innovative problem solving, but displayed repeated innovation by solving more than one solution on the multi-access puzzle box and demonstrated that they learned multiple solutions to a novel problem. Although we found no relationship between our measure of inhibitory control and a raccoon's ability to exhibit repeated innovations, we did find a positive relationship between the diversity of behaviors that an individual exhibited when interacting with the problem and the number of solution types that they solved. We identified other predictors of problem-solving performance, including neophobia and persistence. Finally, we examine the implications of our results in the context of the cognitive-buffer hypothesis and consider whether the widespread success of an adaptive generalist carnivore could be due in part to having these cognitive and behavioral traits.

Differences in persistence between dogs and wolves in an unsolvable task in the absence of humans

Despite being closely related, dogs perform worse than wolves in independent problem-solving tasks. These differences in problem-solving performance have been attributed to dogs’ greater reliance on humans, who are usually present when problem-solving tasks are presented. However, more fundamental motivational factors or behavioural traits such as persistence, motor diversity and neophobia may also be responsible for differences in task performance. Hence, to better understand what drives the differences between dogs’ and wolves’ problem-solving performance, it is essential to test them in the absence of humans. Here, we tested equally raised and kept dogs and wolves with two unsolvable tasks, a commonly used paradigm to study problem-solving behaviour in these species. Differently from previous studies, we ensured no humans were present in the testing situation. We also ensured that the task was unsolvable from the start, which eliminated the possibility that specific manipulative behaviours were reinforced. This allowed us to measure both persistence and motor diversity more accurately. In line with previous studies, we found wolves to be more persistent than dogs. We also found motor diversity to be linked to persistence and persistence to be linked to contact latency. Finally, subjects were consistent in their performance between the two tasks. These results suggest that fundamental differences in motivation to interact with objects drive the differences in the performance of dogs and wolves in problem-solving tasks. Since correlates of problem-solving success, that is persistence, neophobia, and motor diversity are influenced by a species’ ecology, our results support the socioecological hypothesis, which postulates that the different ecological niches of the two species (dogs have evolved to primarily be scavengers and thrive on and around human refuse, while wolves have evolved to primarily be group hunters and have a low hunting success rate) have, at least partly, shaped their behaviours.

Are some individuals generally more behaviorally plastic than others? An experiment with sailfin mollies

Individuals within the same population generally differ among each other not only in their behavioral traits but also in their level of behavioral plasticity (i.e., in their propensity to modify their behavior in response to changing conditions). If the proximate factors underlying individual differences in behavioral plasticity were the same for any measure of plasticity, as commonly assumed, one would expect plasticity to be repeatable across behaviors and contexts. However, this assumption remains largely untested. Here, we conducted an experiment with sailfin mollies (Poecilia latipinna) whose behavioral plasticity was estimated both as the change in their personality traits or mating behavior across a social gradient and using their performance on a reversal-learning task. We found that the correlations between pairwise measures of plasticity were weak and non-significant, thus indicating that the most plastic individuals were not the same in all the tests. This finding might arise because either individuals adjust the magnitude of their behavioral responses depending on the benefits of plasticity, and/or individuals expressing high behavioral plasticity in one context are limited by neural and/or physiological constraints in the amount of plasticity they can express in other contexts. Because the repeatability of behavioral plasticity may have important evolutionary consequences, additional studies are needed to assess the importance of trade-offs between conflicting selection pressures on the maintenance of intra-individual variation in behavioral plasticity.

Are generalists more innovative than specialists? A comparison of innovative abilities in two wild sympatric mouse lemur species

The propensity to flexibly innovate behavioural variants might advantage animals when dealing with novel or modified ecological or social challenges. Interspecific innovative abilities can be predicted by the degree of ecological generalism and intraspecific variation is predicted by personality traits. To examine the effects of these factors on innovation, we compared problem-solving abilities in the generalist grey mouse lemurs (Microcebus murinus) and the more specialized Madame Berthe's mouse lemurs (Microcebus berthae) in western Madagascar. We examined personality traits by testing 54 individuals in open field and novel object tests, and we assessed problem-solving abilities by presenting an artificial feeding-box that could be opened by three different techniques. The first two techniques presented novel problems and the third technique a modified problem to the more complex second novel problem. In both species, motivation, early success and better inhibitory control characterized innovators and predicted superior problem-solving performance. Although both species performed equally well in finding a solution to the novel problems, the specialist species was more efficient in finding a novel solution to a familiar problem. Since the ecological specialist also exhibited more inhibitory control in this task than the generalist, we propose that specialists may dispose of more efficient problem-solving behaviour.